ライブラリ・再生・削除を追加（Range 配信、パスの安全確認、共有ファイル名規則）

internal/media/path.go

@@ -0,0 +1,61 @@
+package media
+
+import (
+	"path/filepath"
+	"strings"
+	"unicode"
+)
+
+const maxComponentRunes = 80
+const maxComponentBytes = 60
+
+// RelativeVideoPath は worker と web が共有する保存先の相対パスを返す。
+func RelativeVideoPath(seriesTitle, episodeTitle, episodeID string) string {
+	series := sanitizeComponent(seriesTitle)
+	episode := sanitizeComponent(episodeTitle)
+	id := sanitizeComponent(episodeID)
+	return filepath.Join(series, series+" "+episode+" ["+id+"].mp4")
+}
+
+func sanitizeComponent(value string) string {
+	var result []rune
+	lastReplacement := false
+	for _, r := range value {
+		invalid := unicode.IsControl(r) || strings.ContainsRune(`<>:"/\|?*`, r)
+		if invalid {
+			if !lastReplacement {
+				result = append(result, '_')
+				lastReplacement = true
+			}
+			continue
+		}
+		if unicode.IsSpace(r) {
+			r = ' '
+		}
+		result = append(result, r)
+		lastReplacement = false
+	}
+	clean := strings.Trim(string(result), " .")
+	if clean == "" || clean == "." || clean == ".." {
+		return "名称未設定"
+	}
+	runes := []rune(clean)
+	if len(runes) > maxComponentRunes {
+		runes = runes[:maxComponentRunes]
+	}
+	var limited []rune
+	bytes := 0
+	for _, r := range runes {
+		size := len(string(r))
+		if bytes+size > maxComponentBytes {
+			break
+		}
+		limited = append(limited, r)
+		bytes += size
+	}
+	clean = strings.Trim(string(limited), " .")
+	if clean == "" || clean == "." || clean == ".." {
+		return "名称未設定"
+	}
+	return clean
+}