feat(*): subsonic client with avfoundation playback and apple music ui

Packages/AmphlifyKit/Sources/Domain/Lyrics.swift

@@ -0,0 +1,75 @@
+import Foundation
+
+public struct LyricLine: Hashable, Sendable, Identifiable {
+    public let time: TimeInterval
+    public let text: String
+
+    public var id: TimeInterval {
+        time
+    }
+
+    public init(time: TimeInterval, text: String) {
+        self.time = time
+        self.text = text
+    }
+}
+
+public struct Lyrics: Hashable, Sendable {
+    public let lines: [LyricLine]
+    public let isSynced: Bool
+
+    public init(lines: [LyricLine], isSynced: Bool) {
+        self.lines = lines
+        self.isSynced = isSynced
+    }
+
+    public init?(lrc: String) {
+        var lines: [LyricLine] = []
+        var plain: [String] = []
+        for raw in lrc.split(whereSeparator: \.isNewline) {
+            var rest = Substring(raw)
+            var stamps: [TimeInterval] = []
+            while rest.first == "[", let close = rest.firstIndex(of: "]") {
+                let tag = rest[rest.index(after: rest.startIndex) ..< close]
+                rest = rest[rest.index(after: close)...]
+                if let time = Self.time(tag) {
+                    stamps.append(time)
+                }
+            }
+            let text = rest.trimmingCharacters(in: .whitespaces)
+            if stamps.isEmpty {
+                if !text.isEmpty {
+                    plain.append(text)
+                }
+            } else {
+                lines += stamps.map { LyricLine(time: $0, text: text) }
+            }
+        }
+        if !lines.isEmpty {
+            self.init(lines: lines.sorted { $0.time < $1.time }, isSynced: true)
+        } else if !plain.isEmpty {
+            self.init(lines: plain.map { LyricLine(time: 0, text: $0) }, isSynced: false)
+        } else {
+            return nil
+        }
+    }
+
+    public func index(at time: TimeInterval) -> Int? {
+        guard isSynced else { return nil }
+        var found: Int?
+        for (index, line) in lines.enumerated() where line.time <= time {
+            found = index
+        }
+        return found
+    }
+
+    private static func time(_ tag: Substring) -> TimeInterval? {
+        let parts = tag.split(separator: ":")
+        guard parts.count == 2, let minutes = Double(parts[0]), let seconds = Double(parts[1]) else { return nil }
+        return minutes * 60 + seconds
+    }
+}
+
+public protocol LyricsSource: LibrarySource {
+    func lyrics(for track: EntityID) async throws -> Lyrics?
+}