Implement attachment uploading

SessionMessagingKit/Jobs/AttachmentUploadJob.swift

@@ -1,26 +1,59 @@
 import SessionUtilitiesKit
 
-// TODO: Implementation
-
 public final class AttachmentUploadJob : NSObject, Job, NSCoding { // NSObject/NSCoding conformance is needed for YapDatabase compatibility
     public var delegate: JobDelegate?
+    private let attachmentID: String
+    private let threadID: String
     public var id: String?
     public var failureCount: UInt = 0
 
+    public enum Error : LocalizedError {
+        case noAttachment
+
+        public var errorDescription: String? {
+            switch self {
+            case .noAttachment: return "No such attachment."
+            }
+        }
+    }
+    
     // MARK: Settings
     public class var collection: String { return "AttachmentUploadJobCollection" }
     public static let maxFailureCount: UInt = 20
 
     // MARK: Initialization
-    public override init() { }
+    public init(attachmentID: String, threadID: String) {
+        self.attachmentID = attachmentID
+        self.threadID = threadID
+    }
     
     // MARK: Coding
-    public init?(coder: NSCoder) { }
+    public init?(coder: NSCoder) {
+        guard let attachmentID = coder.decodeObject(forKey: "attachmentID") as! String?,
+            let threadID = coder.decodeObject(forKey: "threadID") as! String? else { return nil }
+        self.attachmentID = attachmentID
+        self.threadID = threadID
+    }
 
-    public func encode(with coder: NSCoder) { }
+    public func encode(with coder: NSCoder) {
+        coder.encode(attachmentID, forKey: "attachmentID")
+        coder.encode(threadID, forKey: "threadID")
+    }
 
     // MARK: Running
-    public func execute() { }
+    public func execute() {
+        guard let stream = TSAttachmentStream.fetch(uniqueId: attachmentID) else {
+            return handleFailure(error: Error.noAttachment)
+        }
+        guard !stream.isUploaded else { return handleSuccess() } // Should never occur
+        let openGroup = Configuration.shared.storage.getOpenGroup(for: threadID)
+        let server = openGroup?.server ?? FileServerAPI.server
+        FileServerAPI.uploadAttachment(stream, with: attachmentID, to: server).done(on: DispatchQueue.global(qos: .userInitiated)) { // Intentionally capture self
+            self.handleSuccess()
+        }.catch(on: DispatchQueue.global(qos: .userInitiated)) { error in
+            self.handleFailure(error: error)
+        }
+    }
 
     private func handleSuccess() {
         delegate?.handleJobSucceeded(self)

SessionMessagingKit/Storage.swift

@@ -37,6 +37,10 @@ public protocol SessionMessagingKitStorageProtocol {
     func setAuthToken(for server: String, to newValue: String, using transaction: Any)
     func removeAuthToken(for server: String, using transaction: Any)
 
+    // MARK: - Open Groups
+    
+    func getOpenGroup(for threadID: String) -> OpenGroup?
+    
     // MARK: - Open Group Public Keys
 
     func getOpenGroupPublicKey(for server: String) -> String?