//
//  FeatureIntroView.swift
//  QuickLocation
//

import UIKit
import SDCycleScrollView

struct FeatureIntroItem {
    let imageName: String
    let accessibilityTitle: String
    let aspectRatio: CGFloat
    let action: FeatureIntroAction
}

enum FeatureIntroAction {
    case signIn
    case createBubble
    case lockDistract
    case pigeonMessage
    case searchLocation
    case sos
    case placeholder
}

final class FeatureIntroView: UIView {

    var onTapItem: ((FeatureIntroAction) -> Void)?

    private let headerBackgroundView = UIView()
    private let headerBgImg = UIImageView(image: UIImage(named: "Explore/header_bg"))
    private let titleContainer = UIStackView()
    private let titleLineView = UIView()
    private let titleLabel = UILabel()
    private let sheetView = UIView()
    private let scrollView = UIScrollView()
    private let contentView = UIView()
    private let gridStack = UIStackView()

    private static let allItems: [FeatureIntroItem] = [
        FeatureIntroItem(
            imageName: "Explore/sign_in_card",
            accessibilityTitle: "还在吗",
            aspectRatio: 127 / 166,
            action: .signIn
        ),
        FeatureIntroItem(
            imageName: "Explore/pigeon_message_card",
            accessibilityTitle: "飞鸽传书",
            aspectRatio: 127 / 166,
            action: .pigeonMessage
        ),
        FeatureIntroItem(
            imageName: "Explore/lock_distract_card",
            accessibilityTitle: "一键锁机",
            aspectRatio: 130 / 166,
            action: .lockDistract
        ),
        FeatureIntroItem(
            imageName: "Explore/bubble_card",
            accessibilityTitle: "隐身气泡",
            aspectRatio: 130 / 166,
            action: .createBubble
        ),
        FeatureIntroItem(
            imageName: "Explore/search_location_card",
            accessibilityTitle: "查位置",
            aspectRatio: 130 / 166,
            action: .searchLocation
        ),
        FeatureIntroItem(
            imageName: "Explore/sos_card",
            accessibilityTitle: "SOS",
            aspectRatio: 130 / 166,
            action: .sos
        )
    ]

    private var displayedItems: [FeatureIntroItem] = []

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

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

    private func setupUI() {
        backgroundColor = .white

        addSubview(headerBackgroundView)
        headerBackgroundView.backgroundColor = .clear
        
        headerBgImg.contentMode = .scaleAspectFill
        headerBgImg.clipsToBounds = true
        headerBackgroundView.addSubview(headerBgImg)
        headerBackgroundView.addSubview(cycleScrollView)

        sheetView.backgroundColor = .white
        sheetView.layer.cornerRadius = 30
        sheetView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
        sheetView.clipsToBounds = true
        addSubview(sheetView)
        sheetView.translatesAutoresizingMaskIntoConstraints = false

        scrollView.alwaysBounceVertical = false
        scrollView.showsVerticalScrollIndicator = false
        scrollView.contentInset.bottom = 90
        sheetView.addSubview(scrollView)
        scrollView.translatesAutoresizingMaskIntoConstraints = false

        scrollView.addSubview(contentView)
        contentView.translatesAutoresizingMaskIntoConstraints = false

        gridStack.axis = .vertical
        gridStack.alignment = .fill
        gridStack.distribution = .fill
        gridStack.spacing = 13
        contentView.addSubview(gridStack)
        gridStack.translatesAutoresizingMaskIntoConstraints = false
        reloadFeatureItems()

        headerBackgroundView.layoutChain
            .edges(excludingEdge: .bottom)
            .heightToWidth(190 / 375)
        
        headerBgImg.layoutChain.edges()
        
        cycleScrollView.layoutChain.edges()
        
        sheetView.layoutChain
            .topToBottomOfView(headerBackgroundView, offset: -30)
            .edges(excludingEdge: .top)
        
        NSLayoutConstraint.activate([
            scrollView.topAnchor.constraint(equalTo: sheetView.topAnchor),
            scrollView.leadingAnchor.constraint(equalTo: sheetView.leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: sheetView.trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: sheetView.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),

            gridStack.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 19),
            gridStack.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 15),
            gridStack.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -15),
            gridStack.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -20)
        ])
    }

    func reloadFeatureItems() {
        displayedItems = Self.allItems
        rebuildGrid()
    }

    private func rebuildGrid() {
        gridStack.arrangedSubviews.forEach {
            gridStack.removeArrangedSubview($0)
            $0.removeFromSuperview()
        }

        let columns = 2
        var index = 0
        while index < displayedItems.count {
            let rowStack = UIStackView()
            rowStack.axis = .horizontal
            rowStack.alignment = .fill
            rowStack.distribution = .fillEqually
            rowStack.spacing = 13

            for _ in 0..<columns {
                if index < displayedItems.count {
                    let item = displayedItems[index]
                    let card = FeatureIntroCardView(item: item)
                    card.tag = index
                    card.addTarget(self, action: #selector(cardTapped(_:)), for: .touchUpInside)
                    rowStack.addArrangedSubview(card)
                    card.heightAnchor.constraint(equalTo: card.widthAnchor, multiplier: item.aspectRatio).isActive = true
                } else {
                    rowStack.addArrangedSubview(UIView())
                }
                index += 1
            }
            gridStack.addArrangedSubview(rowStack)
        }
    }

    @objc private func cardTapped(_ sender: FeatureIntroCardView) {
        guard displayedItems.indices.contains(sender.tag) else { return }
        onTapItem?(displayedItems[sender.tag].action)
    }
    
    // MARK: - 轮播图
    lazy var cycleScrollView: SDCycleScrollView = {
        let view = SDCycleScrollView(frame: .zero)
        view.backgroundColor = .clear
        view.scrollDirection = .horizontal
//        view.showPageControl = true
        view.bannerImageViewContentMode = .scaleAspectFill
        view.autoScrollTimeInterval = 5
//        view.currentPageDotColor = UIColor(hexStr: "#16B3FF")
//        view.pageDotColor = UIColor(hexStr: "#7AD6FF").withAlphaComponent(0.4)
//        view.pageControlDotSize = CGSize(width: 8, height: 8)
        view.clipsToBounds = false
//        view.pageControlBottomOffset = -34
        view.isHidden = true
        return view
    }()
}

final class FeatureIntroCardView: UIControl {

    private let imageView = UIImageView()

    init(item: FeatureIntroItem) {
        super.init(frame: .zero)

        isAccessibilityElement = true
        accessibilityLabel = item.accessibilityTitle
        accessibilityTraits = .button

        imageView.image = UIImage(named: item.imageName)
        imageView.contentMode = .scaleAspectFit
        imageView.isUserInteractionEnabled = false
        addSubview(imageView)
        imageView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            imageView.topAnchor.constraint(equalTo: topAnchor),
            imageView.leadingAnchor.constraint(equalTo: leadingAnchor),
            imageView.trailingAnchor.constraint(equalTo: trailingAnchor),
            imageView.bottomAnchor.constraint(equalTo: bottomAnchor)
        ])
    }

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

    override var isHighlighted: Bool {
        didSet {
            imageView.alpha = isHighlighted ? 0.78 : 1
        }
    }
}