import Foundation
import ComposableArchitecture
import CasePaths

@Reducer
struct MainFeature {
    enum Tab: Int, Equatable, CaseIterable {
        case feed, other
    }
    
    @ObservableState
    struct State: Equatable {
        var selectedTab: Tab = .feed
        var feedList: FeedListFeature.State = .init()
        var me: MeFeature.State = .init()
        var accountModel: AccountModel? = nil
        // 新增：导航路径和设置页面 State
        var navigationPath: [Destination] = []
        var appSettingState: AppSettingFeature.State? = nil
        // 新增：登出标志
        var isLoggedOut: Bool = false
        
        init() {
            // 默认初始化
        }
    }
    
    // 新增：导航目标
    enum Destination: Hashable, Codable, CaseIterable {
        case appSetting
        case testView
    }
    
    @CasePathable
    enum Action: Equatable {
        case onAppear
        case selectTab(Tab)
        case feedList(FeedListFeature.Action)
        case me(MeFeature.Action)
        case accountModelLoaded(AccountModel?)
        // 新增：导航相关
        case navigationPathChanged([Destination])
        case appSettingButtonTapped
        case appSettingAction(AppSettingFeature.Action)
        // 新增：登出
        case logout
    }
    
    var body: some ReducerOf<Self> {
        Scope(state: \ .feedList, action: \ .feedList) {
            FeedListFeature()
        }
        Scope(state: \ .me, action: \ .me) {
            MeFeature()
        }
        Reduce { state, action in
            switch action {
            case .onAppear:
                return .run { send in
                    let accountModel = await UserInfoManager.getAccountModel()
                    await send(.accountModelLoaded(accountModel))
                }
            case .selectTab(let tab):
                state.selectedTab = tab
                state.navigationPath = []
                if tab == .other, let uidStr = state.accountModel?.uid, let uid = Int(uidStr), uid > 0 {
                    if state.me.uid != uid {
                        state.me.uid = uid
                        state.me.isFirstLoad = true // 仅当用户切换时才重置首次加载
                    }
                    return .send(.me(.onAppear))
                }
                return .none
            case .feedList(.testButtonTapped):
                state.navigationPath.append(.testView)
                return .none
            case .feedList(.createFeedPublishSuccess):
                // CreateFeed发布成功，刷新FeedList和Me页数据
                return .merge(
                    .send(.feedList(.reload)),
                    .send(.me(.refresh))
                )
            case .feedList:
                return .none
            case let .accountModelLoaded(accountModel):
                state.accountModel = accountModel
                // 如果当前选中的是 MeView 标签页，且有有效的 uid，则触发数据加载
                if state.selectedTab == .other, let uidStr = accountModel?.uid, let uid = Int(uidStr), uid > 0 {
                    if state.me.uid != uid {
                        state.me.uid = uid
                        state.me.isFirstLoad = true
                    }
                    return .send(.me(.onAppear))
                }
                return .none
            case .me(.settingButtonTapped):
                // 触发 push 到设置页，带入当前用户信息
                let userInfo = state.me.userInfo
                let avatarURL = userInfo?.avatar
                let nickname = userInfo?.nick ?? ""
                state.appSettingState = AppSettingFeature.State(nickname: nickname, avatarURL: avatarURL, userInfo: userInfo)
                state.navigationPath.append(.appSetting)
                return .none
            case .me:
                return .none
            case .navigationPathChanged(let newPath):
                // pop 回来时清空 settingState
                state.navigationPath = newPath
                return .none
            case .appSettingButtonTapped:
                let userInfo = state.me.userInfo
                let avatarURL = userInfo?.avatar
                let nickname = userInfo?.nick ?? ""
                state.appSettingState = AppSettingFeature.State(nickname: nickname, avatarURL: avatarURL, userInfo: userInfo)
                state.navigationPath.append(.appSetting)
                return .none
            case .appSettingAction(.logoutConfirmed):
                // 监听到确认登出，设置登出标志
                state.isLoggedOut = true
                return .none
            case .appSettingAction(.dismissTapped):
                // 监听到设置页的返回按钮，pop 导航栈
                if !state.navigationPath.isEmpty {
                    state.navigationPath.removeLast()
                }
                return .none
            case .appSettingAction(.updateUser(.success)):
                // 设置页用户信息变更成功，刷新Me页数据
                return .send(.me(.refresh))
            case .appSettingAction:
                return .none
            case .logout:
                // 由上层（SplashView/SplashFeature）监听，切换到登录页
                return .none
            }
        }
        // 设置页作用域
        .ifLet(\ .appSettingState, action: \ .appSettingAction) {
            AppSettingFeature()
        }
    }
}