//
//  VersionUpgradePopVC.swift
//  QuickLocation
//

import UIKit

final class VersionUpgradePopVC: UIViewController {

    var completion: (() -> Void)?
    var dismissHandler: ((VersionUpgradePopVC, @escaping () -> Void) -> Void)?

    private let upgrade: VersionUpgradeModel
    private var isOpeningURL = false
    private var hasFinished = false
    private var contentTextViewHeightConstraint: NSLayoutConstraint?

    init(upgrade: VersionUpgradeModel) {
        self.upgrade = upgrade
        super.init(nibName: nil, bundle: nil)
        modalPresentationStyle = .overFullScreen
        modalTransitionStyle = .crossDissolve
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
        configureContent()
    }

    func showAnimated() {
        view.layoutIfNeeded()
        dimmingView.alpha = 0
        popupContainerView.alpha = 0
        popupContainerView.transform = CGAffineTransform(scaleX: 0.94, y: 0.94)
        UIView.animate(withDuration: 0.25, delay: 0, options: [.curveEaseOut]) {
            self.dimmingView.alpha = 1
            self.popupContainerView.alpha = 1
            self.popupContainerView.transform = .identity
        }
    }

    private func setupUI() {
        view.backgroundColor = .clear

        view.addSubview(dimmingView)
        dimmingView.translatesAutoresizingMaskIntoConstraints = false

        if !upgrade.force {
            dimmingView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(cancelUpgrade)))
        }

        view.addSubview(popupContainerView)
        popupContainerView.addSubview(cardView)
        popupContainerView.addSubview(headerImageView)
        popupContainerView.addSubview(cancelButton)
        cardView.addSubview(contentTextView)
        cardView.addSubview(upgradeButton)

        [popupContainerView, cardView, headerImageView, cancelButton, contentTextView, upgradeButton].forEach {
            $0.translatesAutoresizingMaskIntoConstraints = false
        }

        let contentTextViewHeightConstraint = contentTextView.heightAnchor.constraint(equalToConstant: 96)
        self.contentTextViewHeightConstraint = contentTextViewHeightConstraint

        NSLayoutConstraint.activate([
            dimmingView.topAnchor.constraint(equalTo: view.topAnchor),
            dimmingView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            dimmingView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            dimmingView.bottomAnchor.constraint(equalTo: view.bottomAnchor),

            popupContainerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            popupContainerView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            popupContainerView.widthAnchor.constraint(equalToConstant: 325),
            popupContainerView.leadingAnchor.constraint(greaterThanOrEqualTo: view.leadingAnchor, constant: 20),
            popupContainerView.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor, constant: -20),

            headerImageView.topAnchor.constraint(equalTo: popupContainerView.topAnchor),
            headerImageView.leadingAnchor.constraint(equalTo: cardView.leadingAnchor),
            headerImageView.widthAnchor.constraint(equalTo: cardView.widthAnchor, constant: 10),
            headerImageView.heightAnchor.constraint(equalTo: headerImageView.widthAnchor, multiplier: 132 / 325),

            cardView.topAnchor.constraint(equalTo: popupContainerView.topAnchor, constant: 88),
            cardView.centerXAnchor.constraint(equalTo: popupContainerView.centerXAnchor),
            cardView.widthAnchor.constraint(equalToConstant: 315),

            contentTextView.topAnchor.constraint(equalTo: cardView.topAnchor, constant: 40),
            contentTextView.leadingAnchor.constraint(equalTo: cardView.leadingAnchor, constant: 20),
            contentTextView.trailingAnchor.constraint(equalTo: cardView.trailingAnchor, constant: -20),
            contentTextViewHeightConstraint,

            upgradeButton.topAnchor.constraint(equalTo: contentTextView.bottomAnchor, constant: 28),
            upgradeButton.leadingAnchor.constraint(equalTo: contentTextView.leadingAnchor),
            upgradeButton.trailingAnchor.constraint(equalTo: contentTextView.trailingAnchor),
            upgradeButton.heightAnchor.constraint(equalToConstant: 50),
            upgradeButton.bottomAnchor.constraint(equalTo: cardView.bottomAnchor, constant: -20),

