Gim/internal/command/handlers_test.go

package command

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.gophernest.net/azpect/TextEditor/internal/action"
	"git.gophernest.net/azpect/TextEditor/internal/core"
	tea "github.com/charmbracelet/bubbletea"
)

// ==================================================
// Mock Model Implementation
// ==================================================

type mockModel struct {
	windows       []*core.Window
	activeWindow  *core.Window
	buffers       []*core.Buffer
	settings      core.EditorSettings
	mode          core.Mode
	registers     map[rune]core.Register
	insertKeys    []string
	command       string
	commandCursor int
	commandOutput *core.CommandOutput
	lastFind      core.LastFindCommand
}

func newMockModel() *mockModel {
	buf := core.NewBufferBuilder().
		WithLines([]string{""}).
		Build()

	win := core.NewWindowBuilder().
		WithBuffer(&buf).
		WithHeight(24).
		WithWidth(80).
		Build()

	return &mockModel{
		windows:      []*core.Window{&win},
		activeWindow: &win,
		buffers:      []*core.Buffer{&buf},
		settings:     core.NewDefaultSettings(),
		mode:         core.NormalMode,
		registers:    core.DefaultRegisters(),
	}
}

func newMockModelWithBuffer(buf *core.Buffer) *mockModel {
	win := core.NewWindowBuilder().
		WithBuffer(buf).
		WithHeight(24).
		WithWidth(80).
		Build()

	return &mockModel{
		windows:      []*core.Window{&win},
		activeWindow: &win,
		buffers:      []*core.Buffer{buf},
		settings:     core.NewDefaultSettings(),
		mode:         core.NormalMode,
		registers:    core.DefaultRegisters(),
	}
}

// Core Data Access
func (m *mockModel) Windows() []*core.Window        { return m.windows }
func (m *mockModel) ActiveWindow() *core.Window     { return m.activeWindow }
func (m *mockModel) Buffers() []*core.Buffer        { return m.buffers }
func (m *mockModel) SetBuffers(bufs []*core.Buffer) { m.buffers = bufs }
func (m *mockModel) ActiveBuffer() *core.Buffer     { return m.activeWindow.Buffer }

// Insert Mode State
func (m *mockModel) InsertKeys() []string                               { return m.insertKeys }
func (m *mockModel) SetInsertKeys(keys []string)                        { m.insertKeys = keys }
func (m *mockModel) SetInsertRecording(count int, action action.Action) {}
func (m *mockModel) ExitInsertMode()                                    {}
func (m *mockModel) SetLastFind(char string, forward, inclusive bool) {
	m.lastFind = core.LastFindCommand{Char: char, Forward: forward, Inclusive: inclusive}
}
func (m *mockModel) GetLastFind() *core.LastFindCommand { return &m.lastFind }

// Command Mode State
func (m *mockModel) Command() string                          { return m.command }
func (m *mockModel) SetCommand(cmd string)                    { m.command = cmd }
func (m *mockModel) CommandCursor() int                       { return m.commandCursor }
func (m *mockModel) SetCommandCursor(cur int)                 { m.commandCursor = cur }
func (m *mockModel) CommandOutput() *core.CommandOutput       { return m.commandOutput }
func (m *mockModel) SetCommandOutput(out *core.CommandOutput) { m.commandOutput = out }

// Editor-wide State
func (m *mockModel) Mode() core.Mode                   { return m.mode }
func (m *mockModel) SetMode(mode core.Mode)            { m.mode = mode }
func (m *mockModel) Settings() core.EditorSettings     { return m.settings }
func (m *mockModel) SetSettings(s core.EditorSettings) { m.settings = s }

// Registers
func (m *mockModel) Registers() map[rune]core.Register { return m.registers }
func (m *mockModel) GetRegister(name rune) (core.Register, bool) {
	reg, ok := m.registers[name]
	return reg, ok
}
func (m *mockModel) SetRegister(name rune, t core.RegisterType, cnt []string) error {
	m.registers[name] = core.Register{Type: t, Content: cnt}
	return nil
}
func (m *mockModel) UpdateDefaultRegister(t core.RegisterType, cnt []string) {
	m.registers['"'] = core.Register{Type: t, Content: cnt}
}

// ==================================================
// cmdWrite Tests
// ==================================================

func TestCmdWrite(t *testing.T) {
	t.Run("writes buffer content to file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"line 1", "line 2", "line 3"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file not written: %v", err)
		}

		expected := "line 1\nline 2\nline 3\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("writes to argument filename instead of buffer filename", func(t *testing.T) {
		tmpDir := t.TempDir()
		originalFile := filepath.Join(tmpDir, "original.txt")
		newFile := filepath.Join(tmpDir, "new.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(originalFile).
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{newFile}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify new file was created
		if _, err := os.Stat(newFile); os.IsNotExist(err) {
			t.Error("new file not created")
		}

		// Verify original file was NOT created
		if _, err := os.Stat(originalFile); !os.IsNotExist(err) {
			t.Error("original file should not exist")
		}

		content, _ := os.ReadFile(newFile)
		expected := "content\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("truncates existing file when overwriting", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		// Write longer content first
		originalContent := "this is very long original content\nwith multiple lines\nand more text\n"
		os.WriteFile(filename, []byte(originalContent), 0644)

		// Create buffer with shorter content
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"short"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, _ := os.ReadFile(filename)
		expected := "short\n"
		if string(content) != expected {
			t.Errorf("file not truncated properly: got %q, want %q", string(content), expected)
		}
	})

	t.Run("refuses to write readonly buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for readonly buffer")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "readonly") {
			t.Errorf("error should mention readonly: %v", m.commandOutput.Lines)
		}

		// Verify file was NOT created
		if _, err := os.Stat(filename); !os.IsNotExist(err) {
			t.Error("file should not be created for readonly buffer")
		}
	})

	t.Run("refuses to write scratch buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for scratch buffer")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "ScratchBuffer") {
			t.Errorf("error should mention ScratchBuffer: %v", m.commandOutput.Lines)
		}
	})

	t.Run("errors when no filename and buffer has no filename", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when no filename available")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "no file name") {
			t.Errorf("error should mention no file name: %v", m.commandOutput.Lines)
		}
	})

	t.Run("errors on invalid path", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("/invalid/nonexistent/path/file.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for invalid path")
		}
	})

	t.Run("writes empty buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "empty.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file not created: %v", err)
		}

		// Empty buffer should produce empty file
		if string(content) != "" {
			t.Errorf("expected empty file, got %q", string(content))
		}
	})

	t.Run("writes buffer with empty lines", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"line 1", "", "line 3", ""}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, _ := os.ReadFile(filename)
		expected := "line 1\n\nline 3\n\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("writes buffer with special characters", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "special.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{
				"hello\tworld",
				"unicode: \u00e9\u00e8\u00ea",
				"symbols: !@#$%^&*()",
			}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, _ := os.ReadFile(filename)
		expected := "hello\tworld\nunicode: \u00e9\u00e8\u00ea\nsymbols: !@#$%^&*()\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("writes buffer with unicode content", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "unicode.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{
				"Japanese: \u3053\u3093\u306b\u3061\u306f",
				"Chinese: \u4f60\u597d",
				"Emoji: \U0001F600\U0001F389\U0001F680",
				"Russian: \u041f\u0440\u0438\u0432\u0435\u0442",
			}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, _ := os.ReadFile(filename)
		lines := strings.Split(strings.TrimSuffix(string(content), "\n"), "\n")

		if len(lines) != 4 {
			t.Errorf("expected 4 lines, got %d", len(lines))
		}

		if !strings.Contains(lines[0], "\u3053\u3093\u306b\u3061\u306f") {
			t.Errorf("Japanese content not preserved: %q", lines[0])
		}
	})

	t.Run("sets correct output message", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"line 1", "line 2"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || len(m.commandOutput.Lines) == 0 {
			t.Error("expected output message")
		}

