//
//  LiveDetailViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 直播信息页，对齐 Android `AliveDetailsScreen`。
final class LiveDetailViewController: BaseViewController {
    private let viewModel: LiveDetailViewModel
    private let liveAPI: any LiveServing
    private let scrollView = UIScrollView()
    private let contentStack = UIStackView()
    private let coverImageView = LiveCoverImageView(cornerRadius: 0)
    private let infoCard = LiveInfoCardView()
    private let settingsCard = LiveSettingsCardView()
    private let bottomBar = UIView()
    private let controlButton = LiveActionButton(title: "开始", image: UIImage(systemName: "play.fill"))
    private let finishButton = LiveActionButton(title: "结束", image: UIImage(systemName: "stop.fill"))

    /// 初始化直播信息页。
    @MainActor
    init(liveId: Int, liveAPI: (any LiveServing)? = nil) {
        viewModel = LiveDetailViewModel(liveId: liveId)
        self.liveAPI = liveAPI ?? NetworkServices.shared.liveAPI
        super.init(nibName: nil, bundle: nil)
    }

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

    override func setupNavigationBar() {
        title = "直播信息"
    }

    override func setupUI() {
        view.backgroundColor = AppColor.pageBackground
        contentStack.axis = .vertical
        contentStack.spacing = 16
        scrollView.backgroundColor = AppColor.pageBackground
        bottomBar.backgroundColor = .white
        finishButton.buttonStyle = .danger

        view.addSubview(scrollView)
        scrollView.addSubview(contentStack)
        contentStack.addArrangedSubview(coverImageView)
        contentStack.addArrangedSubview(infoCard)
        contentStack.addArrangedSubview(settingsCard)
        view.addSubview(bottomBar)
        bottomBar.addSubview(controlButton)
        bottomBar.addSubview(finishButton)
    }

    override func setupConstraints() {
        bottomBar.snp.makeConstraints { make in
            make.leading.trailing.bottom.equalToSuperview()
        }
        controlButton.snp.makeConstraints { make in
            make.top.equalToSuperview().offset(16)
            make.leading.equalToSuperview().offset(16)
            make.height.equalTo(48)
            make.bottom.equalTo(view.safeAreaLayoutGuide).inset(16)
        }
        finishButton.snp.makeConstraints { make in
            make.leading.equalTo(controlButton.snp.trailing).offset(8)
            make.trailing.equalToSuperview().inset(16)
            make.top.bottom.width.equalTo(controlButton)
        }
        scrollView.snp.makeConstraints { make in
            make.top.leading.trailing.equalTo(view.safeAreaLayoutGuide)
            make.bottom.equalTo(bottomBar.snp.top)
        }
        contentStack.snp.makeConstraints { make in
            make.edges.equalToSuperview()
            make.width.equalTo(scrollView)
        }
        coverImageView.snp.makeConstraints { make in
            make.height.equalTo(coverImageView.snp.width).multipliedBy(9.0 / 16.0)
        }
        infoCard.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(16)
        }
        settingsCard.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(16)
        }
    }

    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) }
        }
        controlButton.addTarget(self, action: #selector(controlTapped), for: .touchUpInside)
        finishButton.addTarget(self, action: #selector(finishTapped), for: .touchUpInside)
        settingsCard.onCopy = { [weak self] text in
            UIPasteboard.general.string = text
            self?.showToast("已复制")
        }
        settingsCard.onModeSelected = { [weak self] mode in
            guard let self else { return }
            Task { await self.viewModel.changeMode(mode, api: self.liveAPI) }
        }
    }

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

    private func applyViewModel() {
        viewModel.isLoading && viewModel.item == nil ? showLoading() : hideLoading()
        guard let item = viewModel.item else { return }
        coverImageView.setURL(item.coverImg)
        infoCard.apply(item)
        settingsCard.apply(item: item, pushMode: viewModel.pushMode)
        controlButton.setTitle(item.controlTitle, for: .normal)
        controlButton.setImage(UIImage(systemName: item.liveStatus == .living ? "pause.fill" : "play.fill"), for: .normal)
        controlButton.buttonStyle = item.liveStatus == .living ? .warning : .primary
        controlButton.isEnabled = item.liveStatus.isOperable
        finishButton.isEnabled = item.liveStatus.isOperable
    }

