[All Platforms] 2.1.0 - Sync Optimizations

ios/Ascently/Services/SyncService.swift

@@ -136,6 +136,314 @@ class SyncService: ObservableObject {
         }
     }
 
+    func performDeltaSync(dataManager: ClimbingDataManager) async throws {
+        guard isConfigured else {
+            throw SyncError.notConfigured
+        }
+
+        guard let url = URL(string: "\(serverURL)/sync/delta") else {
+            throw SyncError.invalidURL
+        }
+
+        // Get last sync time, or use epoch if never synced
+        let lastSync = lastSyncTime ?? Date(timeIntervalSince1970: 0)
+        let formatter = ISO8601DateFormatter()
+        let lastSyncString = formatter.string(from: lastSync)
+
+        // Collect items modified since last sync
+        let modifiedGyms = dataManager.gyms.filter { gym in
+            gym.updatedAt > lastSync
+        }.map { BackupGym(from: $0) }
+
+        let modifiedProblems = dataManager.problems.filter { problem in
+            problem.updatedAt > lastSync
+        }.map { problem -> BackupProblem in
+            var backupProblem = BackupProblem(from: problem)
+            if !problem.imagePaths.isEmpty {
+                let normalizedPaths = problem.imagePaths.enumerated().map { index, _ in
+                    ImageNamingUtils.generateImageFilename(
+                        problemId: problem.id.uuidString, imageIndex: index)
+                }
+                return BackupProblem(
+                    id: backupProblem.id,
+                    gymId: backupProblem.gymId,
+                    name: backupProblem.name,
+                    description: backupProblem.description,
+                    climbType: backupProblem.climbType,
+                    difficulty: backupProblem.difficulty,
+                    tags: backupProblem.tags,
+                    location: backupProblem.location,
+                    imagePaths: normalizedPaths,
+                    isActive: backupProblem.isActive,
+                    dateSet: backupProblem.dateSet,
+                    notes: backupProblem.notes,
+                    createdAt: backupProblem.createdAt,
+                    updatedAt: backupProblem.updatedAt
+                )
+            }
+            return backupProblem
+        }
+
+        let modifiedSessions = dataManager.sessions.filter { session in
+            session.status != .active && session.updatedAt > lastSync
+        }.map { BackupClimbSession(from: $0) }
+
+        let activeSessionIds = Set(
+            dataManager.sessions.filter { $0.status == .active }.map { $0.id })
+        let modifiedAttempts = dataManager.attempts.filter { attempt in
+            !activeSessionIds.contains(attempt.sessionId) && attempt.createdAt > lastSync
+        }.map { BackupAttempt(from: $0) }
+
+        let modifiedDeletions = dataManager.getDeletedItems().filter { item in
+            if let deletedDate = formatter.date(from: item.deletedAt) {
+                return deletedDate > lastSync
+            }
+            return false
+        }
+
+        print(
+            "iOS DELTA SYNC: Sending gyms=\(modifiedGyms.count), problems=\(modifiedProblems.count), sessions=\(modifiedSessions.count), attempts=\(modifiedAttempts.count), deletions=\(modifiedDeletions.count)"
+        )
+
+        // Create delta request
+        let deltaRequest = DeltaSyncRequest(
+            lastSyncTime: lastSyncString,
+            gyms: modifiedGyms,
+            problems: modifiedProblems,
+            sessions: modifiedSessions,
+            attempts: modifiedAttempts,
+            deletedItems: modifiedDeletions
+        )
+
+        let encoder = JSONEncoder()
+        encoder.dateEncodingStrategy = .iso8601
+        let jsonData = try encoder.encode(deltaRequest)
+
+        var request = URLRequest(url: url)
+        request.httpMethod = "POST"
+        request.setValue("Bearer \(authToken)", forHTTPHeaderField: "Authorization")
+        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.setValue("application/json", forHTTPHeaderField: "Accept")
+        request.httpBody = jsonData
+
+        let (data, response) = try await URLSession.shared.data(for: request)
+
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw SyncError.invalidResponse
+        }
+
+        switch httpResponse.statusCode {
+        case 200:
+            break
+        case 401:
+            throw SyncError.unauthorized
+        default:
+            throw SyncError.serverError(httpResponse.statusCode)
+        }
+
+        let decoder = JSONDecoder()
+        let deltaResponse = try decoder.decode(DeltaSyncResponse.self, from: data)
+
+        print(
+            "iOS DELTA SYNC: Received gyms=\(deltaResponse.gyms.count), problems=\(deltaResponse.problems.count), sessions=\(deltaResponse.sessions.count), attempts=\(deltaResponse.attempts.count), deletions=\(deltaResponse.deletedItems.count)"
+        )
+
+        // Apply server changes to local data
+        try await applyDeltaResponse(deltaResponse, dataManager: dataManager)
+
+        // Sync only modified problem images
+        try await syncModifiedImages(modifiedProblems: modifiedProblems, dataManager: dataManager)
+
+        // Update last sync time to server time
+        if let serverTime = formatter.date(from: deltaResponse.serverTime) {
+            lastSyncTime = serverTime
+            userDefaults.set(lastSyncTime, forKey: Keys.lastSyncTime)
+        }
+    }
+
+    private func applyDeltaResponse(_ response: DeltaSyncResponse, dataManager: ClimbingDataManager)
+        async throws
+    {
+        let formatter = ISO8601DateFormatter()
+
+        // Download images for new/modified problems from server
+        var imagePathMapping: [String: String] = [:]
+        for problem in response.problems {
+            guard let imagePaths = problem.imagePaths, !imagePaths.isEmpty else { continue }
+
+            for (index, imagePath) in imagePaths.enumerated() {
+                let serverFilename = URL(fileURLWithPath: imagePath).lastPathComponent
+
+                do {
+                    let imageData = try await downloadImage(filename: serverFilename)
+                    let consistentFilename = ImageNamingUtils.generateImageFilename(
+                        problemId: problem.id, imageIndex: index)
+                    let imageManager = ImageManager.shared
+                    _ = try imageManager.saveImportedImage(imageData, filename: consistentFilename)
+                    imagePathMapping[serverFilename] = consistentFilename
+                } catch SyncError.imageNotFound {
+                    print("Image not found on server: \(serverFilename)")
+                    continue
+                } catch {
+                    print("Failed to download image \(serverFilename): \(error)")
+                    continue
+                }
+            }
+        }
+
+        // Merge gyms
+        for backupGym in response.gyms {
+            if let index = dataManager.gyms.firstIndex(where: { $0.id.uuidString == backupGym.id })
+            {
