//
//  PunchPointListViewController.swift
//  suixinkan
//

import Kingfisher
import SnapKit
import UIKit

/// 打卡点列表页，对齐 Android `PunchPointListScreen`。
final class PunchPointListViewController: BaseViewController {
    private let viewModel: PunchPointListViewModel
    private let api: any PunchPointAPIProtocol

    private let filterContainer = UIView()
    private let filterButton = UIButton(type: .system)
    private let filterTitleLabel = UILabel()
    private let filterChevronView = UIImageView(image: UIImage(systemName: "chevron.down"))
    private let filterDropdownView = UIView()
    private let filterDropdownStack = UIStackView()
    private let tableView = UITableView(frame: .zero, style: .plain)
    private let bottomBar = UIView()
    private let addButton = UIButton(type: .system)
    private let emptyView = PunchPointEmptyView()
    private var dataSource: UITableViewDiffableDataSource<Int, PunchPointItem>!
    private var filterButtons: [(PunchPointFilterType, UIButton)] = []
    private var needsRefreshOnAppear = false

    /// 初始化打卡点列表页。
    init(
        viewModel: PunchPointListViewModel = PunchPointListViewModel(),
        api: (any PunchPointAPIProtocol)? = nil
    ) {
        self.viewModel = viewModel
        self.api = api ?? NetworkServices.shared.punchPointAPI
        super.init(nibName: nil, bundle: nil)
    }

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

    override func setupNavigationBar() {
        title = "打卡点列表"
    }

    override func setupUI() {
        view.backgroundColor = AppColor.pageBackground

        filterContainer.backgroundColor = .white
        filterButton.backgroundColor = UIColor(hex: 0xF5F5F5)
        filterButton.layer.cornerRadius = 8
        filterTitleLabel.text = PunchPointFilterType.all.title
        filterTitleLabel.font = .systemFont(ofSize: 14)
        filterTitleLabel.textColor = AppColor.textPrimary
        filterChevronView.tintColor = AppColor.textSecondary
        filterChevronView.contentMode = .scaleAspectFit

        filterDropdownView.backgroundColor = .white
        filterDropdownView.layer.cornerRadius = 8
        filterDropdownView.layer.shadowColor = UIColor.black.cgColor
        filterDropdownView.layer.shadowOpacity = 0.12
        filterDropdownView.layer.shadowRadius = 10
        filterDropdownView.layer.shadowOffset = CGSize(width: 0, height: 4)
        filterDropdownView.isHidden = true
        filterDropdownStack.axis = .vertical

        tableView.backgroundColor = AppColor.pageBackground
        tableView.separatorStyle = .none
        tableView.delegate = self
        tableView.rowHeight = UITableView.automaticDimension
        tableView.estimatedRowHeight = 210
        tableView.contentInset = UIEdgeInsets(top: 12, left: 0, bottom: 12, right: 0)
        tableView.refreshControl = UIRefreshControl()
        tableView.register(PunchPointListCell.self, forCellReuseIdentifier: PunchPointListCell.reuseIdentifier)
        dataSource = UITableViewDiffableDataSource<Int, PunchPointItem>(tableView: tableView) { [weak self] tableView, indexPath, item in
            let cell = tableView.dequeueReusableCell(
                withIdentifier: PunchPointListCell.reuseIdentifier,
                for: indexPath
            ) as! PunchPointListCell
            cell.apply(item: item)
            cell.onQRCode = { [weak self] in self?.viewModel.showQRCode(for: item) }
            cell.onDelete = { [weak self] in self?.confirmDelete(item) }
            return cell
        }

        bottomBar.backgroundColor = .white
        addButton.setTitle("添加", for: .normal)
        addButton.setTitleColor(.white, for: .normal)
        addButton.titleLabel?.font = .systemFont(ofSize: 16, weight: .medium)
        addButton.backgroundColor = AppColor.primary
        addButton.layer.cornerRadius = 8

        emptyView.isHidden = true
        emptyView.onAction = { [weak self] in self?.addTapped() }

        view.addSubview(filterContainer)
        filterContainer.addSubview(filterButton)
        filterButton.addSubview(filterTitleLabel)
        filterButton.addSubview(filterChevronView)
        view.addSubview(tableView)
        view.addSubview(emptyView)
        view.addSubview(bottomBar)
        bottomBar.addSubview(addButton)
        view.addSubview(filterDropdownView)
        filterDropdownView.addSubview(filterDropdownStack)
        configureFilterDropdown()
    }

