LeStorage/LeStorage/StoreCenter.swift

//
//  StoreCenter.swift
//  LeStorage
//
//  Created by Laurent Morvillier on 25/06/2024.
//

import Foundation
import UIKit

public class StoreCenter {

    /// The main instance
    public static let main: StoreCenter = StoreCenter()

    /// The name of the directory to store the json files
    let directoryName: String

    /// A dictionary of Stores associated to their id
    fileprivate var _stores: [String: Store] = [:]

    /// Returns a default Store instance
    lazy var mainStore: Store = { Store(storeCenter: self) }()
    
    /// A KeychainStore object used to store the user's token
    var tokenKeychain: KeychainService? = nil
    
    /// A KeychainStore object used to store the user's token
    var deviceKeychain: KeychainService = KeychainStore(serverId: "lestorage.device")

    /// Force the absence of synchronization
    public var forceNoSynchronization: Bool = false

    /// A store for the Settings object
    fileprivate var _settingsStorage: MicroStorage<Settings> = MicroStorage(
        fileName: "settings.json")

    /// The services performing the API calls
    fileprivate var _services: Services?

    /// The WebSocketManager that manages realtime synchronization
    fileprivate var _webSocketManager: WebSocketManager?

    /// The dictionary of registered api collections
    fileprivate var _apiCallCollections: [String: any SomeCallCollection] = [:]

    /// A collection of DataLog objects, used for the synchronization
    lazy fileprivate var _deleteLogs: StoredCollection<DataLog> = { self.mainStore.registerCollection() }()

    /// A synchronized collection of DataAccess
    fileprivate(set) var dataAccessCollection: SyncedCollection<DataAccess>? = nil

    /// A collection storing FailedAPICall objects
    fileprivate var _failedAPICallsCollection: SyncedCollection<FailedAPICall>? = nil

    /// A collection of Log objects
    fileprivate var _logs: SyncedCollection<Log>? = nil

    /// A list of username that cannot synchronize with the server
    fileprivate var _blackListedUserName: [String] = []

    /// The URL manager
    fileprivate var _urlManager: URLManager? = nil
    
    /// Used for testing, gives the project name to retrieve classes from names
    var classProject: String? = nil

    var useWebsockets: Bool = false
    var useSynchronization: Bool = false
    
    init(directoryName: String? = nil) {
        
        self.directoryName = directoryName ?? "storage"
        
        self._createDirectory()
        
        self._setupNotifications()

        self.loadApiCallCollection(type: GetSyncData.self)
        
        if let directoryName {
            self._settingsStorage = MicroStorage(
                fileName: "\(directoryName)/settings.json")
        }
        
        NetworkMonitor.shared.onConnectionEstablished = {
            self._resumeApiCalls()
//            self._configureWebSocket()
        }
//        Logger.log("device Id = \(self.deviceId())")
    }

    public func configureURLs(secureScheme: Bool, domain: String, webSockets: Bool = true, useSynchronization: Bool = false) {
        
        self.useWebsockets = webSockets
        self.useSynchronization = useSynchronization

        let urlManager: URLManager = URLManager(secureScheme: secureScheme, domain: domain)
        self._urlManager = urlManager
        self._services = Services(storeCenter: self, url: urlManager.api)
        self.tokenKeychain = KeychainStore(serverId: urlManager.api)

        if self.useSynchronization {
            self.dataAccessCollection = self.mainStore.registerSynchronizedCollection()
        }

        Logger.log("Sync URL: \(urlManager.api)")
        
        if self.userId != nil {
            self._configureWebSocket()
        }
    }
    
    fileprivate func _configureWebSocket() {
        
        guard self.useWebsockets else {
            return
        }
        
        self._webSocketManager?.disconnect()
        self._webSocketManager = nil
        
        guard let userId = self.userId else {
            Logger.w("Tried to configure websocket but userId is nil")
            return
        }
        guard let urlManager = self._urlManager else {
            Logger.w("Tried to configure websocket no URL has been defined")
            return
        }
        let url = urlManager.websocket(userId: userId)
        self._webSocketManager = WebSocketManager(storeCenter: self, urlString: url)
        Logger.log("websocket configured: \(url)")
    }
    
    public var hasWebSocketManager: Bool {
        return self._webSocketManager != nil
    }
    public var websocketPingStatus: Bool {
        return self._webSocketManager?.pingStatus ?? false
    }
    
    public var websocketFailure: Bool {
        return self._webSocketManager?.failure ?? true
    }
    
    public var apiURL: String? {
        return self._urlManager?.api
    }
    public var lastSyncDate: String {
        return self._settingsStorage.item.lastSynchronization
    }
    
