//
//  SDLNoticeClient.swift
//  Tun
//
//  Created by 安礼成 on 2024/5/20.
//

import Foundation

//
//  SDLanServer.swift
//  Tun
//
//  Created by 安礼成 on 2024/1/31.
//

import Foundation
import NIOCore
import NIOPosix

// 处理和sn-server服务器之间的通讯
actor SDLNoticeClient {
    private let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
    private let asyncChannel: NIOAsyncChannel<AddressedEnvelope<ByteBuffer>, AddressedEnvelope<ByteBuffer>>
    private let remoteAddress: SocketAddress
    private let (writeStream, writeContinuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .unbounded)
    
    // 启动函数
    init() async throws {
        self.remoteAddress = try! SocketAddress(ipAddress: "127.0.0.1", port: 50195)
        
        let bootstrap = DatagramBootstrap(group: self.group)
            .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
        
        self.asyncChannel = try await bootstrap.bind(host: "0.0.0.0", port: 0)
            .flatMapThrowing {channel in
                return try NIOAsyncChannel(wrappingChannelSynchronously: channel, configuration: .init(
                    inboundType: AddressedEnvelope<ByteBuffer>.self,
                    outboundType: AddressedEnvelope<ByteBuffer>.self
                ))
            }
            .get()
        
        SDLLogger.log("[SDLNoticeClient] started and listening on: \(self.asyncChannel.channel.localAddress!)", level: .debug)
    }
    
    func start() async throws {
        try await self.asyncChannel.executeThenClose { inbound, outbound in
            try await withThrowingTaskGroup(of: Void.self) { group in
                group.addTask {
                    defer {
                        self.writeContinuation.finish()
                    }
                    
                    for try await message in self.writeStream {
                        let buf = self.asyncChannel.channel.allocator.buffer(bytes: message)
                        let envelope = AddressedEnvelope<ByteBuffer>(remoteAddress: self.remoteAddress, data: buf)
                        
                        try await outbound.write(envelope)
                    }
                }
                
                try await group.waitForAll()
            }
        }
    }
    
    // 处理写入逻辑
    func send(data: Data) {
        self.writeContinuation.yield(data)
    }
    
    deinit {
        try? self.group.syncShutdownGracefully()
    }
}