		// Should contain filename and line count
		if !strings.Contains(m.commandOutput.Lines[0], filename) {
			t.Errorf("output should contain filename: %q", m.commandOutput.Lines[0])
		}
		if !strings.Contains(m.commandOutput.Lines[0], "2L") {
			t.Errorf("output should contain line count: %q", m.commandOutput.Lines[0])
		}
	})

	t.Run("writes large file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "large.txt")

		// Create buffer with many lines
		lines := make([]string, 10000)
		for i := range lines {
			lines[i] = strings.Repeat("x", 100)
		}

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines(lines).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		info, err := os.Stat(filename)
		if err != nil {
			t.Fatalf("file not created: %v", err)
		}

		// Each line is 100 chars + newline = 101 bytes * 10000 lines
		expectedSize := int64(101 * 10000)
		if info.Size() != expectedSize {
			t.Errorf("expected size %d, got %d", expectedSize, info.Size())
		}
	})

	t.Run("writes to file with spaces in path", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "file with spaces.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if _, err := os.Stat(filename); os.IsNotExist(err) {
			t.Error("file with spaces not created")
		}
	})

	t.Run("creates parent directories via argument", func(t *testing.T) {
		tmpDir := t.TempDir()
		// Note: cmdWrite doesn't create parent dirs, so this should fail
		filename := filepath.Join(tmpDir, "nonexistent", "nested", "file.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("original.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{filename}, false)

		// Current implementation doesn't create parent dirs, so expect error
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when parent directories don't exist")
		}
	})

	t.Run("clears modified flag after successful write", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		if !m.ActiveBuffer().Modified {
			t.Fatal("precondition: buffer should be modified before write")
		}

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if m.ActiveBuffer().Modified {
			t.Error("buffer should not be modified after successful write")
		}
	})

	t.Run("clears modified flag even when writing to different file", func(t *testing.T) {
		tmpDir := t.TempDir()
		originalFile := filepath.Join(tmpDir, "original.txt")
		newFile := filepath.Join(tmpDir, "copy.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(originalFile).
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{newFile}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Modified flag is cleared even when writing to a different file
		if m.ActiveBuffer().Modified {
			t.Error("buffer modified flag should be cleared after write")
		}

		// Buffer filename should NOT change (vim behavior)
		if m.ActiveBuffer().Filename != originalFile {
			t.Errorf("buffer filename should remain %q, got %q",
				originalFile, m.ActiveBuffer().Filename)
		}
	})

	t.Run("does not clear modified flag on write error", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("/invalid/nonexistent/path/file.txt").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Fatal("expected error for invalid path")
		}

		// Modified flag should remain true on error
		if !m.ActiveBuffer().Modified {
			t.Error("buffer should still be modified after failed write")
		}
	})
}

// ==================================================
// cmdEdit Tests
// ==================================================

func TestCmdEdit(t *testing.T) {
	t.Run("errors when no argument provided", func(t *testing.T) {
		m := newMockModel()

		cmdEdit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when no argument")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "requires an argument") {
			t.Errorf("error should mention requires argument: %v", m.commandOutput.Lines)
		}
	})

	t.Run("creates new buffer for nonexistent file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "newfile.txt")

		m := newMockModel()
		initialBufferCount := len(m.buffers)

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Should have added a new buffer
		if len(m.buffers) != initialBufferCount+1 {
			t.Errorf("expected %d buffers, got %d", initialBufferCount+1, len(m.buffers))
		}

		// Active window should point to new buffer
		if m.activeWindow.Buffer.Filename != filename {
			t.Errorf("active buffer filename = %q, want %q",
				m.activeWindow.Buffer.Filename, filename)
		}

		// New buffer should be empty
		if m.activeWindow.Buffer.LineCount() != 1 || m.activeWindow.Buffer.Line(0) != "" {
			t.Errorf("new buffer should have one empty line")
		}

		// Buffer should be FileBuffer type
		if m.activeWindow.Buffer.Type != core.FileBuffer {
			t.Errorf("buffer type = %v, want FileBuffer", m.activeWindow.Buffer.Type)
		}
	})

	t.Run("loads existing file content", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "existing.txt")

		// Create file with content
		content := "line 1\nline 2\nline 3\n"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 3 {
			t.Errorf("expected 3 lines, got %d", buf.LineCount())
		}

		if buf.Line(0) != "line 1" {
			t.Errorf("line 0 = %q, want %q", buf.Line(0), "line 1")
		}
		if buf.Line(1) != "line 2" {
			t.Errorf("line 1 = %q, want %q", buf.Line(1), "line 2")
		}
		if buf.Line(2) != "line 3" {
			t.Errorf("line 2 = %q, want %q", buf.Line(2), "line 3")
		}
	})

	t.Run("loads file without trailing newline", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "notrailing.txt")

		// File without trailing newline
		content := "line 1\nline 2"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 2 {
			t.Errorf("expected 2 lines, got %d", buf.LineCount())
		}
	})

	t.Run("loads empty file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "empty.txt")

		os.WriteFile(filename, []byte(""), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		// Empty file should have 0 lines (scanner produces no lines)
		if buf.LineCount() != 0 {
			t.Errorf("expected 0 lines for empty file, got %d", buf.LineCount())
		}
	})

	t.Run("sets correct filetype from extension", func(t *testing.T) {
		tmpDir := t.TempDir()

		tests := []struct {
			filename string
			expected string
		}{
			{"test.go", ".go"},
			{"test.py", ".py"},
			{"test.js", ".js"},
			{"test.txt", ".txt"},
			{"Makefile", ""},
			{"test.tar.gz", ".gz"},
		}

		for _, tt := range tests {
			t.Run(tt.filename, func(t *testing.T) {
				filename := filepath.Join(tmpDir, tt.filename)
				os.WriteFile(filename, []byte("content"), 0644)

				m := newMockModel()
				cmdEdit(m, []string{filename}, false)

				if m.commandOutput != nil && m.commandOutput.IsError {
					t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
				}

				if m.activeWindow.Buffer.Filetype != tt.expected {
					t.Errorf("filetype = %q, want %q", m.activeWindow.Buffer.Filetype, tt.expected)
				}
			})
		}
	})

	t.Run("converts tabs to spaces based on tabstop", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "tabs.txt")

		// File with tabs
		content := "\tindented\n\t\tdouble"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()
		m.settings.TabStop = 4

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer

		// Tab should be converted to 4 spaces
		expected0 := "    indented"
		if buf.Line(0) != expected0 {
			t.Errorf("line 0 = %q, want %q", buf.Line(0), expected0)
		}

		expected1 := "        double"
		if buf.Line(1) != expected1 {
			t.Errorf("line 1 = %q, want %q", buf.Line(1), expected1)
		}
	})

	t.Run("handles different tabstop values", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "tabs.txt")

		content := "\ttest"
		os.WriteFile(filename, []byte(content), 0644)

		tests := []struct {
			tabstop  int
			expected string
		}{
			{2, "  test"},
			{4, "    test"},
			{8, "        test"},
		}

		for _, tt := range tests {
			t.Run(string(rune('0'+tt.tabstop)), func(t *testing.T) {
				m := newMockModel()
				m.settings.TabStop = tt.tabstop

				cmdEdit(m, []string{filename}, false)

				if m.activeWindow.Buffer.Line(0) != tt.expected {
					t.Errorf("with tabstop=%d: got %q, want %q",
						tt.tabstop, m.activeWindow.Buffer.Line(0), tt.expected)
				}
			})
		}
	})

	t.Run("loads file with unicode content", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "unicode.txt")

		content := "Hello \u4e16\u754c\n\u3053\u3093\u306b\u3061\u306f\nEmoji: \U0001F600\n"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 3 {
			t.Errorf("expected 3 lines, got %d", buf.LineCount())
		}

		if !strings.Contains(buf.Line(0), "\u4e16\u754c") {
			t.Errorf("unicode not preserved in line 0: %q", buf.Line(0))
		}
	})

	t.Run("loads large file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "large.txt")