    override func setupConstraints() {
        filterContainer.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide)
            make.leading.trailing.equalToSuperview()
            make.height.equalTo(64)
        }
        filterButton.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(15)
            make.centerY.equalToSuperview()
            make.height.equalTo(48)
        }
        filterTitleLabel.snp.makeConstraints { make in
            make.leading.equalToSuperview().offset(12)
            make.centerY.equalToSuperview()
        }
        filterChevronView.snp.makeConstraints { make in
            make.trailing.equalToSuperview().inset(12)
            make.centerY.equalToSuperview()
            make.size.equalTo(22)
        }
        bottomBar.snp.makeConstraints { make in
            make.leading.trailing.bottom.equalToSuperview()
        }
        addButton.snp.makeConstraints { make in
            make.top.equalToSuperview().offset(16)
            make.leading.trailing.equalToSuperview().inset(15)
            make.height.equalTo(48)
            make.bottom.equalTo(view.safeAreaLayoutGuide).offset(-16)
        }
        tableView.snp.makeConstraints { make in
            make.top.equalTo(filterContainer.snp.bottom)
            make.leading.trailing.equalToSuperview()
            make.bottom.equalTo(bottomBar.snp.top)
        }
        emptyView.snp.makeConstraints { make in
            make.centerX.equalToSuperview()
            make.centerY.equalTo(tableView)
            make.leading.trailing.equalToSuperview().inset(24)
        }
        filterDropdownView.snp.makeConstraints { make in
            make.top.equalTo(filterButton.snp.bottom)
            make.leading.trailing.equalTo(filterButton)
        }
        filterDropdownStack.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
    }

    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) }
        }
        viewModel.onShowQRCode = { [weak self] url in
            Task { @MainActor in self?.showQRCodeDialog(url: url) }
        }
        tableView.refreshControl?.addTarget(self, action: #selector(refreshPulled), for: .valueChanged)
        filterButton.addTarget(self, action: #selector(filterTapped), for: .touchUpInside)
        addButton.addTarget(self, action: #selector(addTapped), for: .touchUpInside)
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        Task { await viewModel.loadInitial(api: api) }
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        if needsRefreshOnAppear {
            needsRefreshOnAppear = false
            Task { await viewModel.refresh(api: api) }
        }
    }

    @MainActor
    private func applyViewModel() {
        filterTitleLabel.text = viewModel.filterType.title
        filterButtons.forEach { type, button in
            let selected = type == viewModel.filterType
            button.setTitleColor(selected ? AppColor.primary : AppColor.textPrimary, for: .normal)
            button.titleLabel?.font = .systemFont(ofSize: 14, weight: selected ? .medium : .regular)
        }
        var snapshot = NSDiffableDataSourceSnapshot<Int, PunchPointItem>()
        snapshot.appendSections([0])
        snapshot.appendItems(viewModel.items)
        dataSource.apply(snapshot, animatingDifferences: true)
        tableView.refreshControl?.endRefreshing()
        emptyView.isHidden = !viewModel.items.isEmpty || viewModel.isLoading || viewModel.isRefreshing
        viewModel.isLoading && viewModel.items.isEmpty ? showLoading() : hideLoading()
    }

    private func configureFilterDropdown() {
        filterDropdownStack.arrangedSubviews.forEach { $0.removeFromSuperview() }
        filterButtons = PunchPointFilterType.allCases.map { type in
            let button = UIButton(type: .system)
            button.contentHorizontalAlignment = .left
            button.setTitle(type.title, for: .normal)
            button.titleLabel?.font = .systemFont(ofSize: 14)
            var configuration = UIButton.Configuration.plain()
            configuration.contentInsets = NSDirectionalEdgeInsets(top: 13, leading: 12, bottom: 13, trailing: 12)
            button.configuration = configuration
            button.addAction(UIAction { [weak self] _ in
                guard let self else { return }
                self.filterDropdownView.isHidden = true
                Task { await self.viewModel.selectFilter(type, api: self.api) }
            }, for: .touchUpInside)
            filterDropdownStack.addArrangedSubview(button)
            return (type, button)
        }
    }

    private func confirmDelete(_ item: PunchPointItem) {
        let alert = UIAlertController(
            title: "删除打卡点",
            message: "确定删除\(item.name)打卡点吗？",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))
        alert.addAction(UIAlertAction(title: "确定", style: .destructive) { [weak self] _ in
            guard let self else { return }
            Task { await self.viewModel.delete(item: item, api: self.api) }
        })
        present(alert, animated: true)
    }

    private func showQRCodeDialog(url: String) {
        let controller = UIAlertController(title: nil, message: "\n\n\n\n\n\n\n\n", preferredStyle: .alert)
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
        imageView.layer.cornerRadius = 12
        if let imageURL = URL(string: url) {
            imageView.kf.setImage(with: imageURL)
        }
        controller.view.addSubview(imageView)
        imageView.snp.makeConstraints { make in
            make.centerX.equalToSuperview()
            make.top.equalToSuperview().offset(52)
            make.size.equalTo(180)
        }
        controller.addAction(UIAlertAction(title: "确定", style: .default))
        present(controller, animated: true)
    }

