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

import SnapKit
import UIKit

/// 首页工作台，展示景区头部、工作状态、位置上报卡片和常用应用网格。
final class HomeViewController: UIViewController {

    private let viewModel = HomeViewModel()
    private let commonMenuStore = HomeCommonMenuStore()
    private var commonURIs: [String] = []
    private var isOnline = false
    private var reminderMinutes = 0
    private var secondsUntilReport = 0
    private var countdownTimer: Timer?

    private let minimalTopRoleIds: Set<Int> = [46, 47, 52, 53, 54]

    private lazy var scenicButton: UIButton = {
        var config = UIButton.Configuration.plain()
        config.baseForegroundColor = UIColor(hex: 0x333333)
        config.image = UIImage(systemName: "chevron.down")?.withConfiguration(
            UIImage.SymbolConfiguration(pointSize: AppMetrics.FontSize.subheadline, weight: .bold)
        )
        config.imagePlacement = .trailing
        config.imagePadding = AppMetrics.Spacing.xSmall
        config.contentInsets = .zero
        let button = UIButton(configuration: config)
        button.contentHorizontalAlignment = .leading
        button.addTarget(self, action: #selector(scenicTapped), for: .touchUpInside)
        return button
    }()

    private lazy var tableView: UITableView = {
        let table = UITableView(frame: .zero, style: .grouped)
        table.backgroundColor = AppDesignUIKit.pageBackground
        table.separatorStyle = .none
        table.showsVerticalScrollIndicator = false
        table.dataSource = self
        table.delegate = self
        table.register(HomeMenuGridCell.self, forCellReuseIdentifier: HomeMenuGridCell.reuseID)
        table.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
        return table
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = AppDesignUIKit.pageBackground
        setupTopBar()
        setupTableView()
        bindViewModel()
        rebuildMenus()
        observeContextChanges()
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.setNavigationBarHidden(true, animated: animated)
        startCountdownTimerIfNeeded()
    }

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

    private func setupTopBar() {
        let topBar = UIView()
        topBar.backgroundColor = .white
        view.addSubview(topBar)
        topBar.addSubview(scenicButton)

        topBar.snp.makeConstraints { make in
            make.top.leading.trailing.equalTo(view.safeAreaLayoutGuide)
            make.height.equalTo(78)
        }
        scenicButton.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(AppMetrics.Spacing.pageHorizontal)
            make.centerY.equalToSuperview()
        }
        updateScenicTitle()
    }

    private func setupTableView() {
        view.addSubview(tableView)
        tableView.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide).offset(78)
            make.leading.trailing.bottom.equalToSuperview()
        }
    }

    private func bindViewModel() {
        viewModel.onChange = { [weak self] in
            self?.tableView.reloadData()
        }
    }

    private func observeContextChanges() {
        let services = appServices
        services.permissionContext.onChange = { [weak self] in
            self?.rebuildMenus()
        }
        services.accountContext.onChange = { [weak self] in
            self?.updateScenicTitle()
            self?.tableView.reloadData()
        }
    }

    private func rebuildMenus() {
        let services = appServices
        viewModel.buildMenus(
            from: services.permissionContext.rolePermissions,
            currentRoleId: services.permissionContext.currentRole?.id
        )
        commonURIs = commonMenuStore.load(menuItems: viewModel.menuItems)
        tableView.reloadData()
    }

    private func updateScenicTitle() {
        let name = appServices.accountContext.currentScenic?.name ?? "请选择景区"
        scenicButton.configuration?.attributedTitle = AttributedString(
            name,
            attributes: AttributeContainer([
                .font: UIFont.systemFont(ofSize: AppMetrics.FontSize.title3, weight: .semibold)
            ])
        )
    }

    private var currentRoleId: Int? {
        appServices.permissionContext.currentRole?.id
    }

    private var shouldShowWorkStatus: Bool {
        guard let currentRoleId else { return true }
        return !minimalTopRoleIds.contains(currentRoleId)
    }

