//
//  HomeViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 首页 Tab 根页面，按身份与权限展示信息与入口。
final class HomeViewController: BaseViewController {

    private let viewModel = HomeViewModel()
    private let homeAPI = NetworkServices.shared.homeAPI

    private let scenicHeaderView = HomeScenicHeaderView()
    private let scrollView = UIScrollView()
    private let contentStack = UIStackView()
    private let workStatusCardView = HomeWorkStatusCardView()
    private let locationReportCardView = HomeLocationReportCardView()
    private let quickActionsView = HomeQuickActionsView()
    private let storeCardView = HomeStoreCardView()
    private let commonAppsGridView = HomeCommonAppsGridView()

    private var hasInitialized = false
    private var countdownTimer: Timer?
    private var activeDialog: HomeDialogKind?

    override func setupNavigationBar() {
        navigationController?.setNavigationBarHidden(true, animated: false)
    }

    override func setupUI() {
        view.backgroundColor = UIColor(hex: 0xF5F5F5)

        contentStack.axis = .vertical
        contentStack.spacing = 12

        scrollView.showsVerticalScrollIndicator = false
        view.addSubview(scenicHeaderView)
        view.addSubview(scrollView)
        scrollView.addSubview(contentStack)

        contentStack.addArrangedSubview(workStatusCardView)
        contentStack.addArrangedSubview(locationReportCardView)
        contentStack.addArrangedSubview(quickActionsView)
        contentStack.addArrangedSubview(storeCardView)
        contentStack.addArrangedSubview(commonAppsGridView)
    }

    override func setupConstraints() {
        scenicHeaderView.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide)
            make.leading.trailing.equalToSuperview()
            make.height.equalTo(52)
        }
        scrollView.snp.makeConstraints { make in
            make.top.equalTo(scenicHeaderView.snp.bottom)
            make.leading.trailing.bottom.equalToSuperview()
        }
        contentStack.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(16)
            make.width.equalTo(scrollView.snp.width).offset(-32)
        }
    }

    override func bindActions() {
        viewModel.onStateChange = { [weak self] in
            Task { @MainActor in self?.applyViewModel() }
        }
        viewModel.onShowMessage = { [weak self] message in
            Task { @MainActor in self?.showToast(message) }
        }

        scenicHeaderView.onTap = { [weak self] in self?.presentScenicSelection() }
        workStatusCardView.onOnlineTap = { [weak self] in self?.viewModel.showOnlineStatusSwitchDialog() }
        workStatusCardView.onReminderTap = { [weak self] in self?.presentReminderPicker() }
        locationReportCardView.onReportTap = { [weak self] in
            Task { await self?.viewModel.manualReportLocation(api: self?.homeAPI ?? NetworkServices.shared.homeAPI) }
        }
        quickActionsView.onCollectPayment = { [weak self] in self?.showToast("功能开发中") }
        quickActionsView.onSubmitTask = { [weak self] in self?.showToast("功能开发中") }
        quickActionsView.onToggleOnline = { [weak self] in self?.viewModel.showOnlineStatusSwitchDialog() }
        commonAppsGridView.onMenuSelected = { [weak self] menu in
            guard let self else { return }
            HomeRouteHandler.open(uri: menu.uri, from: self, storeItem: self.viewModel.storeItem)
        }

        NotificationCenter.default.addObserver(
            self,
            selector: #selector(handleAccountDidSwitch),
            name: NotificationName.accountDidSwitch,
            object: nil
        )
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(handleScenicDidChange),
            name: NotificationName.scenicDidChange,
            object: nil
        )
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        if !hasInitialized {
            hasInitialized = true
            Task { await initializeHome() }
        } else {
            Task { await viewModel.reloadIfNeeded(api: homeAPI) }
        }
        startCountdownTimer()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        countdownTimer?.invalidate()
        countdownTimer = nil
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    private func initializeHome() async {
        showLoading()
        defer { hideLoading() }
        await viewModel.initialize(api: homeAPI)
        applyViewModel()
        await evaluateDialogsWithDelay()
        await viewModel.refreshLocationInfo()
        applyViewModel()
    }

    private func evaluateDialogsWithDelay() async {
        try? await Task.sleep(nanoseconds: 100_000_000)
        await viewModel.evaluateDialogs(api: homeAPI)
        applyViewModel()
        presentDialogsIfNeeded()
    }

