package editor

import (
	"testing"

	"git.gophernest.net/azpect/TextEditor/internal/action"
)

func TestPasteLinewiseBasic(t *testing.T) {
	t.Run("p pastes single line after cursor line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 3 {
			t.Errorf("LineCount() = %d, want 3", m.LineCount())
		}
		if m.Line(0) != "line 1" {
			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
		}
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
		if m.Line(2) != "line 2" {
			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
		}
	})

	t.Run("p moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2", "line 3"}),
			WithCursorPos(action.Position{Line: 0, Col: 5}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})

	t.Run("p from middle of file", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2", "line 3"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		if m.Line(2) != "inserted" {
			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
		}
		if m.CursorY() != 2 {
			t.Errorf("CursorY() = %d, want 2", m.CursorY())
		}
	})

	t.Run("p at end of file", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 3 {
			t.Errorf("LineCount() = %d, want 3", m.LineCount())
		}
		if m.Line(2) != "inserted" {
			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
		}
	})
}

func TestPasteLinewiseMultipleLines(t *testing.T) {
	t.Run("p pastes multiple lines in correct order", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second", "third"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 5 {
			t.Errorf("LineCount() = %d, want 5", m.LineCount())
		}
		if m.Line(0) != "line 1" {
			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
		}
		if m.Line(1) != "first" {
			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
		}
		if m.Line(2) != "second" {
			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
		}
		if m.Line(3) != "third" {
			t.Errorf("Line(3) = %q, want 'third'", m.Line(3))
		}
		if m.Line(4) != "line 2" {
			t.Errorf("Line(4) = %q, want 'line 2'", m.Line(4))
		}
	})

	t.Run("p with multiple lines moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})
}

func TestPasteLinewiseWithCount(t *testing.T) {
	t.Run("2p pastes content twice", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "2", "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		// Both "inserted" lines should appear after line 1
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
		if m.Line(2) != "inserted" {
			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
		}
		if m.Line(3) != "line 2" {
			t.Errorf("Line(3) = %q, want 'line 2'", m.Line(3))
		}
	})

	t.Run("3p pastes content three times", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"pasted"}),
		)
		sendKeys(tm, "3", "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		for i := 1; i <= 3; i++ {
			if m.Line(i) != "pasted" {
				t.Errorf("Line(%d) = %q, want 'pasted'", i, m.Line(i))
			}
		}
	})

	t.Run("2p with multiple lines pastes all lines twice in order", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
		)
		sendKeys(tm, "2", "p")

		m := getFinalModel(t, tm)
		// Should be: original, first, second, first, second
		if m.LineCount() != 5 {
			t.Errorf("LineCount() = %d, want 5", m.LineCount())
		}
		if m.Line(0) != "original" {
			t.Errorf("Line(0) = %q, want 'original'", m.Line(0))
		}
		if m.Line(1) != "first" {
			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
		}
		if m.Line(2) != "second" {
			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
		}
		if m.Line(3) != "first" {
			t.Errorf("Line(3) = %q, want 'first'", m.Line(3))
		}
		if m.Line(4) != "second" {
			t.Errorf("Line(4) = %q, want 'second'", m.Line(4))
		}
	})

	t.Run("count paste moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "3", "p")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})
}

// Tests for P (paste before)

func TestPasteBeforeLinewiseBasic(t *testing.T) {
	t.Run("P pastes single line before cursor line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 3 {
			t.Errorf("LineCount() = %d, want 3", m.LineCount())
		}
		if m.Line(0) != "line 1" {
			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
		}
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
		if m.Line(2) != "line 2" {
			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
		}
	})

	t.Run("P moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2", "line 3"}),
			WithCursorPos(action.Position{Line: 1, Col: 5}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})

	t.Run("P at first line pastes at very top", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 3 {
			t.Errorf("LineCount() = %d, want 3", m.LineCount())
		}
		if m.Line(0) != "inserted" {
			t.Errorf("Line(0) = %q, want 'inserted'", m.Line(0))
		}
		if m.Line(1) != "line 1" {
			t.Errorf("Line(1) = %q, want 'line 1'", m.Line(1))
		}
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want 0", m.CursorY())
		}
	})

	t.Run("P from middle of file", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2", "line 3"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
		if m.Line(2) != "line 2" {
			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
		}
	})
}

func TestPasteBeforeLinewiseMultipleLines(t *testing.T) {
	t.Run("P pastes multiple lines in correct order", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second", "third"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 5 {
			t.Errorf("LineCount() = %d, want 5", m.LineCount())
		}
		if m.Line(0) != "line 1" {
			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
		}
		if m.Line(1) != "first" {
			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
		}
		if m.Line(2) != "second" {
			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
		}
		if m.Line(3) != "third" {
			t.Errorf("Line(3) = %q, want 'third'", m.Line(3))
		}
		if m.Line(4) != "line 2" {
			t.Errorf("Line(4) = %q, want 'line 2'", m.Line(4))
		}
	})