            cancelButton.topAnchor.constraint(equalTo: cardView.bottomAnchor, constant: 14),
            cancelButton.centerXAnchor.constraint(equalTo: popupContainerView.centerXAnchor),
            cancelButton.heightAnchor.constraint(equalToConstant: 28),
            cancelButton.widthAnchor.constraint(greaterThanOrEqualToConstant: 80),
            cancelButton.bottomAnchor.constraint(equalTo: popupContainerView.bottomAnchor)
        ])
    }

    private func configureContent() {
        cancelButton.isHidden = upgrade.force

        let title = upgrade.title + upgrade.version
        let description = upgrade.description
        let content = NSMutableAttributedString()

        if !title.isEmpty {
            let paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.lineSpacing = 3
            content.append(NSAttributedString(
                string: title,
                attributes: [
                    .font: UIFont.systemFont(ofSize: 15, weight: .medium),
                    .foregroundColor: UIColor(hexStr: "#273246"),
                    .paragraphStyle: paragraphStyle
                ]
            ))
        }

        if !description.isEmpty {
            if !content.string.isEmpty {
                content.append(NSAttributedString(string: "\n"))
            }
            let paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.lineSpacing = 5
            content.append(NSAttributedString(
                string: description,
                attributes: [
                    .font: UIFont.systemFont(ofSize: 15, weight: .regular),
                    .foregroundColor: UIColor(hexStr: "#273246"),
                    .paragraphStyle: paragraphStyle
                ]
            ))
        }

        contentTextView.attributedText = content
        contentTextView.setContentOffset(.zero, animated: false)
        let fittingSize = contentTextView.sizeThatFits(
            CGSize(width: 275, height: CGFloat.greatestFiniteMagnitude)
        )
        contentTextViewHeightConstraint?.constant = max(96, ceil(fittingSize.height))
    }

    @objc private func openUpgradeURL() {
        guard !isOpeningURL else { return }
        let urlString = upgrade.url.trimmingCharacters(in: .whitespacesAndNewlines)
        guard let url = URL(string: urlString),
              let scheme = url.scheme,
              !scheme.isEmpty else {
            DLToast.show(text: "下载地址不可用")
            return
        }

        isOpeningURL = true
        UIApplication.shared.open(url, options: [:]) { [weak self] opened in
            DispatchQueue.main.async {
                guard let self else { return }
                self.isOpeningURL = false
                guard opened else {
                    DLToast.show(text: "下载地址不可用")
                    return
                }
                if !self.upgrade.force {
                    self.finishUpgrade()
                }
            }
        }
    }

    @objc private func cancelUpgrade() {
        guard !upgrade.force else { return }
        finishUpgrade()
    }

    private func finishUpgrade() {
        guard !hasFinished else { return }
        hasFinished = true
        let finish = { [weak self] in
            guard let self else { return }
            let completion = self.completion
            self.completion = nil
            completion?()
        }
        guard let dismissHandler else {
            dismiss(animated: true, completion: finish)
            return
        }
        dismissHandler(self, finish)
    }

    private lazy var dimmingView: UIView = {
        let view = UIView()
        view.backgroundColor = UIColor.black.withAlphaComponent(0.68)
        return view
    }()

    private let popupContainerView = UIView()

    private lazy var cardView: UIView = {
        let cardView = UIView()
        cardView.backgroundColor = .white
        cardView.layer.cornerRadius = 36
        cardView.layer.masksToBounds = true
        return cardView
    }()

    private lazy var headerImageView: UIImageView = {
        let imageView = UIImageView(image: UIImage(named: "VersionUpgrade/header"))
        imageView.contentMode = .scaleAspectFit
        return imageView
    }()

    private lazy var contentTextView: UITextView = {
        let textView = UITextView()
        textView.backgroundColor = UIColor(hexStr: "#F0FAFF")
        textView.layer.cornerRadius = 26
        textView.layer.masksToBounds = true
        textView.isEditable = false
        textView.isSelectable = false
        textView.isScrollEnabled = false
        textView.showsVerticalScrollIndicator = false
        textView.textContainerInset = UIEdgeInsets(top: 15, left: 35, bottom: 15, right: 35)
        textView.textContainer.lineFragmentPadding = 0
        return textView
    }()

