fix(iOS): improve PiP KVO observation, fix recording stop flow and export sheet

- PiPController: add KVO on isPictureInPicturePossible, avoid duplicate setup, better logging
- HLSRecorder: add stopRequested check after Task.sleep to ensure recording exits cleanly
- HLSRecorder: add 120s timeout to remuxToMP4 via TaskGroup to prevent hanging
- HLSRecorder: improve presentActivitySheet VC lookup (key window, foregroundActive scene)
- Add detailed logging throughout recording/export flow for debugging

Sources/HLSRecorder.swift

@@ -36,6 +36,7 @@ final class HLSRecorder: ObservableObject {
         recordTask = Task {
             do {
                 let outputURL = try await recordStream(url: url)
+                NSLog("[MiniPlayer] recordStream completed: %@", outputURL.path)
                 await MainActor.run {
                     self.isRecording = false
                     self.timer?.invalidate()
@@ -43,12 +44,14 @@ final class HLSRecorder: ObservableObject {
                     self.showExportSheet(url: outputURL)
                 }
             } catch is CancellationError {
+                NSLog("[MiniPlayer] Recording task cancelled")
                 // User stopped
                 await MainActor.run {
                     self.isRecording = false
                     self.timer?.invalidate()
                 }
             } catch {
+                NSLog("[MiniPlayer] Recording error: %@", error.localizedDescription)
                 await MainActor.run {
                     self.isRecording = false
                     self.timer?.invalidate()
@@ -59,6 +62,7 @@ final class HLSRecorder: ObservableObject {
     }
     
     func stopRecording() {
+        NSLog("[MiniPlayer] stopRecording called, stopRequested → true")
         // 不 cancel 任务，只设 stopRequested 让轮询循环正常退出
         // 任务会合并已下载片段 → MP4 → 弹出分享面板
         stopRequested = true
@@ -189,16 +193,21 @@ final class HLSRecorder: ObservableObject {
             // 等待 2 秒再拉取（HLS 典型 segment duration 2-10s）
             if !stopRequested {
                 try await Task.sleep(nanoseconds: 2_000_000_000)
+                // sleep 期间 stopRequested 可能已变为 true
+                if stopRequested { break }
             } else {
                 break
             }
         }
         
         guard !downloadedSegments.isEmpty else {
+            NSLog("[MiniPlayer] Recording stopped with 0 segments")
             try? FileManager.default.removeItem(at: tempDir)
             throw RecorderError.noSegments
         }
         
+        NSLog("[MiniPlayer] Recording loop exited: %d segments downloaded", downloadedSegments.count)
+        
         // 4. 合并所有 TS 片段
         let mergedTS = tempDir.appendingPathComponent("merged.ts")
         let output = try FileHandle(forWritingTo: mergedTS)
@@ -207,9 +216,11 @@ final class HLSRecorder: ObservableObject {
             output.write(segData)
         }
         output.closeFile()
+        NSLog("[MiniPlayer] Merged %d segments → %@", downloadedSegments.count, mergedTS.path)
         
-        // 5. TS → MP4
+        // 5. TS → MP4（内部有超时保护）
         let outputURL = try await remuxToMP4(tsURL: mergedTS)
+        NSLog("[MiniPlayer] Remux complete: %@", outputURL.path)
         
         // 6. 清理临时文件
         try? FileManager.default.removeItem(at: tempDir)
@@ -244,7 +255,7 @@ final class HLSRecorder: ObservableObject {
         
         let asset = AVURLAsset(url: tsURL)
         guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetPassthrough) else {
-            // Fallback: 直接保存 TS
+            NSLog("[MiniPlayer] AVAssetExportSession creation failed, fallback to TS")
             let tsOutput = outputMP4.deletingPathExtension().appendingPathExtension("ts")
             try FileManager.default.moveItem(at: tsURL, to: tsOutput)
             return tsOutput
@@ -252,15 +263,33 @@ final class HLSRecorder: ObservableObject {
         
         exportSession.outputURL = outputMP4
         exportSession.outputFileType = .mp4
-        await exportSession.export()
+        
+        NSLog("[MiniPlayer] Starting remux export...")
+        
+        // 用 TaskGroup 实现超时：export + 120s timer
+        try await withThrowingTaskGroup(of: Void.self) { group in
+            group.addTask {
+                await exportSession.export()
+            }
+            group.addTask {
+                try await Task.sleep(nanoseconds: 120_000_000_000)
+                exportSession.cancelExport()
+                throw RecorderError.exportFailed("Remux timed out after 120s")
+            }
+            // 等待第一个完成
+            try await group.next()
+            group.cancelAll()
+        }
         
         if exportSession.status != .completed {
-            // Fallback: 保存为 TS
+            let errMsg = exportSession.error?.localizedDescription ?? "unknown"
+            NSLog("[MiniPlayer] Export failed: status=%d, error=%@", exportSession.status.rawValue, errMsg)
             let tsOutput = outputMP4.deletingPathExtension().appendingPathExtension("ts")
             try FileManager.default.moveItem(at: tsURL, to: tsOutput)
             return tsOutput
         }
         