    private var isStoreManager: Bool {
        currentRoleId == 46
    }

    private var displayMenuItems: [HomeMenuItem] {
        let selected = commonURIs.compactMap { menuItem(for: $0) }
        let fallback = selected.isEmpty ? Array(viewModel.menuItems.prefix(3)) : selected
        return fallback + [HomeMenuItem(title: "更多功能", uri: "more_functions", iconSrc: nil)]
    }

    private func menuItem(for uri: String) -> HomeMenuItem? {
        let availableURIs = Set(viewModel.menuItems.map(\.uri))
        let resolvedUri = HomeMenuRouter.canonicalURI(for: uri, availableURIs: availableURIs)
        guard let existing = viewModel.menuItems.first(where: { $0.uri == resolvedUri }) else { return nil }
        return HomeMenuItem(
            title: HomeMenuRouter.displayTitle(for: resolvedUri, fallback: existing.title),
            uri: resolvedUri,
            iconSrc: existing.iconSrc
        )
    }

    private var countdownDisplay: String {
        let hours = secondsUntilReport / 3_600
        let minutes = (secondsUntilReport % 3_600) / 60
        let seconds = secondsUntilReport % 60
        return "\(hours):\(String(format: "%02d", minutes)):\(String(format: "%02d", seconds))"
    }

    private var reminderText: String {
        reminderMinutes == 0 ? "不提醒" : "提前\(reminderMinutes)分钟"
    }

    private func startCountdownTimerIfNeeded() {
        countdownTimer?.invalidate()
        guard isOnline else { return }
        countdownTimer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] _ in
            guard let self, self.isOnline, self.secondsUntilReport > 0 else { return }
            self.secondsUntilReport -= 1
            self.tableView.reloadSections(IndexSet(integer: 0), with: .none)
        }
    }

    @objc private func scenicTapped() {
        HomeMenuRouting.push(.scenicSelection, from: self)
    }

    @objc private func onlineTapped() {
        let message = isOnline
            ? "是否确认切换为离线状态？离线后将暂停位置上报。"
            : "是否确认切换为在线状态？在线后将开始位置上报和计时。"
        let alert = UIAlertController(title: "切换在线状态", message: message, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))
        alert.addAction(UIAlertAction(title: "确定", style: .default) { [weak self] _ in
            guard let self else { return }
            self.isOnline.toggle()
            if self.isOnline {
                self.secondsUntilReport = 7_200
                self.startCountdownTimerIfNeeded()
            } else {
                self.countdownTimer?.invalidate()
            }
            self.tableView.reloadSections(IndexSet(integer: 0), with: .none)
        })
        present(alert, animated: true)
    }

    @objc private func reminderTapped() {
        let sheet = UIAlertController(title: "提前提醒时间", message: nil, preferredStyle: .actionSheet)
        for minute in [0, 5, 10, 15, 30] {
            let title = minute == 0 ? "不提醒" : "\(minute)分钟"
            sheet.addAction(UIAlertAction(title: title, style: .default) { [weak self] _ in
                self?.reminderMinutes = minute
                self?.tableView.reloadSections(IndexSet(integer: 0), with: .none)
            })
        }
        sheet.addAction(UIAlertAction(title: "取消", style: .cancel))
        present(sheet, animated: true)
    }

    @objc private func locationReportTapped() {
        HomeMenuRouting.openRoute(HomeMenuRouter.resolve(uri: "location_report", title: "位置上报"), from: self)
    }

    @objc private func paymentTapped() {
        HomeMenuRouting.openRoute(HomeMenuRouter.resolve(uri: "payment_collection", title: "立即收款"), from: self)
    }

    @objc private func taskCreateTapped() {
        HomeMenuRouting.openRoute(HomeMenuRouter.resolve(uri: "task_create", title: "提交任务"), from: self)
    }
}

// MARK: - UITableView

extension HomeViewController: UITableViewDataSource, UITableViewDelegate {
    func numberOfSections(in tableView: UITableView) -> Int {
        var count = 1
        if shouldShowWorkStatus { count += 2 }
        if isStoreManager, appServices.accountContext.currentStore != nil { count += 1 }
        return count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        1
    }

