Switch to async logic

ios/App/App.xcodeproj/project.pbxproj

@@ -38,6 +38,7 @@
 		C4B265F5285A5A6600E1B5C3 /* LocalLibrary.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4B265F4285A5A6600E1B5C3 /* LocalLibrary.swift */; };
 		C4D0677528106D0C00B8F875 /* DataClasses.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4D0677428106D0C00B8F875 /* DataClasses.swift */; };
 		E99C8C932883A00F00E3279A /* LocalLibraryExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E99C8C922883A00F00E3279A /* LocalLibraryExtensions.swift */; };
+		E9D38158289A0A6F0019EEED /* LibraryItemDownloadSession.swift in Sources */ = {isa = PBXBuildFile; fileRef = E9D38157289A0A6F0019EEED /* LibraryItemDownloadSession.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -76,6 +77,7 @@
 		C4B265F4285A5A6600E1B5C3 /* LocalLibrary.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LocalLibrary.swift; sourceTree = "<group>"; };
 		C4D0677428106D0C00B8F875 /* DataClasses.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DataClasses.swift; sourceTree = "<group>"; };
 		E99C8C922883A00F00E3279A /* LocalLibraryExtensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LocalLibraryExtensions.swift; sourceTree = "<group>"; };
+		E9D38157289A0A6F0019EEED /* LibraryItemDownloadSession.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LibraryItemDownloadSession.swift; sourceTree = "<group>"; };
 		FC68EB0AF532CFC21C3344DD /* Pods-App.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-App.debug.xcconfig"; path = "Pods/Target Support Files/Pods-App/Pods-App.debug.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -156,6 +158,7 @@
 				3AF1970B2806E2590096F747 /* ApiClient.swift */,
 				3AB34052280829BF0039308B /* Extensions.swift */,
 				3AB34054280832720039308B /* PlayerEvents.swift */,
+				E9D38157289A0A6F0019EEED /* LibraryItemDownloadSession.swift */,
 			);
 			path = util;
 			sourceTree = "<group>";
@@ -341,6 +344,7 @@
 				C4D0677528106D0C00B8F875 /* DataClasses.swift in Sources */,
 				4D66B954282EE87C008272D4 /* AbsDownloader.swift in Sources */,
 				3AB34055280832720039308B /* PlayerEvents.swift in Sources */,
+				E9D38158289A0A6F0019EEED /* LibraryItemDownloadSession.swift in Sources */,
 				E99C8C932883A00F00E3279A /* LocalLibraryExtensions.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

ios/App/App/plugins/AbsDownloader.swift

@@ -10,8 +10,6 @@ import Capacitor
 
 @objc(AbsDownloader)
 public class AbsDownloader: CAPPlugin {
-    let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
-    
     @objc func downloadLibraryItem(_ call: CAPPluginCall) {
         let libraryItemId = call.getString("libraryItemId")
         let episodeId = call.getString("episodeId")
@@ -24,90 +22,19 @@ public class AbsDownloader: CAPPlugin {
                 call.resolve()
             } else {
                 NSLog("Got library item from server \(libraryItem!.id)")
-                self.startLibraryItemDownload(item: libraryItem!)
+                Task {
-                call.resolve()
+                    do {
+                        let downloadSession = LibraryItemDownloadSession(libraryItem!)
+                        let localLibraryItem = try await downloadSession.startDownload()
+                        Database.shared.saveLocalLibraryItem(localLibraryItem: localLibraryItem)
+                    } catch {
+                        NSLog("Failed to download \(error)")
+                    }
+                    call.resolve()
+                }
             }
         }
     }
-    
-    private func startLibraryItemDownload(item: LibraryItem) {
-        let length = item.media.tracks?.count ?? 0
-        if length > 0 {
-            let downloadDispatch = DispatchGroup()
-            let files = item.media.tracks!.enumerated().map {
-                position, track -> LocalFile in startLibraryItemTrackDownload(item: item, position: position, track: track, dispatch: downloadDispatch)
-            }
-            downloadDispatch.notify(queue: .main) {
-                let localLibraryItem = LocalLibraryItem(item, localUrl: self.documentsDirectory, server: Store.serverConfig!, files: files)
-                Database.shared.saveLocalLibraryItem(localLibraryItem: localLibraryItem)
-            }
-        } else {
-            NSLog("No audio tracks for the supplied library item")
-        }
-    }
-    
-    private func startLibraryItemTrackDownload(item: LibraryItem, position: Int, track: AudioTrack, dispatch: DispatchGroup) -> LocalFile {
-        NSLog("TRACK \(track.contentUrl!)")
-        
-        // If we don't name metadata, then we can't proceed
-        guard let filename = track.metadata?.filename else {
-            NSLog("No metadata for track, unable to download")
-            return LocalFile()
-        }
-        
-        let serverUrl = urlForTrack(item: item, track: track)
-        let itemDirectory = createLibraryItemFileDirectory(item: item)
-        let localUrl = itemDirectory.appendingPathComponent("\(filename)")
-        
-        downloadTrack(serverUrl: serverUrl, localUrl: localUrl, dispatch: dispatch)
-        return LocalFile(item.id, filename, track.mimeType, localUrl)
-    }
-    
-    private func urlForTrack(item: LibraryItem, track: AudioTrack) -> URL {
-        // filename needs to be encoded otherwise would just use contentUrl
-        let filenameEncoded = track.metadata?.filename.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed)
-        let urlstr = "\(Store.serverConfig!.address)/s/item/\(item.id)/\(filenameEncoded ?? "")?token=\(Store.serverConfig!.token)"
-        return URL(string: urlstr)!
-    }
-    
-    private func createLibraryItemFileDirectory(item: LibraryItem) -> URL {
-        let itemDirectory = documentsDirectory.appendingPathComponent("\(item.id)")
-        
-        NSLog("ITEM DIR \(itemDirectory)")
-        
-        // Create library item directory
-        do {
-            try FileManager.default.createDirectory(at: itemDirectory, withIntermediateDirectories: true)
-        } catch {
-            NSLog("Failed to CREATE LI DIRECTORY \(error)")
-        }
-        
-        return itemDirectory
-    }
-    
-    private func downloadTrack(serverUrl: URL, localUrl: URL, dispatch: DispatchGroup) {
-        dispatch.enter()
-        
-        let downloadTask = URLSession.shared.downloadTask(with: serverUrl) { urlOrNil, responseOrNil, errorOrNil in
-            defer { dispatch.leave() }
-            
-            guard let fileURL = urlOrNil else {
-                return
-            }
-            
-            do {
-                NSLog("Download TMP file URL \(fileURL)")
-                let audioData = try Data(contentsOf:fileURL)
-                try audioData.write(to: localUrl)
-                NSLog("Download written to \(localUrl)")
-            } catch {
-                NSLog("FILE ERROR: \(error)")
-            }
-        }
-        
-        // Start the download
-        downloadTask.resume()
-    }
 }
 
