//
//  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 + 拉起 mqqapi://
//    - 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，
//  新外壳走 URL Scheme + pasteboard 兜底实现等价 UX。
//
//  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 → pasteboard → 拉起 QQ（用户在聊天里粘贴）。
    private func shareScreenshot() {
        do {
            let shot = try ImageProvider.captureScreenshot()
            UIPasteboard.general.image = shot
        } catch {
            Self.log.error("QQShare 截图失败 \(error.localizedDescription, privacy: .public)")
        }

        let candidates = [
            "mqqapi://share/to_fri?file_type=news&version=1&cflag=0",
            "mqq://im/chat?chat_type=select",
            "mqqapi://",
            "mqq://"
        ]
        for s in candidates {
            guard let url = URL(string: s),
                  UIApplication.shared.canOpenURL(url) else { continue }
            UIApplication.shared.open(url)
            return
        }
    }

    // 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) ?? ""
    }
}