package media

import (
	"path/filepath"
	"strings"
	"testing"
	"unicode"
	"unicode/utf8"
)

func TestRelativeVideoPath(t *testing.T) {
	got := RelativeVideoPath("番組名", "第1話", "ep123")
	want := filepath.Join("番組名", "番組名 第1話 [ep123].mp4")
	if got != want {
		t.Fatalf("path=%q want=%q", got, want)
	}
	other := RelativeVideoPath("番組名", "第1話", "ep456")
	if got == other || !strings.Contains(other, "[ep456]") {
		t.Fatalf("ID による衝突回避: %q %q", got, other)
	}
}

func TestRelativeVideoPathSanitizesComponents(t *testing.T) {
	got := RelativeVideoPath(" 番組:/\\*?<>|\"\x00\n\t\x7f\u0085. ", "\x00\n", "../")
	if filepath.IsAbs(got) || strings.ContainsAny(got, `:*?<>|"`) || strings.Contains(got, "..") {
		t.Fatalf("禁止文字が残った: %q", got)
	}
	for _, r := range got {
		if unicode.IsControl(r) {
			t.Errorf("制御文字が残った: %U in %q", r, got)
		}
	}
	parts := strings.Split(filepath.ToSlash(got), "/")
	if len(parts) != 2 || parts[0] == "" || !strings.HasSuffix(got, ".mp4") {
		t.Fatalf("相対パスの形: %q", got)
	}
}

func TestRelativeVideoPathHandlesEmptyAndLongNames(t *testing.T) {
	for _, name := range []string{"", " ", ".", "..", "..."} {
		got := RelativeVideoPath(name, name, "")
		if !strings.Contains(got, "名称未設定") {
			t.Errorf("空の代替名 %q: %q", name, got)
		}
	}
	long := strings.Repeat("界", 200)
	got := RelativeVideoPath(long, long, "id")
	parts := strings.Split(filepath.ToSlash(got), "/")
	if len(parts) != 2 || len([]byte(parts[0])) != 60 || !utf8.ValidString(parts[0]) {
		t.Fatalf("番組名の60バイト境界: %q (%d bytes)", parts[0], len([]byte(parts[0])))
	}
	for _, part := range strings.Split(filepath.ToSlash(got), "/") {
		if len([]byte(part)) > 240 {
			t.Fatalf("長すぎる要素: %d bytes", len([]byte(part)))
		}
		if !utf8.ValidString(part) {
			t.Fatalf("不正な UTF-8: %q", part)
		}
	}
	if got := sanitizeComponent(strings.Repeat("a", 61)); len([]byte(got)) != 60 {
		t.Fatalf("ASCII の60バイト境界: %d %q", len([]byte(got)), got)
	}
}

func TestSanitizeComponentTrimsWhitespaceBeforeLengthLimit(t *testing.T) {
	for _, tt := range []struct {
		name, input, want string
	}{
		{"前後の空白", " \t　番組名\n ", "_ 番組名_"},
		{"空白のみ", " 　 ", "名称未設定"},
		{"制御文字のみ", "\t\n", "_"},
		{"多数の先頭空白", strings.Repeat(" ", maxComponentRunes+10) + "番組名", "番組名"},
		{"先頭空白と長い名前", strings.Repeat(" ", 70) + strings.Repeat("a", 70), strings.Repeat("a", 60)},
	} {
		t.Run(tt.name, func(t *testing.T) {
			if got := sanitizeComponent(tt.input); got != tt.want {
				t.Errorf("sanitizeComponent()=%q want=%q", got, tt.want)
			}
		})
	}
}

func TestSanitizeComponentTrimsAgainAfterLengthLimit(t *testing.T) {
	for _, tt := range []struct {
		name, input, want string
	}{
		{"60バイト目が空白", strings.Repeat("a", 59) + " " + "b", strings.Repeat("a", 59)},
		{"60バイト目がドット", strings.Repeat("a", 59) + "." + "b", strings.Repeat("a", 59)},
		{"切り詰め部分が空白のみ", "a" + strings.Repeat(" ", 59) + "b", "a"},
		{"切り詰め部分がドットのみ", "a" + strings.Repeat(".", 59) + "b", "a"},
		{"複数バイト文字の直後がドット", strings.Repeat("界", 19) + ".続", strings.Repeat("界", 19)},
	} {
		t.Run(tt.name, func(t *testing.T) {
			got := sanitizeComponent(tt.input)
			if got != tt.want {
				t.Errorf("sanitizeComponent()=%q want=%q", got, tt.want)
			}
			if strings.Trim(got, " .") != got || got == "" {
				t.Errorf("切り詰め後の名前が不正: %q", got)
			}
		})
	}
}

func TestSanitizeComponentSafetyProperties(t *testing.T) {
	var controls strings.Builder
	for r := rune(0); r <= 0x9f; r++ {
		if unicode.IsControl(r) {
			controls.WriteRune(r)
		}
	}
	inputs := []string{
		"", " ", ".", "..", "...", `<>:"/\|?*`, controls.String(),
		" \t　番組名\n. ", "a/b\\c", strings.Repeat("a", 500),
		strings.Repeat("界", 500), strings.Repeat("😀", 500),
		strings.Repeat(".", 100) + "name" + strings.Repeat(" ", 100),
		string([]byte{0xff, 0xfe, 'a', 0xc0, 0xaf}),
	}
	for i, input := range inputs {
		got := sanitizeComponent(input)
		if got == "" || got == "." || got == ".." {
			t.Errorf("case %d: 空またはdot segment: %q", i, got)
		}
		if strings.Trim(got, " .") != got {
			t.Errorf("case %d: 前後に空白またはdot: %q", i, got)
		}
		if len([]byte(got)) > maxComponentBytes || utf8.RuneCountInString(got) > maxComponentRunes {
			t.Errorf("case %d: 上限超過: bytes=%d runes=%d %q", i, len([]byte(got)), utf8.RuneCountInString(got), got)
		}
		if !utf8.ValidString(got) {
			t.Errorf("case %d: 不正なUTF-8: %q", i, got)
		}
		if strings.ContainsAny(got, `<>:"/\|?*`) {
			t.Errorf("case %d: 禁止文字が残った: %q", i, got)
		}
		for _, r := range got {
			if unicode.IsControl(r) {
				t.Errorf("case %d: 制御文字が残った: %U in %q", i, r, got)
			}
		}
		if again := sanitizeComponent(got); again != got {
			t.Errorf("case %d: 再適用で変化: %q -> %q", i, got, again)
		}

		path := RelativeVideoPath(input, input, input)
		parts := strings.Split(filepath.ToSlash(path), "/")
		if filepath.IsAbs(path) || len(parts) != 2 || parts[0] == "" || parts[0] == "." || parts[0] == ".." || !strings.HasSuffix(parts[1], ".mp4") {
			t.Errorf("case %d: 安全でない相対パス: %q parts=%q", i, path, parts)
		}
		if !utf8.ValidString(path) {
			t.Errorf("case %d: パスが不正なUTF-8: %q", i, path)
		}
	}
}