Batches api calls by transactionId

LeStorage/ApiCallCollection.swift

@@ -183,34 +183,48 @@ actor ApiCallCollection<T: SyncedStorable>: SomeCallCollection {
 
         await self._wait()
         
-        let apiCallsCopy = self.items
+        let batches = Dictionary(grouping: self.items, by: { $0.transactionId })
-        for apiCall in apiCallsCopy {
-            apiCall.attemptsCount += 1
-            apiCall.lastAttemptDate = Date()
         
+        for batch in batches.values {
             do {
-                switch apiCall.method {
+                if batch.count == 1, let apiCall = batch.first, apiCall.method == .get {
-                case .post:
+                    let _: Empty = try await self._executeGetCall(apiCall)
-                    let result: T = try await self._executeApiCall(apiCall)
+                } else {
-                    StoreCenter.main.updateFromServerInstance(result)
+                    try await self._executeApiCalls(batch)
-//                    Logger.log("\(T.resourceName()) > SUCCESS!")
-                case .put:
-                    let _: T = try await self._executeApiCall(apiCall)
-                case .delete:
-                    let _: Empty = try await self._executeApiCall(apiCall)
-                case .get:
-                    if T.self == GetSyncData.self {
-                        let _: Empty = try await self._executeApiCall(apiCall)
-                    } else {
-                        let _: [T] = try await self._executeApiCall(apiCall)
-                    }
                 }
             } catch {
-//                Logger.log("\(T.resourceName()) > API CALL RETRY ERROR:")
+                Logger.error(error)
-//                Logger.error(error)
             }
         }
         
+//        let apiCallsCopy = self.items
+//        for apiCall in apiCallsCopy {
+//            apiCall.attemptsCount += 1
+//            apiCall.lastAttemptDate = Date()
+//
+//            do {
+//                switch apiCall.method {
+//                case .post:
+//                    let result: T = try await self._executeApiCall(apiCall)
+//                    StoreCenter.main.updateFromServerInstance(result)
+////                    Logger.log("\(T.resourceName()) > SUCCESS!")
+//                case .put:
+//                    let _: T = try await self._executeApiCall(apiCall)
+//                case .delete:
+//                    let _: Empty = try await self._executeApiCall(apiCall)
+//                case .get:
+//                    if T.self == GetSyncData.self {
+//                        let _: Empty = try await self._executeApiCall(apiCall)
+//                    } else {
+//                        let _: [T] = try await self._executeApiCall(apiCall)
+//                    }
+//                }
+//            } catch {
+////                Logger.log("\(T.resourceName()) > API CALL RETRY ERROR:")
+////                Logger.error(error)
+//            }
+//        }
+
         self._isRescheduling = false
         if self.items.isNotEmpty {
             await self._rescheduleApiCalls()
@@ -271,10 +285,10 @@ actor ApiCallCollection<T: SyncedStorable>: SomeCallCollection {
     }
 
     /// Creates an API call for the Storable [instance] and an HTTP [method]
-    fileprivate func _createCall(_ method: HTTPMethod, instance: T? = nil) throws -> ApiCall<T> {
+    fileprivate func _createCall(_ method: HTTPMethod, instance: T? = nil, transactionId: String? = nil) throws -> ApiCall<T> {
         if let instance {
             let jsonString = try instance.jsonString()
-            return ApiCall(method: method, dataId: instance.stringId, body: jsonString)
+            return ApiCall(method: method, dataId: instance.stringId, body: jsonString, transactionId: transactionId)
         } else {
             return ApiCall(method: .get)
         }
@@ -299,43 +313,65 @@ actor ApiCallCollection<T: SyncedStorable>: SomeCallCollection {
         }
     }
 
-    /// Sends an insert api call for the provided [instance]
+    func executeBatch(_ batch: BatchPreparation<T>) async throws {
-    func sendInsertion(_ instance: T) async throws -> T? {
-        do {
-            return try await self._sendServerRequest(HTTPMethod.post, instance: instance)
-        } catch {
-            self.rescheduleApiCallsIfNecessary()
-            StoreCenter.main.log(message: "POST failed for \(instance): \(error.localizedDescription)")
-            Logger.error(error)
-        }
-        return nil
-
-    }
         
