package editor

import (
	"testing"

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

func TestDeleteLine(t *testing.T) {
	t.Run("test 'dd' deletes first line", func(t *testing.T) {
		lines := []string{"hello", "world"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want '1'", m.LineCount())
		}
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want '0'", m.CursorY())
		}
		if m.Line(0) != "world" {
			t.Errorf("Line(0) = %s, want 'world'", m.Line(0))
		}
	})

	t.Run("test 'dd' deletes middle line", func(t *testing.T) {
		lines := []string{"hello", "world", "testing"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want '2'", m.LineCount())
		}
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want '1'", m.CursorY())
		}
		if m.Line(0) != "hello" {
			t.Errorf("Line(0) = %s, want 'hello'", m.Line(0))
		}
		if m.Line(1) != "testing" {
			t.Errorf("Line(1) = %s, want 'testing'", m.Line(1))
		}
	})

	t.Run("test 'dd' deletes last line", func(t *testing.T) {
		lines := []string{"hello", "world"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want '1'", m.LineCount())
		}
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want '0'", m.CursorY())
		}
		if m.Line(0) != "hello" {
			t.Errorf("Line(0) = %s, want 'hello'", m.Line(0))
		}
	})

	t.Run("test 'dd' deletes line and preserves column", func(t *testing.T) {
		lines := []string{"hello", "world"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 3, Line: 0})
		sendKeys(tm, "d", "d")

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

	t.Run("test '3dd' deletes three lines", func(t *testing.T) {
		lines := []string{"hello", "world", "testing", "line", "another line"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "3", "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 2 {
			t.Errorf("LineCount() = %d, want '2'", m.LineCount())
		}
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.CursorY() != 1 {
			t.Errorf("CursorY() = %d, want '1'", m.CursorY())
		}
		if m.Line(0) != "hello" {
			t.Errorf("Line(0) = %s, want 'hello'", m.Line(0))
		}

		if m.Line(1) != "another line" {
			t.Errorf("Line(1) = %s, want 'another line'", m.Line(1))
		}
	})

	t.Run("test 'dd' deletes only line and preserves content", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "d")

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

	t.Run("test 'dd' with no lines preserves content", func(t *testing.T) {
		lines := []string{""}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "d")

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

	t.Run("test 'dd' clamps cursor when next line is shorter", func(t *testing.T) {
		lines := []string{"hello world", "hi"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 7, Line: 0})
		sendKeys(tm, "d", "d")

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

	t.Run("test '3dd' count exceeds remaining lines", func(t *testing.T) {
		lines := []string{"hello", "world"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "3", "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.LineCount())
		}
		if m.Line(0) != "" {
			t.Errorf("Line(0) = %q, want \"\"", m.Line(0))
		}
	})

	t.Run("test '3dd' starting near end of file", func(t *testing.T) {
		lines := []string{"hello", "world", "testing"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "3", "d", "d")

		m := getFinalModel(t, tm)
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.LineCount())
		}
		if m.Line(0) != "hello" {
			t.Errorf("Line(0) = %q, want \"hello\"", m.Line(0))
		}
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want 0", m.CursorY())
		}
	})

}

func TestDeleteOperatorWithHorozontalMotion(t *testing.T) {
	t.Run("test 'dl' deletes current character from start", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "l")

		m := getFinalModel(t, tm)
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.Line(0) != "ello" {
			t.Errorf("Line(0) = %s, want 'ello'", m.Line(0))
		}
	})

	t.Run("test 'dl' deletes current character from middle", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 2, Line: 0})
		sendKeys(tm, "d", "l")

		m := getFinalModel(t, tm)
		if m.CursorX() != 2 {
			t.Errorf("CursorX() = %d, want '2'", m.CursorX())
		}
		if m.Line(0) != "helo" {
			t.Errorf("Line(0) = %s, want 'helo'", m.Line(0))
		}
	})

	t.Run("test 'dl' deletes current character from end", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 4, Line: 0})
		sendKeys(tm, "d", "l")

		m := getFinalModel(t, tm)
		if m.CursorX() != 4 {
			t.Errorf("CursorX() = %d, want '4'", m.CursorX())
		}
		if m.Line(0) != "hell" {
			t.Errorf("Line(0) = %s, want 'hell'", m.Line(0))
		}
	})

	t.Run("test 'dh' does nothing on first char", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "h")

		m := getFinalModel(t, tm)
		if m.CursorX() != 0 {
			t.Errorf("CursorX() = %d, want '0'", m.CursorX())
		}
		if m.Line(0) != "hello" {
			t.Errorf("Line(0) = %s, want 'hello'", m.Line(0))
		}
	})

	t.Run("test 'dh' deletes character to the left from middle", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 2, Line: 0})
		sendKeys(tm, "d", "h")