    /// Returns the service instance
    public func service() throws -> Services {
        if let service = self._services {
            return service
        } else {
            throw StoreError.missingService
        }
    }

    private func _setupNotifications() {
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(_willEnterForegroundNotification),
            name: UIScene.willEnterForegroundNotification,
            object: nil)
    }

    @objc fileprivate func _willEnterForegroundNotification() {
//        Logger.log("_willEnterForegroundNotification")
        self._launchSynchronization()
    }

    @objc fileprivate func _launchSynchronization() {
        Task {
            do {
                try await self.synchronizeLastUpdates()
            } catch {
                Logger.error(error)
            }
        }
    }

    /// Registers a store into the list of stores
    /// - Parameters:
    ///   - store: A store to save
    fileprivate func _registerStore(store: Store) {
        guard let identifier = store.identifier else {
            fatalError("The store has no identifier")
        }
        if self._stores[identifier] != nil {
            fatalError("A store with this identifier has already been registered: \(identifier)")
        }
        self._stores[identifier] = store
    }

    /// Returns a store using its identifier, and registers it if it does not exists
    /// - Parameters:
    ///   - identifier: The store identifer
    ///   - parameter: The parameter name used to filter data on the server
    public func requestStore(identifier: String) -> Store {
        if let store = self._stores[identifier] {
            return store
        } else {
            let store = Store(storeCenter: self, identifier: identifier)
            self._registerStore(store: store)
            return store
        }
    }
    
    public func store(identifier: String) throws -> Store {
        if let store = self._stores[identifier] {
            return store
        }
        throw StoreError.storeNotRegistered(id: identifier)
    }

    // MARK: - Settings

    /// Sets the user info given a user
    func userDidLogIn(user: UserBase, at date: Date) {
        self._settingsStorage.update { settings in
            settings.userId = user.id
            settings.lastSynchronization = Date.microSecondFormatter.string(from: date)
            self._configureWebSocket()
        }
    }

    /// Returns the stored user Id
    public var userId: String? {
        return self._settingsStorage.item.userId
    }

    /// Returns the username
    public var userName: String? {
        return self._settingsStorage.item.username
    }

    /// Returns the stored token
    public func token() throws -> String {
        guard self.userName != nil else { throw StoreError.missingUsername }
        guard let tokenKeychain else { throw StoreError.missingKeychainStore }
        return try tokenKeychain.getValue()
    }
    
    public func rawTokenShouldNotBeUsed() throws -> String? {
        return try self.tokenKeychain?.getValue()
    }

    /// Disconnect the user from the storage and resets collection
    public func disconnect() {
        try? self.tokenKeychain?.deleteValue()

        self.resetApiCalls()
        self._failedAPICallsCollection?.reset()

        self._stores.removeAll()
        self.dataAccessCollection?.reset()
        self._deleteLogs.reset()
        
        self._settingsStorage.update { settings in
            settings.username = nil
            settings.userId = nil
            settings.lastSynchronization = Date.microSecondFormatter.string(from: Date())
            
            self._webSocketManager = nil
        }

    }

    /// Returns whether the system has a user token
    public var isAuthenticated: Bool {
        guard self.userName != nil else { return false }
        do {
            let _ = try self.token()
            return true
        } catch {
            return false
        }
    }

    /// Stores a token for a corresponding username
    /// - Parameters:
    ///  - username: the key used to store the token
    ///  - token: the token to store
    func storeToken(username: String, token: String) throws {
        self._settingsStorage.item.username = username
        guard let tokenKeychain else { throw StoreError.missingKeychainStore }
        try tokenKeychain.deleteValue()
        try tokenKeychain.add(username: username, value: token)
    }
    
    /// Returns a generated device id
    /// If created, stores it inside the keychain to get a consistent value even if the app is deleted
    /// as UIDevice.current.identifierForVendor value changes when the app is deleted and installed again
    func deviceId() -> String {
        
        do {
            return try self.deviceKeychain.getValue()
        } catch {
            let deviceId: String =
                UIDevice.current.identifierForVendor?.uuidString ?? UUID().uuidString
            do {
                try self.deviceKeychain.add(value: deviceId)
            } catch {
                Logger.error(error)
            }
            return deviceId
        }
    }