-    /// Sends an update api call for the provided [instance]
+        var apiCalls: [ApiCall<T>] = []
-    func sendUpdate(_ instance: T) async throws -> T? {
+        let transactionId = Store.randomId()
-        do {
+        for insert in batch.inserts {
-            return try await self._sendServerRequest(HTTPMethod.put, instance: instance)
+            let call = try self._createCall(.post, instance: insert, transactionId: transactionId)
-        } catch {
+            self._prepareCall(apiCall: call)
-            self.rescheduleApiCallsIfNecessary()
+            apiCalls.append(call)
-            StoreCenter.main.log(message: "PUT failed for \(instance): \(error.localizedDescription)")
-            Logger.error(error)
         }
-        return nil
+        for update in batch.updates {
-    }
+            let call = try self._createCall(.put, instance: update, transactionId: transactionId)
-
+            self._prepareCall(apiCall: call)
-    /// Sends an delete api call for the provided [instance]
+            apiCalls.append(call)
-    func sendDeletion(_ instance: T) async throws {
+        }
-        do {
+        for delete in batch.deletes {
-            let _: Empty? = try await self._sendServerRequest(HTTPMethod.delete, instance: instance)
+            let call = try self._createCall(.delete, instance: delete, transactionId: transactionId)
-        } catch {
+            self._prepareCall(apiCall: call)
-            self.rescheduleApiCallsIfNecessary()
+            apiCalls.append(call)
-            StoreCenter.main.log(message: "DELETE failed for \(instance): \(error.localizedDescription)")
-            Logger.error(error)
         }
-        return
+        try await self._executeApiCalls(apiCalls)
     }
     
+    /// Sends an insert api call for the provided [instance]
+//    func sendInsertion(_ instance: T) async throws -> T? {
+//        do {
+//            return try await self._sendServerRequest(HTTPMethod.post, instance: instance)
+//        } catch {
+//            self.rescheduleApiCallsIfNecessary()
+//            StoreCenter.main.log(message: "POST failed for \(instance): \(error.localizedDescription)")
+//            Logger.error(error)
+//        }
+//        return nil
+//
+//    }
+//
+//    /// Sends an update api call for the provided [instance]
+//    func sendUpdate(_ instance: T) async throws -> T? {
+//        do {
+//            return try await self._sendServerRequest(HTTPMethod.put, instance: instance)
+//        } catch {
+//            self.rescheduleApiCallsIfNecessary()
+//            StoreCenter.main.log(message: "PUT failed for \(instance): \(error.localizedDescription)")
+//            Logger.error(error)
+//        }
+//        return nil
+//    }
+//
+//    /// Sends an delete api call for the provided [instance]
+//    func sendDeletion(_ instance: T) async throws {
+//        do {
+//            let _: Empty? = try await self._sendServerRequest(HTTPMethod.delete, instance: instance)
+//        } catch {
+//            self.rescheduleApiCallsIfNecessary()
+//            StoreCenter.main.log(message: "DELETE failed for \(instance): \(error.localizedDescription)")
+//            Logger.error(error)
+//        }
+//        return
+//    }
+
     /// Initiates the process of sending the data with the server
     fileprivate func _sendServerRequest<V: Decodable>(_ method: HTTPMethod, instance: T? = nil) async throws -> V? {
         if let apiCall = try self._call(method: method, instance: instance) {
@@ -349,13 +385,19 @@ actor ApiCallCollection<T: SyncedStorable>: SomeCallCollection {
 
     fileprivate func _prepareAndSendCall<V: Decodable>(_ apiCall: ApiCall<T>) async throws -> V? {
         self._prepareCall(apiCall: apiCall)
-        return try await self._executeApiCall(apiCall)
+        return try await self._executeGetCall(apiCall)
+    }
+    
+    /// Executes an API call
+    /// For POST requests, potentially copies additional data coming from the server during the insert
+    fileprivate func _executeGetCall<V: Decodable>(_ apiCall: ApiCall<T>) async throws -> V {
+        return try await StoreCenter.main.executeGet(apiCall: apiCall)
     }
     