		// Create large file
		var content strings.Builder
		for range 10000 {
			content.WriteString(strings.Repeat("x", 100))
			content.WriteString("\n")
		}
		os.WriteFile(filename, []byte(content.String()), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 10000 {
			t.Errorf("expected 10000 lines, got %d", buf.LineCount())
		}
	})

	t.Run("sets buffer as loaded and listed", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")
		os.WriteFile(filename, []byte("content"), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		buf := m.activeWindow.Buffer
		if !buf.Loaded {
			t.Error("buffer should be marked as loaded")
		}
		if !buf.Listed {
			t.Error("buffer should be marked as listed")
		}
	})

	t.Run("new file buffer is loaded and listed", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "newfile.txt")

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		buf := m.activeWindow.Buffer
		if !buf.Loaded {
			t.Error("new buffer should be marked as loaded")
		}
		if !buf.Listed {
			t.Error("new buffer should be marked as listed")
		}
	})

	t.Run("errors on permission denied", func(t *testing.T) {
		if os.Getuid() == 0 {
			t.Skip("test requires non-root user")
		}

		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "noperm.txt")

		// Create file then remove read permission
		os.WriteFile(filename, []byte("content"), 0644)
		os.Chmod(filename, 0000)
		defer os.Chmod(filename, 0644) // Cleanup

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for permission denied")
		}
	})

	t.Run("handles file with long lines", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "longlines.txt")

		// Use 50000 chars - within bufio.Scanner's default 64KB limit
		longLine := strings.Repeat("x", 50000)
		content := longLine + "\nshort\n" + longLine
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if len(buf.Line(0)) != 50000 {
			t.Errorf("long line not preserved: got %d chars", len(buf.Line(0)))
		}
	})

	t.Run("bufio.Scanner limitation with extremely long lines", func(t *testing.T) {
		// NOTE: This documents a known limitation
		// bufio.Scanner has a default max token size of ~64KB
		// Lines longer than this will cause scanner.Scan() to return false
		// with scanner.Err() returning bufio.ErrTooLong
		//
		// A future improvement would be to use bufio.Reader.ReadString
		// or increase scanner buffer size with scanner.Buffer()
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "verylonglines.txt")

		// Create line exceeding 64KB limit
		veryLongLine := strings.Repeat("x", 100000)
		os.WriteFile(filename, []byte(veryLongLine+"\n"), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		// Currently this will result in 0 lines loaded due to scanner limitation
		// This test documents the current behavior
		buf := m.activeWindow.Buffer
		if buf.LineCount() > 0 && len(buf.Line(0)) == 100000 {
			t.Log("Scanner handled very long line - limitation may be fixed")
		} else {
			t.Log("Known limitation: bufio.Scanner cannot handle lines > 64KB")
		}
	})

	t.Run("strips carriage return from CRLF line endings", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "crlf.txt")

		// Windows-style line endings
		content := "line 1\r\nline 2\r\nline 3\r\n"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 3 {
			t.Errorf("expected 3 lines, got %d", buf.LineCount())
		}

		// Verify \r is stripped from all lines
		for i := 0; i < buf.LineCount(); i++ {
			line := buf.Line(i)
			if strings.HasSuffix(line, "\r") {
				t.Errorf("line %d has trailing \\r: %q", i, line)
			}
			if strings.Contains(line, "\r") {
				t.Errorf("line %d contains \\r: %q", i, line)
			}
		}

		// Verify content is correct
		if buf.Line(0) != "line 1" {
			t.Errorf("line 0 = %q, want %q", buf.Line(0), "line 1")
		}
		if buf.Line(1) != "line 2" {
			t.Errorf("line 1 = %q, want %q", buf.Line(1), "line 2")
		}
	})

	t.Run("handles mixed line endings", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "mixed.txt")

		// Mix of Unix (\n) and Windows (\r\n) line endings
		content := "unix line\nwindows line\r\nunix again\n"
		os.WriteFile(filename, []byte(content), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		buf := m.activeWindow.Buffer
		if buf.LineCount() != 3 {
			t.Errorf("expected 3 lines, got %d", buf.LineCount())
		}

		// All lines should be clean (no \r)
		for i := 0; i < buf.LineCount(); i++ {
			if strings.Contains(buf.Line(i), "\r") {
				t.Errorf("line %d contains \\r: %q", i, buf.Line(i))
			}
		}
	})

	t.Run("does not panic when editing nonexistent file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "does_not_exist.txt")

		m := newMockModel()

		// This should NOT panic (tests the nil pointer fix)
		cmdEdit(m, []string{filename}, false)

		// Should succeed - creates new buffer
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Buffer should be created with the filename
		if m.activeWindow.Buffer.Filename != filename {
			t.Errorf("buffer filename = %q, want %q",
				m.activeWindow.Buffer.Filename, filename)
		}
	})

	t.Run("adds buffer to buffer list", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")
		os.WriteFile(filename, []byte("content"), 0644)

		m := newMockModel()
		initialCount := len(m.buffers)

		cmdEdit(m, []string{filename}, false)

		if len(m.buffers) != initialCount+1 {
			t.Errorf("buffer not added: expected %d, got %d", initialCount+1, len(m.buffers))
		}

		// Find the new buffer in the list
		found := false
		for _, buf := range m.buffers {
			if buf.Filename == filename {
				found = true
				break
			}
		}
		if !found {
			t.Error("new buffer not found in buffer list")
		}
	})

	t.Run("handles path with spaces", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "file with spaces.txt")
		os.WriteFile(filename, []byte("content"), 0644)

		m := newMockModel()

		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if m.activeWindow.Buffer.Filename != filename {
			t.Errorf("filename = %q, want %q", m.activeWindow.Buffer.Filename, filename)
		}
	})

	t.Run("switches to existing buffer instead of creating duplicate", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "existing.txt")
		os.WriteFile(filename, []byte("original content"), 0644)

		m := newMockModel()
		initialBufferCount := len(m.buffers)

		// First edit - loads the file
		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error on first edit: %v", m.commandOutput.Lines)
		}

		if len(m.buffers) != initialBufferCount+1 {
			t.Errorf("expected %d buffers after first edit, got %d", initialBufferCount+1, len(m.buffers))
		}

		firstBuffer := m.activeWindow.Buffer
		if firstBuffer.Filename != filename {
			t.Fatalf("first buffer filename = %q, want %q", firstBuffer.Filename, filename)
		}

		// Modify the buffer to verify we get the same instance
		firstBuffer.SetLine(0, "modified content")
		bufferId := firstBuffer.Id

		// Second edit - should switch to existing buffer, not create new one
		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error on second edit: %v", m.commandOutput.Lines)
		}

		// Should not have created a new buffer
		if len(m.buffers) != initialBufferCount+1 {
			t.Errorf("expected buffer count to remain %d, got %d (created duplicate buffer)",
				initialBufferCount+1, len(m.buffers))
		}

		// Should be the same buffer instance
		if m.activeWindow.Buffer.Id != bufferId {
			t.Errorf("expected to switch to existing buffer (ID %d), got different buffer (ID %d)",
				bufferId, m.activeWindow.Buffer.Id)
		}

		// Should have our modifications, not reload from disk
		if m.activeWindow.Buffer.Line(0) != "modified content" {
			t.Errorf("expected modified buffer content %q, got %q (buffer was reloaded from disk)",
				"modified content", m.activeWindow.Buffer.Line(0))
		}
	})

	t.Run("switches to existing buffer even if file was modified on disk", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "file.txt")
		os.WriteFile(filename, []byte("version 1"), 0644)

		m := newMockModel()

		// First edit
		cmdEdit(m, []string{filename}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		bufferId := m.activeWindow.Buffer.Id
		originalLine := m.activeWindow.Buffer.Line(0)

		// Modify file on disk
		os.WriteFile(filename, []byte("version 2 - changed on disk"), 0644)

		// Second edit - should switch to buffer, not reload from disk
		cmdEdit(m, []string{filename}, false)

		// Should still be the same buffer
		if m.activeWindow.Buffer.Id != bufferId {
			t.Errorf("expected same buffer ID %d, got %d", bufferId, m.activeWindow.Buffer.Id)
		}