    // MARK: - File system
    
    /// Creates the store directory
    /// - Parameters:
    ///   - directory: the name of the directory
    fileprivate func _createDirectory() {
        FileManager.default.createDirectoryInDocuments(directoryName: self.directoryName)
    }
    
    public func directoryURL() throws -> URL {
        return try FileUtils.pathForDirectoryInDocuments(directory: self.directoryName)
    }
    
    /// Returns the URL of the Storable json file
    func jsonFileURL<T: Storable>(for type: T.Type) throws -> URL {
        var storageDirectory = try self.directoryURL()
        storageDirectory.append(component: T.fileName())
        return storageDirectory
    }
    
    func write(content: String, fileName: String) throws {
        var fileURL = try self.directoryURL()
        fileURL.append(component: fileName)
        try content.write(to: fileURL, atomically: false, encoding: .utf8)
    }
    
    // MARK: - Api Calls management

    /// Instantiates and loads an ApiCallCollection with the provided type
    public func loadApiCallCollection<T: SyncedStorable>(type: T.Type) {
        if self._apiCallCollections[T.resourceName()] == nil {
            let apiCallCollection = ApiCallCollection<T>(storeCenter: self)
            self._apiCallCollections[T.resourceName()] = apiCallCollection
            Task {
                do {
                    try await apiCallCollection.loadFromFile()
//                    let count = await apiCallCollection.items.count
//                    Logger.log("collection \(T.resourceName()) loaded with \(count)")
                    await apiCallCollection.rescheduleApiCallsIfNecessary()
                } catch {
                    Logger.error(error)
                }
            }
        }
    }

    /// Returns the ApiCall collection using the resource name of the provided T type
    func apiCallCollection<T: Storable>() throws -> ApiCallCollection<T> {
        if let collection = self._apiCallCollections[T.resourceName()] as? ApiCallCollection<T> {
            return collection
        }
        throw StoreError.apiCallCollectionNotRegistered(type: T.resourceName())
    }

    /// Deletes an ApiCall, identifying it by dataId
    /// - Parameters:
    ///   - type: the subsequent type of the ApiCall
    ///   - id: the id of the data stored inside the ApiCall
    func deleteApiCallByDataId<T: SyncedStorable>(type: T.Type, id: String) async throws {
        let apiCallCollection: ApiCallCollection<T> = try self.apiCallCollection()
        await apiCallCollection.deleteByDataId(id)
    }

    /// Deletes an ApiCall by its id
    /// - Parameters:
    ///   - type: the subsequent type of the ApiCall
    ///   - id: the id of the ApiCall
    func deleteApiCallById<T: SyncedStorable>(type: T.Type, id: String) async throws {
        let apiCallCollection: ApiCallCollection<T> = try self.apiCallCollection()
        await apiCallCollection.deleteById(id)
    }

    /// Deletes an ApiCall by its id
    /// - Parameters:
    ///   - id: the id of the ApiCall
    ///   - collectionName: the name of the collection of ApiCall
    func deleteApiCallById(_ id: String, collectionName: String) async throws {
        if let apiCallCollection = self._apiCallCollections[collectionName] {
            await apiCallCollection.deleteById(id)
        } else {
            throw StoreError.collectionNotRegistered(type: collectionName)
        }
    }

    /// Resets all the api call collections
    public func resetApiCalls() {
        Task {
            for collection in self._apiCallCollections.values {
                await collection.reset()
            }
        }
    }
    
    public func resetLoggingCollections() {
        
        Task {
            do {
                let logURL = try self.jsonFileURL(for: Log.self)
                try FileManager.default.removeItem(at: logURL)
                
                let facURL = try self.jsonFileURL(for: FailedAPICall.self)
                try FileManager.default.removeItem(at: facURL)

                let facApiCallCollection: ApiCallCollection<FailedAPICall> = try self.apiCallCollection()
                await facApiCallCollection.reset()
                let logApiCallCollection: ApiCallCollection<Log> = try self.apiCallCollection()
                await logApiCallCollection.reset()
            } catch {
                Logger.error(error)
            }
        }
    }
    