     /// Executes an API call
     /// For POST requests, potentially copies additional data coming from the server during the insert
-    fileprivate func _executeApiCall<V: Decodable>(_ apiCall: ApiCall<T>) async throws -> V {
+    fileprivate func _executeApiCalls(_ apiCalls: [ApiCall<T>]) async throws {
-        return try await StoreCenter.main.execute(apiCall: apiCall)
+        try await StoreCenter.main.execute(apiCalls: apiCalls)
     }
 
     /// Returns the content of the API call file as a String

LeStorage/Codables/ApiCall.swift

@@ -20,6 +20,9 @@ class ApiCall<T: Storable>: ModelObject, Storable, SomeCall {
     
     var id: String = Store.randomId()
 
+    /// The transactionId to group calls together
+    var transactionId: String = Store.randomId()
+    
     /// Creation date of the call
     var creationDate: Date? = Date()
     
@@ -41,10 +44,13 @@ class ApiCall<T: Storable>: ModelObject, Storable, SomeCall {
     /// The parameters to add in the URL to obtain : "?p1=v1&p2=v2"
     var urlParameters: [String : String]? = nil
     
-    init(method: HTTPMethod, dataId: String? = nil, body: String? = nil) {
+    init(method: HTTPMethod, dataId: String? = nil, body: String? = nil, transactionId: String? = nil) {
         self.method = method
         self.dataId = dataId
         self.body = body
+        if let transactionId {
+            self.transactionId = transactionId
+        }
     }
     
     func copy(from other: any Storable) {

LeStorage/Services.swift

@@ -79,6 +79,64 @@ public class Services {
         return try await _runRequest(request)
     }
 
+    /// Runs a request using a traditional URLRequest
+    /// - Parameters:
+    ///   - request: the URLRequest to run
+    ///   - apiCallId: the id of the ApiCall to delete in case of success, or to schedule for a rerun in case of failure
+    fileprivate func _runSyncPostRequest<T: SyncedStorable>(
+        _ request: URLRequest, type: T.Type) async throws {
+        let debugURL = request.url?.absoluteString ?? ""
+        //        print("Run \(request.httpMethod ?? "") \(debugURL)")
+        let task: (Data, URLResponse) = try await URLSession.shared.data(for: request)
+        print("sync POST \(String(describing: T.self)) => \(String(data: task.0, encoding: .utf8) ?? "")")
+        
+        var rescheduleApiCalls: Bool = false
+        
+        if let response = task.1 as? HTTPURLResponse {
+            let statusCode = response.statusCode
+            print("\(debugURL) ended, status code = \(statusCode)")
+            switch statusCode {
+            case 200..<300: // success
+                
+                let decoded: BatchResponse<T> = try self._decode(data: task.0)
+                for result in decoded.results {
+                    switch result.status {
+                    case 200..<300:
+                        
+                        try await StoreCenter.main.deleteApiCallById(type: T.self, id: result.apiCallId)
+                    default:
+                        rescheduleApiCalls = true
+                    }
+                }
+                
+            default:  // error
+                Logger.log(
+                    "Failed Run \(request.httpMethod ?? "") \(request.url?.absoluteString ?? "")")
+                let errorString: String = String(data: task.0, encoding: .utf8) ?? ""
+                var errorMessage = ErrorMessage(error: errorString, domain: "")
+                
+                if let message = self.errorMessageFromResponse(data: task.0) {
+                    errorMessage = message
+                }
+                try await StoreCenter.main.rescheduleApiCalls(type: T.self)
+                
+                //                StoreCenter.main.logFailedAPICall(
+                //                    apiCall.id, request: request, collectionName: T.resourceName(),
+                //                    error: errorMessage.message)
+                
+                throw ServiceError.responseError(response: errorMessage.error)
+            }
+        } else {
+            let message: String = "Unexpected and unmanaged URL Response \(task.1)"
+            StoreCenter.main.log(message: message)
+            Logger.w(message)
+        }
+        
+        if rescheduleApiCalls {
+            try await StoreCenter.main.rescheduleApiCalls(type: T.self)
+        }
+    }
+
     /// Runs a request using a traditional URLRequest
     /// - Parameters:
     ///   - request: the URLRequest to run
@@ -112,7 +170,7 @@ public class Services {
                     errorMessage = message
                 }
 