+                let existing = dataManager.gyms[index]
+                if backupGym.updatedAt >= formatter.string(from: existing.updatedAt) {
+                    dataManager.gyms[index] = try backupGym.toGym()
+                }
+            } else {
+                dataManager.gyms.append(try backupGym.toGym())
+            }
+        }
+
+        // Merge problems
+        for backupProblem in response.problems {
+            var problemToMerge = backupProblem
+            if !imagePathMapping.isEmpty, let imagePaths = backupProblem.imagePaths {
+                let updatedPaths = imagePaths.compactMap { imagePathMapping[$0] ?? $0 }
+                problemToMerge = BackupProblem(
+                    id: backupProblem.id,
+                    gymId: backupProblem.gymId,
+                    name: backupProblem.name,
+                    description: backupProblem.description,
+                    climbType: backupProblem.climbType,
+                    difficulty: backupProblem.difficulty,
+                    tags: backupProblem.tags,
+                    location: backupProblem.location,
+                    imagePaths: updatedPaths,
+                    isActive: backupProblem.isActive,
+                    dateSet: backupProblem.dateSet,
+                    notes: backupProblem.notes,
+                    createdAt: backupProblem.createdAt,
+                    updatedAt: backupProblem.updatedAt
+                )
+            }
+
+            if let index = dataManager.problems.firstIndex(where: {
+                $0.id.uuidString == problemToMerge.id
+            }) {
+                let existing = dataManager.problems[index]
+                if problemToMerge.updatedAt >= formatter.string(from: existing.updatedAt) {
+                    dataManager.problems[index] = try problemToMerge.toProblem()
+                }
+            } else {
+                dataManager.problems.append(try problemToMerge.toProblem())
+            }
+        }
+
+        // Merge sessions
+        for backupSession in response.sessions {
+            if let index = dataManager.sessions.firstIndex(where: {
+                $0.id.uuidString == backupSession.id
+            }) {
+                let existing = dataManager.sessions[index]
+                if backupSession.updatedAt >= formatter.string(from: existing.updatedAt) {
+                    dataManager.sessions[index] = try backupSession.toClimbSession()
+                }
+            } else {
+                dataManager.sessions.append(try backupSession.toClimbSession())
+            }
+        }
+
+        // Merge attempts
+        for backupAttempt in response.attempts {
+            if let index = dataManager.attempts.firstIndex(where: {
+                $0.id.uuidString == backupAttempt.id
+            }) {
+                let existing = dataManager.attempts[index]
+                if backupAttempt.createdAt >= formatter.string(from: existing.createdAt) {
+                    dataManager.attempts[index] = try backupAttempt.toAttempt()
+                }
+            } else {
+                dataManager.attempts.append(try backupAttempt.toAttempt())
+            }
+        }
+
+        // Apply deletions
+        let allDeletions = dataManager.getDeletedItems() + response.deletedItems
+        let uniqueDeletions = Array(Set(allDeletions))
+        applyDeletionsToDataManager(deletions: uniqueDeletions, dataManager: dataManager)
+
+        // Save all changes
+        dataManager.saveGyms()
+        dataManager.saveProblems()
+        dataManager.saveSessions()
+        dataManager.saveAttempts()
+
+        // Update deletion records
+        dataManager.clearDeletedItems()
+        if let data = try? JSONEncoder().encode(uniqueDeletions) {
+            UserDefaults.standard.set(data, forKey: "ascently_deleted_items")
+        }
+
+        DataStateManager.shared.updateDataState()
+    }
+
+    private func applyDeletionsToDataManager(
+        deletions: [DeletedItem], dataManager: ClimbingDataManager
+    ) {
+        let deletedGymIds = Set(deletions.filter { $0.type == "gym" }.map { $0.id })
+        let deletedProblemIds = Set(deletions.filter { $0.type == "problem" }.map { $0.id })
+        let deletedSessionIds = Set(deletions.filter { $0.type == "session" }.map { $0.id })
+        let deletedAttemptIds = Set(deletions.filter { $0.type == "attempt" }.map { $0.id })
+
+        dataManager.gyms.removeAll { deletedGymIds.contains($0.id.uuidString) }
+        dataManager.problems.removeAll { deletedProblemIds.contains($0.id.uuidString) }
+        dataManager.sessions.removeAll { deletedSessionIds.contains($0.id.uuidString) }
+        dataManager.attempts.removeAll { deletedAttemptIds.contains($0.id.uuidString) }
+    }
+
+    private func syncModifiedImages(
+        modifiedProblems: [BackupProblem], dataManager: ClimbingDataManager
+    ) async throws {
+        guard !modifiedProblems.isEmpty else { return }
+
+        print("iOS DELTA SYNC: Syncing images for \(modifiedProblems.count) modified problems")
+
+        for backupProblem in modifiedProblems {
+            guard
+                let problem = dataManager.problems.first(where: {
+                    $0.id.uuidString == backupProblem.id
+                })
+            else {
+                continue
+            }
+
+            for (index, imagePath) in problem.imagePaths.enumerated() {
+                let filename = URL(fileURLWithPath: imagePath).lastPathComponent
+                let consistentFilename = ImageNamingUtils.generateImageFilename(
+                    problemId: problem.id.uuidString, imageIndex: index)
+
+                let imageManager = ImageManager.shared
+                let fullPath = imageManager.imagesDirectory.appendingPathComponent(filename).path
+
+                if let imageData = imageManager.loadImageData(fromPath: fullPath) {
+                    do {
+                        if filename != consistentFilename {
+                            let newPath = imageManager.imagesDirectory.appendingPathComponent(
+                                consistentFilename
+                            ).path
+                            try? FileManager.default.moveItem(atPath: fullPath, toPath: newPath)
+                        }
+
+                        try await uploadImage(filename: consistentFilename, imageData: imageData)
+                        print("Uploaded modified problem image: \(consistentFilename)")
+                    } catch {
+                        print("Failed to upload image \(consistentFilename): \(error)")
+                    }
+                }
+            }
+        }
+    }
+
     func uploadImage(filename: String, imageData: Data) async throws {
         guard isConfigured else {
             throw SyncError.notConfigured
@@ -246,6 +554,17 @@ class SyncService: ObservableObject {
                 !serverBackup.gyms.isEmpty || !serverBackup.problems.isEmpty
                 || !serverBackup.sessions.isEmpty || !serverBackup.attempts.isEmpty
 