    private lazy var upgradeButton: VersionUpgradeGradientButton = {
        let button = VersionUpgradeGradientButton(type: .custom)
        button.setTitle("立即体验", for: .normal)
        button.setTitleColor(.white, for: .normal)
        button.titleLabel?.font = .systemFont(ofSize: 18, weight: .medium)
        button.addTarget(self, action: #selector(openUpgradeURL), for: .touchUpInside)
        return button
    }()

    private lazy var cancelButton: UIButton = {
        let button = UIButton(type: .custom)
        button.setTitle("取消", for: .normal)
        button.setTitleColor(.white, for: .normal)
        button.titleLabel?.font = .systemFont(ofSize: 17, weight: .regular)
        button.addTarget(self, action: #selector(cancelUpgrade), for: .touchUpInside)
        return button
    }()
}

private final class VersionUpgradeGradientButton: UIButton {

    private let gradientLayer = CAGradientLayer()

    override init(frame: CGRect) {
        super.init(frame: frame)
        gradientLayer.colors = [
            UIColor(hexStr: "#08B5FF").cgColor,
            UIColor(hexStr: "#48C7FF").cgColor
        ]
        gradientLayer.startPoint = CGPoint(x: 0, y: 0.5)
        gradientLayer.endPoint = CGPoint(x: 1, y: 0.5)
        layer.insertSublayer(gradientLayer, at: 0)
        layer.masksToBounds = true
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        gradientLayer.frame = bounds
        layer.cornerRadius = 16
    }
}

extension UIViewController {

    func showVersionUpgradePop(
        upgrade: VersionUpgradeModel,
        completion: (() -> Void)? = nil
    ) {
        VersionUpgradeWindowPresenter.show(
            upgrade: upgrade,
            preferredScene: viewIfLoaded?.window?.windowScene,
            completion: completion
        )
    }
}

private enum VersionUpgradeWindowPresenter {

    private static var hostWindow: UIWindow?
    private static weak var previousKeyWindow: UIWindow?

    static func show(
        upgrade: VersionUpgradeModel,
        preferredScene: UIWindowScene?,
        completion: (() -> Void)?
    ) {
        let showBlock = {
            guard hostWindow == nil,
                  let windowScene = preferredScene ?? activeWindowScene() else { return }

            previousKeyWindow = windowScene.windows.first { $0.isKeyWindow }

            let viewController = VersionUpgradePopVC(upgrade: upgrade)
            viewController.completion = completion
            viewController.dismissHandler = { viewController, finish in
                dismiss(viewController, finish: finish)
            }

            let window = UIWindow(windowScene: windowScene)
            window.frame = windowScene.coordinateSpace.bounds
            window.windowLevel = .alert + 1
            window.backgroundColor = .clear
            window.rootViewController = viewController
            hostWindow = window
            window.makeKeyAndVisible()
            viewController.showAnimated()
        }

        if Thread.isMainThread {
            showBlock()
        } else {
            DispatchQueue.main.async(execute: showBlock)
        }
    }

    private static func dismiss(
        _ viewController: VersionUpgradePopVC,
        finish: @escaping () -> Void
    ) {
        guard hostWindow?.rootViewController === viewController else {
            finish()
            return
        }

        UIView.animate(withDuration: 0.2, delay: 0, options: [.curveEaseIn]) {
            viewController.view.alpha = 0
        } completion: { _ in
            hostWindow?.isHidden = true
            hostWindow?.rootViewController = nil
            hostWindow = nil
            previousKeyWindow?.makeKey()
            previousKeyWindow = nil
            finish()
        }
    }

    private static func activeWindowScene() -> UIWindowScene? {
        let scenes = UIApplication.shared.connectedScenes.compactMap { $0 as? UIWindowScene }
        return scenes.first { $0.activationState == .foregroundActive }
            ?? scenes.first { $0.activationState == .foregroundInactive }
            ?? scenes.first
    }
}