-                try await StoreCenter.main.rescheduleApiCalls(id: apiCall.id, type: T.self)
+                try await StoreCenter.main.rescheduleApiCalls(type: T.self)
                 StoreCenter.main.logFailedAPICall(
                     apiCall.id, request: request, collectionName: T.resourceName(),
                     error: errorMessage.message)
@@ -265,7 +323,7 @@ public class Services {
     /// Returns the URLRequest for an ApiCall
     /// - Parameters:
     ///  - apiCall: An ApiCall instance to configure the returned request
-    fileprivate func _syncRequest<T: SyncedStorable>(from apiCall: ApiCall<T>) throws -> URLRequest {
+    fileprivate func _syncGetRequest<T: SyncedStorable>(from apiCall: ApiCall<T>) throws -> URLRequest {
 
         var urlString = baseURL + "data/"
         if let urlParameters = apiCall.formattedURLParameters() {
@@ -277,36 +335,54 @@ public class Services {
         }
         
         var request = URLRequest(url: url)
-        if apiCall.method == .get {
+        request.httpMethod = HTTPMethod.get.rawValue
-            request.httpMethod = HTTPMethod.get.rawValue
+        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
-        } else {
+
-            request.httpMethod = HTTPMethod.post.rawValue
+        if self._isTokenRequired(type: T.self, method: apiCall.method) {
+            let token = try self.keychainStore.getValue()
+            request.addValue("Token \(token)", forHTTPHeaderField: "Authorization")
         }
 
+        return request
+    }
+    
+    /// Returns the URLRequest for an ApiCall
+    /// - Parameters:
+    ///  - apiCall: An ApiCall instance to configure the returned request
+    fileprivate func _syncPostRequest<T: SyncedStorable>(from apiCalls: [ApiCall<T>]) throws -> URLRequest {
+
+        let urlString = baseURL + "data/"
+
+        guard let url = URL(string: urlString) else {
+            throw ServiceError.urlCreationError(url: urlString)
+        }
+        
+        var request = URLRequest(url: url)
+        request.httpMethod = HTTPMethod.post.rawValue
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        let token = try self.keychainStore.getValue()
+        request.addValue("Token \(token)", forHTTPHeaderField: "Authorization")
 
-        if let body = apiCall.body {
+        let modelName = String(describing: T.self)
-            if let data = body.data(using: .utf8) {
+        let operations = try apiCalls.map { apiCall in
-                let object = try JSON.decoder.decode(T.self, from: data)
-                let modelName = String(describing: T.self)
-                let payload = SyncPayload(
-                    operation: apiCall.method.rawValue,
-                    modelName: modelName,
-                    data: object,
-                    storeId: object.getStoreId(),
-                    deviceId: StoreCenter.main.deviceId())
-                request.httpBody = try JSON.encoder.encode(payload)
             
+            if let body = apiCall.body, let data = body.data(using: .utf8) {
+                let object = try JSON.decoder.decode(T.self, from: data)
+                return Operation(apiCallId: apiCall.id,
+                                 operation: apiCall.method.rawValue,
+                                 modelName: modelName,
+                                 data: object,
+                                 storeId: object.getStoreId())
             } else {
                 throw ServiceError.cantDecodeData(resource: T.resourceName(), method: apiCall.method.rawValue, content: apiCall.body)
             }
-        }
             
-        if self._isTokenRequired(type: T.self, method: apiCall.method) {
-            let token = try self.keychainStore.getValue()
-            request.addValue("Token \(token)", forHTTPHeaderField: "Authorization")
         }
         
+        let payload = SyncPayload(operations: operations,
+                                  deviceId: StoreCenter.main.deviceId())
+        request.httpBody = try JSON.encoder.encode(payload)
+        
         return request
     }
     
