package lipgloss

import (
	"testing"
	"time"

	"github.com/charmbracelet/x/ansi"
)

func TestWhitespaceRenderWithTab(t *testing.T) {
	// This test verifies that rendering whitespace with tab characters
	// doesn't cause an infinite loop (issue #108)
	done := make(chan bool, 1)

	go func() {
		ws := newWhitespace(WithWhitespaceChars("\t"))
		_ = ws.render(10)
		done <- true
	}()

	select {
	case <-done:
		// Success - render completed
	case <-time.After(2 * time.Second):
		t.Fatal("whitespace.render() with tab character caused infinite loop")
	}
}

func TestWhitespaceRenderWithZeroWidthChar(t *testing.T) {
	// Test with zero-width joiner (another zero-width character)
	done := make(chan bool, 1)

	go func() {
		ws := newWhitespace(WithWhitespaceChars("\u200d")) // zero-width joiner
		_ = ws.render(5)
		done <- true
	}()

	select {
	case <-done:
		// Success
	case <-time.After(2 * time.Second):
		t.Fatal("whitespace.render() with zero-width character caused infinite loop")
	}
}

func TestWhitespaceRenderNormal(t *testing.T) {
	// Verify normal behavior still works
	ws := newWhitespace(WithWhitespaceChars("*"))
	result := ws.render(5)
	if len(result) != 5 {
		t.Errorf("expected 5 characters, got %d", len(result))
	}
}

func TestWhitespaceRenderWideRune(t *testing.T) {
	// A whitespace char that is more than one cell wide must never render
	// wider than the requested width; the trailing cells are padded with
	// spaces instead of overflowing.
	ws := newWhitespace(WithWhitespaceChars("東")) // width 2
	for _, width := range []int{0, 1, 2, 3, 4, 5} {
		got := ansi.StringWidth(ws.render(width))
		if got != width {
			t.Errorf("render(%d): expected rendered width %d, got %d", width, width, got)
		}
	}
}

func TestPlaceHorizontalWideWhitespace(t *testing.T) {
	// Placing content in a box with a wide whitespace char must keep the
	// box exactly the requested width.
	got := PlaceHorizontal(5, Left, "ab", WithWhitespaceChars("東"))
	if w := ansi.StringWidth(got); w != 5 {
		t.Errorf("PlaceHorizontal width: expected 5, got %d (%q)", w, got)
	}
}