    @objc private func controlTapped() {
        Task { await viewModel.controlLive(api: liveAPI) }
    }

    @objc private func finishTapped() {
        showAlert(title: "确认结束", message: "是否确认结束该直播？") { [weak self] in
            guard let self else { return }
            Task { await self.viewModel.finishLive(api: self.liveAPI) }
        }
    }
}

/// 直播信息卡片，显示时长和观众数。
private final class LiveInfoCardView: UIView {
    private let titleLabel = UILabel()
    private let durationRow = LiveIconTextRow(iconName: "clock", text: "")
    private let watchRow = LiveIconTextRow(iconName: "eye", text: "")

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

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

    /// 应用直播详情。
    func apply(_ item: LiveItem) {
        durationRow.text = "直播时长: \(LiveUIFormatter.duration(item.duration))"
        watchRow.text = "在线观众: \(item.viewsCount)"
    }

    private func setup() {
        backgroundColor = .white
        layer.cornerRadius = 12
        titleLabel.text = "直播信息"
        titleLabel.font = .systemFont(ofSize: 14, weight: .bold)
        titleLabel.textColor = AppColor.textPrimary
        addSubview(titleLabel)
        addSubview(durationRow)
        addSubview(watchRow)
        titleLabel.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview().inset(16)
        }
        durationRow.snp.makeConstraints { make in
            make.top.equalTo(titleLabel.snp.bottom).offset(6)
            make.leading.trailing.equalToSuperview().inset(16)
            make.height.equalTo(22)
        }
        watchRow.snp.makeConstraints { make in
            make.top.equalTo(durationRow.snp.bottom).offset(4)
            make.leading.trailing.bottom.equalToSuperview().inset(16)
            make.height.equalTo(22)
        }
    }
}

/// 直播推流设置卡片，显示推流地址和模式选择。
private final class LiveSettingsCardView: UIView {
    var onCopy: ((String) -> Void)?
    var onModeSelected: ((LivePushMode) -> Void)?

    private let titleLabel = UILabel()
    private let addressTitleLabel = UILabel()
    private let addressContainer = UIView()
    private let addressLabel = UILabel()
    private let copyButton = UIButton(type: .system)
    private let modeTitleLabel = UILabel()
    private let clarityButton = UIButton(type: .system)
    private let smoothButton = UIButton(type: .system)
    private var pushURL = ""

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

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

    /// 应用直播详情与当前推流模式。
    func apply(item: LiveItem, pushMode: LivePushMode) {
        pushURL = item.pushUrl
        addressLabel.text = item.pushUrl
        setMode(pushMode)
        clarityButton.isEnabled = item.liveStatus.isOperable
        smoothButton.isEnabled = item.liveStatus.isOperable
    }

    private func setup() {
        backgroundColor = .white
        layer.cornerRadius = 12
        titleLabel.text = "推流设置"
        titleLabel.font = .systemFont(ofSize: 14, weight: .bold)
        titleLabel.textColor = AppColor.textPrimary
        addressTitleLabel.text = "推流地址"
        addressTitleLabel.font = .systemFont(ofSize: 14)
        addressTitleLabel.textColor = UIColor(hex: 0x4B5563)
        addressContainer.backgroundColor = AppColor.inputBackground
        addressContainer.layer.borderWidth = 1
        addressContainer.layer.borderColor = AppColor.border.cgColor
        addressContainer.layer.cornerRadius = 4
        addressLabel.font = .systemFont(ofSize: 14)
        addressLabel.textColor = AppColor.textPrimary
        addressLabel.lineBreakMode = .byTruncatingMiddle
        copyButton.setTitle("复制", for: .normal)
        copyButton.titleLabel?.font = .systemFont(ofSize: 14)
        copyButton.backgroundColor = AppColor.primary
        copyButton.setTitleColor(.white, for: .normal)
        copyButton.layer.cornerRadius = 4
        modeTitleLabel.text = "直播模式"
        modeTitleLabel.font = .systemFont(ofSize: 14)
        modeTitleLabel.textColor = UIColor(hex: 0x4B5563)
        [clarityButton, smoothButton].forEach { button in
            button.titleLabel?.font = .systemFont(ofSize: 14)
            button.layer.cornerRadius = 4
            button.contentEdgeInsets = UIEdgeInsets(top: 5, left: 12, bottom: 5, right: 12)
        }
        clarityButton.setTitle(LivePushMode.clarityFirst.title, for: .normal)
        smoothButton.setTitle(LivePushMode.smoothFirst.title, for: .normal)