 struct DownloadItem: Codable {

ios/App/Shared/util/LibraryItemDownloadSession.swift

@@ -0,0 +1,102 @@
+//
+//  LibraryItemDownloadSession.swift
+//  App
+//
+//  Created by Ron Heft on 8/2/22.
+//
+
+import Foundation
+
+enum LibraryItemDownloadError: String, Error {
+    case noTracks = "No tracks on library item"
+    case noMetadata = "No metadata for track, unable to download"
+    case failedDownload = "Failed to download item"
+}
+
+class LibraryItemDownloadSession {
+    
+    let item: LibraryItem
+    
+    private let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
+    
+    init(_ item: LibraryItem) {
+        self.item = item
+    }
+    
+    public func startDownload() async throws -> LocalLibraryItem {
+        guard let tracks = item.media.tracks else {
+            throw LibraryItemDownloadError.noTracks
+        }
+        
+        return try await withThrowingTaskGroup(of: LocalFile.self, returning: LocalLibraryItem.self) { group in
+            for (position, track) in tracks.enumerated() {
+                group.addTask { try await self.startLibraryItemTrackDownload(item: self.item, position: position, track: track) }
+            }
+            
+            var files = [LocalFile]()
+            for try await file in group {
+                files.append(file)
+            }
+            
+            return LocalLibraryItem(self.item, localUrl: self.documentsDirectory, server: Store.serverConfig!, files: files)
+        }
+    }
+    
+    private func startLibraryItemTrackDownload(item: LibraryItem, position: Int, track: AudioTrack) async throws -> LocalFile {
+        NSLog("TRACK \(track.contentUrl!)")
+        
+        // If we don't name metadata, then we can't proceed
+        guard let filename = track.metadata?.filename else {
+            throw LibraryItemDownloadError.noMetadata
+        }
+        
+        let serverUrl = urlForTrack(item: item, track: track)
+        let itemDirectory = createLibraryItemFileDirectory(item: item)
+        let localUrl = itemDirectory.appendingPathComponent("\(filename)")
+        
+        try await downloadFile(serverUrl: serverUrl, localUrl: localUrl)
+        return LocalFile(item.id, filename, track.mimeType, localUrl)
+    }
+    
+    private func createLibraryItemFileDirectory(item: LibraryItem) -> URL {
+        let itemDirectory = documentsDirectory.appendingPathComponent("\(item.id)")
+        
+        NSLog("ITEM DIR \(itemDirectory)")
+        
+        // Create library item directory
+        do {
+            try FileManager.default.createDirectory(at: itemDirectory, withIntermediateDirectories: true)
+        } catch {
+            NSLog("Failed to CREATE LI DIRECTORY \(error)")
+        }
+        
+        return itemDirectory
+    }
+    
+    private func urlForTrack(item: LibraryItem, track: AudioTrack) -> URL {
+        // filename needs to be encoded otherwise would just use contentUrl
+        let filenameEncoded = track.metadata?.filename.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed)
+        let urlstr = "\(Store.serverConfig!.address)/s/item/\(item.id)/\(filenameEncoded ?? "")?token=\(Store.serverConfig!.token)"
+        return URL(string: urlstr)!
+    }
+    
+    private func downloadFile(serverUrl: URL, localUrl: URL) async throws {
+        return try await withCheckedThrowingContinuation { continuation in
+            let downloadTask = URLSession.shared.downloadTask(with: serverUrl) { urlOrNil, responseOrNil, errorOrNil in
+                guard let tempUrl = urlOrNil else {
+                    continuation.resume(throwing: errorOrNil!)
+                    return
+                }
+                
+                do {
+                    try FileManager.default.moveItem(at: tempUrl, to: localUrl)
+                    continuation.resume()
+                } catch {
+                    continuation.resume(throwing: error)
+                }
+            }
+            downloadTask.resume()
+        }
+    }
+    
+}