    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        if section == tableView.numberOfSections - 1 {
            return "常用应用"
        }
        return nil
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if indexPath.section == tableView.numberOfSections - 1 {
            let cell = tableView.dequeueReusableCell(withIdentifier: HomeMenuGridCell.reuseID, for: indexPath) as! HomeMenuGridCell
            cell.configure(items: displayMenuItems) { [weak self] item in
                self.flatMap { HomeMenuRouting.openMenu(item, from: $0) }
            }
            return cell
        }

        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
        cell.selectionStyle = .none
        cell.contentView.subviews.forEach { $0.removeFromSuperview() }

        if shouldShowWorkStatus {
            if indexPath.section == 0 {
                cell.contentView.addSubview(makeStatusCard())
            } else if indexPath.section == 1 {
                cell.contentView.addSubview(makeLocationCard())
            } else if indexPath.section == 2, isStoreManager, let store = appServices.accountContext.currentStore {
                cell.contentView.addSubview(makeStoreCard(store))
            } else {
                cell.contentView.addSubview(makeQuickActionsRow())
            }
        } else if isStoreManager, let store = appServices.accountContext.currentStore, indexPath.section == 0 {
            cell.contentView.addSubview(makeStoreCard(store))
        }

        cell.contentView.subviews.first?.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(UIEdgeInsets(
                top: AppMetrics.Spacing.xxSmall,
                left: AppMetrics.Spacing.pageHorizontal,
                bottom: AppMetrics.Spacing.xxSmall,
                right: AppMetrics.Spacing.pageHorizontal
            ))
        }
        cell.backgroundColor = .clear
        return cell
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        if indexPath.section == tableView.numberOfSections - 1 { return 240 }
        if shouldShowWorkStatus {
            switch indexPath.section {
            case 0: return 100
            case 1: return 148
            case 2 where isStoreManager && appServices.accountContext.currentStore != nil: return 88
            default: return 118
            }
        }
        if isStoreManager, appServices.accountContext.currentStore != nil, indexPath.section == 0 { return 88 }
        return UITableView.automaticDimension
    }

    private func makeStatusCard() -> UIView {
        let card = makeCardView()

        let onlineButton = UIButton(type: .system)
        onlineButton.setTitle(isOnline ? "在线" : "离线", for: .normal)
        onlineButton.titleLabel?.font = .systemFont(ofSize: AppMetrics.FontSize.caption, weight: .medium)
        onlineButton.setTitleColor(isOnline ? UIColor(hex: 0xF0FDF4) : UIColor(hex: 0x7B8EAA), for: .normal)
        onlineButton.backgroundColor = isOnline ? UIColor(hex: 0x22C55E) : UIColor(hex: 0xF4F4F4)
        onlineButton.layer.cornerRadius = 4
        onlineButton.contentEdgeInsets = UIEdgeInsets(top: 6, left: 12, bottom: 6, right: 12)
        onlineButton.addTarget(self, action: #selector(onlineTapped), for: .touchUpInside)

        let clockLabel = UILabel()
        clockLabel.text = "  \(countdownDisplay)"
        clockLabel.font = .systemFont(ofSize: AppMetrics.FontSize.body, weight: .medium)
        clockLabel.textColor = AppDesignUIKit.primary

        let reminderButton = UIButton(type: .system)
        reminderButton.setTitle(" \(reminderText)", for: .normal)
        reminderButton.titleLabel?.font = .systemFont(ofSize: AppMetrics.FontSize.body, weight: .medium)
        reminderButton.setTitleColor(AppDesignUIKit.primary, for: .normal)
        reminderButton.addTarget(self, action: #selector(reminderTapped), for: .touchUpInside)

        let stack = UIStackView(arrangedSubviews: [onlineButton, clockLabel, reminderButton])
        stack.axis = .horizontal
        stack.distribution = .equalSpacing
        stack.alignment = .center
        card.addSubview(stack)
        stack.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(15)
        }
        return card
    }

    private func makeLocationCard() -> UIView {
        let card = makeCardView()