    /// Resets the ApiCall whose type identifies with the provided collection
    /// - Parameters:
    ///   - collection: The collection identifying the Storable type
    public func resetApiCalls<T: SyncedStorable>(type: T.Type) {
        do {
            let apiCallCollection: ApiCallCollection<T> = try self.apiCallCollection()
            Task {
                await apiCallCollection.reset()
            }
        } catch {
            Logger.error(error)
        }
    }
    
    // MARK: - Api call rescheduling

    /// Retry API calls immediately
    fileprivate func _resumeApiCalls() {
        guard self.forceNoSynchronization == false else {
            return
        }
//        Logger.log("_resumeApiCalls")
        Task {
            for collection in self._apiCallCollections.values {
                await collection.resumeApiCalls()
            }
        }
    }
    
    /// Reschedule an ApiCall by id
    func rescheduleApiCalls<T: SyncedStorable>(type: T.Type) async throws {
        guard self.forceNoSynchronization == false else {
            return
        }
        let collection: ApiCallCollection<T> = try self.apiCallCollection()
        await collection.rescheduleApiCallsIfNecessary()
    }

    /// Executes an ApiCall
//    fileprivate func _executeApiCall<T: SyncedStorable, V: Decodable>(_ apiCall: ApiCall<T>)
//        async throws -> V
//    {
//        return try await self.service().runApiCall(apiCall)
//    }

    /// Executes an API call
    func executeGet<T: SyncedStorable>(apiCall: ApiCall<T>) async throws -> Data {
        return try await self.service().runGetApiCall(apiCall)
    }

    /// Executes an API call
    public func execute<T: SyncedStorable>(apiCalls: [ApiCall<T>]) async throws -> [OperationResult<T>] {
        return try await self.service().runApiCalls(apiCalls)
    }

    // MARK: - Api calls

    /// Returns whether the collection can synchronize
    fileprivate func _canSynchronise() -> Bool {
        return !self.forceNoSynchronization
            && self.isAuthenticated
            && self.userIsAllowed()
    }

    func sendOperationBatch<T: SyncedStorable>(_ batch: OperationBatch<T>) async throws {
        guard self._canSynchronise() else {
            return
        }
        return try await self.apiCallCollection().executeBatch(batch)
    }
    
    func singleBatchExecution<T: SyncedStorable>(_ batch: OperationBatch<T>) async throws {
        return try await self.apiCallCollection().singleBatchExecution(batch)
    }
    
    /// Transmit the insertion request to the ApiCall collection
    /// - Parameters:
    ///   - instance: an object to insert
//    func sendInsertion<T: SyncedStorable>(_ instance: T) async throws -> T? {
//        guard self._canSynchronise() else {
//            return nil
//        }
//        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] {
        return try await self.service().get(identifier: identifier)
    }

    func itemsRetrieved<T: SyncedStorable>(_ results: [T], storeId: String?, clear: Bool) async {
        await self._store(id: storeId).loadCollectionItems(results, clear: clear)
    }
    
    /// Returns the names of all collections
    public func apiCollectionDescriptors() async -> [(String, any Storable.Type)] {
        var descriptors: [(String, any Storable.Type)] = []
        for collection in self._apiCallCollections.values {
            let name = await collection.resourceName()
            let type = await collection.type()
            descriptors.append((name, type))
        }
        return descriptors
    }
    
    // MARK: - Synchronization

    /// Creates the ApiCallCollection to manage the calls to the API
    fileprivate func _createSyncApiCallCollection() {
        self.loadApiCallCollection(type: GetSyncData.self)
    }
    
    /// Loads all the data from the server for the users
    public func initialSynchronization(clear: Bool) {
        self.mainStore.loadCollectionsFromServer(clear: clear)
        
        // request data that has been shared with the user
        if self.useSynchronization {
            Task {
                do {
                    try await self.service().getUserDataAccessContent()
                } catch {
                    Logger.error(error)
                }
            }
        }
        
    }

    /// Basically asks the server for new content
    public func synchronizeLastUpdates() async throws {
        
        guard self.isAuthenticated else {
            return
        }
        
        let lastSync = self._settingsStorage.item.lastSynchronization
        
        let syncGetCollection: ApiCallCollection<GetSyncData> = try self.apiCallCollection()
        if await syncGetCollection.hasPendingCalls() {
            await syncGetCollection.rescheduleImmediately()
        } else {
            let getSyncData = GetSyncData()
            getSyncData.date = lastSync
            try await syncGetCollection.sendGetRequest(instance: getSyncData)
        }
        
