//
//  SOSPracticeView.swift
//  QuickLocation
//

import UIKit
import SwiftyUserDefaults

final class SOSPracticeView: UIView, UIScrollViewDelegate {

    private enum State {
        case guide
        case practiceIdle
        case practiceCountdown
        case success
    }

    private let guideView = UIView()
    private let practiceIdleView = UIView()
    private let practiceCountdownView = UIView()
    private let successView = UIView()
    private let guideScrollView = UIScrollView()
    private let pageControl = UIPageControl()
    private let practicePulseView = SOSPulseButtonView()
    private let practiceCountdownRing = SOSCountdownRingView()
    private let practiceSlider = SOSSlideCancelView(thumbImageName: "SOS/slider")
    private var state: State = .guide

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .white
        setupUI()
        setupActions()
        setState(.guide)
    }

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

    override func didMoveToWindow() {
        super.didMoveToWindow()
        if window == nil {
            practiceCountdownRing.stop()
        }
    }

    private func setupUI() {
        [guideView, practiceIdleView, practiceCountdownView, successView].forEach {
            addSubview($0)
            $0.translatesAutoresizingMaskIntoConstraints = false
            NSLayoutConstraint.activate([
                $0.topAnchor.constraint(equalTo: topAnchor),
                $0.leadingAnchor.constraint(equalTo: leadingAnchor),
                $0.trailingAnchor.constraint(equalTo: trailingAnchor),
                $0.bottomAnchor.constraint(equalTo: bottomAnchor)
            ])
        }

        setupGuideView()
        setupPracticeIdleView()
        setupPracticeCountdownView()
        setupSuccessView()
    }

    private func setupGuideView() {
        guideScrollView.isPagingEnabled = true
        guideScrollView.showsHorizontalScrollIndicator = false
        guideScrollView.bounces = false
        guideScrollView.delegate = self
        guideView.addSubview(guideScrollView)
        guideScrollView.translatesAutoresizingMaskIntoConstraints = false

        let pageStack = UIStackView()
        pageStack.axis = .horizontal
        pageStack.alignment = .fill
        pageStack.distribution = .fill
        pageStack.spacing = 0
        guideScrollView.addSubview(pageStack)
        pageStack.translatesAutoresizingMaskIntoConstraints = false

        for index in 1...3 {
            let page = makeGuidePage(index: index)
            pageStack.addArrangedSubview(page)
            page.widthAnchor.constraint(equalTo: guideScrollView.frameLayoutGuide.widthAnchor).isActive = true
        }

        pageControl.numberOfPages = 3
        pageControl.currentPage = 0
        pageControl.currentPageIndicatorTintColor = UIColor(hexStr: "#4CC7F8")
        pageControl.pageIndicatorTintColor = UIColor(hexStr: "#D9D9D9")
        pageControl.isUserInteractionEnabled = false
        guideView.addSubview(pageControl)
        pageControl.translatesAutoresizingMaskIntoConstraints = false

        let startButton = UIButton(type: .custom)
        startButton.setTitle("开始练习", for: .normal)
        startButton.setTitleColor(.white, for: .normal)
        startButton.titleLabel?.font = FontManager.boboBold(18)
        startButton.setBackgroundImage(UIImage(named: "Common/button_bg_2"), for: .normal)
        startButton.cornerRadius = 20
        startButton.addTarget(self, action: #selector(startPractice), for: .touchUpInside)
        guideView.addSubview(startButton)
        startButton.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            guideScrollView.topAnchor.constraint(equalTo: guideView.topAnchor),
            guideScrollView.leadingAnchor.constraint(equalTo: guideView.leadingAnchor),
            guideScrollView.trailingAnchor.constraint(equalTo: guideView.trailingAnchor),
            guideScrollView.bottomAnchor.constraint(equalTo: pageControl.topAnchor, constant: -8),

            pageStack.topAnchor.constraint(equalTo: guideScrollView.contentLayoutGuide.topAnchor),
            pageStack.leadingAnchor.constraint(equalTo: guideScrollView.contentLayoutGuide.leadingAnchor),
            pageStack.trailingAnchor.constraint(equalTo: guideScrollView.contentLayoutGuide.trailingAnchor),
            pageStack.bottomAnchor.constraint(equalTo: guideScrollView.contentLayoutGuide.bottomAnchor),
            pageStack.heightAnchor.constraint(equalTo: guideScrollView.frameLayoutGuide.heightAnchor),