    @objc private func filterTapped() {
        filterDropdownView.isHidden.toggle()
    }

    @objc private func refreshPulled() {
        Task { await viewModel.refresh(api: api) }
    }

    @objc private func addTapped() {
        let controller = PunchPointFormViewController(mode: .create)
        controller.onSubmitSuccess = { [weak self] in self?.needsRefreshOnAppear = true }
        navigationController?.pushViewController(controller, animated: true)
    }
}

extension PunchPointListViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        guard let item = dataSource.itemIdentifier(for: indexPath) else { return }
        let controller = PunchPointDetailViewController(punchPointId: item.id)
        controller.onChanged = { [weak self] in self?.needsRefreshOnAppear = true }
        navigationController?.pushViewController(controller, animated: true)
    }

    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
        Task { await viewModel.loadMoreIfNeeded(lastVisibleIndex: indexPath.row, api: api) }
    }
}

/// 打卡点列表卡片。
/// 打卡点列表卡片，复刻 Android 卡片中的封面、状态、负责人、时间、地址与操作区。
private final class PunchPointListCell: UITableViewCell {
    static let reuseIdentifier = "PunchPointListCell"

    private let cardView = UIView()
    private let coverImageView = UIImageView()
    private let nameLabel = UILabel()
    private let operatingTag = PunchPointStatusChip()
    private let creatorLabel = UILabel()
    private let createdAtLabel = UILabel()
    private let locationIcon = UIImageView(image: UIImage(systemName: "mappin.and.ellipse"))
    private let addressLabel = UILabel()
    private let reviewTag = PunchPointStatusChip()
    private let auditTimeLabel = UILabel()
    private let qrButton = UIButton(type: .system)
    private let deleteButton = UIButton(type: .system)

    var onQRCode: (() -> Void)?
    var onDelete: (() -> Void)?

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        backgroundColor = .clear
        contentView.backgroundColor = .clear
        selectionStyle = .none
        cardView.backgroundColor = .white
        cardView.layer.cornerRadius = 16
        cardView.clipsToBounds = true

        coverImageView.contentMode = .scaleAspectFill
        coverImageView.clipsToBounds = true
        coverImageView.layer.cornerRadius = 12
        coverImageView.backgroundColor = UIColor(hex: 0xF5F5F5)
        nameLabel.font = .systemFont(ofSize: 16, weight: .semibold)
        nameLabel.textColor = .black
        nameLabel.lineBreakMode = .byTruncatingTail
        [creatorLabel, createdAtLabel, auditTimeLabel].forEach {
            $0.font = .systemFont(ofSize: 12)
            $0.textColor = AppColor.textSecondary
        }
        locationIcon.tintColor = UIColor(hex: 0x4B5563)
        addressLabel.font = .systemFont(ofSize: 12)
        addressLabel.textColor = UIColor(hex: 0x4B5563)
        addressLabel.numberOfLines = 2
        qrButton.setImage(UIImage(systemName: "qrcode"), for: .normal)
        qrButton.tintColor = AppColor.textPrimary
        deleteButton.setImage(UIImage(systemName: "trash"), for: .normal)
        deleteButton.tintColor = AppColor.textPrimary

        contentView.addSubview(cardView)
        [coverImageView, nameLabel, operatingTag, creatorLabel, createdAtLabel, locationIcon, addressLabel, reviewTag, auditTimeLabel, qrButton, deleteButton].forEach(cardView.addSubview)

        cardView.snp.makeConstraints { make in
            make.top.bottom.equalToSuperview().inset(6)
            make.leading.trailing.equalToSuperview().inset(15)
        }
        coverImageView.snp.makeConstraints { make in
            make.top.leading.equalToSuperview().offset(16)
            make.size.equalTo(128)
        }
        nameLabel.snp.makeConstraints { make in
            make.top.equalTo(coverImageView)
            make.leading.equalTo(coverImageView.snp.trailing).offset(12)
            make.trailing.lessThanOrEqualTo(operatingTag.snp.leading).offset(-8)
        }
        operatingTag.snp.makeConstraints { make in
            make.centerY.equalTo(nameLabel)
            make.trailing.equalToSuperview().inset(16)
        }
        creatorLabel.snp.makeConstraints { make in
            make.top.equalTo(nameLabel.snp.bottom).offset(8)
            make.leading.equalTo(nameLabel)
            make.trailing.equalToSuperview().inset(16)
        }
        createdAtLabel.snp.makeConstraints { make in
            make.top.equalTo(creatorLabel.snp.bottom).offset(6)
            make.leading.trailing.equalTo(creatorLabel)
        }
        locationIcon.snp.makeConstraints { make in
            make.top.equalTo(createdAtLabel.snp.bottom).offset(8)
            make.leading.equalTo(nameLabel)
            make.size.equalTo(14)
        }
        addressLabel.snp.makeConstraints { make in
            make.top.equalTo(locationIcon).offset(-1)
            make.leading.equalTo(locationIcon.snp.trailing).offset(4)
            make.trailing.equalToSuperview().inset(16)
        }
        reviewTag.snp.makeConstraints { make in
            make.top.equalTo(coverImageView.snp.bottom).offset(14)
            make.leading.equalToSuperview().offset(16)
            make.bottom.equalToSuperview().inset(16)
        }
        auditTimeLabel.snp.makeConstraints { make in
            make.centerY.equalTo(reviewTag)
            make.leading.equalTo(reviewTag.snp.trailing).offset(8)
        }
        deleteButton.snp.makeConstraints { make in
            make.centerY.equalTo(reviewTag)
            make.trailing.equalToSuperview().inset(16)
            make.size.equalTo(32)
        }
        qrButton.snp.makeConstraints { make in
            make.centerY.equalTo(reviewTag)
            make.trailing.equalTo(deleteButton.snp.leading).offset(-4)
            make.size.equalTo(32)
        }