		// Should have old content, not reload
		if m.activeWindow.Buffer.Line(0) != originalLine {
			t.Errorf("buffer was reloaded from disk, expected %q, got %q",
				originalLine, m.activeWindow.Buffer.Line(0))
		}

		// Note: Real vim would warn about file change, but for now we just switch to buffer
	})

	t.Run("creates new buffer for different file even if similar name", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "test.txt")
		file2 := filepath.Join(tmpDir, "test2.txt")

		os.WriteFile(file1, []byte("file 1"), 0644)
		os.WriteFile(file2, []byte("file 2"), 0644)

		m := newMockModel()

		cmdEdit(m, []string{file1}, false)
		bufferCount := len(m.buffers)

		cmdEdit(m, []string{file2}, false)

		// Should have created a new buffer for different file
		if len(m.buffers) != bufferCount+1 {
			t.Errorf("expected new buffer for different file, buffer count = %d", len(m.buffers))
		}

		if m.activeWindow.Buffer.Filename != file2 {
			t.Errorf("active buffer filename = %q, want %q", m.activeWindow.Buffer.Filename, file2)
		}
	})

	t.Run("matches buffer by absolute path", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "file.txt")
		os.WriteFile(filename, []byte("content"), 0644)

		m := newMockModel()

		// First edit with absolute path
		cmdEdit(m, []string{filename}, false)

		bufferId := m.activeWindow.Buffer.Id
		bufferCount := len(m.buffers)

		// Second edit with same absolute path - should match
		cmdEdit(m, []string{filename}, false)

		if len(m.buffers) != bufferCount {
			t.Error("created duplicate buffer for same absolute path")
		}

		if m.activeWindow.Buffer.Id != bufferId {
			t.Error("did not switch to existing buffer")
		}
	})
}

// ==================================================
// Round-trip Tests (Edit then Write)
// ==================================================

func TestEditWriteRoundTrip(t *testing.T) {
	t.Run("edit then write preserves content", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "roundtrip.txt")

		original := "line 1\nline 2\nline 3\n"
		os.WriteFile(filename, []byte(original), 0644)

		m := newMockModel()

		// Edit
		cmdEdit(m, []string{filename}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("edit error: %v", m.commandOutput.Lines)
		}

		// Write
		cmdWrite(m, []string{}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("write error: %v", m.commandOutput.Lines)
		}

		// Read back
		content, _ := os.ReadFile(filename)
		if string(content) != original {
			t.Errorf("content not preserved:\ngot:  %q\nwant: %q", string(content), original)
		}
	})

	t.Run("edit new file then write creates file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "newfile.txt")

		m := newMockModel()

		// Edit (creates new buffer)
		cmdEdit(m, []string{filename}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("edit error: %v", m.commandOutput.Lines)
		}

		// Add content to buffer
		m.activeWindow.Buffer.InsertLine(0, "hello world")

		// Write
		cmdWrite(m, []string{}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("write error: %v", m.commandOutput.Lines)
		}

		// Verify file exists
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file not created: %v", err)
		}

		expected := "hello world\n\n" // Original empty line + inserted line
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("edit modifies write to different file", func(t *testing.T) {
		tmpDir := t.TempDir()
		original := filepath.Join(tmpDir, "original.txt")
		newFile := filepath.Join(tmpDir, "copy.txt")

		os.WriteFile(original, []byte("content\n"), 0644)

		m := newMockModel()

		// Edit original
		cmdEdit(m, []string{original}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("edit error: %v", m.commandOutput.Lines)
		}

		// Modify
		m.activeWindow.Buffer.SetLine(0, "modified content")

		// Write to new file
		cmdWrite(m, []string{newFile}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("write error: %v", m.commandOutput.Lines)
		}

		// Verify new file has modified content
		content, _ := os.ReadFile(newFile)
		if string(content) != "modified content\n" {
			t.Errorf("new file content = %q", string(content))
		}

		// Verify original is unchanged
		origContent, _ := os.ReadFile(original)
		if string(origContent) != "content\n" {
			t.Errorf("original was modified: %q", string(origContent))
		}
	})
}

// ==================================================
// cmdQuit Tests
// ==================================================
//
// Expected Vim behavior for quit commands with readonly buffers:
//
// :quit / :q
//   - Quits if no buffers are modified (readonly or not)
//   - Errors if any buffer is modified (readonly or not)
//
// :quitall / :qa
//   - Same as :quit but for all windows
//
// :write / :w
//   - Errors if buffer is readonly (even if not modified)
//
// :wall / :wa
//   - Only writes MODIFIED buffers
//   - Skips unmodified buffers (including readonly ones)
//   - Errors if any MODIFIED buffer is readonly
//
// :wq
//   - Writes current buffer and quits
//   - Errors if buffer is readonly AND modified
//   - If buffer is NOT modified, just quits (no write needed)
//
// :wqall / :wqa
//   - Writes all MODIFIED buffers and quits
//   - Skips unmodified buffers (including readonly ones)
//   - Errors if any MODIFIED buffer is readonly
//
// Force variants (with !) override readonly protection
// ==================================================

func TestCmdQuit(t *testing.T) {
	t.Run("quits when no buffers are modified", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("test.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command, got nil")
		}

		// Execute the command and verify it returns quit message
		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("errors when buffer is modified", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("unsaved.txt").
			WithLines([]string{"unsaved content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for modified buffer")
		}

		if cmd != nil {
			t.Error("should not return quit command when buffer is modified")
		}
	})

	t.Run("error message includes filename of modified buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("important_file.txt").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Fatal("expected error")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "important_file.txt") {
			t.Errorf("error should mention filename: %v", m.commandOutput.Lines)
		}
	})

	t.Run("errors when any buffer in list is modified", func(t *testing.T) {
		// Active buffer is not modified
		activeBuf := core.NewBufferBuilder().
			WithFilename("active.txt").
			WithLines([]string{"content"}).
			Build()
		activeBuf.Modified = false

		// Another buffer IS modified
		modifiedBuf := core.NewBufferBuilder().
			WithFilename("modified.txt").
			WithLines([]string{"unsaved"}).
			Build()
		modifiedBuf.Modified = true

		m := newMockModelWithBuffer(&activeBuf)
		m.buffers = append(m.buffers, &modifiedBuf)

		cmd := cmdQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when any buffer is modified")
		}

		if cmd != nil {
			t.Error("should not return quit command")
		}
	})

	t.Run("switches to modified buffer when quitting fails", func(t *testing.T) {
		activeBuf := core.NewBufferBuilder().
			WithFilename("active.txt").
			WithLines([]string{"content"}).
			Build()
		activeBuf.Modified = false

		modifiedBuf := core.NewBufferBuilder().
			WithFilename("modified.txt").
			WithLines([]string{"unsaved"}).
			Build()
		modifiedBuf.Modified = true

		m := newMockModelWithBuffer(&activeBuf)
		m.buffers = append(m.buffers, &modifiedBuf)

		cmdQuit(m, []string{}, false)

		// Should switch active window to show the modified buffer
		if m.activeWindow.Buffer.Filename != "modified.txt" {
			t.Errorf("should switch to modified buffer, got %q",
				m.activeWindow.Buffer.Filename)
		}
	})

	t.Run("handles buffer with no filename", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("").
			WithLines([]string{"unsaved content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for modified buffer without filename")
		}

		// Error message should still be meaningful
		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "unsaved") {
			t.Logf("Note: error message for unnamed buffer: %v", m.commandOutput.Lines)
		}
	})

	t.Run("quits with multiple unmodified buffers", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("file1.txt").
			WithLines([]string{"content"}).
			Build()
		buf1.Modified = false

		buf2 := core.NewBufferBuilder().
			WithFilename("file2.txt").
			WithLines([]string{"content"}).
			Build()
		buf2.Modified = false

		buf3 := core.NewBufferBuilder().
			WithFilename("file3.txt").
			WithLines([]string{"content"}).
			Build()
		buf3.Modified = false