            pageControl.centerXAnchor.constraint(equalTo: guideView.centerXAnchor),
            pageControl.bottomAnchor.constraint(equalTo: startButton.topAnchor, constant: -14),

            startButton.leadingAnchor.constraint(equalTo: guideView.leadingAnchor, constant: 30),
            startButton.trailingAnchor.constraint(equalTo: guideView.trailingAnchor, constant: -30),
            startButton.heightAnchor.constraint(equalToConstant: 56),
            startButton.bottomAnchor.constraint(equalTo: safeAreaLayoutGuide.bottomAnchor, constant: -20)
        ])
    }

    private func makeGuidePage(index: Int) -> UIView {
        let page = UIView()

        let verticalScrollView = UIScrollView()
        verticalScrollView.showsVerticalScrollIndicator = false
        verticalScrollView.alwaysBounceVertical = false
        page.addSubview(verticalScrollView)
        verticalScrollView.translatesAutoresizingMaskIntoConstraints = false

        let contentView = UIView()
        verticalScrollView.addSubview(contentView)
        contentView.translatesAutoresizingMaskIntoConstraints = false

        let imageView = UIImageView(image: UIImage(named: "SOS/sos_guide_\(index)"))
        imageView.contentMode = .scaleAspectFit
        contentView.addSubview(imageView)
        imageView.translatesAutoresizingMaskIntoConstraints = false

        let bulletList = makeBulletList()
        contentView.addSubview(bulletList)
        bulletList.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            verticalScrollView.topAnchor.constraint(equalTo: page.topAnchor),
            verticalScrollView.leadingAnchor.constraint(equalTo: page.leadingAnchor),
            verticalScrollView.trailingAnchor.constraint(equalTo: page.trailingAnchor),
            verticalScrollView.bottomAnchor.constraint(equalTo: page.bottomAnchor),

            contentView.topAnchor.constraint(equalTo: verticalScrollView.contentLayoutGuide.topAnchor),
            contentView.leadingAnchor.constraint(equalTo: verticalScrollView.contentLayoutGuide.leadingAnchor),
            contentView.trailingAnchor.constraint(equalTo: verticalScrollView.contentLayoutGuide.trailingAnchor),
            contentView.bottomAnchor.constraint(equalTo: verticalScrollView.contentLayoutGuide.bottomAnchor),
            contentView.widthAnchor.constraint(equalTo: verticalScrollView.frameLayoutGuide.widthAnchor),
            contentView.heightAnchor.constraint(greaterThanOrEqualTo: verticalScrollView.frameLayoutGuide.heightAnchor),

            imageView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 36),
            imageView.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            imageView.widthAnchor.constraint(equalToConstant: 240),
            imageView.heightAnchor.constraint(equalTo: imageView.widthAnchor),

            bulletList.topAnchor.constraint(equalTo: imageView.bottomAnchor, constant: 28),
            bulletList.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 45),
            bulletList.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -30),
            bulletList.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -16)
        ])
        return page
    }

    private func makeBulletList() -> UIStackView {
        let stack = UIStackView()
        stack.axis = .vertical
        stack.alignment = .leading
        stack.distribution = .fillEqually
        stack.spacing = 10

        ["夜间独自行走", "遇见突发危机事件", "遇到医疗紧急情况"].forEach { text in
            let label = UILabel()
            label.textColor = UIColor(hexStr: "#333333")
            label.font = .systemFont(ofSize: 16, weight: .regular)
            let attributed = NSMutableAttributedString(string: "✦  \(text)")
            attributed.addAttribute(
                .foregroundColor,
                value: UIColor(hexStr: "#11B8F4"),
                range: NSRange(location: 0, length: 1)
            )
            label.attributedText = attributed
            stack.addArrangedSubview(label)
        }
        return stack
    }

    private func setupPracticeIdleView() {
        let contentView = makeVerticalContentView(in: practiceIdleView)
        let modeBadge = SOSPracticeModeBadge()
        contentView.addSubview(modeBadge)
        modeBadge.translatesAutoresizingMaskIntoConstraints = false