    }

    func testSynchronizeOnceAsync() async throws -> Data {
        guard self.isAuthenticated else {
            throw StoreError.missingToken
        }
        let lastSync = self._settingsStorage.item.lastSynchronization
        let syncGetCollection: ApiCallCollection<GetSyncData> = try self.apiCallCollection()
        
        let getSyncData = GetSyncData()
        getSyncData.date = lastSync
        return try await syncGetCollection.executeSingleGet(instance: getSyncData)
    }
    
    func sendGetRequest<T: SyncedStorable>(_ type: T.Type, storeId: String?, clear: Bool) async throws {
        guard self._canSynchronise(), self.canPerformGet(T.self) else {
            return
        }
        
        let apiCallCollection: ApiCallCollection<T> = try self.apiCallCollection()
        try await apiCallCollection.sendGetRequest(storeId: storeId, clear: clear)
    }
    
    func canPerformGet<T: SyncedStorable>(_ type: T.Type) -> Bool {
        return T.tokenExemptedMethods().contains(where: { $0 == .get }) || self.isAuthenticated
    }
    
    /// Processes Data Access data
    func userDataAccessRetrieved(_ data: Data) async {
        do {
            guard
                let json = try JSONSerialization.jsonObject(with: data, options: [])
                    as? [String: Any]
            else {
                let string = String(data: data, encoding: .utf8) ?? "--"
                Logger.w("data unrecognized: \(string)")
                return
            }
            
            let array = try self.decodeDictionary(json)
            await self._syncAddOrUpdate(array, shared: true)
        } catch {
            Logger.error(error)
        }
    }
    
    /// Processes the data coming from a sync request
    @MainActor func synchronizeContent(_ syncData: SyncData) async {

        self._syncAddOrUpdate(syncData.updates)
        await self._syncDelete(syncData.deletions)
        self._syncAddOrUpdate(syncData.grants, shared: true)
        await self.syncRevoke(syncData.revocations, parents: syncData.revocationParents)
//        self._syncAddOrUpdate(syncData.relationshipSets)
//        await self._syncDelete(syncData.relationshipRemovals)
        self._syncAddOrUpdate(syncData.sharedRelationshipSets, shared: true)
        self._syncRevoke(syncData.sharedRelationshipRemovals)

        Logger.log("sync content: updates = \(syncData.updates.count) / deletions = \(syncData.deletions.count), grants = \(syncData.grants.count)")
        
        if let dateString = syncData.date {
            Logger.log("Sets sync date = \(dateString)")
            self._settingsStorage.update { settings in
                settings.lastSynchronization = dateString
            }
        }

        NotificationCenter.default.post(
            name: NSNotification.Name.LeStorageDidSynchronize, object: self)

    }

    /// Processes data that should be inserted or updated inside the app
    /// - Parameters:
    ///   - updateArrays: the server updates
    ///   - shared: indicates if the content should be flagged as shared
    @MainActor func _syncAddOrUpdate(_ updateArrays: [SyncedStorableArray], shared: Bool = false) {
        
        for updateArray in updateArrays {
            for item in updateArray.items {
                let storeId: String? = item.getStoreId()
                self.synchronizationAddOrUpdate(item, storeId: storeId, shared: shared)
            }
        }
        
    }

    /// Processes data that should be deleted inside the app
    fileprivate func _syncDelete(_ deletionArrays: [ObjectIdentifierArray]) async {
        
        for deletionArray in deletionArrays {
            for deletedObject in deletionArray.items {
                await self.synchronizationDelete(id: deletedObject.modelId, type: deletionArray.type, storeId: deletedObject.storeId)
            }
        }

    }

    /// Processes data that has been revoked
    fileprivate func syncRevoke(_ revokedArrays: [ObjectIdentifierArray], parents: [[ObjectIdentifierArray]]) async {
        
        self._syncRevoke(revokedArrays)
        for revokedArray in revokedArrays {
            for revoked in revokedArray.items {
                await self.synchronizationDelete(id: revoked.modelId, type: revokedArray.type, storeId: revoked.storeId) // or synchronizationRevoke ?
            }
        }
        
        for level in parents {
            self._syncRevoke(level)
        }
    }
    
    fileprivate func _syncRevoke(_ revokeArrays: [ObjectIdentifierArray]) {
        
        for revokeArray in revokeArrays {
            for revoked in revokeArray.items {
                self.synchronizationRevoke(id: revoked.modelId, type: revokeArray.type, storeId: revoked.storeId)
            }
        }

