//
//  GroupIMService.swift
//  QuickLocation
//
//  Created by 八条 on 2026/6/4.
//

import Foundation
import OpenIMSDK

final class GroupIMService {

    static let shared = GroupIMService()

    private var isInited = false
    private var isLogining = false
    /// 登录进行中时排队的回调，登录结束统一回调，避免并发重复登录
    private var pendingLoginCompletions: [(Bool) -> Void] = []

    private init() {}

    // MARK: - Init SDK
    func initSDK() {
        // 幂等：SDK 全局只初始化一次
        guard !isInited else { return }
        isInited = true
        let config = OIMInitConfig()
        config.apiAddr = URLManager.shared.openIM_API
        config.wsAddr = URLManager.shared.openIM_WS
        config.platform = .iPhone
        OIMManager.manager.initSDK(with: config,
                                   onConnecting: {},
                                   onConnectFailure: { _, _ in },
                                   onConnectSuccess: {},
                                   onKickedOffline: {},
                                   onUserTokenExpired: {},
                                   onUserTokenInvalid: { _ in })
    }

    // MARK: - Login
    /// 确保已登录（幂等）：已登录直接回调，否则发起登录；登录中则排队等待
    func ensureLogin(completion: @escaping (Bool) -> Void) {
        if OIMManager.manager.getLoginStatus() == .logged {
            completion(true)
            return
        }
        login(completion: completion)
    }

    func login(completion: @escaping (Bool) -> Void) {
        // 已登录，直接成功
        if OIMManager.manager.getLoginStatus() == .logged {
            completion(true)
            return
        }
        guard let token = AppContextManager.shared.imToken, !token.isEmpty else {
            completion(false)
            return
        }
        let userId = AppContextManager.shared.userId
        guard !userId.isEmpty else {
            completion(false)
            return
        }

        // 登录中：排队，复用同一次登录结果，避免重复发起
        pendingLoginCompletions.append(completion)
        guard !isLogining else { return }
        isLogining = true

        OIMManager.manager.login(userId, token: token) { [weak self] _ in
            self?.finishLogin(success: true)
        } onFailure: { [weak self] code, msg in
            print("OpenIM login failed: \(code) \(msg ?? "")")
            self?.finishLogin(success: false)
        }
    }

    private func finishLogin(success: Bool) {
        isLogining = false
        let callbacks = pendingLoginCompletions
        pendingLoginCompletions.removeAll()
        callbacks.forEach { $0(success) }
    }

    // MARK: - Logout
    func logout(completion: ((Bool) -> Void)? = nil) {
        OIMManager.manager.logoutWith(onSuccess: { (_: String?) in
            completion?(true)
        }, onFailure: { (code: Int, msg: String?) in
            print("OpenIM logout failed: \(code) \(msg ?? "")")
            completion?(false)
        })
    }

    // MARK: - Get Joined Groups
    func getJoinedGroups(completion: @escaping ([OIMGroupInfo]) -> Void) {
        OIMManager.manager.getJoinedGroupListWith(onSuccess: { groups in
            completion(groups ?? [])
        }, onFailure: { code, msg in
            print("GroupIMService: getJoinedGroups failed: \(code) \(msg ?? "")")
            completion([])
        })
    }

    // MARK: - Conversation List (for unread count & last msg time)
    func getConversationList(completion: @escaping ([OIMConversationInfo]) -> Void) {
        OIMManager.manager.getAllConversationListWith(onSuccess: { list in
            completion(list ?? [])
        }, onFailure: { code, msg in
            completion([])
        })
    }

    // MARK: - Conversation Listener
    private var conversationListener: ConversationListenerProxy?

    func setConversationListener(_ handler: @escaping ([OIMConversationInfo]) -> Void) {
        conversationListener = ConversationListenerProxy(handler: handler)
        OIMManager.callbacker.addConversationListener(listener: conversationListener!)
    }

    // MARK: - Group Listener
    private var groupListener: GroupListenerProxy?

    /// 监听群组变化（加群/退群/群信息变更），用于 SDK 同步到新群时刷新列表
    func setGroupListener(_ handler: @escaping () -> Void) {
        groupListener = GroupListenerProxy(handler: handler)
        OIMManager.callbacker.addGroupListener(listener: groupListener!)
    }
}

// MARK: - GroupListenerProxy
private class GroupListenerProxy: NSObject, OIMGroupListener {
    private let handler: () -> Void

    init(handler: @escaping () -> Void) {
        self.handler = handler
    }

    func onJoinedGroupAdded(_ groupInfo: OIMGroupInfo) {
        handler()
    }

    func onJoinedGroupDeleted(_ groupInfo: OIMGroupInfo) {
        handler()
    }

    func onGroupInfoChanged(_ changeInfo: OIMGroupInfo) {
        handler()
    }
}

// MARK: - ConversationListenerProxy
private class ConversationListenerProxy: NSObject, OIMConversationListener {
    private let handler: ([OIMConversationInfo]) -> Void

    init(handler: @escaping ([OIMConversationInfo]) -> Void) {
        self.handler = handler
    }

    func onConversationChanged(_ conversations: [OIMConversationInfo]) {
        handler(conversations)
    }

    func onNewConversation(_ conversations: [OIMConversationInfo]) {
        handler(conversations)
    }
}