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2, &buf3)

		cmd := cmdQuit(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})
}

// ==================================================
// cmdQuitAll Tests
// ==================================================

func TestCmdQuitAll(t *testing.T) {
	t.Run("quits when no buffers are modified", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("test.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuitAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command, got nil")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("errors when any buffer is modified", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("saved.txt").
			WithLines([]string{"content"}).
			Build()
		buf1.Modified = false

		buf2 := core.NewBufferBuilder().
			WithFilename("unsaved.txt").
			WithLines([]string{"modified content"}).
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when any buffer is modified")
		}

		if cmd != nil {
			t.Error("should not return quit command")
		}
	})

	t.Run("quits with multiple unmodified buffers", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("file1.txt").
			Build()
		buf1.Modified = false

		buf2 := core.NewBufferBuilder().
			WithFilename("file2.txt").
			Build()
		buf2.Modified = false

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("error mentions which buffer is modified", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("important_document.txt").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdQuitAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Fatal("expected error")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "important_document.txt") {
			t.Errorf("error should mention filename: %v", m.commandOutput.Lines)
		}
	})

	t.Run("reports first modified buffer found", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("first_modified.txt").
			Build()
		buf1.Modified = true

		buf2 := core.NewBufferBuilder().
			WithFilename("second_modified.txt").
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdQuitAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Fatal("expected error")
		}

		// Should report first modified buffer
		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "first_modified.txt") {
			t.Errorf("should report first modified buffer: %v", m.commandOutput.Lines)
		}
	})
}

// ==================================================
// cmdQuitForce Tests (q!)
// ==================================================

func TestCmdQuitForce(t *testing.T) {
	t.Run("quits with modified buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("unsaved.txt").
			WithLines([]string{"unsaved content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, true)

		// Should NOT error
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Should return quit command
		if cmd == nil {
			t.Fatal("expected quit command, got nil")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with readonly modified buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("readonly.txt").
			WithLines([]string{"modified content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, true)

		// Force quit should work even with readonly modified buffer
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with multiple modified buffers", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("file1.txt").
			WithLines([]string{"unsaved 1"}).
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("file2.txt").
			WithLines([]string{"unsaved 2"}).
			Modified().
			Build()

		buf3 := core.NewBufferBuilder().
			WithFilename("file3.txt").
			WithLines([]string{"unsaved 3"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2, &buf3)

		cmd := cmdQuit(m, []string{}, true)

		// Should quit regardless of multiple modified buffers
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with unmodified buffers", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("test.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, false)

		// Should work with unmodified buffers too
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with buffer without filename", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithFilename("").
			WithLines([]string{"unsaved content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, true)

		// Force quit works even without filename
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with scratch buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, true)

		// Force quit works with scratch buffers
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with mix of modified and unmodified buffers", func(t *testing.T) {
		modifiedBuf := core.NewBufferBuilder().
			WithFilename("modified.txt").
			WithLines([]string{"unsaved"}).
			Modified().
			Build()

		unmodifiedBuf := core.NewBufferBuilder().
			WithFilename("unmodified.txt").
			WithLines([]string{"saved"}).
			Build()

		readonlyModifiedBuf := core.NewBufferBuilder().
			WithFilename("readonly.txt").
			WithLines([]string{"readonly unsaved"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&modifiedBuf)
		m.buffers = append(m.buffers, &unmodifiedBuf, &readonlyModifiedBuf)

		cmd := cmdQuit(m, []string{}, true)

		// Should quit regardless of buffer states
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("does not switch buffers", func(t *testing.T) {
		activeBuf := core.NewBufferBuilder().
			WithFilename("active.txt").
			WithLines([]string{"active"}).
			Build()

		modifiedBuf := core.NewBufferBuilder().
			WithFilename("modified.txt").
			WithLines([]string{"unsaved"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&activeBuf)
		m.buffers = append(m.buffers, &modifiedBuf)

		// Remember active buffer
		activeFilename := m.activeWindow.Buffer.Filename

		cmdQuit(m, []string{}, true)

		// Should NOT switch to modified buffer (unlike regular quit)
		if m.activeWindow.Buffer.Filename != activeFilename {
			t.Errorf("should not switch buffers, got %q", m.activeWindow.Buffer.Filename)
		}
	})
}

// ==================================================
// cmdQuitAllForce Tests (qall! / qa!)
// ==================================================

func TestCmdQuitAllForce(t *testing.T) {
	t.Run("quits with all buffers modified", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("file1.txt").
			WithLines([]string{"unsaved 1"}).
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("file2.txt").
			WithLines([]string{"unsaved 2"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		// Should quit even with all buffers modified
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command, got nil")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with mix of modified and unmodified", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("saved.txt").
			WithLines([]string{"content"}).
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("unsaved.txt").
			WithLines([]string{"modified content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with readonly buffers", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("readonly1.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("readonly2.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		// Force quit should work with readonly buffers
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with scratch buffers", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch1").
			WithLines([]string{"content"}).
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch2").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		// Should quit with scratch buffers
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with buffers without filenames", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("").
			WithLines([]string{"unsaved 1"}).
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("").
			WithLines([]string{"unsaved 2"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		// Force quit works even without filenames
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with no buffers", func(t *testing.T) {
		m := newMockModel()
		// Clear buffers
		m.buffers = []*core.Buffer{}

		cmd := cmdQuitAll(m, []string{}, true)

		// Should quit even with no buffers
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with complex buffer states", func(t *testing.T) {
		// Mix of all different buffer states
		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("file.txt").
			WithLines([]string{"modified file"}).
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"readonly modified"}).
			ReadOnly().
			Modified().
			Build()

		buf3 := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"scratch modified"}).
			Modified().
			Build()

		buf4 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"no name"}).
			Modified().
			Build()

		buf5 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("saved.txt").
			WithLines([]string{"saved content"}).
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2, &buf3, &buf4, &buf5)

		cmd := cmdQuitAll(m, []string{}, true)

		// Force quit should work regardless of any buffer state
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("quits with all buffers unmodified", func(t *testing.T) {
		buf1 := core.NewBufferBuilder().
			WithFilename("file1.txt").
			WithLines([]string{"content"}).
			Build()

		buf2 := core.NewBufferBuilder().
			WithFilename("file2.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdQuitAll(m, []string{}, true)

		// Should work with unmodified buffers too
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})
}

// ==================================================
// cmdWriteAll Tests
// ==================================================

func TestCmdWriteAll(t *testing.T) {
	t.Run("writes all modified buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")
		file2 := filepath.Join(tmpDir, "file2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content 1"}).
			Build()
		buf1.Modified = true

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content 2"}).
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify both files were written
		content1, err := os.ReadFile(file1)
		if err != nil {
			t.Errorf("file1 not written: %v", err)
		} else if string(content1) != "content 1\n" {
			t.Errorf("file1 content = %q", string(content1))
		}

		content2, err := os.ReadFile(file2)
		if err != nil {
			t.Errorf("file2 not written: %v", err)
		} else if string(content2) != "content 2\n" {
			t.Errorf("file2 content = %q", string(content2))
		}
	})

	t.Run("skips unmodified buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		modifiedFile := filepath.Join(tmpDir, "modified.txt")
		unmodifiedFile := filepath.Join(tmpDir, "unmodified.txt")

		modifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(modifiedFile).
			WithLines([]string{"new content"}).
			Build()
		modifiedBuf.Modified = true

		unmodifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(unmodifiedFile).
			WithLines([]string{"old content"}).
			Build()
		unmodifiedBuf.Modified = false

		m := newMockModelWithBuffer(&modifiedBuf)
		m.buffers = append(m.buffers, &unmodifiedBuf)

		cmdWriteAll(m, []string{}, false)

		// Modified file should be written
		if _, err := os.Stat(modifiedFile); os.IsNotExist(err) {
			t.Error("modified file should be written")
		}