+        NSLog("[MiniPlayer] Export completed: %@", outputMP4.lastPathComponent)
         return outputMP4
     }
     
@@ -316,33 +345,48 @@ final class HLSRecorder: ObservableObject {
     }
     
     private func presentActivitySheet(url: URL) {
-        guard let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene else {
+        NSLog("[MiniPlayer] presentActivitySheet called for: %@", url.lastPathComponent)
+        
+        guard let windowScene = UIApplication.shared.connectedScenes
+            .compactMap({ $0 as? UIWindowScene })
+            .first(where: { $0.activationState == .foregroundActive }) ?? UIApplication.shared.connectedScenes.compactMap({ $0 as? UIWindowScene }).first else {
             NSLog("[MiniPlayer] No window scene found")
             return
         }
         
-        // 找最顶层可见的 VC
+        // 找最顶层可见的 VC（遍历所有 window）
-        var topVC = windowScene.windows.first?.rootViewController
+        var topVC: UIViewController?
+        for window in windowScene.windows where window.isKeyWindow {
+            topVC = window.rootViewController
+            break
+        }
+        if topVC == nil {
+            topVC = windowScene.windows.first?.rootViewController
+        }
+        
+        // 沿着 presentedViewController 链找到最顶层
         while let presented = topVC?.presentedViewController {
             topVC = presented
         }
         
         guard let vc = topVC else {
-            NSLog("[MiniPlayer] No root view controller found")
+            NSLog("[MiniPlayer] No view controller found to present share sheet")
             return
         }
         
+        NSLog("[MiniPlayer] Presenting from VC: %@", String(describing: type(of: vc)))
+        
         let activityVC = UIActivityViewController(activityItems: [url], applicationActivities: nil)
         
         // iPad 适配
         if let popover = activityVC.popoverPresentationController {
             popover.sourceView = vc.view
-            popover.sourceRect = CGRect(x: vc.view.bounds.midX, y: vc.view.bounds.midY, width: 0, height: 0)
+            popover.sourceRect = CGRect(x: vc.view?.bounds.midX ?? 0, y: vc.view?.bounds.midY ?? 0, width: 0, height: 0)
             popover.permittedArrowDirections = []
         }
         
         vc.present(activityVC, animated: true) {
-            NSLog("[MiniPlayer] Share sheet presented")
+            NSLog("[MiniPlayer] Share sheet presented successfully")
         }
     }
     

Sources/PiPController.swift

@@ -13,9 +13,13 @@ final class PiPController: NSObject, ObservableObject {
     
     private var pipController: AVPictureInPictureController?
     private weak var playerLayer: AVPlayerLayer?
+    private var pipPossibleObservation: NSKeyValueObservation?
     
     /// 用 AVPlayerLayer 初始化 PiP 控制器
     func setup(with playerLayer: AVPlayerLayer) {
+        // 避免重复初始化
+        guard pipController == nil else { return }
+        
         self.playerLayer = playerLayer
         
         guard AVPictureInPictureController.isPictureInPictureSupported() else {
@@ -26,11 +30,25 @@ final class PiPController: NSObject, ObservableObject {
         
         isPiPSupported = true
         
-        let pip = AVPictureInPictureController(playerLayer: playerLayer)
+        guard let pip = AVPictureInPictureController(playerLayer: playerLayer) else {
-        pip?.delegate = self
+            NSLog("[MiniPlayer] PiP controller creation returned nil")
+            isPiPSupported = false
+            return
+        }
+        pip.delegate = self
         self.pipController = pip
         
-        NSLog("[MiniPlayer] PiP controller initialized")
+        // KVO 观察 isPictureInPicturePossible 变化
+        pipPossibleObservation = pip.observe(\.isPictureInPicturePossible, options: [.new]) { [weak self] controller, _ in
+            let possible = controller.isPictureInPicturePossible
+            NSLog("[MiniPlayer] PiP possible changed: %d", possible)
+            Task { @MainActor in
+                // 触发 UI 刷新（按钮状态可能需要更新）
+                self?.objectWillChange.send()
+            }
+        }
+        
+        NSLog("[MiniPlayer] PiP controller initialized, possible=%d", pip.isPictureInPicturePossible)
     }
     
     /// 切换画中画状态
@@ -40,12 +58,14 @@ final class PiPController: NSObject, ObservableObject {
             return
         }
         
+        NSLog("[MiniPlayer] togglePiP: active=%d, possible=%d", pip.isPictureInPictureActive, pip.isPictureInPicturePossible)
+        
         if pip.isPictureInPictureActive {
             pip.stopPictureInPicture()
         } else if pip.isPictureInPicturePossible {
             pip.startPictureInPicture()
         } else {
-            NSLog("[MiniPlayer] PiP not possible right now (player may not be ready)")
+            NSLog("[MiniPlayer] PiP not possible — check: 1) player has content 2) Xcode project has 'Audio, AirPlay, and Picture in Picture' background mode enabled in Signing & Capabilities")
         }
     }
     
@@ -55,6 +75,7 @@ final class PiPController: NSObject, ObservableObject {
     }
     
     deinit {
+        pipPossibleObservation = nil
         pipController?.delegate = nil
     }
 }