ios: add playback progress and error reporting

ios/QueueCube/Backend/API.swift

@@ -62,6 +62,9 @@ struct NowPlayingInfo: Codable
     let playingItem: MediaItem?
     let isPaused: Bool
     let volume: Int
+    let timePosition: Double?
+    let duration: Double?
+    let seekable: Bool?
 }
 
 actor API
@@ -173,6 +176,13 @@ actor API
             .post()
     }
 
+    public func seek(to time: Double) async throws {
+        try await request()
+            .path("/player/seek")
+            .body([ "time" : time ])
+            .post()
+    }
+    
     public func search(query: String) async throws -> FetchResult<[SearchResultItem]> {
         try await request()
             .pathString("/search?q=\(query.uriEncoded())")
@@ -255,10 +265,19 @@ actor API
     
     // MARK: - Types
     
-    enum Error: Swift.Error
+    enum Error: Swift.Error, LocalizedError
     {
         case apiNotConfigured
         case websocketError(Swift.Error)
+
+        var errorDescription: String? {
+            switch self {
+            case .apiNotConfigured:
+                "No server is configured."
+            case .websocketError(let error):
+                error.localizedDescription
+            }
+        }
     }
     
     enum StreamEvent {

ios/QueueCube/Backend/Utilities.swift

@@ -61,8 +61,7 @@ struct RequestBuilder
     }
     
     public func json<T: Decodable>() async throws -> T {
-        let urlRequest = self.build()
-        let (data, _) = try await URLSession.shared.data(for: urlRequest)
+        let data = try await responseData()
         return try JSONDecoder().decode(T.self, from: data)
     }
     
@@ -71,13 +70,24 @@ struct RequestBuilder
     }
     
     public func execute() async throws {
-        let urlRequest = self.build()
-        let (data, response) = try await URLSession.shared.data(for: urlRequest)
-        if let httpResponse = response as? HTTPURLResponse {
-            if httpResponse.statusCode != 200 {
-                print("POST error \(httpResponse.statusCode): \(String(data: data, encoding: .utf8)!)")
+        _ = try await responseData()
     }
+
+    private func responseData() async throws -> Data {
+        let (data, response) = try await URLSession.shared.data(for: build())
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw RequestError.invalidResponse
         }
+
+        guard (200..<300).contains(httpResponse.statusCode) else {
+            let serverError = try? JSONDecoder().decode(ServerErrorResponse.self, from: data)
+            throw RequestError.httpError(
+                statusCode: httpResponse.statusCode,
+                message: serverError?.error
+            )
+        }
+
+        return data
     }
     
     public func websocket() -> URL {
@@ -93,6 +103,28 @@ struct RequestBuilder
         case post = "POST"
         case delete = "DELETE"
     }
+
+    private struct ServerErrorResponse: Decodable {
+        let error: String?
+    }
+
+    enum RequestError: Swift.Error, LocalizedError {
+        case invalidResponse
+        case httpError(statusCode: Int, message: String?)
+
+        var errorDescription: String? {
+            switch self {
+            case .invalidResponse:
+                "The server returned an invalid response."
+            case .httpError(let statusCode, let message):
+                if let message, !message.isEmpty {
+                    "Server error (\(statusCode)): \(message)"
+                } else {
+                    "Server error (\(statusCode)): \(HTTPURLResponse.localizedString(forStatusCode: statusCode))"
+                }
+            }
+        }
+    }
 }
 
 extension Color

ios/QueueCube/Views/ContentView.swift

@@ -17,6 +17,7 @@ struct ContentView: View
         MainView(model: $model)
             .task(id: websocketRestartTrigger) { await watchWebsocket() }
             .task { await refresh([.nowPlaying, .playlist, .favorites]) }
+            .task { await pollPlaybackProgress() }
             .task { await watchForSettingsChanges() }
             .onChange(of: scenePhase) { oldPhase, newPhase in
                 handleScenePhaseChange(from: oldPhase, to: newPhase)
@@ -24,7 +25,7 @@ struct ContentView: View
             .sheet(isPresented: $model.isNowPlayingSheetPresented) {
                 NowPlayingView(model: model.nowPlayingViewModel)
                     .presentationBackground(.regularMaterial)
-                    .presentationDetents([ .height(320.0) ])
+                    .presentationDetents([ .height(390.0) ])
             }
             .sheet(isPresented: $model.isAddMediaSheetPresented) {
                 AddMediaView(model: $model.addMediaViewModel)
@@ -75,6 +76,9 @@ extension ContentView
                 
                 model.nowPlayingViewModel.isPlaying = !nowPlaying.isPaused
                 model.nowPlayingViewModel.volume = Double(nowPlaying.volume) / 100.0
+                model.nowPlayingViewModel.timePosition = nowPlaying.timePosition
+                model.nowPlayingViewModel.duration = nowPlaying.duration
+                model.nowPlayingViewModel.isSeekable = nowPlaying.seekable ?? false
                 model.playlistModel.isPlaying = !nowPlaying.isPaused
                 model.favoritesModel.isPlaying = !nowPlaying.isPaused
             }
@@ -109,6 +113,17 @@ extension ContentView
         }
     }
 
+    private func pollPlaybackProgress() async {
+        while !Task.isCancelled {
+            try? await Task.sleep(for: .seconds(1.0))
+            guard !Task.isCancelled else { return }
+
+            if scenePhase == .active && model.nowPlayingViewModel.isPlaying {
+                await refresh(.nowPlaying)
+            }
+        }
+    }
+    
     private func watchWebsocket() async {
         guard let api = model.selectedServer?.api else { return }
 

ios/QueueCube/Views/MainView.swift

@@ -78,6 +78,14 @@ class MainViewModel
             try await api.previous()
         }
 