    @MainActor
    private func applyViewModel() {
        scenicHeaderView.apply(scenicName: viewModel.currentScenicName)
        let showWorkBlock = !viewModel.isMinimalTopRole
        workStatusCardView.isHidden = !showWorkBlock
        locationReportCardView.isHidden = !showWorkBlock
        quickActionsView.isHidden = !showWorkBlock

        if showWorkBlock {
            workStatusCardView.apply(
                isOnline: viewModel.isOnline,
                countdownText: viewModel.countdownDisplayText,
                reminderMinutes: viewModel.reminderMinutes
            )
            locationReportCardView.apply(
                address: viewModel.locationInfoText,
                isReporting: viewModel.isLocationReporting
            )
            quickActionsView.apply(isOnline: viewModel.isOnline)
        }

        let showStore = viewModel.currentAppRole == .storeAdmin && viewModel.storeItem != nil
        storeCardView.isHidden = !showStore
        if showStore, let store = viewModel.storeItem {
            storeCardView.apply(store: store)
        }

        commonAppsGridView.apply(menus: viewModel.commonMenus)
        presentDialogsIfNeeded()
    }

    private func presentDialogsIfNeeded() {
        if viewModel.showPermissionDialog {
            presentDialog(.permission)
            return
        }
        if viewModel.showScenicDialog {
            presentDialog(.scenic)
            return
        }
        if viewModel.showOnlineStatusDialog {
            presentDialog(.onlineStatus)
            return
        }
        if viewModel.showLocationTimeoutDialog {
            presentDialog(.locationTimeout)
            return
        }
        if viewModel.showLocationReportSuccessDialog {
            presentDialog(.locationSuccess)
            return
        }
        activeDialog = nil
    }

    private enum HomeDialogKind {
        case permission
        case scenic
        case onlineStatus
        case locationTimeout
        case locationSuccess
    }

    private func presentDialog(_ kind: HomeDialogKind) {
        guard activeDialog != kind, presentedViewController == nil else { return }
        activeDialog = kind
        switch kind {
        case .permission: presentPermissionDialog()
        case .scenic: presentScenicDialog()
        case .onlineStatus: presentOnlineStatusDialog()
        case .locationTimeout: presentLocationTimeoutDialog()
        case .locationSuccess: presentLocationSuccessDialog()
        }
    }

    private func presentPermissionDialog() {
        let alert = UIAlertController(
            title: "权限提示",
            message: "您还没有权限，请先申请权限",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "取消", style: .cancel) { [weak self] _ in
            self?.viewModel.hidePermissionDialog()
            self?.activeDialog = nil
        })
        alert.addAction(UIAlertAction(title: "去申请", style: .default) { [weak self] _ in
            self?.showToast("功能开发中")
            self?.activeDialog = nil
        })
        present(alert, animated: true)
    }

    private func presentScenicDialog() {
        let alert = UIAlertController(
            title: "请选择景区",
            message: "使用首页功能前需要先选择当前景区",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "稍后", style: .cancel) { [weak self] _ in
            self?.viewModel.hideScenicDialog()
            self?.activeDialog = nil
        })
        alert.addAction(UIAlertAction(title: "去选择", style: .default) { [weak self] _ in
            self?.viewModel.hideScenicDialog()
            self?.activeDialog = nil
            self?.presentScenicSelection()
        })
        present(alert, animated: true)
    }