+            // If both client and server have been synced before, use delta sync
+            if hasLocalData && hasServerData && lastSyncTime != nil {
+                print("iOS SYNC: Using delta sync for incremental updates")
+                try await performDeltaSync(dataManager: dataManager)
+
+                // Update last sync time
+                lastSyncTime = Date()
+                userDefaults.set(lastSyncTime, forKey: Keys.lastSyncTime)
+                return
+            }
+
             if !hasLocalData && hasServerData {
                 // Case 1: No local data - do full restore from server
                 print("iOS SYNC: Case 1 - No local data, performing full restore from server")
@@ -286,7 +605,6 @@ class SyncService: ObservableObject {
         }
     }
 
-    /// Parses ISO8601 timestamp to milliseconds for comparison
     private func parseISO8601ToMillis(timestamp: String) -> Int64 {
         let formatter = ISO8601DateFormatter()
         if let date = formatter.date(from: timestamp) {
@@ -1150,7 +1468,6 @@ class SyncService: ObservableObject {
         // Get active session IDs to protect their attempts
         let activeSessionIds = Set(
             local.compactMap { attempt in
-                // This is a simplified check - in a real implementation you'd want to cross-reference with sessions
                 return attempt.sessionId
             }.filter { sessionId in
                 // Check if this session ID belongs to an active session