@@ -388,44 +464,41 @@ public class Services {
     }
 
     /// Executes a POST request
-    public func post<T: Storable>(_ instance: T) async throws -> T {
+//    public func post<T: Storable>(_ instance: T) async throws -> T {
-
+//
-        let method: HTTPMethod = .post
+//        let method: HTTPMethod = .post
-        let payload = SyncPayload(
+//        let payload = SyncPayload(
-            operation: method.rawValue,
+//            operation: method.rawValue,
-            modelName: String(describing: T.self),
+//            modelName: String(describing: T.self),
-            data: instance,
+//            data: instance,
-            deviceId: StoreCenter.main.deviceId())
+//            deviceId: StoreCenter.main.deviceId())
-        let syncRequest = try self._baseSyncRequest(method: .post, payload: payload)
+//        let syncRequest = try self._baseSyncRequest(method: .post, payload: payload)
-        return try await self._runRequest(syncRequest)
+//        return try await self._runRequest(syncRequest)
-
+//    }
-        //        var postRequest = try self._postRequest(type: T.self)
+//
-        //        postRequest.httpBody = try jsonEncoder.encode(instance)
+//    /// Executes a PUT request
-        //        return try await self._runRequest(postRequest)
+//    public func put<T: SyncedStorable>(_ instance: T) async throws -> T {
-    }
+//
-
+//        let method: HTTPMethod = .put
-    /// Executes a PUT request
+//        let payload = SyncPayload(
-    public func put<T: SyncedStorable>(_ instance: T) async throws -> T {
+//            operation: method.rawValue,
-
+//            modelName: String(describing: T.self),
-        let method: HTTPMethod = .put
+//            data: instance,
-        let payload = SyncPayload(
+//            deviceId: StoreCenter.main.deviceId())
-            operation: method.rawValue,
+//        let syncRequest = try self._baseSyncRequest(method: .post, payload: payload)
-            modelName: String(describing: T.self),
+//        return try await self._runRequest(syncRequest)
-            data: instance,
+//    }
-            deviceId: StoreCenter.main.deviceId())
-        let syncRequest = try self._baseSyncRequest(method: .post, payload: payload)
-        return try await self._runRequest(syncRequest)
 
-        //        var postRequest = try self._putRequest(type: T.self, id: instance.stringId)
+    /// Executes an ApiCall
-        //        postRequest.httpBody = try jsonEncoder.encode(instance)
+    func runGetApiCall<T: SyncedStorable, V: Decodable>(_ apiCall: ApiCall<T>) async throws -> V {
-        //        return try await self._runRequest(postRequest)
+        let request = try self._syncGetRequest(from: apiCall)
+        return try await self._runRequest(request, apiCall: apiCall)
     }
 
     /// Executes an ApiCall
-    func runApiCall<T: SyncedStorable, V: Decodable>(_ apiCall: ApiCall<T>) async throws -> V {
+    func runApiCalls<T: SyncedStorable>(_ apiCalls: [ApiCall<T>]) async throws {
-        let request = try self._syncRequest(from: apiCall)
+        let request = try self._syncPostRequest(from: apiCalls)
-//        print("HTTP \(request.httpMethod ?? "") : id = \(apiCall.dataId)")
+        try await self._runSyncPostRequest(request, type: T.self)
-        return try await self._runRequest(request, apiCall: apiCall)
     }
 
     /// Returns the URLRequest for an ApiCall
@@ -649,11 +722,26 @@ public class Services {
 }
 
 struct SyncPayload<T: Encodable>: Encodable {
+    var operations: [Operation<T>]
+    var deviceId: String?
+}
+
+struct Operation<T: Encodable>: Encodable {
+    var apiCallId: String
     var operation: String
     var modelName: String
     var data: T
     var storeId: String?
-    var deviceId: String?
+}
+
+struct BatchResponse<T: Decodable>: Decodable {
+    var results: [OperationResult<T>]
+}
+
+struct OperationResult<T: Decodable>: Decodable {
+    var apiCallId: String
+    var status: Int
+    var data: T
 }
 