    }
    
    /// Returns a Type object for a class name
    func classFromName(_ className: String) throws -> any SyncedStorable.Type {
        if let type = ClassLoader.getClass(className, classProject: self.classProject) {
            if let syncedType = type as? any SyncedStorable.Type {
                return syncedType
            } else {
                throw LeStorageError.cantFindClassFromName(name: className)
            }
        } else {
            throw LeStorageError.cantFindClassFromName(name: className)
        }
        
    }

    /// Returns the store corresponding to the provided id, and creates one if necessary
    fileprivate func _store(id: String?) -> Store {
        if let storeId = id {
            if let store = self._stores[storeId] {
                return store
            } else {
                let store = Store(storeCenter: self, identifier: storeId)
                self._registerStore(store: store)
                return store
            }
        } else {
            return self.mainStore
        }
    }

    /// Returns whether a data has already been deleted by, to avoid inserting it again
    fileprivate func _hasAlreadyBeenDeleted<T: Storable>(_ instance: T) -> Bool {
        return self._deleteLogs.contains(where: {
            $0.dataId == instance.stringId && $0.operation == .delete
        })
    }

    /// Adds or updates an instance into the store
    func synchronizationAddOrUpdate<T: SyncedStorable>(_ instance: T, storeId: String?, shared: Bool) {
        let hasAlreadyBeenDeleted: Bool = self._hasAlreadyBeenDeleted(instance)
        if !hasAlreadyBeenDeleted {
            DispatchQueue.main.async {
                self._store(id: storeId).addOrUpdateIfNewer(instance, shared: shared)
            }
        }
    }

    /// Deletes an instance with the given parameters
    @MainActor
    func synchronizationDelete<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) {
        do {
            try self._store(id: storeId).deleteNoSync(type: type, id: id)
        } catch {
            Logger.error(error)
        }
        self._cleanupDataLog(dataId: id)
    }
    
    /// Revokes a data that has been shared with the user
    func synchronizationRevoke<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) {
        
        DispatchQueue.main.async {
            do {
//                let type = try self.classFromName(model)
                if self._instanceShared(id: id, type: type) {
                    let count = self.mainStore.referenceCount(type: type, id: id)
                    if count == 0 {
                        try self._store(id: storeId).deleteNoSync(type: type, id: id)
                    }
                }
            } catch {
                Logger.error(error)
            }
        }
    }
    
    /// Returns whether an instance has been shared with the user
    fileprivate func _instanceShared<T: SyncedStorable>(id: String, type: T.Type) -> Bool {
        let realId: T.ID = T.buildRealId(id: id)
        let instance: T? = self.mainStore.findById(realId)
        return instance?.shared == true
    }

    /// Deletes a data log by data id
    fileprivate func _cleanupDataLog(dataId: String) {
        let logs = self._deleteLogs.filter { $0.dataId == dataId }
        self._deleteLogs.delete(contentOfs: logs)
    }

    /// Creates a delete log for an instance
    func createDeleteLog<T: Storable>(_ instance: T) {
        let dataLog = DataLog(dataId: instance.stringId,
                              modelName: String(describing: T.self),
                              operation: .delete)
        self._deleteLogs.addOrUpdate(instance: dataLog)
    }

    // MARK: - Sync data conversion
    
    func decodeObjectIdentifierDictionary(_ dictionary: [String: Any]) throws -> [ObjectIdentifierArray] {
        
        var objectIdentifierArray: [ObjectIdentifierArray] = []
        
        for (className, dataArray) in dictionary {
            
            guard let array = dataArray as? [[String: Any]] else {
                Logger.w("Invalid update data for \(className)")
                continue
            }
            let type = try self.classFromName(className)
            let decodedArray = try self._decodeArray(type: ObjectIdentifier.self, array: array)
            objectIdentifierArray.append(ObjectIdentifierArray(type: type, items: decodedArray))
        }
        return objectIdentifierArray
    }
    
    func decodeDictionary(_ dictionary: [String: Any]) throws -> [SyncedStorableArray] {
        
