//
//  SDLPuncherActor.swift
//  Tun
//
//  Created by 安礼成 on 2026/1/7.
//

import Foundation
import NIOCore

actor SDLPuncherActor {
    // 10秒内只需要提交一次查询
    nonisolated private let cooldownInterval: TimeInterval = 10
    
    struct RequestContext {
        let expireAt: Date
        let request: RegisterRequest
        
        func isExpired() -> Bool {
            return expireAt < Date()
        }
    }
    
    // dstMac
    private var pendingRequests: [Data: RequestContext] = [:]
    
    struct RegisterRequest {
        let srcMac: Data
        let dstMac: Data
        let networkId: UInt32
    }
    
    func submitRegisterRequest(quicClient: SDLQUICClient?, request: RegisterRequest) {
        guard let quicClient else {
            return
        }
        
        // 数据不存在，或者已经过期；才能提交
        let dstMac = request.dstMac
        guard self.isRequestExpired(dstMac: dstMac) else {
            return
        }
        
        self.pendingRequests[dstMac] = .init(expireAt: Date().addingTimeInterval(cooldownInterval), request: request)
        // 触发一次打洞
        var queryInfo = SDLQueryInfo()
        queryInfo.dstMac = request.dstMac
        if let queryData = try? queryInfo.serializedData() {
            quicClient.send(type: .queryInfo, data: queryData)
        }
    }
    
    func handlePeerInfo(using udpHole: SDLUDPHole?, peerInfo: SDLPeerInfo) async {
        // 如果服务器返回了值，优先删除掉; 避免数据堆积
        guard let requestContext = pendingRequests.removeValue(forKey: peerInfo.dstMac) else {
            return
        }
        
        // 判断必要的值是否存在
        guard let udpHole, peerInfo.hasV4Info else {
            return
        }
        
        if let remoteAddress = try? await peerInfo.v4Info.socketAddress() {
            SDLLogger.shared.log("[SDLContext] hole sock address: \(remoteAddress)", level: .debug)
            // 发送register包
            var register = SDLRegister()
            register.networkID = requestContext.request.networkId
            register.srcMac = requestContext.request.srcMac
            register.dstMac = requestContext.request.dstMac
            
            if let registerData = try? register.serializedData() {
                udpHole.send(type: .register, data: registerData, remoteAddress: remoteAddress)
            }
        }
    }
    
    // 判断是否需要提交
    func isRequestExpired(dstMac: Data) -> Bool {
        if let context = pendingRequests[dstMac] {
            return context.isExpired()
        }
        return true
    }
    
}