        let titleLabel = UILabel()
        titleLabel.text = "立即上报"
        titleLabel.font = .systemFont(ofSize: 22, weight: .bold)
        titleLabel.textColor = UIColor(hex: 0x333333)

        let subtitleLabel = UILabel()
        subtitleLabel.text = "您已进入打卡范围"
        subtitleLabel.font = .systemFont(ofSize: 15)
        subtitleLabel.textColor = UIColor(hex: 0x999999)

        let textStack = UIStackView(arrangedSubviews: [titleLabel, subtitleLabel])
        textStack.axis = .vertical
        textStack.spacing = AppMetrics.Spacing.xxSmall

        let actionButton = UIButton(type: .system)
        actionButton.setImage(UIImage(systemName: "hand.tap.fill"), for: .normal)
        actionButton.tintColor = .white
        actionButton.backgroundColor = AppDesignUIKit.primary
        actionButton.layer.cornerRadius = 46
        actionButton.addTarget(self, action: #selector(locationReportTapped), for: .touchUpInside)

        card.addSubview(textStack)
        card.addSubview(actionButton)
        textStack.snp.makeConstraints { make in
            make.leading.top.bottom.equalToSuperview().inset(15)
            make.trailing.lessThanOrEqualTo(actionButton.snp.leading).offset(-12)
        }
        actionButton.snp.makeConstraints { make in
            make.trailing.equalToSuperview().inset(15)
            make.centerY.equalToSuperview()
            make.width.height.equalTo(92)
        }
        return card
    }

    private func makeQuickActionsRow() -> UIView {
        let stack = UIStackView()
        stack.axis = .horizontal
        stack.spacing = AppMetrics.Spacing.small
        stack.distribution = .fillEqually

        stack.addArrangedSubview(quickActionButton(icon: "qrcode", title: "立即收款", action: #selector(paymentTapped)))
        stack.addArrangedSubview(quickActionButton(icon: "checklist.checked", title: "提交任务", action: #selector(taskCreateTapped)))
        stack.addArrangedSubview(quickActionButton(
            icon: isOnline ? "wifi" : "wifi.slash",
            title: isOnline ? "在线" : "离线",
            action: #selector(onlineTapped),
            active: isOnline
        ))
        return stack
    }

    private func quickActionButton(icon: String, title: String, action: Selector, active: Bool = false) -> UIView {
        let card = makeCardView()
        card.backgroundColor = active ? UIColor(hex: 0xE3F2FD) : .white

        let iconView = UIImageView(image: UIImage(systemName: icon))
        iconView.tintColor = AppDesignUIKit.primary
        iconView.contentMode = .scaleAspectFit

        let label = UILabel()
        label.text = title
        label.font = .systemFont(ofSize: AppMetrics.FontSize.body)
        label.textAlignment = .center

        let stack = UIStackView(arrangedSubviews: [iconView, label])
        stack.axis = .vertical
        stack.spacing = AppMetrics.Spacing.xSmall
        stack.alignment = .center
        card.addSubview(stack)
        stack.snp.makeConstraints { make in
            make.center.equalToSuperview()
        }
        iconView.snp.makeConstraints { make in
            make.height.equalTo(34)
        }

        let button = UIButton(type: .custom)
        button.addTarget(self, action: action, for: .touchUpInside)
        card.addSubview(button)
        button.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
        card.snp.makeConstraints { make in
            make.height.equalTo(102)
        }
        return card
    }

    private func makeStoreCard(_ store: BusinessScope) -> UIView {
        let card = makeCardView()

        let nameLabel = UILabel()
        nameLabel.text = store.name
        nameLabel.font = .systemFont(ofSize: AppMetrics.FontSize.title2, weight: .bold)

        let scenicLabel = UILabel()
        scenicLabel.text = appServices.accountContext.currentScenic?.name
        scenicLabel.font = .systemFont(ofSize: AppMetrics.FontSize.subheadline)
        scenicLabel.textColor = UIColor(hex: 0x7B8EAA)
        scenicLabel.numberOfLines = 2

