Make MP3Gain options configurable

2026-06-07 13:45:15 +02:00
parent 1b38395af9
commit a2aa4e36d2
3 changed files with 108 additions and 12 deletions
@@ -426,17 +426,59 @@ struct SDCardCleaner {
 }

 struct MP3GainNormalizer {
+    struct Options {
+        enum GainMode: Hashable {
+            case track
+            case album
+        }
+
+        let gainMode: GainMode
+        let preventClipping: Bool
+        let dbOffset: String
+
+        var arguments: [String] {
+            var result: [String] = []
+
+            switch gainMode {
+            case .track:
+                result.append("-r")
+            case .album:
+                result.append("-a")
+            }
+
+            if preventClipping {
+                result.append("-k")
+            }
+
+            let trimmedOffset = dbOffset.trimmingCharacters(in: .whitespacesAndNewlines)
+            if !trimmedOffset.isEmpty {
+                result.append(contentsOf: ["-d", trimmedOffset.replacingOccurrences(of: ",", with: ".")])
+            }
+
+            return result
+        }
+
+        var commandDescription: String {
+            (["mp3gain"] + arguments).joined(separator: " ")
+        }
+    }
+
    private let fileManager: FileManager

    init(fileManager: FileManager) {
        self.fileManager = fileManager
    }

-    func normalize(rootURL: URL) -> [ExportMessage] {
+    func normalize(rootURL: URL, options: Options) -> [ExportMessage] {
        guard let mp3gainURL = mp3gainExecutableURL() else {
            return [.error("mp3gain wurde nicht gefunden. Erwartet z. B. /opt/homebrew/bin/mp3gain.")]
        }

+        let validationMessages = validate(options: options)
+        if !validationMessages.isEmpty {
+            return validationMessages
+        }
+
        do {
            let mp3Files = try MP3FileFinder(fileManager: fileManager).mp3Files(in: rootURL)
            guard !mp3Files.isEmpty else {
@@ -447,7 +489,7 @@ struct MP3GainNormalizer {
            var processed = 0

            for batch in mp3Files.chunked(into: 50) {
-                let result = runMP3Gain(executableURL: mp3gainURL, files: batch)
+                let result = runMP3Gain(executableURL: mp3gainURL, options: options, files: batch)
                messages.append(contentsOf: result.messages)
                if result.success {
                    processed += batch.count
@@ -461,10 +503,27 @@ struct MP3GainNormalizer {
        }
    }

-    private func runMP3Gain(executableURL: URL, files: [URL]) -> (success: Bool, messages: [ExportMessage]) {
+    private func validate(options: Options) -> [ExportMessage] {
+        let trimmedOffset = options.dbOffset.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmedOffset.isEmpty else {
+            return []
+        }
+
+        guard Double(trimmedOffset.replacingOccurrences(of: ",", with: ".")) != nil else {
+            return [.error("dB-Offset muss eine Zahl sein, z. B. 4 oder -2.5.")]
+        }
+
+        return []
+    }
+
+    private func runMP3Gain(
+        executableURL: URL,
+        options: Options,
+        files: [URL]
+    ) -> (success: Bool, messages: [ExportMessage]) {
        let process = Process()
        process.executableURL = executableURL
-        process.arguments = ["-r", "-k", "-d", "4"] + files.map { $0.path(percentEncoded: false) }
+        process.arguments = options.arguments + files.map { $0.path(percentEncoded: false) }

        let outputPipe = Pipe()
        let errorPipe = Pipe()