package preview

import (
	"strings"
	"testing"
)

var testColors = Colors{
	Background: "#100F0F", Text: "#CECDC3", Heading: "#D14D41", Code: "#879A39", Link: "#4385BE",
}

func renderPreview(t *testing.T, md string) string {
	t.Helper()
	m := New("dark")
	m.SetColors(testColors)
	m.SetSize(40, 20)
	if err := m.Render(md); err != nil {
		t.Fatal(err)
	}
	return m.View()
}

// H1 text must sit on the heading background, not the paper background.
func TestH1BackgroundBehindText(t *testing.T) {
	out := renderPreview(t, "# glint\n")
	if !strings.Contains(out, "48;2;209;77;65") {
		t.Fatalf("H1 missing heading background (209;77;65):\n%q", out)
	}
	// the word "glint" itself must carry the heading bg, not paper (16;15;15)
	if !strings.Contains(out, "48;2;209;77;65;1mglint") {
		t.Fatalf("H1 text not painted on heading background:\n%q", out)
	}
}

// Every ANSI reset must be followed by a re-assert of the paper background so
// unstyled regions (table borders, cell padding) never fall back to the
// terminal default — the table-background-between-themes bug.
func TestPaperBackgroundReassertedAfterResets(t *testing.T) {
	out := renderPreview(t, "| Key | Action |\n| --- | --- |\n| `Tab` | indent |\n")
	paper := "\x1b[48;2;16;15;15m"
	resets := strings.Count(out, "\x1b[0m")
	reasserted := strings.Count(out, "\x1b[0m"+paper)
	if resets == 0 {
		t.Fatal("expected some resets in table output")
	}
	if resets != reasserted {
		t.Fatalf("bare resets remain: %d resets, %d re-asserted paper bg", resets, reasserted)
	}
}