//
//  SharePanel.swift
//  ylgamehall
//
//  原生分享面板：底部弹出三选一（微信好友 / QQ / 抖音）。
//
//  与 msext SharePanel.m 等价行为：
//    - 半透明黑底覆盖全屏，点击空白区关闭
//    - 内容视图从屏幕底部滑入，0.25s 动画
//    - 三个圆形按钮 + label，等间距居中布局
//    - 点击按钮后先 dismiss 再触发对应 SharePlatform.share
//
//  Phase 4.B 阶段：UI 完整 + 调用 SharePlatform stub；
//  Phase 4.C/4.D 阶段：SharePlatform 升级为真实 URL Scheme 实现，本类不变。
//

import UIKit
import os.log

@MainActor
public final class SharePanel: UIView {

    private static let log = Logger(subsystem: "ylgamehall", category: "SharePanel")

    private static let panelHeight: CGFloat = 150
    private static let buttonSize: CGFloat = 60
    private static let animationDuration: TimeInterval = 0.25

    private let content: ShareContent

    private let contentView = UIView()

    public init(content: ShareContent) {
        self.content = content
        super.init(frame: UIScreen.main.bounds)
        backgroundColor = UIColor(white: 0, alpha: 0)
        setupUI()
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) is not supported")
    }

    // MARK: - 公共入口

    /// 弹出分享面板。fire-and-forget：sharesuccess 已在 FriendsShareHandler 立即触发，
    /// 用户取消（点空白）或选好平台后不再向 H5 回报结果。
    public static func show(content: ShareContent) {
        guard let window = topWindow() else { return }
        let panel = SharePanel(content: content)
        window.addSubview(panel)
        panel.animateIn()
    }

    private static func topWindow() -> UIWindow? {
        UIApplication.shared.connectedScenes
            .compactMap { $0 as? UIWindowScene }
            .flatMap(\.windows)
            .first { $0.isKeyWindow }
    }

    // MARK: - UI 装配

    private func setupUI() {
        // 半透明背景手势
        let tap = UITapGestureRecognizer(target: self, action: #selector(handleBackgroundTap(_:)))
        addGestureRecognizer(tap)

        // 内容视图（屏幕底部，初始 Y 在屏幕外）
        let screen = UIScreen.main.bounds
        contentView.frame = CGRect(x: 0, y: screen.height, width: screen.width, height: Self.panelHeight)
        contentView.backgroundColor = .white
        let mask = CAShapeLayer()
        mask.path = UIBezierPath(
            roundedRect: contentView.bounds,
            byRoundingCorners: [.topLeft, .topRight],
            cornerRadii: CGSize(width: 10, height: 10)
        ).cgPath
        contentView.layer.mask = mask
        addSubview(contentView)

        // 三个按钮 + label 等间距居中布局
        let buttonsContainer = UIView(frame: CGRect(x: 0, y: 30, width: screen.width, height: 110))
        contentView.addSubview(buttonsContainer)

        let buttons: [(title: String, platform: SharePlatform, imageName: String)] = [
            ("微信", WechatShare.shared, "shareWechat"),
            ("QQ",   QQShare.shared,     "shareQQ"),
            ("抖音", DouyinShare.shared, "shareDouyin")
        ]

        let totalButtonsWidth = Self.buttonSize * CGFloat(buttons.count)
        let spacing = (screen.width - totalButtonsWidth) / CGFloat(buttons.count + 1)
        for (index, b) in buttons.enumerated() {
            let x = spacing + CGFloat(index) * (Self.buttonSize + spacing)
            let button = UIButton(type: .custom)
            button.frame = CGRect(x: x, y: 0, width: Self.buttonSize, height: Self.buttonSize)
            button.setImage(UIImage(named: b.imageName), for: .normal)
            button.imageView?.contentMode = .scaleAspectFit
            button.layer.cornerRadius = Self.buttonSize / 2
            button.clipsToBounds = true
            button.alpha = b.platform.isInstalled ? 1.0 : 0.4
            button.tag = index
            button.addTarget(self, action: #selector(handleButtonTap(_:)), for: .touchUpInside)
            buttonsContainer.addSubview(button)

            let label = UILabel(frame: CGRect(x: x, y: Self.buttonSize + 8, width: Self.buttonSize, height: 20))
            label.text = b.title
            label.textAlignment = .center
            label.font = .systemFont(ofSize: 13)
            label.textColor = .darkGray
            buttonsContainer.addSubview(label)
        }
    }

    // MARK: - 动画

    private func animateIn() {
        UIView.animate(withDuration: Self.animationDuration) {
            self.backgroundColor = UIColor(white: 0, alpha: 0.5)
            var frame = self.contentView.frame
            frame.origin.y = UIScreen.main.bounds.height - Self.panelHeight
            self.contentView.frame = frame
        }
    }

    private func dismiss(then action: (() -> Void)? = nil) {
        UIView.animate(withDuration: Self.animationDuration, animations: {
            self.backgroundColor = UIColor(white: 0, alpha: 0)
            var frame = self.contentView.frame
            frame.origin.y = UIScreen.main.bounds.height
            self.contentView.frame = frame
        }, completion: { _ in
            self.removeFromSuperview()
            action?()
        })
    }

    // MARK: - 事件

    @objc private func handleBackgroundTap(_ gesture: UITapGestureRecognizer) {
        let point = gesture.location(in: self)
        if !contentView.frame.contains(point) {
            dismiss()
        }
    }

    @objc private func handleButtonTap(_ sender: UIButton) {
        let platforms: [SharePlatform] = [WechatShare.shared, QQShare.shared, DouyinShare.shared]
        let platform = platforms[sender.tag]
        let scene: ShareScene = content.sharefriend == "2" ? .timeline : .friend
        let snapshotContent = content
        dismiss { [weak platform] in
            guard let platform else { return }
            Self.log.debug("share via \(platform.name, privacy: .public)")
            platform.share(snapshotContent, scene: scene)
        }
    }
}