//
//  QQShare.swift
//  ylgamehall
//
//  QQ 分享 SharePlatform 实现，对齐 daoqi msext QQShareManager
//  `shareWithContent:completion:`（按 type 分两个分支）：
//    - type == "2" → 截图分享：复制截图到 UIPasteboard + 弹引导框（"立即打开 QQ"）
//    - else        → 链接分享：mqqapi://share/to_fri?req_type=1&url=...
//
//  **不依赖 QQ SDK**（CLAUDE.md ADR-006）：原项目走 SDK 弹原生会话列表带
//  图片预览；无 SDK 路径下退化为"剪贴板 + 引导框"，与 Douyin 同款 UX 模式。
//
//  encodeString 与 msext line 1262-1268 等价：unreserved 字符集（RFC 3986
//  alphanumeric + "-._~"），其它全部 percent encode。
//
//  fire-and-forget：sharesuccess 已在 FriendsShareHandler 立即触发。
//

import UIKit
import os.log

@MainActor
public final class QQShare: SharePlatform {

    public static let shared = QQShare()

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

    public let name = "QQ"

    public var isInstalled: Bool {
        guard let url = URL(string: "mqqapi://") else { return false }
        return UIApplication.shared.canOpenURL(url)
    }

    public init() {}

    public func share(_ content: ShareContent, scene: ShareScene) {
        guard isInstalled else { return }

        if content.type == "2" {
            shareScreenshot()
        } else {
            shareLink(content, scene: scene)
        }
    }

    // MARK: - 截图分享

    /// 对齐 msext QQShareManager.m:1876-1906 isScreenshotShare 分支：
    /// 原项目用 QQ SDK shareToQQFriend QQShareTypeImage 直接传 UIImage 给 SDK；
    /// 无 SDK 路径下退化为：截图 → UIPasteboard.image → 弹引导框（"立即打开 QQ"）。
    /// UX 模式与 DouyinShare 截图分享对齐（都是非 SDK 平台的剪贴板兜底）。
    private func shareScreenshot() {
        do {
            let shot = try ImageProvider.captureScreenshot()
            UIPasteboard.general.image = shot
            Self.log.debug("QQShare 截图已复制到剪贴板")
        } catch {
            Self.log.error("QQShare 截图失败 \(error.localizedDescription, privacy: .public)")
            return
        }

        let message = """
        ✅ 图片已复制到剪贴板

        🎯 分享到好友或群聊步骤：
        1️⃣ 打开 QQ，选择好友或群聊进入聊天
        2️⃣ 在输入框长按粘贴图片
        3️⃣ 点击发送即可分享
        """
        showGuidanceAlert(title: "QQ 分享准备完成", message: message)
    }

    /// 弹"立即打开 QQ / 稍后分享"二选一 Alert，与 DouyinShare 同款 UX。
    private func showGuidanceAlert(title: String, message: String) {
        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "立即打开 QQ", style: .default) { _ in
            if let url = URL(string: "mqqapi://"),
               UIApplication.shared.canOpenURL(url) {
                UIApplication.shared.open(url)
            } else if let url = URL(string: "mqq://"),
                      UIApplication.shared.canOpenURL(url) {
                UIApplication.shared.open(url)
            }
        })
        alert.addAction(UIAlertAction(title: "稍后分享", style: .cancel))

        guard let topVC = Self.topViewController() else { return }
        topVC.present(alert, animated: true)
    }

    private static func topViewController() -> UIViewController? {
        let scene = UIApplication.shared.connectedScenes
            .compactMap { $0 as? UIWindowScene }
            .first(where: { $0.activationState == .foregroundActive })
            ?? UIApplication.shared.connectedScenes.compactMap { $0 as? UIWindowScene }.first
        guard var top = scene?.windows.first(where: \.isKeyWindow)?.rootViewController
                    ?? scene?.windows.first?.rootViewController else { return nil }
        while let presented = top.presentedViewController { top = presented }
        if let nav = top as? UINavigationController, let visible = nav.visibleViewController {
            return visible
        }
        return top
    }

    // MARK: - 链接分享

    /// 对齐 msext QQShareManager.m simpleShareToQQFriend：
    ///   mqqapi://share/to_fri?version=1&cflag=0&req_type=1
    ///     &url=<encoded webpageUrl>&title=<encoded title>&description=<encoded desc>
    /// scene == .timeline 走 QQ 空间 (to_qzone)；.friend 走 QQ 好友 (to_fri)
    private func shareLink(_ content: ShareContent, scene: ShareScene) {
        let host = scene == .timeline ? "share/to_qzone" : "share/to_fri"
        var parts: [String] = ["version=1", "cflag=0"]
        if !content.webpageUrl.isEmpty {
            parts.append("req_type=1")
            parts.append("url=\(Self.encode(content.webpageUrl))")
        } else {
            parts.append("req_type=0")
        }
        if !content.title.isEmpty {
            parts.append("title=\(Self.encode(content.title))")
        }
        if !content.desc.isEmpty {
            parts.append("description=\(Self.encode(content.desc))")
        }
        let urlString = "mqqapi://\(host)?\(parts.joined(separator: "&"))"

        guard let qqURL = URL(string: urlString),
              UIApplication.shared.canOpenURL(qqURL) else { return }
        UIApplication.shared.open(qqURL)
    }

    nonisolated static func encode(_ string: String) -> String {
        var allowed = CharacterSet.alphanumerics
        allowed.insert(charactersIn: "-._~")
        return string.addingPercentEncoding(withAllowedCharacters: allowed) ?? ""
    }
}