package preview

import (
	"reflect"
	"strings"
	"testing"
)

func TestSplitFrontmatter(t *testing.T) {
	md := "---\ncreated: 2026-07-08\nstatus: \"🟢 In progress\"\ntags:\n  - daily\n  - tui\ncategories: [\"[[Projects]]\", Notes]\n---\n\n# Body\n\ntext\n"
	props, body := splitFrontmatter(md)
	want := []prop{
		{"created", "2026-07-08"},
		{"status", "🟢 In progress"},
		{"tags", "daily · tui"},
		{"categories", "[[Projects]] · Notes"},
	}
	if !reflect.DeepEqual(props, want) {
		t.Errorf("props = %#v, want %#v", props, want)
	}
	if body != "\n# Body\n\ntext\n" {
		t.Errorf("body = %q", body)
	}
}

func TestSplitFrontmatterNone(t *testing.T) {
	md := "# Body\n\ntext\n"
	props, body := splitFrontmatter(md)
	if len(props) != 0 || body != md {
		t.Errorf("no frontmatter: props=%v body=%q", props, body)
	}
	// A "---" that isn't on line one is a horizontal rule, not frontmatter.
	md2 := "intro\n\n---\nkey: value\n---\n"
	props, body = splitFrontmatter(md2)
	if len(props) != 0 || body != md2 {
		t.Errorf("mid-document rule treated as frontmatter: props=%v", props)
	}
}

func TestSplitFrontmatterUnterminated(t *testing.T) {
	md := "---\nkey: value\n\n# Body\n"
	props, body := splitFrontmatter(md)
	if len(props) != 0 || body != md {
		t.Errorf("unterminated block should be left alone: props=%v body=%q", props, body)
	}
}

func TestSplitFrontmatterEmptyValues(t *testing.T) {
	md := "---\naliases:\ntitle: Note\n---\nbody\n"
	props, _ := splitFrontmatter(md)
	want := []prop{{"aliases", ""}, {"title", "Note"}}
	if !reflect.DeepEqual(props, want) {
		t.Errorf("props = %#v, want %#v", props, want)
	}
}

// A colon inside a value (a URL, a time) must not split the key twice.
func TestSplitFrontmatterColonInValue(t *testing.T) {
	md := "---\nsource: https://example.com/a\nat: 09:30\n---\nbody\n"
	props, _ := splitFrontmatter(md)
	want := []prop{{"source", "https://example.com/a"}, {"at", "09:30"}}
	if !reflect.DeepEqual(props, want) {
		t.Errorf("props = %#v, want %#v", props, want)
	}
}

func TestHeaderTitleFromFrontmatter(t *testing.T) {
	m := New("")
	m.SetColors(testColors)
	m.SetSize(60, 20)
	m.SetTitle("filename-title")
	if err := m.Render("---\ntitle: Frontmatter Title\ncreated: 2026-07-08\n---\n\nbody\n"); err != nil {
		t.Fatal(err)
	}
	out := strings.Join(stripANSI(m.vp.View()), "\n")
	if !strings.Contains(out, "Frontmatter Title") {
		t.Errorf("frontmatter title not used as doc name:\n%s", out)
	}
	if strings.Contains(out, "filename-title") {
		t.Errorf("filename should lose to frontmatter title:\n%s", out)
	}
	// The title key is consumed by the heading, not repeated as a property.
	if strings.Contains(out, "title ") {
		t.Errorf("title still listed as a property:\n%s", out)
	}
}

func TestHeaderPropsAreTightAndRuleFree(t *testing.T) {
	m := New("")
	m.SetColors(testColors)
	m.SetSize(60, 30)
	m.SetTitle("My Note")
	if err := m.Render("---\ncreated: 2026-07-08\nstatus: In progress\ntags:\n  - daily\n---\n\nbody text\n"); err != nil {
		t.Fatal(err)
	}
	lines := stripANSI(m.vp.View())
	find := func(want string) int {
		for i, ln := range lines {
			if strings.HasPrefix(strings.TrimSpace(ln), want) {
				return i
			}
		}
		t.Fatalf("line starting %q not found in:\n%s", want, strings.Join(lines, "\n"))
		return -1
	}
	title := find("My Note")
	created := find("created")
	// Doc name sits above the properties, with one blank line between.
	if created != title+2 {
		t.Errorf("properties start at %d, want %d (one blank line under the title)", created, title+2)
	}
	// Properties are consecutive: no blank lines between them.
	if got := strings.TrimSpace(lines[created+1]); !strings.HasPrefix(got, "status") {
		t.Errorf("line after created = %q, want status", got)
	}
	if got := strings.TrimSpace(lines[created+2]); !strings.HasPrefix(got, "tags") {
		t.Errorf("line after status = %q, want tags", got)
	}
	// The --- fences never render as horizontal rules.
	for _, ln := range lines {
		if strings.HasPrefix(strings.TrimSpace(ln), "---") {
			t.Errorf("frontmatter fence rendered as a rule:\n%s", strings.Join(lines, "\n"))
			break
		}
	}
	// Values are aligned in a column, keys padded to the widest key.
	for _, ln := range lines[created : created+3] {
		if !strings.Contains(ln, "  2026-07-08") && !strings.Contains(ln, "  In progress") && !strings.Contains(ln, "  daily") {
			t.Errorf("property value not in an aligned column: %q", ln)
		}
	}
}

func TestHeaderTitleBarIsStyled(t *testing.T) {
	m := New("")
	m.SetColors(testColors)
	m.SetSize(60, 20)
	m.SetTitle("My Note")
	if err := m.Render("body\n"); err != nil {
		t.Fatal(err)
	}
	raw := m.vp.View()
	line := strings.Split(raw, "\n")[0]
	if !strings.Contains(line, "My Note") {
		t.Fatalf("title not on the first line: %q", line)
	}
	// The heading color paints the bar background, with legible text on top.
	if !strings.Contains(line, "48;2;209;77;65") {
		t.Errorf("title bar missing the heading background: %q", line)
	}
	if !strings.Contains(line, "38;2;255;252;240") {
		t.Errorf("title bar missing legible foreground: %q", line)
	}
	// The bar spans the full preview width, like a filled H1 block.
	if w := len(stripANSI(line)[0]); w != 60 {
		t.Errorf("title bar width = %d, want 60", w)
	}
}

func TestHeaderAbsentWithoutTitleOrProps(t *testing.T) {
	m := New("")
	m.SetColors(testColors)
	m.SetSize(60, 20)
	if err := m.Render("# Heading\n\nbody\n"); err != nil {
		t.Fatal(err)
	}
	if h := m.renderHeader("", nil); h != "" {
		t.Errorf("renderHeader with nothing to show = %q", h)
	}
	// The document opens on glamour's own H1, not a doc-name bar above it.
	lines := stripANSI(m.vp.View())
	if got := strings.TrimSpace(lines[0]); got != "" {
		t.Errorf("untitled doc grew a header: %q", got)
	}
	if got := strings.TrimSpace(lines[1]); got != "Heading" {
		t.Errorf("body H1 should be the first thing rendered, got %q", got)
	}
}

func TestHeaderWrapsLongValues(t *testing.T) {
	m := New("")
	m.SetColors(testColors)
	m.SetSize(40, 20)
	m.SetTitle("N")
	if err := m.Render("---\ntags: alpha beta gamma delta epsilon zeta eta theta\n---\nbody\n"); err != nil {
		t.Fatal(err)
	}
	for _, ln := range stripANSI(m.vp.View()) {
		if w := len([]rune(ln)); w > 40 {
			t.Errorf("line exceeds width 40 (%d): %q", w, ln)
		}
	}
}