        contentView.addSubview(practicePulseView)
        practicePulseView.translatesAutoresizingMaskIntoConstraints = false

        let hintLabel = UILabel()
        hintLabel.textAlignment = .center
        hintLabel.font = .systemFont(ofSize: 20, weight: .regular)
        let hint = NSMutableAttributedString(
            string: "轻点感叹号发送SOS",
            attributes: [.foregroundColor: UIColor(hexStr: "#333333")]
        )
        hint.addAttribute(
            .foregroundColor,
            value: UIColor(hexStr: "#FF383C"),
            range: NSRange(location: 7, length: 3)
        )
        hintLabel.attributedText = hint
        contentView.addSubview(hintLabel)
        hintLabel.translatesAutoresizingMaskIntoConstraints = false

        let pulseWidth = practicePulseView.widthAnchor.constraint(equalTo: contentView.widthAnchor, constant: -30)
        pulseWidth.priority = .defaultHigh
        NSLayoutConstraint.activate([
            modeBadge.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 28),
            modeBadge.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            modeBadge.widthAnchor.constraint(equalToConstant: 139),
            modeBadge.heightAnchor.constraint(equalToConstant: 40),

            practicePulseView.topAnchor.constraint(equalTo: modeBadge.bottomAnchor, constant: 18),
            practicePulseView.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            pulseWidth,
            practicePulseView.widthAnchor.constraint(lessThanOrEqualToConstant: 345),
            practicePulseView.heightAnchor.constraint(equalTo: practicePulseView.widthAnchor),

            hintLabel.topAnchor.constraint(equalTo: practicePulseView.bottomAnchor, constant: 16),
            hintLabel.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            hintLabel.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -20)
        ])
    }

    private func setupPracticeCountdownView() {
        let contentView = makeVerticalContentView(in: practiceCountdownView)
        let modeBadge = SOSPracticeModeBadge()
        contentView.addSubview(modeBadge)
        modeBadge.translatesAutoresizingMaskIntoConstraints = false

        contentView.addSubview(practiceCountdownRing)
        practiceCountdownRing.translatesAutoresizingMaskIntoConstraints = false

        let titleLabel = UILabel()
        titleLabel.attributedText = Self.cancelTitle
        titleLabel.font = .systemFont(ofSize: 22, weight: .regular)
        titleLabel.textAlignment = .center
        contentView.addSubview(titleLabel)
        titleLabel.translatesAutoresizingMaskIntoConstraints = false

        let bodyLabel = UILabel()
        bodyLabel.text = "10秒后，会将你的SOS和位置发送到你的圈子和紧急联系人。"
        bodyLabel.textColor = UIColor(hexStr: "#273246")
        bodyLabel.font = .systemFont(ofSize: 15, weight: .regular)
        bodyLabel.textAlignment = .center
        bodyLabel.numberOfLines = 0
        contentView.addSubview(bodyLabel)
        bodyLabel.translatesAutoresizingMaskIntoConstraints = false

        contentView.addSubview(practiceSlider)
        practiceSlider.translatesAutoresizingMaskIntoConstraints = false

        let ringWidth = practiceCountdownRing.widthAnchor.constraint(equalTo: contentView.widthAnchor, constant: -30)
        ringWidth.priority = .defaultHigh
        NSLayoutConstraint.activate([
            modeBadge.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 28),
            modeBadge.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            modeBadge.widthAnchor.constraint(equalToConstant: 139),
            modeBadge.heightAnchor.constraint(equalToConstant: 40),

            practiceCountdownRing.topAnchor.constraint(equalTo: modeBadge.bottomAnchor, constant: 8),
            practiceCountdownRing.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            ringWidth,
            practiceCountdownRing.widthAnchor.constraint(lessThanOrEqualToConstant: 345),
            practiceCountdownRing.heightAnchor.constraint(equalTo: practiceCountdownRing.widthAnchor),

            titleLabel.topAnchor.constraint(equalTo: practiceCountdownRing.bottomAnchor, constant: 2),
            titleLabel.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),

            bodyLabel.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 24),
            bodyLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 40),
            bodyLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -40),