        var syncedStorableArray: [SyncedStorableArray] = []
        
        for (className, dataArray) in dictionary {
            
            guard let array = dataArray as? [[String: Any]] else {
                Logger.w("Invalid update data for \(className)")
                continue
            }
            Logger.log(">>> UPDATE \(array.count) \(className)")
            
            let type = try self.classFromName(className)
            let decodedArray = try self._decodeArray(type: type, array: array)
            syncedStorableArray.append(SyncedStorableArray(type: type, items: decodedArray))
        }
        return syncedStorableArray
    }
    
    fileprivate func _decodeArray<T: Decodable>(type: T.Type, array: [[String : Any]]) throws -> [T] {
        let jsonData = try JSONSerialization.data(withJSONObject: array, options: [])
        return try JSON.decoder.decode([T].self, from: jsonData)
    }
    
    // MARK: - Miscellanous

    /// Returns the count of api calls for a Type
    public func apiCallCount<T: SyncedStorable>(type: T.Type) async -> Int {
        do {
            let collection: ApiCallCollection<T> = try self.apiCallCollection()
            return await collection.items.count
        } catch {
            return -1
        }
    }

    /// Resets all registered collection
//    public func reset() {
//        Store.main.reset()
//        for store in self._stores.values {
//            store.reset()
//        }
//    }

    /// Returns whether any collection has pending API calls
    public func hasPendingAPICalls() async -> Bool {
        for collection in self._apiCallCollections.values {
            if await collection.hasPendingCalls() {
                return true
            }
        }
        return false
    }

    /// Returns the content of the api call file
    public func apiCallsFileContent(resourceName: String) async -> String {
        return await self._apiCallCollections[resourceName]?.contentOfFile() ?? ""
    }
    
    public func apiCalls<T: SyncedStorable>(type: T.Type) async -> [ApiCall<T>] {
        if let apiCallCollection: ApiCallCollection<T> = try? self.apiCallCollection() {
            return await apiCallCollection.apiCalls()
        }
        return []
    }

    /// This method triggers the framework to save and send failed api calls
    public func logsFailedAPICalls() {
        self._failedAPICallsCollection = self.mainStore.registerSynchronizedCollection(limit: 50)
    }

    /// If configured for, logs and send to the server a failed API call
    /// Logs a failed API call that has failed at least 5 times
    func logFailedAPICall(
        _ apiCallId: String, request: URLRequest, collectionName: String, error: String
    ) {

        guard let failedAPICallsCollection = self._failedAPICallsCollection,
            let collection = self._apiCallCollections[collectionName],
            collectionName != FailedAPICall.resourceName()
        else {
            return
        }

        Task {
            if let apiCall = await collection.findCallById(apiCallId) {

                if !failedAPICallsCollection.contains(where: { $0.callId == apiCallId })
                    && apiCall.attemptsCount > 6
                {

                    do {
                        let authValue = request.allHTTPHeaderFields?["Authorization"]
                        let string = try apiCall.jsonString()
                        let failedAPICall = FailedAPICall(
                            callId: apiCall.id, type: collectionName, apiCall: string, error: error,
                            authentication: authValue)

                        DispatchQueue.main.async {
                            failedAPICallsCollection.addOrUpdate(instance: failedAPICall)
                        }
                    } catch {
                        Logger.error(error)
                    }
                }
            }
        }

    }

    /// Logs a failed Api call with its request and error message
    func logFailedAPICall(request: URLRequest, error: String) {

        guard let failedAPICallsCollection = self._failedAPICallsCollection,
            let body: Data = request.httpBody,
            let bodyString = String(data: body, encoding: .utf8),
            let url = request.url?.absoluteString
        else {
            return
        }

        let authValue = request.allHTTPHeaderFields?["Authorization"]
        let failedAPICall = FailedAPICall(
            callId: request.hashValue.formatted(), type: url, apiCall: bodyString, error: error,
            authentication: authValue)
        failedAPICallsCollection.addOrUpdate(instance: failedAPICall)

    }

    /// Adds a userName to the black list
    /// Black listed username cannot send data to the server
    /// - Parameters:
    ///   - collection: The collection identifying the Storable type
    public func blackListUserName(_ userName: String) {
        self._blackListedUserName.append(userName)
    }