        let statusLabel = UILabel()
        statusLabel.text = "营业中"
        statusLabel.font = .systemFont(ofSize: AppMetrics.FontSize.caption)
        statusLabel.textColor = UIColor(hex: 0x22C55E)
        statusLabel.backgroundColor = UIColor(hex: 0xF0FDF4)
        statusLabel.layer.cornerRadius = 4
        statusLabel.clipsToBounds = true
        statusLabel.textAlignment = .center

        let textStack = UIStackView(arrangedSubviews: [nameLabel, scenicLabel])
        textStack.axis = .vertical
        textStack.spacing = AppMetrics.Spacing.xSmall

        card.addSubview(textStack)
        card.addSubview(statusLabel)
        textStack.snp.makeConstraints { make in
            make.leading.top.bottom.equalToSuperview().inset(AppMetrics.Spacing.medium)
            make.trailing.lessThanOrEqualTo(statusLabel.snp.leading).offset(-8)
        }
        statusLabel.snp.makeConstraints { make in
            make.trailing.top.equalToSuperview().inset(AppMetrics.Spacing.medium)
            make.width.greaterThanOrEqualTo(52)
            make.height.equalTo(22)
        }
        return card
    }
}

// MARK: - Menu Grid Cell

private final class HomeMenuGridCell: UITableViewCell {
    static let reuseID = "HomeMenuGridCell"

    private var onSelect: ((HomeMenuItem) -> Void)?
    private var items: [HomeMenuItem] = []

    private lazy var collectionView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.minimumInteritemSpacing = 15
        layout.minimumLineSpacing = 15
        let view = UICollectionView(frame: .zero, collectionViewLayout: layout)
        view.backgroundColor = .clear
        view.isScrollEnabled = false
        view.dataSource = self
        view.delegate = self
        view.register(HomeMenuItemCell.self, forCellWithReuseIdentifier: HomeMenuItemCell.reuseID)
        return view
    }()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        backgroundColor = .clear
        selectionStyle = .none
        contentView.addSubview(collectionView)
        collectionView.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(AppMetrics.Spacing.pageHorizontal)
            make.height.equalTo(220)
        }
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func configure(items: [HomeMenuItem], onSelect: @escaping (HomeMenuItem) -> Void) {
        self.items = items
        self.onSelect = onSelect
        collectionView.reloadData()
    }
}

extension HomeMenuGridCell: UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        items.count
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: HomeMenuItemCell.reuseID, for: indexPath) as! HomeMenuItemCell
        cell.configure(item: items[indexPath.item])
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        onSelect?(items[indexPath.item])
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = (collectionView.bounds.width - 30) / 3
        return CGSize(width: width, height: 102)
    }
}

private final class HomeMenuItemCell: UICollectionViewCell {
    static let reuseID = "HomeMenuItemCell"

    private let iconView = UIImageView()
    private let titleLabel = UILabel()

    override init(frame: CGRect) {
        super.init(frame: frame)
        contentView.backgroundColor = .white
        contentView.layer.cornerRadius = 8

        titleLabel.font = .systemFont(ofSize: AppMetrics.FontSize.body)
        titleLabel.textColor = UIColor(hex: 0x4B5563)
        titleLabel.textAlignment = .center
        titleLabel.numberOfLines = 1
        titleLabel.adjustsFontSizeToFitWidth = true

        let stack = UIStackView(arrangedSubviews: [iconView, titleLabel])
        stack.axis = .vertical
        stack.spacing = AppMetrics.Spacing.small
        stack.alignment = .center
        contentView.addSubview(stack)
        stack.snp.makeConstraints { make in
            make.center.equalToSuperview()
            make.leading.trailing.equalToSuperview().inset(4)
        }
        iconView.snp.makeConstraints { make in
            make.width.height.equalTo(30)
        }
        iconView.contentMode = .scaleAspectFit
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func configure(item: HomeMenuItem) {
        titleLabel.text = item.title
        let symbol = UIImage(systemName: HomeIconCatalog.iconName(for: item.uri))
        iconView.loadRemoteImage(urlString: item.iconSrc, contentMode: .scaleAspectFit, placeholder: symbol)
        iconView.tintColor = AppDesign.primary
    }
}