            practiceSlider.topAnchor.constraint(greaterThanOrEqualTo: bodyLabel.bottomAnchor, constant: 28),
            practiceSlider.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 30),
            practiceSlider.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -30),
            practiceSlider.heightAnchor.constraint(equalToConstant: 56),
            practiceSlider.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -(kSafeBottomMargin + 20))
        ])
    }

    private func setupSuccessView() {
        let contentView = makeVerticalContentView(in: successView)
        let modeBadge = SOSPracticeModeBadge()
        contentView.addSubview(modeBadge)
        modeBadge.translatesAutoresizingMaskIntoConstraints = false

        let imageView = UIImageView(image: UIImage(named: "SOS/sos_practice_success"))
        imageView.contentMode = .scaleAspectFit
        contentView.addSubview(imageView)
        imageView.translatesAutoresizingMaskIntoConstraints = false

        let titleLabel = UILabel()
        titleLabel.textAlignment = .center
        titleLabel.font = .systemFont(ofSize: 22, weight: .regular)
        let title = NSMutableAttributedString(
            string: "求救成功",
            attributes: [.foregroundColor: UIColor(hexStr: "#333333")]
        )
        title.addAttribute(
            .foregroundColor,
            value: UIColor(hexStr: "#FF383C"),
            range: NSRange(location: 2, length: 2)
        )
        titleLabel.attributedText = title
        contentView.addSubview(titleLabel)
        titleLabel.translatesAutoresizingMaskIntoConstraints = false

        let subtitleLabel = UILabel()
        subtitleLabel.text = "太好了！您可以使用sos了"
        subtitleLabel.textColor = UIColor(hexStr: "#273246")
        subtitleLabel.font = .systemFont(ofSize: 16, weight: .regular)
        subtitleLabel.textAlignment = .center
        contentView.addSubview(subtitleLabel)
        subtitleLabel.translatesAutoresizingMaskIntoConstraints = false

        let doneButton = UIButton(type: .custom)
        doneButton.setTitle("我知道了", for: .normal)
        doneButton.setTitleColor(.white, for: .normal)
        doneButton.titleLabel?.font = FontManager.boboBold(18)
        doneButton.setBackgroundImage(UIImage(named: "Common/button_bg_2"), for: .normal)
        doneButton.cornerRadius = 20
        doneButton.addTarget(self, action: #selector(finishPractice), for: .touchUpInside)
        contentView.addSubview(doneButton)
        doneButton.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            modeBadge.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 28),
            modeBadge.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            modeBadge.widthAnchor.constraint(equalToConstant: 139),
            modeBadge.heightAnchor.constraint(equalToConstant: 40),

            imageView.topAnchor.constraint(equalTo: modeBadge.bottomAnchor, constant: 72),
            imageView.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            imageView.widthAnchor.constraint(equalToConstant: 270),
            imageView.heightAnchor.constraint(equalToConstant: 190),

            titleLabel.topAnchor.constraint(equalTo: imageView.bottomAnchor, constant: 52),
            titleLabel.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),

            subtitleLabel.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 34),
            subtitleLabel.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),

            doneButton.topAnchor.constraint(greaterThanOrEqualTo: subtitleLabel.bottomAnchor, constant: 30),
            doneButton.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 30),
            doneButton.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -30),
            doneButton.heightAnchor.constraint(equalToConstant: 56),
            doneButton.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -(kSafeBottomMargin + 20))
        ])
    }

    private func makeVerticalContentView(in container: UIView) -> UIView {
        let scrollView = UIScrollView()
        scrollView.showsVerticalScrollIndicator = false
        scrollView.alwaysBounceVertical = false
        container.addSubview(scrollView)
        scrollView.translatesAutoresizingMaskIntoConstraints = false

        let contentView = UIView()
        scrollView.addSubview(contentView)
        contentView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            scrollView.topAnchor.constraint(equalTo: container.topAnchor),
            scrollView.leadingAnchor.constraint(equalTo: container.leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: container.trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: container.bottomAnchor),

