feat: remember playback progress across player restarts

Persist authoritative per-video positions in UserDefaults. Save periodic checkpoints, pause, close, replacement, and quit; restore a validated position before autoplay. Canonical YouTube webpage URLs survive fresh stream extraction, and local symlinks share file progress. Clear completed or out-of-duration bookmarks. Leave failed opens and live/non-seekable inputs out of persistence. Pending opens hide errors belonging to the previous source. Verified separate-process restart, source replacement, failed-open recovery, completion, checkpoints, real YouTube short-link resume, live exclusion, and make all check.
2026-10-10 23:27:10 +02:00
parent 5bc0d81bbf
commit 0411064f0c
5 changed files with 149 additions and 6 deletions
@@ -0,0 +1,29 @@
+import Foundation
+
+struct PlaybackProgress {
+    private let defaults: UserDefaults
+    private var positions: [String: Double]
+
+    init(defaults: UserDefaults = .standard) {
+        self.defaults = defaults
+        positions = defaults.dictionary(forKey: "playbackPositions") as? [String: Double] ?? [:]
+    }
+
+    func position(for url: URL) -> Double? {
+        guard let position = positions[key(for: url)], position.isFinite, position > 0 else { return nil }
+        return position
+    }
+
+    mutating func save(_ position: Double?, for url: URL) {
+        let key = key(for: url)
+        let position = position.flatMap { $0.isFinite && $0 > 0 ? $0 : nil }
+        guard positions[key] != position else { return }
+        positions[key] = position
+        defaults.set(positions, forKey: "playbackPositions")
+    }
+
+    private func key(for url: URL) -> String {
+        // YouTube callers supply the canonical webpage URL, never an expiring media URL.
+        return url.isFileURL ? url.standardizedFileURL.resolvingSymlinksInPath().absoluteString : url.absoluteString
+    }
+}