		// Unmodified file should NOT be written (doesn't exist)
		if _, err := os.Stat(unmodifiedFile); !os.IsNotExist(err) {
			t.Error("unmodified file should not be written")
		}
	})

	t.Run("clears modified flag on written buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if buf.Modified {
			t.Error("modified flag should be cleared after write")
		}
	})

	t.Run("errors on modified readonly buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Fatal("expected error for modified readonly buffer")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "readonly") {
			t.Errorf("error should mention readonly: %v", m.commandOutput.Lines)
		}
	})

	t.Run("skips unmodified readonly buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		writableFile := filepath.Join(tmpDir, "writable.txt")

		writableBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(writableFile).
			WithLines([]string{"writable content"}).
			Modified().
			Build()

		// Readonly but NOT modified - should be skipped
		readonlyBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"readonly content"}).
			ReadOnly().
			Build()
		// NOT modified!

		m := newMockModelWithBuffer(&writableBuf)
		m.buffers = append(m.buffers, &readonlyBuf)

		cmdWriteAll(m, []string{}, false)

		// Should succeed - readonly buffer not modified, so skip it
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("should not error for unmodified readonly buffer: %v", m.commandOutput.Lines)
		}

		// Writable file should be written
		content, _ := os.ReadFile(writableFile)
		if string(content) != "writable content\n" {
			t.Errorf("writable buffer not written: %q", string(content))
		}
	})

	t.Run("errors on scratch buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for scratch buffer")
		}
	})

	t.Run("errors on buffer with no filename", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for buffer without filename")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "no file name") ||
			!strings.Contains(strings.ToLower(strings.Join(m.commandOutput.Lines, " ")), "name") {
			t.Logf("error message: %v", m.commandOutput.Lines)
		}
	})

	t.Run("succeeds with no modified buffers", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("unchanged.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, false)

		// Should succeed even with nothing to write
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Errorf("unexpected error: %v", m.commandOutput.Lines)
		}
	})

	t.Run("reports number of buffers written", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")
		file2 := filepath.Join(tmpDir, "file2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content"}).
			Build()
		buf1.Modified = true

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content"}).
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdWriteAll(m, []string{}, false)

		// Should have some output indicating what was written
		if m.commandOutput == nil || len(m.commandOutput.Lines) == 0 {
			t.Log("Note: cmdWriteAll doesn't set output message")
		} else if !strings.Contains(m.commandOutput.Lines[0], "2") {
			t.Logf("Output message: %q", m.commandOutput.Lines[0])
		}
	})

	t.Run("stops on first error", func(t *testing.T) {
		tmpDir := t.TempDir()
		validFile := filepath.Join(tmpDir, "valid.txt")

		// First buffer - valid
		validBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(validFile).
			WithLines([]string{"content"}).
			Build()
		validBuf.Modified = true

		// Second buffer - invalid (no filename)
		invalidBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()
		invalidBuf.Modified = true

		m := newMockModelWithBuffer(&invalidBuf) // Invalid first
		m.buffers = append(m.buffers, &validBuf)

		cmdWriteAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error")
		}

		// Valid file might or might not be written depending on implementation
		// (stops on first error vs continues and reports all errors)
	})
}

// ==================================================
// cmdWriteQuit Tests
// ==================================================

func TestCmdWriteQuit(t *testing.T) {
	t.Run("writes buffer and quits", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content to save"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify file was written
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Errorf("file not written: %v", err)
		} else if string(content) != "content to save\n" {
			t.Errorf("file content = %q", string(content))
		}

		// Verify quit command returned
		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("errors on readonly buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for readonly buffer")
		}

		if cmd != nil {
			t.Error("should not return quit command on error")
		}
	})

	t.Run("errors on scratch buffer", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for scratch buffer")
		}

		if cmd != nil {
			t.Error("should not return quit command on error")
		}
	})

	t.Run("errors on buffer with no filename", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for buffer without filename")
		}

		if cmd != nil {
			t.Error("should not return quit command on error")
		}
	})

	t.Run("errors on invalid path", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("/invalid/nonexistent/path/file.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for invalid path")
		}

		if cmd != nil {
			t.Error("should not return quit command on error")
		}
	})

	t.Run("writes to argument filename if provided", func(t *testing.T) {
		tmpDir := t.TempDir()
		originalFile := filepath.Join(tmpDir, "original.txt")
		newFile := filepath.Join(tmpDir, "new.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(originalFile).
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{newFile}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// New file should exist
		if _, err := os.Stat(newFile); os.IsNotExist(err) {
			t.Error("new file not created")
		}

		// Original should not exist
		if _, err := os.Stat(originalFile); !os.IsNotExist(err) {
			t.Error("original file should not exist")
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("clears modified flag before quit", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteQuit(m, []string{}, false)

		if buf.Modified {
			t.Error("modified flag should be cleared")
		}
	})
}

// ==================================================
// cmdWriteQuitAll Tests (wqall / wqa / xa)
// ==================================================

func TestCmdWriteQuitAll(t *testing.T) {
	// Note: This command may not be implemented yet
	// These tests define expected behavior

	t.Run("writes all buffers and quits", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")
		file2 := filepath.Join(tmpDir, "file2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content 1"}).
			Build()
		buf1.Modified = true

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content 2"}).
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify files were written
		content1, _ := os.ReadFile(file1)
		if string(content1) != "content 1\n" {
			t.Errorf("file1 content = %q", string(content1))
		}

		content2, _ := os.ReadFile(file2)
		if string(content2) != "content 2\n" {
			t.Errorf("file2 content = %q", string(content2))
		}

		// Verify quit command
		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("skips unmodified buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		modifiedFile := filepath.Join(tmpDir, "modified.txt")
		unmodifiedFile := filepath.Join(tmpDir, "unmodified.txt")

		modifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(modifiedFile).
			WithLines([]string{"new content"}).
			Build()
		modifiedBuf.Modified = true

		unmodifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(unmodifiedFile).
			WithLines([]string{"unchanged"}).
			Build()
		unmodifiedBuf.Modified = false

		m := newMockModelWithBuffer(&modifiedBuf)
		m.buffers = append(m.buffers, &unmodifiedBuf)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Should still quit even if some buffers unmodified
		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("errors if readonly buffer is modified", func(t *testing.T) {
		tmpDir := t.TempDir()
		validFile := filepath.Join(tmpDir, "valid.txt")

		validBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(validFile).
			WithLines([]string{"content"}).
			Modified().
			Build()

		// Readonly buffer that IS modified - should cause error
		readonlyBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&validBuf)
		m.buffers = append(m.buffers, &readonlyBuf)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for modified readonly buffer")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "readonly") {
			t.Errorf("error should mention readonly: %v", m.commandOutput.Lines)
		}

		if cmd != nil {
			t.Error("should not quit when readonly buffer has unsaved changes")
		}
	})

	t.Run("quits with readonly buffer that is NOT modified", func(t *testing.T) {
		tmpDir := t.TempDir()
		writableFile := filepath.Join(tmpDir, "writable.txt")

		writableBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(writableFile).
			WithLines([]string{"modified content"}).
			Modified().
			Build()

		// Readonly buffer that is NOT modified - should be skipped, not prevent quit
		readonlyBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("readonly.txt").
			WithLines([]string{"unchanged content"}).
			ReadOnly().
			Build()
		// NOT modified - this is the key

		m := newMockModelWithBuffer(&writableBuf)
		m.buffers = append(m.buffers, &readonlyBuf)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("should not error for unmodified readonly buffer: %v", m.commandOutput.Lines)
		}

		// Should write the modified writable buffer
		content, _ := os.ReadFile(writableFile)
		if string(content) != "modified content\n" {
			t.Errorf("writable buffer not written: %q", string(content))
		}

		// Should return quit command
		if cmd == nil {
			t.Error("expected quit command (readonly buffer not modified)")
		}
	})

	t.Run("errors if any buffer has no filename", func(t *testing.T) {
		noNameBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()
		noNameBuf.Modified = true

		m := newMockModelWithBuffer(&noNameBuf)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for buffer without filename")
		}

		if cmd != nil {
			t.Error("should not quit when write fails")
		}
	})

	t.Run("quits with no modified buffers", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("unchanged.txt").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuitAll(m, []string{}, false)

