package meta

import (
	"strings"
	"testing"
)

const docTemplate = "{albumartist}/{year} - {album}/{disc:1-}{track:02} - {title}.{ext}"

func in(f Fields, discs int, ext string) TemplateInput {
	return TemplateInput{Fields: f, DiscCount: discs, Ext: ext}
}

func TestRenderTemplate(t *testing.T) {
	tpl, err := ParseTemplate(docTemplate)
	if err != nil {
		t.Fatal(err)
	}
	f := Fields{Artist: "Кино", Album: "Группа крови", Year: "1988-01-05", Track: "3/11", Disc: "1", Title: "Война"}
	cases := []struct {
		name  string
		input TemplateInput
		want  string
	}{
		{"single disc", in(f, 1, "FLAC"), "Кино/1988 - Группа крови/03 - Война.flac"},
		{"multi disc", in(f, 2, "mp3"), "Кино/1988 - Группа крови/1-03 - Война.mp3"},
		{"forbidden chars and trailing dots", in(Fields{Artist: "AC/DC", Album: "What?...", Year: "1980", Track: "1", Title: ".hidden: x"}, 1, "mp3"),
			"AC_DC/1980 - What_/01 - .hidden_ x.mp3"},
	}
	for _, c := range cases {
		got, err := tpl.Render(c.input)
		if err != nil || got != c.want {
			t.Errorf("%s: got %q, %v; want %q", c.name, got, err, c.want)
		}
	}

	if _, err := tpl.Render(in(Fields{Artist: "A", Album: "B", Track: "1", Title: "C"}, 1, "mp3")); err == nil {
		t.Error("missing year outside [ ] must fail")
	}
	opt, _ := ParseTemplate("{albumartist}/[{year} - ]{album}/{track:02} - {title}.{ext}")
	if got, _ := opt.Render(in(Fields{Artist: "A", Album: "B", Track: "1", Title: "C"}, 1, "mp3")); got != "A/B/01 - C.mp3" {
		t.Errorf("optional part: %q", got)
	}
	long, _ := opt.Render(in(Fields{Artist: "A", Album: "B", Track: "1", Title: strings.Repeat("я", 300)}, 1, "flac"))
	if seg := long[strings.LastIndex(long, "/")+1:]; len(seg) > MaxSegmentBytes || !strings.HasSuffix(seg, ".flac") {
		t.Errorf("long title segment: %d bytes %q", len(seg), seg[len(seg)-10:])
	}
}

func TestParseTemplateErrors(t *testing.T) {
	for _, bad := range []string{"", "/{artist}/{title}.{ext}", "{artist}/{title}.mp3", "{artist}/{nope}/{title}.{ext}",
		"{artist}/../{title}.{ext}", "[{artist}/{title}.{ext}", "{artist}/{year:02}/{title}.{ext}", "{artist}//{title}.{ext}"} {
		if _, err := ParseTemplate(bad); err == nil {
			t.Errorf("%q must be rejected", bad)
		}
	}
}

// Шаблоны из docs/library-and-storage.md превращаются в шаблоны записи и проходят проверку обратимости.
func TestSuggestAndCheck(t *testing.T) {
	exprs := []string{
		`^(?P<skip>_incoming)/`,
		`^(?P<artist>[^/]+)/(?P<year>\d{4}) - (?P<album>[^/]+)/(?:(?P<disc>\d)-)?(?P<track>\d{1,3}) - (?P<title>[^/]+)\.\w+$`,
		`^(?P<genre>[^/]+)/(?P<artist>[^/]+)/(?P<album>.+?) \((?P<year>\d{4})\)/(?P<track>\d+)\. (?P<title>[^/]+)\.\w+$`,
	}
	paths := []string{"Кино/1988 - Группа крови/01 - Группа крови.flac", "Кино/1988 - Группа крови/02 - Закрой за мной дверь.flac",
		"Rock/Queen/Jazz (1978)/3. Jealousy.mp3"}
	got, err := SuggestTemplate(exprs, paths)
	if err != nil {
		t.Fatal(err)
	}
	if got != "{artist}/{year} - {album}/{disc:1-}{track:02} - {title}.{ext}" {
		t.Fatalf("suggested %q", got)
	}

	tpl, _ := ParseTemplate(got)
	patterns, _ := CompilePatterns(exprs)
	samples := []TemplateSample{
		{RelPath: paths[0], Input: in(Fields{Artist: "Кино", Year: "1988", Album: "Группа крови", Track: "1", Title: "Группа крови"}, 1, "flac")},
		{RelPath: paths[1], Input: in(Fields{Artist: "Кино", Year: "1988", Album: "Группа крови", Track: "2", Title: "Закрой за мной дверь"}, 1, "flac")},
		{RelPath: "Pink Floyd/1979 - The Wall/2-01 - Hey You.flac",
			Input: in(Fields{Artist: "Pink Floyd", Year: "1979", Album: "The Wall", Disc: "2", Track: "1", Title: "Hey You"}, 2, "flac")},
	}
	res := CheckTemplate(tpl, patterns, samples)
	if !res.OK || res.RoundTrip != 3 || res.SamePath != 3 {
		t.Fatalf("check: %+v", res)
	}

	// Шаблон, который регэкспы источника не разберут обратно.
	bad, _ := ParseTemplate("{artist} - {album}/{title}.{ext}")
	res = CheckTemplate(bad, patterns, samples)
	if res.OK || res.RoundTrip != 0 || len(res.Mismatches) != 3 || res.Mismatches[0].Fields[0] != "pattern" {
		t.Fatalf("bad template check: %+v", res)
	}
}