add cache

yobble/CoreData/ChatCacheWriter.swift

@@ -0,0 +1,233 @@
+import Foundation
+import CoreData
+
+final class ChatCacheWriter {
+    static let shared = ChatCacheWriter()
+
+    private let persistenceController: PersistenceController
+    private let userDefaults: UserDefaults
+    private let keychainService: KeychainService
+
+    init(
+        persistenceController: PersistenceController = .shared,
+        userDefaults: UserDefaults = .standard,
+        keychainService: KeychainService = .shared
+    ) {
+        self.persistenceController = persistenceController
+        self.userDefaults = userDefaults
+        self.keychainService = keychainService
+    }
+
+    func storePrivateChatList(_ data: PrivateChatListData) {
+        guard !AppConfig.DISABLE_DB else { return }
+        guard let accountUserId = resolveCurrentAccountUserId() else { return }
+
+        let context = persistenceController.newBackgroundContext()
+        context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
+
+        context.perform { [weak self] in
+            guard let self else { return }
+            do {
+                try self.sync(chatList: data, accountUserId: accountUserId, context: context)
+                if context.hasChanges {
+                    try context.save()
+                }
+            } catch {
+                if AppConfig.DEBUG {
+                    print("[ChatCacheWriter] Failed to store private chat list: \(error)")
+                }
+            }
+        }
+    }
+
+    private func resolveCurrentAccountUserId() -> String? {
+        guard let login = userDefaults.string(forKey: "currentUser") else {
+            return nil
+        }
+        return keychainService.get(forKey: "userId", service: login)
+    }
+
+    private func sync(chatList: PrivateChatListData, accountUserId: String, context: NSManagedObjectContext) throws {
+        var profileCache: [String: CDProfile] = [:]
+        var chatCache: [String: CDPrivateChat] = [:]
+        var messageCache: [String: CDMessage] = [:]
+
+        for item in chatList.items {
+            let chat = try upsertChat(item, accountUserId: accountUserId, context: context, cache: &chatCache)
+            let previousLastMessage = chat.lastMessage
+
+            if let profileData = item.chatData {
+                let profile = try upsertProfile(profileData, accountUserId: accountUserId, context: context, cache: &profileCache)
+                chat.chatData = profile
+            } else {
+                chat.chatData = nil
+            }
+
+            if let lastMessageData = item.lastMessage {
+                let message = try upsertMessage(
+                    lastMessageData,
+                    accountUserId: accountUserId,
+                    chat: chat,
+                    context: context,
+                    profileCache: &profileCache,
+                    messageCache: &messageCache
+                )
+                if let previous = previousLastMessage, previous.objectID != message.objectID {
+                    previous.chatAsLastMessage = nil
+                }
+                chat.lastMessage = message
+            } else {
+                previousLastMessage?.chatAsLastMessage = nil
+                chat.lastMessage = nil
+            }
+        }
+    }
+
+    private func upsertChat(
+        _ chatItem: PrivateChatListItem,
+        accountUserId: String,
+        context: NSManagedObjectContext,
+        cache: inout [String: CDPrivateChat]
+    ) throws -> CDPrivateChat {
+        if let cached = cache[chatItem.chatId] {
+            apply(chatItem: chatItem, to: cached, accountUserId: accountUserId)
+            return cached
+        }
+
+        let chat = try fetchChat(chatId: chatItem.chatId, accountUserId: accountUserId, context: context) ?? CDPrivateChat(context: context)
+        apply(chatItem: chatItem, to: chat, accountUserId: accountUserId)
+        cache[chatItem.chatId] = chat
+        return chat
+    }
+
+    private func apply(chatItem: PrivateChatListItem, to chat: CDPrivateChat, accountUserId: String) {
+        chat.accountUserId = accountUserId
+        chat.chatId = chatItem.chatId
+        chat.chatType = chatItem.chatType.rawValue
+        chat.createdAt = chatItem.createdAt
+        chat.unreadCount = Int32(chatItem.unreadCount)
+    }
+
+    private func upsertProfile(
+        _ profileData: ChatProfile,
+        accountUserId: String,
+        context: NSManagedObjectContext,
+        cache: inout [String: CDProfile]
+    ) throws -> CDProfile {
+        if let cached = cache[profileData.userId] {
+            apply(profile: profileData, to: cached, accountUserId: accountUserId)
+            return cached
+        }
+
+        let profile = try fetchProfile(userId: profileData.userId, accountUserId: accountUserId, context: context) ?? CDProfile(context: context)
+        apply(profile: profileData, to: profile, accountUserId: accountUserId)
+        cache[profileData.userId] = profile
+        return profile
+    }
+
+    private func apply(profile profileData: ChatProfile, to profile: CDProfile, accountUserId: String) {
+        profile.accountUserId = accountUserId
+        profile.userId = profileData.userId
+        profile.login = profileData.login
+        profile.fullName = profileData.fullName
+        profile.customName = profileData.customName
+        profile.bio = profileData.bio
+        if let lastSeen = profileData.lastSeen {
+            profile.setValue(NSNumber(value: lastSeen), forKey: "lastSeen")
+        } else {
+            profile.setValue(nil, forKey: "lastSeen")
+        }
+        profile.createdAt = profileData.createdAt
+        profile.isOfficial = profileData.isOfficial
+    }
+
+    private func upsertMessage(
+        _ messageData: MessageItem,
+        accountUserId: String,
+        chat: CDPrivateChat,
+        context: NSManagedObjectContext,
+        profileCache: inout [String: CDProfile],
+        messageCache: inout [String: CDMessage]
+    ) throws -> CDMessage {
+        if let cached = messageCache[messageData.messageId] {
+            apply(message: messageData, to: cached, accountUserId: accountUserId, chat: chat, context: context, profileCache: &profileCache)
+            return cached
+        }
+
+        let message = try fetchMessage(messageId: messageData.messageId, accountUserId: accountUserId, context: context) ?? CDMessage(context: context)
+        apply(message: messageData, to: message, accountUserId: accountUserId, chat: chat, context: context, profileCache: &profileCache)
+        messageCache[messageData.messageId] = message
+        return message
+    }
+
+    private func apply(
+        message messageData: MessageItem,
+        to message: CDMessage,
+        accountUserId: String,
+        chat: CDPrivateChat,
+        context: NSManagedObjectContext,
+        profileCache: inout [String: CDProfile]
+    ) {
+        message.accountUserId = accountUserId
+        message.messageId = messageData.messageId
+        message.chatId = messageData.chatId
+        message.messageType = messageData.messageType
+        message.content = messageData.content
+        message.mediaLink = messageData.mediaLink
+        message.createdAt = messageData.createdAt
+        message.updatedAt = messageData.updatedAt
+        message.senderId = messageData.senderId
+        message.chat = chat
+        message.chatAsLastMessage = chat
+
+        if let isViewed = messageData.isViewed {
+            message.setValue(NSNumber(value: isViewed), forKey: "isViewed")
+        } else {
+            message.setValue(nil, forKey: "isViewed")
+        }
+
+        if let forward = messageData.forwardMetadata {
+            message.forwardType = forward.forwardType
+            message.forwardSenderId = forward.forwardSenderId
+            message.forwardMessageId = forward.forwardMessageId
+        } else {
+            message.forwardType = nil
+            message.forwardSenderId = nil
+            message.forwardMessageId = nil
+        }
+
+        if let senderProfileData = messageData.senderData {
+            if let profile = try? upsertProfile(
+                senderProfileData,
+                accountUserId: accountUserId,
+                context: context,
+                cache: &profileCache
+            ) {
+                message.sender = profile
+            }
+        } else {
+            message.sender = nil
+        }
+    }
+
+    private func fetchChat(chatId: String, accountUserId: String, context: NSManagedObjectContext) throws -> CDPrivateChat? {
+        let request = NSFetchRequest<CDPrivateChat>(entityName: "CDPrivateChat")
+        request.fetchLimit = 1
+        request.predicate = NSPredicate(format: "accountUserId == %@ AND chatId == %@", accountUserId, chatId)
+        return try context.fetch(request).first
+    }
+
+    private func fetchProfile(userId: String, accountUserId: String, context: NSManagedObjectContext) throws -> CDProfile? {
+        let request = NSFetchRequest<CDProfile>(entityName: "CDProfile")
+        request.fetchLimit = 1
+        request.predicate = NSPredicate(format: "accountUserId == %@ AND userId == %@", accountUserId, userId)
+        return try context.fetch(request).first
+    }
+
+    private func fetchMessage(messageId: String, accountUserId: String, context: NSManagedObjectContext) throws -> CDMessage? {
+        let request = NSFetchRequest<CDMessage>(entityName: "CDMessage")
+        request.fetchLimit = 1
+        request.predicate = NSPredicate(format: "accountUserId == %@ AND messageId == %@", accountUserId, messageId)
+        return try context.fetch(request).first
+    }
+}