		// Should still quit even if nothing to write
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("clears modified flags on all buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")
		file2 := filepath.Join(tmpDir, "file2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content"}).
			Build()
		buf1.Modified = true

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content"}).
			Build()
		buf2.Modified = true

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdWriteQuitAll(m, []string{}, false)

		if buf1.Modified {
			t.Error("buf1 modified flag should be cleared")
		}
		if buf2.Modified {
			t.Error("buf2 modified flag should be cleared")
		}
	})
}

// ==================================================
// Force Write Tests (w!)
// ==================================================

func TestCmdWriteForce(t *testing.T) {
	t.Run("force writes readonly buffer to its own file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "readonly.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"forced content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, true)

		// Force should bypass readonly check
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify file was written
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file not written: %v", err)
		}

		expected := "forced content\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("force writes readonly buffer to argument file", func(t *testing.T) {
		tmpDir := t.TempDir()
		originalFile := filepath.Join(tmpDir, "readonly_original.txt")
		newFile := filepath.Join(tmpDir, "new_destination.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(originalFile).
			WithLines([]string{"readonly content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{newFile}, true)

		// Should succeed with force
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify new file was created
		content, err := os.ReadFile(newFile)
		if err != nil {
			t.Fatalf("new file not created: %v", err)
		}

		expected := "readonly content\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}

		// Original should not exist (never written)
		if _, err := os.Stat(originalFile); !os.IsNotExist(err) {
			t.Error("original file should not exist")
		}
	})

	t.Run("force writes scratch buffer to argument file", func(t *testing.T) {
		tmpDir := t.TempDir()
		targetFile := filepath.Join(tmpDir, "from_scratch.txt")

		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"scratch content", "line 2"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{targetFile}, true)

		// Force with filename should work for scratch buffer
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify file was written
		content, err := os.ReadFile(targetFile)
		if err != nil {
			t.Fatalf("file not written: %v", err)
		}

		expected := "scratch content\nline 2\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}
	})

	t.Run("force writes readonly scratch buffer to argument file", func(t *testing.T) {
		tmpDir := t.TempDir()
		targetFile := filepath.Join(tmpDir, "from_readonly_scratch.txt")

		// Readonly scratch buffer - double protection
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"protected content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{targetFile}, true)

		// Force should bypass BOTH readonly AND scratch checks
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error with force: %v", m.commandOutput.Lines)
		}

		// Verify file was written
		content, err := os.ReadFile(targetFile)
		if err != nil {
			t.Fatalf("file not written: %v", err)
		}

		expected := "protected content\n"
		if string(content) != expected {
			t.Errorf("got %q, want %q", string(content), expected)
		}

		// Verify modified flag was cleared
		if buf.Modified {
			t.Error("modified flag should be cleared after successful write")
		}
	})

	t.Run("force write scratch buffer without filename still errors", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, true)

		// Force doesn't help if there's no filename to write to
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when no filename provided")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "no file name") {
			t.Errorf("error should mention no file name: %v", m.commandOutput.Lines)
		}
	})

	t.Run("force write to invalid path still errors", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("/invalid/nonexistent/path/file.txt").
			WithLines([]string{"content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, true)

		// Force bypasses buffer checks but not OS-level checks
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for invalid path even with force")
		}
	})

	t.Run("force write without force flag still errors on readonly", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "readonly.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			ReadOnly().
			Build()

		m := newMockModelWithBuffer(&buf)

		// force=false should still prevent write
		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for readonly without force flag")
		}

		if !strings.Contains(strings.Join(m.commandOutput.Lines, " "), "readonly") {
			t.Errorf("error should mention readonly: %v", m.commandOutput.Lines)
		}
	})

	t.Run("force write clears modified flag even for readonly buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		if !buf.Modified {
			t.Fatal("precondition: buffer should be modified")
		}

		cmdWrite(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Modified flag should be cleared
		if buf.Modified {
			t.Error("modified flag should be cleared after force write")
		}
	})

	t.Run("force write preserves buffer type", func(t *testing.T) {
		tmpDir := t.TempDir()
		targetFile := filepath.Join(tmpDir, "output.txt")

		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{targetFile}, true)

		// Buffer type should remain ScratchBuffer
		if buf.Type != core.ScatchBuffer {
			t.Errorf("buffer type changed to %v, should remain ScatchBuffer", buf.Type)
		}

		// Filename should NOT change (Vim behavior)
		if buf.Filename != "scratch" {
			t.Errorf("buffer filename changed to %q, should remain 'scratch'", buf.Filename)
		}
	})

	t.Run("force write with empty scratch buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "empty.txt")

		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("").
			WithLines([]string{}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{filename}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Should create empty file
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file not created: %v", err)
		}

		if string(content) != "" {
			t.Errorf("expected empty file, got %q", string(content))
		}
	})
}

// ==================================================
// Force WriteAll Tests (wall!)
// ==================================================

func TestCmdWriteAllForce(t *testing.T) {
	t.Run("force writes all modified readonly buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "readonly1.txt")
		file2 := filepath.Join(tmpDir, "readonly2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content 1"}).
			ReadOnly().
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content 2"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdWriteAll(m, []string{}, true)

		// Should succeed with force
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Both files should be written
		content1, err := os.ReadFile(file1)
		if err != nil {
			t.Errorf("file1 not written: %v", err)
		} else if string(content1) != "content 1\n" {
			t.Errorf("file1 content = %q", string(content1))
		}

		content2, err := os.ReadFile(file2)
		if err != nil {
			t.Errorf("file2 not written: %v", err)
		} else if string(content2) != "content 2\n" {
			t.Errorf("file2 content = %q", string(content2))
		}
	})

	t.Run("force writeall still errors on scratch buffer without filename argument", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, true)

		// Force can bypass scratch type check, but if buffer has no filename
		// it should still error with "no file name provided"
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for scratch buffer without filename")
		}
	})

	t.Run("force writeall with mix of protected buffer types", func(t *testing.T) {
		tmpDir := t.TempDir()
		readonlyFile := filepath.Join(tmpDir, "readonly.txt")
		normalFile := filepath.Join(tmpDir, "normal.txt")

		readonlyBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(readonlyFile).
			WithLines([]string{"readonly content"}).
			ReadOnly().
			Modified().
			Build()

		normalBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(normalFile).
			WithLines([]string{"normal content"}).
			Modified().
			Build()

		unmodifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filepath.Join(tmpDir, "unmodified.txt")).
			WithLines([]string{"unchanged"}).
			Build()

		m := newMockModelWithBuffer(&readonlyBuf)
		m.buffers = append(m.buffers, &normalBuf, &unmodifiedBuf)

		cmdWriteAll(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Both modified files should be written
		if _, err := os.Stat(readonlyFile); os.IsNotExist(err) {
			t.Error("readonly file should be written with force")
		}
		if _, err := os.Stat(normalFile); os.IsNotExist(err) {
			t.Error("normal file should be written")
		}

		// Unmodified should be skipped (doesn't exist)
		unmodifiedFile := filepath.Join(tmpDir, "unmodified.txt")
		if _, err := os.Stat(unmodifiedFile); !os.IsNotExist(err) {
			t.Error("unmodified file should not be written")
		}
	})

	t.Run("force writeall clears modified flags", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWriteAll(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		if buf.Modified {
			t.Error("modified flag should be cleared")
		}
	})
}

// ==================================================
// Force WriteQuit Tests (wq!)
// ==================================================

func TestCmdWriteQuitForce(t *testing.T) {
	t.Run("force write-quit with readonly buffer", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "readonly.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// File should be written
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Errorf("file not written: %v", err)
		} else if string(content) != "content\n" {
			t.Errorf("content = %q", string(content))
		}

		// Should quit
		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("force write-quit with scratch buffer and filename arg", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "output.txt")