    private func presentOnlineStatusDialog() {
        let goingOnline = !viewModel.isOnline
        let alert = UIAlertController(
            title: goingOnline ? "切换在线" : "切换离线",
            message: goingOnline ? "确认切换到在线状态并上报位置？" : "确认切换到离线状态？",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "取消", style: .cancel) { [weak self] _ in
            self?.viewModel.hideOnlineStatusSwitchDialog()
            self?.activeDialog = nil
        })
        alert.addAction(UIAlertAction(title: "确定", style: .default) { [weak self] _ in
            guard let self else { return }
            self.activeDialog = nil
            Task { await self.viewModel.switchOnlineStatus(api: self.homeAPI) }
        })
        present(alert, animated: true)
    }

    private func presentLocationTimeoutDialog() {
        let alert = UIAlertController(
            title: "位置上报提醒",
            message: "您的位置上报即将超时，请立即上报",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "稍后", style: .cancel) { [weak self] _ in
            self?.viewModel.hideLocationTimeoutDialog()
            self?.activeDialog = nil
        })
        alert.addAction(UIAlertAction(title: "立即上报", style: .default) { [weak self] _ in
            guard let self else { return }
            self.activeDialog = nil
            Task { await self.viewModel.confirmLocationTimeoutReport(api: self.homeAPI) }
        })
        present(alert, animated: true)
    }

    private func presentLocationSuccessDialog() {
        let alert = UIAlertController(
            title: "上报成功",
            message: "上报时间：\(viewModel.reportTimeText)",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "确定", style: .default) { [weak self] _ in
            self?.viewModel.hideLocationReportSuccessDialog()
            self?.activeDialog = nil
        })
        present(alert, animated: true)
    }

    private func presentReminderPicker() {
        let alert = UIAlertController(title: "提前提醒", message: "选择位置超时提前提醒时间", preferredStyle: .actionSheet)
        [0, 5, 10, 15, 30].forEach { minutes in
            let title = minutes == 0 ? "不提醒" : "提前\(minutes)分钟"
            alert.addAction(UIAlertAction(title: title, style: .default) { [weak self] _ in
                self?.viewModel.updateReminderMinutes(minutes)
            })
        }
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))
        present(alert, animated: true)
    }

    private func presentScenicSelection() {
        let scenicList = AppStore.shared.roleScenicList()
        guard !scenicList.isEmpty else {
            showToast("暂无可选景区")
            return
        }
        let controller = ScenicSelectionViewController(scenicList: scenicList)
        controller.onSelected = { [weak self] in
            guard let self else { return }
            Task {
                await self.viewModel.reloadIfNeeded(api: self.homeAPI)
                await self.viewModel.loadStoreListIfNeeded(api: self.homeAPI)
                self.applyViewModel()
                await self.evaluateDialogsWithDelay()
            }
        }
        let nav = UINavigationController(rootViewController: controller)
        nav.modalPresentationStyle = .pageSheet
        present(nav, animated: true)
    }

    private func startCountdownTimer() {
        countdownTimer?.invalidate()
        countdownTimer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] _ in
            guard let self else { return }
            self.viewModel.triggerLocationTimeoutIfNeeded()
            if !self.viewModel.isMinimalTopRole {
                self.workStatusCardView.apply(
                    isOnline: self.viewModel.isOnline,
                    countdownText: self.viewModel.countdownDisplayText,
                    reminderMinutes: self.viewModel.reminderMinutes
                )
            }
        }
    }

    @objc private func handleAccountDidSwitch() {
        viewModel.markNeedsPermissionReload()
        Task {
            await viewModel.reloadIfNeeded(api: homeAPI)
            applyViewModel()
            await evaluateDialogsWithDelay()
        }
    }

    @objc private func handleScenicDidChange() {
        viewModel.refreshLocalDisplayState()
        Task {
            await viewModel.loadStoreListIfNeeded(api: homeAPI)
            applyViewModel()
        }
    }
}