 struct ErrorMessage {

LeStorage/Store.swift

@@ -287,23 +287,23 @@ final public class Store {
     /// Requests an insertion to the StoreCenter
     /// - Parameters:
     ///   - instance: an object to insert
-    func sendInsertion<T: SyncedStorable>(_ instance: T) async throws -> T? {
+//    func sendInsertion<T: SyncedStorable>(_ instance: T) async throws -> T? {
-        return try await StoreCenter.main.sendInsertion(instance)
+//        return try await StoreCenter.main.sendInsertion(instance)
-    }
+//    }
-    
+//    
-    /// Requests an update to the StoreCenter
+//    /// Requests an update to the StoreCenter
-    /// - Parameters:
+//    /// - Parameters:
-    ///   - instance: an object to update
+//    ///   - instance: an object to update
-    @discardableResult func sendUpdate<T: SyncedStorable>(_ instance: T) async throws -> T? {
+//    @discardableResult func sendUpdate<T: SyncedStorable>(_ instance: T) async throws -> T? {
-        return try await StoreCenter.main.sendUpdate(instance)
+//        return try await StoreCenter.main.sendUpdate(instance)
-    }
+//    }
-    
+//    
-    /// Requests a deletion to the StoreCenter
+//    /// Requests a deletion to the StoreCenter
-    /// - Parameters:
+//    /// - Parameters:
-    ///   - instance: an object to delete
+//    ///   - instance: an object to delete
-    func sendDeletion<T: SyncedStorable>(_ instance: T) async throws {
+//    func sendDeletion<T: SyncedStorable>(_ instance: T) async throws {
-        return try await StoreCenter.main.sendDeletion(instance)
+//        return try await StoreCenter.main.sendDeletion(instance)
-    }
+//    }
     
     /// Returns whether all collections have loaded locally
     public func fileCollectionsAllLoaded() -> Bool {

LeStorage/StoreCenter.swift

@@ -344,7 +344,7 @@ public class StoreCenter {
     }
     
     /// Reschedule an ApiCall by id
-    func rescheduleApiCalls<T: SyncedStorable>(id: String, type: T.Type) async throws {
+    func rescheduleApiCalls<T: SyncedStorable>(type: T.Type) async throws {
         guard self.collectionsCanSynchronize else {
             return
         }
@@ -360,8 +360,13 @@ public class StoreCenter {
 //    }
 
     /// Executes an API call
-    func execute<T: SyncedStorable, V: Decodable>(apiCall: ApiCall<T>) async throws -> V {
+    func executeGet<T: SyncedStorable, V: Decodable>(apiCall: ApiCall<T>) async throws -> V {
-        return try await self.service().runApiCall(apiCall)
+        return try await self.service().runGetApiCall(apiCall)
+    }
+
+    /// Executes an API call
+    func execute<T: SyncedStorable>(apiCalls: [ApiCall<T>]) async throws {
+        try await self.service().runApiCalls(apiCalls)
     }
 
     // MARK: - Api calls
@@ -372,35 +377,44 @@ public class StoreCenter {
             && self.userIsAllowed()
     }
 
-    /// Transmit the insertion request to the ApiCall collection
+    func prepareOperationBatch<T: SyncedStorable>(_ batch: BatchPreparation<T>) {
-    /// - Parameters:
-    ///   - instance: an object to insert
-    func sendInsertion<T: SyncedStorable>(_ instance: T) async throws -> T? {
         guard self._canSynchronise() else {
-            return nil
+            return
         }
-        return try await self.apiCallCollection().sendInsertion(instance)
+        Task {
-    }
+            try await self.apiCallCollection().executeBatch(batch)
-
-    /// Transmit the update request to the ApiCall collection
-    /// - Parameters:
-    ///   - instance: an object to update
-    func sendUpdate<T: SyncedStorable>(_ instance: T) async throws -> T? {
-        guard self._canSynchronise() else {
-            return nil
         }
-        return try await self.apiCallCollection().sendUpdate(instance)
     }
     