    /// Returns whether the current userName is allowed to sync with the server
    func userIsAllowed() -> Bool {
        guard let userName else { return true }
        return !self._blackListedUserName.contains(where: { $0 == userName })
    }

    /// Deletes the directory using its identifier
    /// - Parameters:
    ///   - identifier: The name of the directory
    public func destroyStore(identifier: String) {
        let directory = "\(self.directoryName)/\(identifier)"
        FileManager.default.deleteDirectoryInDocuments(directoryName: directory)
        self._stores.removeValue(forKey: identifier)
    }

    // MARK: - Instant update

    /// Updates a local object with a server instance
    func updateLocalInstances<T: SyncedStorable>(_ results: [T]) {
        for result in results {
            if let syncedCollection: SyncedCollection<T> = self.collectionOfInstance(result) as? SyncedCollection<T> {
                if syncedCollection.findById(result.id) != nil {
                    syncedCollection.updateFromServerInstance(result)
                }
            }
        }
    }
    
    /// Returns the collection hosting an instance
    func collectionOfInstance<T: Storable>(_ instance: T) -> BaseCollection<T>? {
        do {
            let collection: BaseCollection<T> = try self.mainStore.collection()
            if collection.findById(instance.id) != nil {
                return collection
            } else {
                return self.collectionOfInstanceInSubStores(instance)
            }
        } catch {
            return self.collectionOfInstanceInSubStores(instance)
        }
    }

    /// Search inside the additional stores to find the collection hosting the instance
    func collectionOfInstanceInSubStores<T: Storable>(_ instance: T) -> BaseCollection<T>? {
        for store in self._stores.values {
            let collection: BaseCollection<T>? = try? store.collection()
            if collection?.findById(instance.id) != nil {
                return collection
            }
        }
        return nil
    }

    // MARK: - Data Access
    
    /// Returns the list of users have access to a data given its id
    public func authorizedUsers(for modelId: String) -> [String] {
        guard let dataAccessCollection = self.dataAccessCollection else {
            return []
        }
        if let dataAccess = dataAccessCollection.first(where: { $0.modelId == modelId }) {
            return dataAccess.sharedWith
        }
        return []
    }
    
    public func setAuthorizedUsersAsync<T: SyncedStorable>(for instance: T, users: [String]) async throws {
        
        guard let dataAccessCollection = self.dataAccessCollection else {
            throw StoreError.synchronizationInactive
        }
        guard let userId = self.userId else {
            throw LeStorageError.cantCreateDataAccessBecauseUserIdIsNil
        }

        if let dataAccess = dataAccessCollection.first(where: { $0.modelId == instance.stringId }) {
            if users.isEmpty {
                try await dataAccessCollection.deleteAsync(instance: dataAccess)
            } else {
                dataAccess.sharedWith.removeAll()
                dataAccess.sharedWith = users
                try await dataAccessCollection.addOrUpdateAsync(instance: dataAccess)
            }
        } else {
            let dataAccess = DataAccess(owner: userId, sharedWith: users, modelName: String(describing: type(of: instance)), modelId: instance.stringId)
            try await dataAccessCollection.addOrUpdateAsync(instance: dataAccess)
        }

    }
    
    /// Sets the the list of authorized users for an instance
    public func setAuthorizedUsers<T: SyncedStorable>(for instance: T, users: [String]) throws {
        Task {
            do {
                try await self.setAuthorizedUsersAsync(for: instance, users: users)
            } catch {
                Logger.error(error)
            }
        }
    }

    // MARK: - Logs

    /// Returns the logs collection and instantiates it if necessary
    fileprivate func _logsCollection() -> SyncedCollection<Log> {
        if let logs = self._logs {
            return logs
        } else {
            let logsCollection: SyncedCollection<Log> = self.mainStore.registerSynchronizedCollection(limit: 50)
            self._logs = logsCollection
            return logsCollection
        }
    }

    /// Logs a message in the logs collection
    public func log(message: String) {
        DispatchQueue.main.async {
            let log = Log(message: message)
            self._logsCollection().addOrUpdate(instance: log)
        }
    }

    // MARK: - Migration

    /// Migrates the token from the provided service to the main Services instance
//    public func migrateToken(_ services: Services) throws {
//        guard let userName = self.userName() else {
//            return
//        }
//        try self.service().migrateToken(services, userName: userName)
//    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

}

class ObjectIdentifier: Codable {
    var modelId: String
    var storeId: String?
}