		m := getFinalModel(t, tm)
		// dh deletes char to the left (position 1, 'e'), cursor moves to that position
		if m.CursorX() != 1 {
			t.Errorf("CursorX() = %d, want 1", m.CursorX())
		}
		if m.Line(0) != "hllo" {
			t.Errorf("Line(0) = %q, want 'hllo'", m.Line(0))
		}
	})

	t.Run("test 'dh' deletes character to the left from end", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 4, Line: 0})
		sendKeys(tm, "d", "h")

		m := getFinalModel(t, tm)
		// dh deletes char to the left (position 3, 'l'), cursor moves to that position
		if m.CursorX() != 3 {
			t.Errorf("CursorX() = %d, want 3", m.CursorX())
		}
		if m.Line(0) != "helo" {
			t.Errorf("Line(0) = %q, want 'helo'", m.Line(0))
		}
	})

	t.Run("test '2dl' deletes two characters", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "2", "d", "l")

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

	t.Run("test 'd2l' deletes two characters", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "2", "l")

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

	t.Run("test '2dh' deletes two characters backwards", func(t *testing.T) {
		lines := []string{"hello"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 4, Line: 0})
		sendKeys(tm, "2", "d", "h")

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

func TestDeleteOperatorWithVerticalMotion(t *testing.T) {
	t.Run("test 'dj' deletes current and next line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "j")

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

	t.Run("test 'dj' from first line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "j")

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

	// Note: In vim, dj from last line does nothing. Our implementation treats all
	// linewise motions consistently - they operate on at least the current line.
	t.Run("test 'dj' from last line deletes current line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "j")

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

	t.Run("test 'd2j' deletes current and next two lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "2", "j")

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

	t.Run("test '2dj' deletes current and next two lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "2", "d", "j")

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

	t.Run("test 'dk' deletes current and previous line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "k")

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

	// Note: In vim, dk from first line does nothing. Our implementation treats all
	// linewise motions consistently - they operate on at least the current line.
	t.Run("test 'dk' from first line deletes current line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "k")

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

	t.Run("test 'dk' from second line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "k")

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

	t.Run("test 'd2k' deletes current and previous two lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 3})
		sendKeys(tm, "d", "2", "k")

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

	t.Run("test '2dk' deletes current and previous two lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 3})
		sendKeys(tm, "2", "d", "k")

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

	t.Run("test 'dj' with count exceeding remaining lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "5", "j")

		m := getFinalModel(t, tm)
		// Should delete from line 1 to end
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.LineCount())
		}
		if m.Line(0) != "line 1" {
			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
		}
	})

	t.Run("test 'dk' with count exceeding previous lines", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 1})
		sendKeys(tm, "d", "5", "k")

		m := getFinalModel(t, tm)
		// Should delete from line 0 to line 1
		if m.LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.LineCount())
		}
		if m.Line(0) != "line 3" {
			t.Errorf("Line(0) = %q, want 'line 3'", m.Line(0))
		}
	})
}

func TestDeleteOperatorWithJumpMotion(t *testing.T) {
	t.Run("test 'dG' deletes from cursor to end of file", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "G")

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

	t.Run("test 'dG' from first line deletes everything", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "G")

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

	t.Run("test 'dG' from last line deletes only last line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "G")

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

	t.Run("test 'dG' positions cursor correctly", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 3, Line: 1})
		sendKeys(tm, "d", "G")

		m := getFinalModel(t, tm)
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want 0", m.CursorY())
		}
	})

	t.Run("test 'dgg' deletes from cursor to start of file", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "g", "g")

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

	t.Run("test 'dgg' from last line deletes everything", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 0, Line: 2})
		sendKeys(tm, "d", "g", "g")

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

	t.Run("test 'dgg' from first line deletes only first line", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "g", "g")

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

	t.Run("test 'dgg' positions cursor at start", func(t *testing.T) {
		lines := []string{"line 1", "line 2", "line 3", "line 4"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 3, Line: 2})
		sendKeys(tm, "d", "g", "g")

		m := getFinalModel(t, tm)
		if m.CursorY() != 0 {
			t.Errorf("CursorY() = %d, want 0", m.CursorY())
		}
	})

	t.Run("test 'dG' on single line file deletes the line", func(t *testing.T) {
		lines := []string{"only line"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "G")

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

	t.Run("test 'dgg' on single line file deletes the line", func(t *testing.T) {
		lines := []string{"only line"}
		tm := newTestModelWithLines(t, lines)
		sendKeys(tm, "d", "g", "g")

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

	t.Run("test 'dG' clamps cursor when file shrinks", func(t *testing.T) {
		lines := []string{"short", "this is a longer line", "line 3", "line 4"}
		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 10, Line: 1})
		sendKeys(tm, "d", "G")

		m := getFinalModel(t, tm)
		// Cursor was at col 10, but "short" only has 5 chars
		if m.CursorX() > len("short") {
			t.Errorf("CursorX() = %d, should be clamped to line length %d", m.CursorX(), len("short"))
		}
	})
}