-    /// Transmit the deletion request to the ApiCall collection
+    /// Transmit the insertion request to the ApiCall collection
     /// - Parameters:
-    ///   - instance: an object to delete
+    ///   - instance: an object to insert
-    func sendDeletion<T: SyncedStorable>(_ instance: T) async throws {
+//    func sendInsertion<T: SyncedStorable>(_ instance: T) async throws -> T? {
-        guard self._canSynchronise() else {
+//        guard self._canSynchronise() else {
-            return
+//            return nil
-        }
+//        }
-        try await self.apiCallCollection().sendDeletion(instance)
+//        return try await self.apiCallCollection().sendInsertion(instance)
-    }
+//    }
+//
+//    /// Transmit the update request to the ApiCall collection
+//    /// - Parameters:
+//    ///   - instance: an object to update
+//    func sendUpdate<T: SyncedStorable>(_ instance: T) async throws -> T? {
+//        guard self._canSynchronise() else {
+//            return nil
+//        }
+//        return try await self.apiCallCollection().sendUpdate(instance)
+//    }
+//
+//    /// Transmit the deletion request to the ApiCall collection
+//    /// - Parameters:
+//    ///   - instance: an object to delete
+//    func sendDeletion<T: SyncedStorable>(_ instance: T) async throws {
+//        guard self._canSynchronise() else {
+//            return
+//        }
+//        try await self.apiCallCollection().sendDeletion(instance)
+//    }
 
     /// Retrieves all the items on the server
     func getItems<T: SyncedStorable>(identifier: String? = nil) async throws -> [T] {

LeStorage/StoredCollection+Sync.swift

@@ -102,10 +102,10 @@ extension StoredCollection: SomeSyncedCollection where T : SyncedStorable {
         instance.lastUpdate = Date()
         if let index = self.items.firstIndex(where: { $0.id == instance.id }) {
             self.updateItem(instance, index: index)
-            self._sendUpdateIfNecessary(instance)
+            self._sendUpdate(instance)
         } else {
             self.addItem(instance: instance)
-            self._sendInsertionIfNecessary(instance)
+            self._sendInsertion(instance)
         }
     }
     
@@ -115,17 +115,24 @@ extension StoredCollection: SomeSyncedCollection where T : SyncedStorable {
             self.setChanged()
         }
         
+        let date = Date()
+        let batch = BatchPreparation<T>()
+        
         for instance in sequence {
-            instance.lastUpdate = Date()
+            instance.lastUpdate = date
             if let index = self.items.firstIndex(where: { $0.id == instance.id }) {
                 self.updateItem(instance, index: index)
-                self._sendUpdateIfNecessary(instance)
+                batch.addUpdate(instance)
+//                self._sendUpdateIfNecessary(instance)
             } else { // insert
                 self.addItem(instance: instance)
-                self._sendInsertionIfNecessary(instance)
+                batch.addInsert(instance)
+//                self._sendInsertionIfNecessary(instance)
             }
         }
         
+        self._prepareBatch(batch)
+
     }
     
     /// Proceeds to delete all instance of the collection, properly cleaning up dependencies and sending API calls
@@ -141,8 +148,13 @@ extension StoredCollection: SomeSyncedCollection where T : SyncedStorable {
         }
 
         for instance in sequence {
-            self._deleteNoWrite(instance: instance)
+            self.deleteItem(instance)
+            StoreCenter.main.createDeleteLog(instance)
         }
+        
+        let batch = BatchPreparation<T>()
+        batch.deletes = sequence
+        self._prepareBatch(batch)
     }
     
     /// Deletes an instance and writes
@@ -157,54 +169,71 @@ extension StoredCollection: SomeSyncedCollection where T : SyncedStorable {
     fileprivate func _deleteNoWrite(instance: T) {
         self.deleteItem(instance)
         StoreCenter.main.createDeleteLog(instance)
-        self._sendDeletionIfNecessary(instance)
+        
+        self._sendDeletion(instance)
     }
     
-    // MARK: - Reschedule calls
+    // MARK: - Send requests
     
-    /// Sends an insert api call for the provided
+    fileprivate func _sendInsertion(_ instance: T) {
-    /// Calls copyFromServerInstance on the instance with the result of the HTTP call
+        self._prepareBatch(BatchPreparation(insert: instance))
-    /// - Parameters:
+    }
-    ///   - instance: the object to POST
-    fileprivate func _sendInsertionIfNecessary(_ instance: T) {
     
