package editor

import (
	"fmt"
	"testing"

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

func TestScreenTopMotion(t *testing.T) {
	t.Run("H moves to the top visible line first non-blank", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[82] = "    top"

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "H")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 82, 4)
	})

	t.Run("3H moves to third visible line from top", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[84] = "  third"

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "3", "H")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 84, 2)
	})

	t.Run("H count clamps to bottom visible line", func(t *testing.T) {
		tm := newTestModelWithTermSize(t, screenMotionLines(100), core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "9", "9", "9", "H")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 99, 0)
	})
}

func TestScreenMiddleMotion(t *testing.T) {
	t.Run("M moves to middle visible line first non-blank", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[90] = "\tmiddle"

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "M")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 90, 1)
	})

	t.Run("count before M is ignored", func(t *testing.T) {
		tm := newTestModelWithTermSize(t, screenMotionLines(100), core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "9", "M")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 90, 0)
	})
}

func TestScreenBottomMotion(t *testing.T) {
	t.Run("L moves to bottom visible line first non-blank", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[99] = "  bottom"

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "L")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 99, 2)
	})

	t.Run("3L moves to third visible line from bottom", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[97] = "    above"

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "3", "L")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 97, 4)
	})

	t.Run("L count clamps to top visible line", func(t *testing.T) {
		tm := newTestModelWithTermSize(t, screenMotionLines(100), core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "9", "9", "9", "L")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 82, 0)
	})
}

func TestScreenMotionsEdgeCases(t *testing.T) {
	t.Run("small file: H and L clamp to file bounds", func(t *testing.T) {
		lines := []string{"    one", "two", "three", "four", "five"}
		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "L")
		sendKeys(tm, "H")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 0, 4)
	})

	t.Run("M on blank middle line lands at column 0", func(t *testing.T) {
		lines := screenMotionLines(100)
		lines[90] = ""

		tm := newTestModelWithTermSize(t, lines, core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "M")

		m := getFinalModel(t, tm)
		assertCursorPos(t, m, 90, 0)
	})
}

func TestScreenMotionsIntegration(t *testing.T) {
	t.Run("dH treats H as a linewise motion", func(t *testing.T) {
		tm := newTestModelWithTermSize(t, screenMotionLines(100), core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "d", "H")

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().LineCount() != 82 {
			t.Errorf("LineCount() = %d, want 82", m.ActiveBuffer().LineCount())
		}
		if m.ActiveBuffer().Line(81) != "line 81" {
			t.Errorf("Line(81) = %q, want %q", m.ActiveBuffer().Line(81), "line 81")
		}
	})

	t.Run("H works as a visual line motion", func(t *testing.T) {
		tm := newTestModelWithTermSize(t, screenMotionLines(100), core.Position{Col: 0, Line: 0}, 80, 20)
		sendKeys(tm, "G", "V", "H", "d")

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().LineCount() != 82 {
			t.Errorf("LineCount() = %d, want 82", m.ActiveBuffer().LineCount())
		}
		if m.Mode() != core.NormalMode {
			t.Errorf("Mode() = %v, want %v", m.Mode(), core.NormalMode)
		}
	})
}

func screenMotionLines(n int) []string {
	lines := make([]string, n)
	for i := range n {
		lines[i] = fmt.Sprintf("line %d", i)
	}
	return lines
}

func assertCursorPos(t *testing.T, m *Model, wantLine, wantCol int) {
	t.Helper()
	if m.ActiveWindow().Cursor.Line != wantLine {
		t.Errorf("Cursor.Line = %d, want %d", m.ActiveWindow().Cursor.Line, wantLine)
	}
	if m.ActiveWindow().Cursor.Col != wantCol {
		t.Errorf("Cursor.Col = %d, want %d", m.ActiveWindow().Cursor.Col, wantCol)
	}
}