+        nowPlayingViewModel.onSeek = { [weak self] model, time in
+            Task {
+                await self?.withModificationsViaAPI { api in
+                    try await api.seek(to: time)
+                }
+            }
+        }
+        
         nowPlayingViewModel.onSheetDismiss = { [weak self] _ in
             self?.isNowPlayingSheetPresented = false
         }
@@ -411,4 +419,3 @@ extension View {
         modifier(ErrorDisplayModifier(error: error))
     }
 }
-

ios/QueueCube/Views/NowPlayingMiniView.swift

@@ -28,6 +28,7 @@ struct NowPlayingMiniView: View {
                 onTap()
             }
 
+        VStack(spacing: 0.0) {
             HStack {
                 VStack(alignment: .leading) {
                     if let title = model.title, !title.isEmpty {
@@ -58,6 +59,13 @@ struct NowPlayingMiniView: View {
                     .padding(12.0)
             }
             .padding(EdgeInsets(top: 4.0, leading: 14.0, bottom: 4.0, trailing: 10.0))
+
+            if let progress = model.playbackProgress {
+                ProgressView(value: progress)
+                    .progressViewStyle(.linear)
+                    .tint(.accentColor)
+            }
+        }
         .background(
             RoundedRectangle(cornerRadius: 12)
                 .fill(tapGestureState ? .ultraThinMaterial : .bar)

ios/QueueCube/Views/NowPlayingView.swift

@@ -5,6 +5,7 @@
 //  Created by James Magahern on 3/3/25.
 //
 
+import Foundation
 import SwiftUI
 
 @Observable
@@ -14,17 +15,40 @@ class NowPlayingViewModel
     var onStop:         (NowPlayingViewModel) -> Void = { _ in }
     var onNext:         (NowPlayingViewModel) -> Void = { _ in }
     var onPrev:         (NowPlayingViewModel) -> Void = { _ in }
+    var onSeek:         (NowPlayingViewModel, Double) -> Void = { _, _ in }
     var onSheetDismiss: (NowPlayingViewModel) -> Void = { _ in }
     
     var isPlaying: Bool    = false
     var title:     String?  = ""
     var subtitle:  String?  = ""
     var volume:    Double  = 0.5
+    var timePosition: Double?
+    var duration: Double?
+    var isSeekable: Bool = false
     
     fileprivate var isSettingVolume: Bool = false
     fileprivate var settingVolume: Double = 0.0 {
         didSet { volume = settingVolume }
     }
+
+    fileprivate var isSettingPlaybackPosition: Bool = false
+    fileprivate var settingPlaybackPosition: Double = 0.0
+
+    var playbackDuration: Double? {
+        guard let duration, duration.isFinite, duration > 0 else { return nil }
+        return duration
+    }
+
+    var displayedPlaybackPosition: Double {
+        let position = isSettingPlaybackPosition ? settingPlaybackPosition : (timePosition ?? 0.0)
+        guard position.isFinite else { return 0.0 }
+        return min(max(position, 0.0), playbackDuration ?? position)
+    }
+
+    var playbackProgress: Double? {
+        guard let playbackDuration else { return nil }
+        return displayedPlaybackPosition / playbackDuration
+    }
 }
 
 struct NowPlayingView: View
@@ -60,7 +84,29 @@ struct NowPlayingView: View
                     }
                 }
                 
-                Spacer(minLength: 24.0)
+                Spacer(minLength: 20.0)
+
+                if let duration = model.playbackDuration {
+                    VStack(spacing: 2.0) {
+                        Slider(
+                            value: playbackPositionBinding,
+                            in: 0.0...duration,
+                            onEditingChanged: playbackPositionEditingChanged
+                        )
+                        .disabled(!model.isSeekable || nothingQueued)
+
+                        HStack {
+                            Text(formatTime(model.displayedPlaybackPosition))
+                            Spacer()
+                            Text(formatTime(duration))
+                        }
+                        .font(.caption.monospacedDigit())
+                        .foregroundStyle(.secondary)
+                    }
+                    .padding(.horizontal, 4.0)
+
+                    Spacer(minLength: 20.0)
+                }
                 
                 VStack {
                     HStack {
@@ -124,6 +170,38 @@ struct NowPlayingView: View
         }
     }
 
+    private var playbackPositionBinding: Binding<Double> {
+        Binding(
+            get: { model.displayedPlaybackPosition },
+            set: { model.settingPlaybackPosition = $0 }
+        )
+    }
+
+    private func playbackPositionEditingChanged(_ editing: Bool) {
+        if editing {
+            model.settingPlaybackPosition = model.displayedPlaybackPosition
+            model.isSettingPlaybackPosition = true
+        } else if model.isSettingPlaybackPosition {
+            let position = model.settingPlaybackPosition
+            model.timePosition = position
+            model.isSettingPlaybackPosition = false
+            model.onSeek(model, position)
+        }
+    }
+
+    private func formatTime(_ time: Double) -> String {
+        let totalSeconds = max(Int(time), 0)
+        let hours = totalSeconds / 3_600
+        let minutes = (totalSeconds % 3_600) / 60
+        let seconds = totalSeconds % 60
+
+        if hours > 0 {
+            return String(format: "%d:%02d:%02d", hours, minutes, seconds)
+        }
+
+        return String(format: "%d:%02d", minutes, seconds)
+    }
+    
     // MARK: - Types
     
     private enum Buttons: Int, CaseIterable, Identifiable {