        qrButton.addTarget(self, action: #selector(qrTapped), for: .touchUpInside)
        deleteButton.addTarget(self, action: #selector(deleteTapped), for: .touchUpInside)
    }

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

    func apply(item: PunchPointItem) {
        nameLabel.text = item.name
        creatorLabel.text = "负责人:\(item.creator?.nonEmptyTrimmed ?? "--")"
        createdAtLabel.text = "创建时间:\(item.createdAt)"
        addressLabel.text = item.displayAddress.nonEmptyTrimmed ?? "--"
        auditTimeLabel.text = "审核时间：\(item.auditTime?.nonEmptyTrimmed ?? "--")"
        operatingTag.apply(text: item.statusLabel.nonEmptyTrimmed ?? "--", status: item.status)
        reviewTag.apply(text: item.statusLabel.nonEmptyTrimmed ?? "--", status: item.status)
        if let url = item.guideImages.first.flatMap(URL.init(string:)) {
            coverImageView.kf.setImage(with: url, placeholder: UIImage(systemName: "photo"))
        } else {
            coverImageView.image = UIImage(systemName: "photo")
        }
    }

    @objc private func qrTapped() {
        onQRCode?()
    }

    @objc private func deleteTapped() {
        onDelete?()
    }
}

/// 打卡点状态标签。
/// 打卡点状态标签视图。
final class PunchPointStatusChip: UIView {
    private let label = UILabel()

    override init(frame: CGRect) {
        super.init(frame: frame)
        layer.cornerRadius = 10
        clipsToBounds = true
        label.font = .systemFont(ofSize: 12, weight: .medium)
        label.textAlignment = .center
        addSubview(label)
        label.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(UIEdgeInsets(top: 3, left: 8, bottom: 3, right: 8))
        }
    }

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

    /// 应用标签文案和状态色。
    func apply(text: String, status: Int) {
        label.text = text
        let colors = PunchPointDisplayFormatter.statusColors(status)
        backgroundColor = UIColor(hex: colors.background)
        label.textColor = UIColor(hex: colors.text)
    }
}

/// 打卡点列表空状态。
/// 打卡点空列表视图，提供空状态文案与新增入口。
private final class PunchPointEmptyView: UIView {
    private let titleLabel = UILabel()
    private let button = UIButton(type: .system)
    var onAction: (() -> Void)?

    override init(frame: CGRect) {
        super.init(frame: frame)
        titleLabel.text = "暂无打卡点"
        titleLabel.font = .systemFont(ofSize: 15)
        titleLabel.textColor = AppColor.textSecondary
        titleLabel.textAlignment = .center
        button.setTitle("添加打卡点", for: .normal)
        button.setTitleColor(.white, for: .normal)
        button.titleLabel?.font = .systemFont(ofSize: 14, weight: .medium)
        button.backgroundColor = AppColor.primary
        button.layer.cornerRadius = 8
        addSubview(titleLabel)
        addSubview(button)
        titleLabel.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview()
        }
        button.snp.makeConstraints { make in
            make.top.equalTo(titleLabel.snp.bottom).offset(12)
            make.centerX.bottom.equalToSuperview()
            make.width.equalTo(128)
            make.height.equalTo(40)
        }
        button.addTarget(self, action: #selector(actionTapped), for: .touchUpInside)
    }

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

    @objc private func actionTapped() {
        onAction?()
    }
}

private extension String {
    var nonEmptyTrimmed: String? {
        let text = trimmingCharacters(in: .whitespacesAndNewlines)
        return text.isEmpty ? nil : text
    }
}