-        Task {
+    fileprivate func _sendUpdate(_ instance: T) {
-            do {
+        self._prepareBatch(BatchPreparation(update: instance))
-                if let result = try await self.store.sendInsertion(instance) {
-                    self.updateFromServerInstance(result)
-                }
-            } catch {
-                Logger.error(error)
-            }
-        }
     }
     
-    /// Sends an update api call for the provided [instance]
+    fileprivate func _sendDeletion(_ instance: T) {
-    /// - Parameters:
+        self._prepareBatch(BatchPreparation(delete: instance))
-    ///   - instance: the object to PUT
-    fileprivate func _sendUpdateIfNecessary(_ instance: T) {
-        Task {
-            do {
-                try await self.store.sendUpdate(instance)
-            } catch {
-                Logger.error(error)
-            }
-        }
     }
     
-    /// Sends an delete api call for the provided [instance]
+    fileprivate func _prepareBatch(_ batch: BatchPreparation<T>) {
-    /// - Parameters:
+        StoreCenter.main.prepareOperationBatch(batch)
-    ///   - instance: the object to DELETE
-    fileprivate func _sendDeletionIfNecessary(_ instance: T) {
-        Task {
-            do {
-                try await self.store.sendDeletion(instance)
-            } catch {
-                Logger.error(error)
-            }
-        }
     }
     
+    /// Sends an insert api call for the provided
+    /// Calls copyFromServerInstance on the instance with the result of the HTTP call
+    /// - Parameters:
+    ///   - instance: the object to POST
+//    fileprivate func _sendInsertionIfNecessary(_ instance: T) {
+//
+//        Task {
+//            do {
+//                if let result = try await self.store.sendInsertion(instance) {
+//                    self.updateFromServerInstance(result)
+//                }
+//            } catch {
+//                Logger.error(error)
+//            }
+//        }
+//    }
+//    
+//    /// Sends an update api call for the provided [instance]
+//    /// - Parameters:
+//    ///   - instance: the object to PUT
+//    fileprivate func _sendUpdateIfNecessary(_ instance: T) {
+//        Task {
+//            do {
+//                try await self.store.sendUpdate(instance)
+//            } catch {
+//                Logger.error(error)
+//            }
+//        }
+//    }
+//    
+//    /// Sends an delete api call for the provided [instance]
+//    /// - Parameters:
+//    ///   - instance: the object to DELETE
+//    fileprivate func _sendDeletionIfNecessary(_ instance: T) {
+//        Task {
+//            do {
+//                try await self.store.sendDeletion(instance)
+//            } catch {
+//                Logger.error(error)
+//            }
+//        }
+//    }
+    
     // MARK: - Synchronization
     
     /// Adds or update an instance if it is newer than the local instance 
@@ -229,24 +258,38 @@ extension StoredCollection: SomeSyncedCollection where T : SyncedStorable {
     
     // MARK: - Migrations
     
-    /// Makes POST ApiCall for all items in the collection
-    public func insertAllIntoCurrentService() {
-        for item in self.items {
-            self._sendInsertionIfNecessary(item)
-        }
-    }
-    
-    /// Makes POST ApiCall for the provided item
-    public func insertIntoCurrentService(item: T) {
-        self._sendInsertionIfNecessary(item)
-    }
-    
     /// Sends a POST request for the instance, and changes the collection to perform a write
     public func writeChangeAndInsertOnServer(instance: T) {
         defer {
             self.setChanged()
         }
-        self._sendInsertionIfNecessary(instance)
+        self._sendInsertion(instance)
     }
     
 }
+
+class BatchPreparation<T> {
+    var inserts: [T] = []
+    var updates: [T] = []
+    var deletes: any Sequence<T> = []
+    
+    init() {
+        
+    }
+    init(insert: T) {
+        self.inserts = [insert]
+    }
+    init(update: T) {
+        self.updates = [update]
+    }
+    init(delete: T) {
+        self.deletes = [delete]
+    }
+    
+    func addInsert(_ instance: T) {
+        self.inserts.append(instance)
+    }
+    func addUpdate(_ instance: T) {
+        self.updates.append(instance)
+    }
+}