yobble/Network/ChatService.swift

@@ -19,12 +19,14 @@ enum ChatServiceError: LocalizedError {
 final class ChatService {
     private let client: NetworkClient
     private let decoder: JSONDecoder
+    private let cacheWriter: ChatCacheWriter
 
-    init(client: NetworkClient = .shared) {
+    init(client: NetworkClient = .shared, cacheWriter: ChatCacheWriter = .shared) {
         self.client = client
         self.decoder = JSONDecoder()
         self.decoder.keyDecodingStrategy = .convertFromSnakeCase
         self.decoder.dateDecodingStrategy = .custom(Self.decodeDate)
+        self.cacheWriter = cacheWriter
     }
 
     func fetchPrivateChats(
@@ -42,7 +44,7 @@ final class ChatService {
             method: .get,
             query: query,
             requiresAuth: true
-        ) { [decoder] result in
+        ) { [decoder, weak self] result in
             switch result {
             case .success(let response):
                 do {
@@ -52,7 +54,9 @@ final class ChatService {
                         completion(.failure(ChatServiceError.unexpectedStatus(message)))
                         return
                     }
-                    completion(.success(apiResponse.data))
+                    let chatData = apiResponse.data
+                    self?.cacheWriter.storePrivateChatList(chatData)
+                    completion(.success(chatData))
                 } catch {
                     let debugMessage = Self.describeDecodingError(error: error, data: response.data)
                     if AppConfig.DEBUG {