	t.Run("P with multiple lines moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})
}

func TestPasteBeforeLinewiseWithCount(t *testing.T) {
	t.Run("2P pastes content twice", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "2", "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		// Both "inserted" lines should appear before line 2
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
		if m.Line(2) != "inserted" {
			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
		}
		if m.Line(3) != "line 2" {
			t.Errorf("Line(3) = %q, want 'line 2'", m.Line(3))
		}
	})

	t.Run("3P pastes content three times", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"pasted"}),
		)
		sendKeys(tm, "3", "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 4 {
			t.Errorf("LineCount() = %d, want 4", m.LineCount())
		}
		for i := 0; i < 3; i++ {
			if m.Line(i) != "pasted" {
				t.Errorf("Line(%d) = %q, want 'pasted'", i, m.Line(i))
			}
		}
		if m.Line(3) != "original" {
			t.Errorf("Line(3) = %q, want 'original'", m.Line(3))
		}
	})

	t.Run("2P with multiple lines pastes all lines twice in order", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
		)
		sendKeys(tm, "2", "P")

		m := getFinalModel(t, tm)
		// Should be: first, second, first, second, original
		if m.LineCount() != 5 {
			t.Errorf("LineCount() = %d, want 5", m.LineCount())
		}
		if m.Line(0) != "first" {
			t.Errorf("Line(0) = %q, want 'first'", m.Line(0))
		}
		if m.Line(1) != "second" {
			t.Errorf("Line(1) = %q, want 'second'", m.Line(1))
		}
		if m.Line(2) != "first" {
			t.Errorf("Line(2) = %q, want 'first'", m.Line(2))
		}
		if m.Line(3) != "second" {
			t.Errorf("Line(3) = %q, want 'second'", m.Line(3))
		}
		if m.Line(4) != "original" {
			t.Errorf("Line(4) = %q, want 'original'", m.Line(4))
		}
	})

	t.Run("count paste before moves cursor to first pasted line", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 1, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "3", "P")

		m := getFinalModel(t, tm)
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want 1", m.CursorY())
		}
	})
}

func TestPasteBeforeLinewiseEdgeCases(t *testing.T) {
	t.Run("P on single line buffer", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"only line"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want 2", m.LineCount())
		}
		if m.Line(0) != "inserted" {
			t.Errorf("Line(0) = %q, want 'inserted'", m.Line(0))
		}
		if m.Line(1) != "only line" {
			t.Errorf("Line(1) = %q, want 'only line'", m.Line(1))
		}
	})

	t.Run("P with empty register content does nothing", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want 2", m.LineCount())
		}
	})

	t.Run("P preserves indentation in pasted lines", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"    indented", "\ttabbed"}),
		)
		sendKeys(tm, "P")

		m := getFinalModel(t, tm)
		if m.Line(0) != "    indented" {
			t.Errorf("Line(0) = %q, want '    indented'", m.Line(0))
		}
		if m.Line(1) != "\ttabbed" {
			t.Errorf("Line(1) = %q, want '\\ttabbed'", m.Line(1))
		}
	})

	t.Run("P with large count", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"x"}),
		)
		sendKeys(tm, "1", "0", "P") // 10P

		m := getFinalModel(t, tm)
		if m.LineCount() != 11 {
			t.Errorf("LineCount() = %d, want 11", m.LineCount())
		}
		// Original should be at the end
		if m.Line(10) != "original" {
			t.Errorf("Line(10) = %q, want 'original'", m.Line(10))
		}
	})
}

func TestPasteLinewiseEdgeCases(t *testing.T) {
	t.Run("p on single line buffer", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"only line"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want 2", m.LineCount())
		}
		if m.Line(0) != "only line" {
			t.Errorf("Line(0) = %q, want 'only line'", m.Line(0))
		}
		if m.Line(1) != "inserted" {
			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
		}
	})

	t.Run("p with empty register content does nothing", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1", "line 2"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want 2", m.LineCount())
		}
	})

	t.Run("p preserves indentation in pasted lines", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"line 1"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"    indented", "\ttabbed"}),
		)
		sendKeys(tm, "p")

		m := getFinalModel(t, tm)
		if m.Line(1) != "    indented" {
			t.Errorf("Line(1) = %q, want '    indented'", m.Line(1))
		}
		if m.Line(2) != "\ttabbed" {
			t.Errorf("Line(2) = %q, want '\\ttabbed'", m.Line(2))
		}
	})

	t.Run("p with large count", func(t *testing.T) {
		tm := newTestModel(t,
			WithLines([]string{"original"}),
			WithCursorPos(action.Position{Line: 0, Col: 0}),
			WithRegister('"', action.LinewiseRegister, []string{"x"}),
		)
		sendKeys(tm, "1", "0", "p") // 10p

		m := getFinalModel(t, tm)
		if m.LineCount() != 11 {
			t.Errorf("LineCount() = %d, want 11", m.LineCount())
		}
	})
}