#if os(macOS)
import AppKit
import CryptoKit
import Foundation

// Mac 剪贴板自动同步（上行）：轮询 NSPasteboard.general.changeCount（~500ms），本机复制的普通文本
// 自动上传云剪贴板。移植桌面 desktop/platform/clipboard.go 的 Monitor 策略（selfHash 回环守卫 +
// lastHash 去重）与 clipboard_darwin.m 的过滤（org.nspasteboard.{Concealed,Transient,AutoGenerated}
// 敏感标记跳过、Handoff/shared-pasteboard 暂存路径跳过、富文本从 RTF/RTFD 派生纯文本）。beginActivity
// 防 App Nap 挂起轮询。下行（远端 → 本机）仍走手动拉取（设置 / 菜单栏）——自动下行须引擎 JS 侧改动 +
// prod 部署（Mac 从线上加载 engine.html），见 handoff。
final class MacClipboardMonitor
{
    static let shared = MacClipboardMonitor()
    private init() {}

    // 采纳文本上传去哪：app 在 start 时接好（→ engine.uploadClipboardText）。
    private var upload: ((String) -> Void)?
    private var timer: Timer?
    private var activity: NSObjectProtocol?
    private var lastChangeCount = 0
    private var lastHash = ""      // 上次采纳文本的哈希（去重）
    private var selfHash = ""      // 最近一次自写文本的哈希（回环守卫）

    private static let pollInterval: TimeInterval = 0.5

    var isRunning: Bool { timer != nil }

    func start(upload: @escaping (String) -> Void)
    {
        self.upload = upload
        guard timer == nil else { return }
        lastChangeCount = NSPasteboard.general.changeCount   // 起始不追认当前已有内容
        // 防 App Nap：非前台时系统会挂起 Timer，此 activity 令轮询在后台仍运行。
        activity = ProcessInfo.processInfo.beginActivity(
            options: .userInitiatedAllowingIdleSystemSleep, reason: "clipboard sync")
        let t = Timer(timeInterval: Self.pollInterval, repeats: true)
        { [weak self] _ in self?.poll() }
        RunLoop.main.add(t, forMode: .common)
        timer = t
    }

    func stop()
    {
        timer?.invalidate()
        timer = nil
        if let activity { ProcessInfo.processInfo.endActivity(activity) }
        activity = nil
    }

    // 引擎写本机剪贴板（下行 / 手动拉取）前调用：把即将写入的内容标为「自写」，使随之而来的
    // changeCount 变化被识别为自身回声、不再上传。对齐桌面 Monitor.WillWrite。
    func armSelfWrite(_ text: String)
    {
        selfHash = Self.hash(text)
    }

    private func poll()
    {
        let cc = NSPasteboard.general.changeCount
        guard cc != lastChangeCount else { return }
        lastChangeCount = cc
        guard let text = Self.readText() else { return }   // 非文本 / 敏感 / 暂存路径 → 忽略
        let h = Self.hash(text)
        if h == selfHash { selfHash = ""; lastHash = h; return }   // 自写回声：消费一次并解除守卫
        if h == lastHash { return }                                 // 内容未变
        lastHash = h
        upload?(text)
    }

    // 读剪贴板纯文本 + 过滤（移植 clipboard_darwin.m）。
    private static func readText() -> String?
    {
        let pb = NSPasteboard.general
        let sensitive: Set<String> = [
            "org.nspasteboard.ConcealedType",
            "org.nspasteboard.TransientType",
            "org.nspasteboard.AutoGeneratedType",
        ]
        if let types = pb.types, types.contains(where: { sensitive.contains($0.rawValue) })
        {
            return nil
        }
        var s = pb.string(forType: .string)
        if s == nil || isStagingPath(s!) { s = plainFromRich(pb) }
        guard let out = s, !isStagingPath(out), !out.isEmpty else { return nil }
        return out
    }

    // Universal Clipboard / Handoff 暂存路径（富文本复制时纯文本可能是 .../shared-pasteboard/xxx.rtfd
    // 这类路径而非内容），绝不当剪贴板文本上传。
    private static func isStagingPath(_ s: String) -> Bool
    {
        s.contains("/shared-pasteboard/") || s.contains("com.apple.coreservices.useractivityd")
    }

    private static func plainFromRich(_ pb: NSPasteboard) -> String?
    {
        for (type, doc) in [ (NSPasteboard.PasteboardType.rtfd, NSAttributedString.DocumentType.rtfd),
                             (NSPasteboard.PasteboardType.rtf, NSAttributedString.DocumentType.rtf) ]
        {
            if let data = pb.data(forType: type),
               let a = try? NSAttributedString(data: data,
                                               options: [ .documentType: doc ],
                                               documentAttributes: nil)
            {
                return a.string
            }
        }
        return nil
    }

    private static func hash(_ s: String) -> String
    {
        SHA256.hash(data: Data(s.utf8)).map { String(format: "%02x", $0) }.joined()
    }
}
#endif