            contentView.topAnchor.constraint(equalTo: scrollView.contentLayoutGuide.topAnchor),
            contentView.leadingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.leadingAnchor),
            contentView.trailingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.trailingAnchor),
            contentView.bottomAnchor.constraint(equalTo: scrollView.contentLayoutGuide.bottomAnchor),
            contentView.widthAnchor.constraint(equalTo: scrollView.frameLayoutGuide.widthAnchor),
            contentView.heightAnchor.constraint(greaterThanOrEqualTo: scrollView.frameLayoutGuide.heightAnchor)
        ])
        return contentView
    }

    private func setupActions() {
        practicePulseView.onTap = { [weak self] in
            guard let self, self.state == .practiceIdle else { return }
            self.setState(.practiceCountdown)
        }
        practiceCountdownRing.onCompleted = { [weak self] in
            guard let self, self.state == .practiceCountdown else { return }
            self.setState(.success)
        }
        practiceSlider.onCompleted = { [weak self] in
            guard let self, self.state == .practiceCountdown else { return }
            self.practiceCountdownRing.stop()
            self.setState(.practiceIdle)
        }
    }

    private func setState(_ state: State) {
        self.state = state
        guideView.isHidden = state != .guide
        practiceIdleView.isHidden = state != .practiceIdle
        practiceCountdownView.isHidden = state != .practiceCountdown
        successView.isHidden = state != .success

        switch state {
        case .guide:
            practiceCountdownRing.stop()
            practicePulseView.setAnimationEnabled(false)
        case .practiceIdle:
            practiceCountdownRing.stop()
            practiceSlider.configure(style: .practiceCountdown)
            practiceSlider.setInteractionEnabled(true)
            practicePulseView.setShowsHand(true)
            practicePulseView.setAnimationEnabled(true)
        case .practiceCountdown:
            practicePulseView.setAnimationEnabled(false)
            practiceSlider.configure(style: .practiceCountdown)
            practiceSlider.setInteractionEnabled(true)
            practiceCountdownRing.start(duration: 10)
        case .success:
            practiceCountdownRing.stop(reset: false)
            practicePulseView.setAnimationEnabled(false)
        }
    }

    @objc private func startPractice() {
        setState(.practiceIdle)
    }

    @objc private func finishPractice() {
        var completedUsers = Defaults[\.sosIsPracticeList]
        if !completedUsers.contains(AppContextManager.shared.userId) {
            completedUsers.append(AppContextManager.shared.userId)
            Defaults[\.sosIsPracticeList] = completedUsers
        }

        UIView.animate(withDuration: 0.25, animations: {
            self.alpha = 0
        }, completion: { _ in
            self.isHidden = true
            self.alpha = 1
        })
    }

    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
        guard scrollView === guideScrollView, scrollView.bounds.width > 0 else { return }
        pageControl.currentPage = Int(round(scrollView.contentOffset.x / scrollView.bounds.width))
    }

    private static var cancelTitle: NSAttributedString {
        let title = NSMutableAttributedString(
            string: "滑动取消",
            attributes: [.foregroundColor: UIColor(hexStr: "#333333")]
        )
        title.addAttribute(
            .foregroundColor,
            value: UIColor(hexStr: "#FF383C"),
            range: NSRange(location: 2, length: 2)
        )
        return title
    }
}

private final class SOSPracticeModeBadge: UIView {

    private let gradientLayer = CAGradientLayer()

    override init(frame: CGRect) {
        super.init(frame: frame)
        gradientLayer.colors = [
            UIColor(hexStr: "#DDF4FF").cgColor,
            UIColor(hexStr: "#52C5F4").cgColor,
            UIColor(hexStr: "#DDF4FF").cgColor
        ]
        gradientLayer.startPoint = CGPoint(x: 0, y: 0.5)
        gradientLayer.endPoint = CGPoint(x: 1, y: 0.5)
        layer.addSublayer(gradientLayer)

        let label = UILabel()
        label.text = "练习模式"
        label.textColor = .white
        label.font = .systemFont(ofSize: 16, weight: .semibold)
        label.textAlignment = .center
        addSubview(label)
        label.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            label.topAnchor.constraint(equalTo: topAnchor),
            label.leadingAnchor.constraint(equalTo: leadingAnchor),
            label.trailingAnchor.constraint(equalTo: trailingAnchor),
            label.bottomAnchor.constraint(equalTo: bottomAnchor)
        ])
    }

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

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