package editor

import (
	"regexp"
	"strings"
	"testing"

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

var ansiPattern = regexp.MustCompile(`\x1b\[[0-9;]*m`)

func stripANSI(s string) string {
	return ansiPattern.ReplaceAllString(s, "")
}

func firstViewLine(view string) string {
	lines := strings.Split(view, "\n")
	if len(lines) == 0 {
		return ""
	}
	return stripANSI(lines[0])
}

func TestHorizontalScrollRender(t *testing.T) {
	line := "0123456789abcdef"
	tm := newTestModelWithTermSize(t, []string{line}, core.Position{Line: 0, Col: 0}, 12, 10)

	for range 10 {
		sendKeys(tm, "l")
	}

	m := getFinalModel(t, tm)
	if m.ActiveWindow().ScrollX != 4 {
		t.Fatalf("ScrollX() = %d, want 4", m.ActiveWindow().ScrollX)
	}

	visible := firstViewLine(m.View())
	if !strings.Contains(visible, "456789a") {
		t.Fatalf("first visible line = %q, want it to contain %q", visible, "456789a")
	}
}

func TestHorizontalScrollRenderReturnsWhenMovingLeft(t *testing.T) {
	line := "0123456789abcdef"
	tm := newTestModelWithTermSize(t, []string{line}, core.Position{Line: 0, Col: 0}, 12, 10)

	for range 10 {
		sendKeys(tm, "l")
	}
	for range 10 {
		sendKeys(tm, "h")
	}

	m := getFinalModel(t, tm)
	if m.ActiveWindow().ScrollX != 0 {
		t.Fatalf("ScrollX() after moving back left = %d, want 0", m.ActiveWindow().ScrollX)
	}

	visible := firstViewLine(m.View())
	if !strings.Contains(visible, "0123456") {
		t.Fatalf("first visible line after moving back left = %q, want it to contain %q", visible, "0123456")
	}
}

func TestHorizontalScrollResizeClampWithRunes(t *testing.T) {
	line := "abécdefghij"
	tm := newTestModelWithTermSize(t, []string{line}, core.Position{Line: 0, Col: 0}, 10, 10)

	for range 10 {
		sendKeys(tm, "l")
	}

	tm.Send(tea.WindowSizeMsg{Width: 12, Height: 10})

	m := getFinalModel(t, tm)
	if m.ActiveWindow().ScrollX != 5 {
		t.Fatalf("ScrollX() after resize = %d, want 5", m.ActiveWindow().ScrollX)
	}

	visible := firstViewLine(m.View())
	if !strings.Contains(visible, "efghij") {
		t.Fatalf("first visible line after resize = %q, want it to contain %q", visible, "efghij")
	}
}