		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("scratch").
			WithLines([]string{"scratch data"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{filename}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// File should be written
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Errorf("file not written: %v", err)
		} else if string(content) != "scratch data\n" {
			t.Errorf("content = %q", string(content))
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("force write-quit without filename on scratch buffer still errors", func(t *testing.T) {
		buf := core.NewBufferBuilder().
			WithType(core.ScatchBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdWriteQuit(m, []string{}, true)

		// Can't write without a filename even with force
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error when no filename")
		}

		if cmd != nil {
			t.Error("should not quit on error")
		}
	})
}

// ==================================================
// Force WriteQuitAll Tests (wqall! / wqa! / xa!)
// ==================================================

func TestCmdWriteQuitAllForce(t *testing.T) {
	t.Run("force write-quit-all with readonly buffers", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "readonly1.txt")
		file2 := filepath.Join(tmpDir, "readonly2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content 1"}).
			ReadOnly().
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content 2"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmd := cmdWriteQuitAll(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Both files should be written
		content1, _ := os.ReadFile(file1)
		if string(content1) != "content 1\n" {
			t.Errorf("file1 content = %q", string(content1))
		}

		content2, _ := os.ReadFile(file2)
		if string(content2) != "content 2\n" {
			t.Errorf("file2 content = %q", string(content2))
		}

		// Should quit
		if cmd == nil {
			t.Fatal("expected quit command")
		}

		msg := cmd()
		if _, ok := msg.(tea.QuitMsg); !ok {
			t.Errorf("expected tea.QuitMsg, got %T", msg)
		}
	})

	t.Run("force write-quit-all with mix of buffer types", func(t *testing.T) {
		tmpDir := t.TempDir()
		readonlyFile := filepath.Join(tmpDir, "readonly.txt")
		normalFile := filepath.Join(tmpDir, "normal.txt")

		readonlyBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(readonlyFile).
			WithLines([]string{"readonly"}).
			ReadOnly().
			Modified().
			Build()

		normalBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(normalFile).
			WithLines([]string{"normal"}).
			Modified().
			Build()

		unmodifiedBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("unmodified.txt").
			WithLines([]string{"unchanged"}).
			Build()

		m := newMockModelWithBuffer(&readonlyBuf)
		m.buffers = append(m.buffers, &normalBuf, &unmodifiedBuf)

		cmd := cmdWriteQuitAll(m, []string{}, true)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Modified buffers should be written
		if _, err := os.Stat(readonlyFile); os.IsNotExist(err) {
			t.Error("readonly file should be written")
		}
		if _, err := os.Stat(normalFile); os.IsNotExist(err) {
			t.Error("normal file should be written")
		}

		if cmd == nil {
			t.Error("expected quit command")
		}
	})

	t.Run("force write-quit-all still errors on buffer without filename", func(t *testing.T) {
		tmpDir := t.TempDir()
		validFile := filepath.Join(tmpDir, "valid.txt")

		validBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(validFile).
			WithLines([]string{"content"}).
			Modified().
			Build()

		noNameBuf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename("").
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&validBuf)
		m.buffers = append(m.buffers, &noNameBuf)

		cmd := cmdWriteQuitAll(m, []string{}, true)

		// Force can't help when there's no filename
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for buffer without filename")
		}

		if cmd != nil {
			t.Error("should not quit when write fails")
		}
	})

	t.Run("force write-quit-all clears all modified flags", func(t *testing.T) {
		tmpDir := t.TempDir()
		file1 := filepath.Join(tmpDir, "file1.txt")
		file2 := filepath.Join(tmpDir, "file2.txt")

		buf1 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file1).
			WithLines([]string{"content"}).
			ReadOnly().
			Modified().
			Build()

		buf2 := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(file2).
			WithLines([]string{"content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf1)
		m.buffers = append(m.buffers, &buf2)

		cmdWriteQuitAll(m, []string{}, true)

		if buf1.Modified {
			t.Error("buf1 modified flag should be cleared")
		}
		if buf2.Modified {
			t.Error("buf2 modified flag should be cleared")
		}
	})
}

// ==================================================
// Edge Case Tests
// ==================================================

func TestEdgeCases(t *testing.T) {
	t.Run("write to file that becomes readonly during editing", func(t *testing.T) {
		if os.Getuid() == 0 {
			t.Skip("test requires non-root user")
		}

		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		// Create file
		os.WriteFile(filename, []byte("original"), 0644)

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"modified content"}).
			Modified().
			Build()

		// Make file readonly on filesystem (different from buffer readonly flag)
		os.Chmod(filename, 0444)
		defer os.Chmod(filename, 0644) // Cleanup

		m := newMockModelWithBuffer(&buf)

		// Regular write should fail (OS permission denied)
		cmdWrite(m, []string{}, false)

		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error for OS-level readonly file")
		}
	})

	t.Run("write unmodified readonly buffer is allowed with force", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "readonly.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			ReadOnly().
			Build()
		buf.Modified = false

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, true)

		// Force write should work even for unmodified readonly
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		content, _ := os.ReadFile(filename)
		if string(content) != "content\n" {
			t.Errorf("file not written correctly")
		}
	})

	t.Run("buffer with both readonly and modified flags", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "test.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"edited readonly content"}).
			ReadOnly().
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		// Without force - should error
		cmdWrite(m, []string{}, false)
		if m.commandOutput == nil || !m.commandOutput.IsError {
			t.Error("expected error without force")
		}

		// With force - should succeed
		m.commandOutput = nil
		cmdWrite(m, []string{}, true)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Errorf("force write failed: %v", m.commandOutput.Lines)
		}

		// Modified flag should be cleared
		if buf.Modified {
			t.Error("modified flag should be cleared")
		}
	})

	t.Run("write buffer with very long filename", func(t *testing.T) {
		tmpDir := t.TempDir()
		// Create a long but valid filename (255 chars is typical limit)
		longName := strings.Repeat("a", 200) + ".txt"
		filename := filepath.Join(tmpDir, longName)

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"content"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify file exists
		if _, err := os.Stat(filename); os.IsNotExist(err) {
			t.Error("file with long name not created")
		}
	})

	t.Run("write buffer with unicode in filename", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "テスト_файл_测试.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"unicode filename test"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		cmdWrite(m, []string{}, false)

		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("unexpected error: %v", m.commandOutput.Lines)
		}

		// Verify file exists and content is correct
		content, err := os.ReadFile(filename)
		if err != nil {
			t.Fatalf("file with unicode name not created: %v", err)
		}

		if string(content) != "unicode filename test\n" {
			t.Errorf("content = %q", string(content))
		}
	})

	t.Run("multiple sequential writes to same file", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "multi_write.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"version 1"}).
			Build()

		m := newMockModelWithBuffer(&buf)

		// First write
		cmdWrite(m, []string{}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("first write failed: %v", m.commandOutput.Lines)
		}

		// Modify buffer
		buf.SetLine(0, "version 2")
		buf.SetModified(true)

		// Second write
		cmdWrite(m, []string{}, false)
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Fatalf("second write failed: %v", m.commandOutput.Lines)
		}

		// Verify final content
		content, _ := os.ReadFile(filename)
		if string(content) != "version 2\n" {
			t.Errorf("final content = %q", string(content))
		}
	})

	t.Run("force quit does not write", func(t *testing.T) {
		tmpDir := t.TempDir()
		filename := filepath.Join(tmpDir, "not_written.txt")

		buf := core.NewBufferBuilder().
			WithType(core.FileBuffer).
			WithFilename(filename).
			WithLines([]string{"unsaved content"}).
			Modified().
			Build()

		m := newMockModelWithBuffer(&buf)

		cmd := cmdQuit(m, []string{}, true)

		// Should quit without error
		if m.commandOutput != nil && m.commandOutput.IsError {
			t.Errorf("unexpected error: %v", m.commandOutput.Lines)
		}

		if cmd == nil {
			t.Fatal("expected quit command")
		}

		// File should NOT be written
		if _, err := os.Stat(filename); !os.IsNotExist(err) {
			t.Error("file should not be written with force quit")
		}

		// Buffer should still be modified (not saved)
		if !buf.Modified {
			t.Error("buffer should still be modified (force quit doesn't save)")
		}
	})
}