        addSubview(titleLabel)
        addSubview(addressTitleLabel)
        addSubview(addressContainer)
        addressContainer.addSubview(addressLabel)
        addSubview(copyButton)
        addSubview(modeTitleLabel)
        addSubview(clarityButton)
        addSubview(smoothButton)

        titleLabel.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview().inset(16)
        }
        addressTitleLabel.snp.makeConstraints { make in
            make.top.equalTo(titleLabel.snp.bottom).offset(8)
            make.leading.trailing.equalToSuperview().inset(16)
        }
        addressContainer.snp.makeConstraints { make in
            make.top.equalTo(addressTitleLabel.snp.bottom).offset(4)
            make.leading.equalToSuperview().offset(16)
            make.height.equalTo(28)
        }
        addressLabel.snp.makeConstraints { make in
            make.leading.trailing.equalToSuperview().inset(8)
            make.centerY.equalToSuperview()
        }
        copyButton.snp.makeConstraints { make in
            make.leading.equalTo(addressContainer.snp.trailing).offset(4)
            make.trailing.equalToSuperview().inset(16)
            make.top.bottom.equalTo(addressContainer)
            make.width.equalTo(52)
        }
        modeTitleLabel.snp.makeConstraints { make in
            make.top.equalTo(addressContainer.snp.bottom).offset(8)
            make.leading.equalToSuperview().offset(16)
            make.bottom.equalToSuperview().inset(16)
        }
        smoothButton.snp.makeConstraints { make in
            make.trailing.equalToSuperview().inset(16)
            make.centerY.equalTo(modeTitleLabel)
            make.height.equalTo(28)
        }
        clarityButton.snp.makeConstraints { make in
            make.trailing.equalTo(smoothButton.snp.leading).offset(-4)
            make.centerY.height.equalTo(smoothButton)
        }

        copyButton.addTarget(self, action: #selector(copyTapped), for: .touchUpInside)
        clarityButton.addTarget(self, action: #selector(clarityTapped), for: .touchUpInside)
        smoothButton.addTarget(self, action: #selector(smoothTapped), for: .touchUpInside)
    }

    private func setMode(_ mode: LivePushMode) {
        updateModeButton(clarityButton, selected: mode == .clarityFirst)
        updateModeButton(smoothButton, selected: mode == .smoothFirst)
    }

    private func updateModeButton(_ button: UIButton, selected: Bool) {
        button.backgroundColor = selected ? AppColor.primary : AppColor.inputBackground
        button.setTitleColor(selected ? .white : UIColor(hex: 0xB6BECA), for: .normal)
    }

    @objc private func copyTapped() {
        onCopy?(pushURL)
    }

    @objc private func clarityTapped() {
        onModeSelected?(.clarityFirst)
    }

    @objc private func smoothTapped() {
        onModeSelected?(.smoothFirst)
    }
}

/// 图标文字行，用于直播详情信息项。
private final class LiveIconTextRow: UIView {
    var text: String = "" {
        didSet { label.text = text }
    }

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

    /// 初始化图标文字行。
    init(iconName: String, text: String) {
        super.init(frame: .zero)
        iconView.image = UIImage(systemName: iconName)
        iconView.tintColor = AppColor.primary
        iconView.contentMode = .scaleAspectFit
        label.text = text
        label.font = .systemFont(ofSize: 14)
        label.textColor = UIColor(hex: 0x4B5563)
        addSubview(iconView)
        addSubview(label)
        iconView.snp.makeConstraints { make in
            make.leading.centerY.equalToSuperview()
            make.size.equalTo(16)
        }
        label.snp.makeConstraints { make in
            make.leading.equalTo(iconView.snp.trailing).offset(8)
            make.trailing.centerY.equalToSuperview()
        }
    }

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