using System.Net;
using System.Net.Sockets;
using System.Text;
using DotNext;
using WebProtocol;

/// <summary>
/// UDP客户端发送池
/// </summary>
public class UDPClientPool
{
    private static NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();

    private static IPAddress localhost = IPAddress.Parse("127.0.0.1");

    /// <summary>
    /// 发送字符串
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="stringArray">字符串数组</param>
    /// <returns>是否成功</returns>
    public static bool SendString(IPEndPoint endPoint, string[] stringArray)
    {
        var isSuccessful = true;
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

        foreach (var str in stringArray)
        {
            byte[] sendbuf = Encoding.ASCII.GetBytes(str);
            var sendLen = socket.SendTo(sendbuf, endPoint);
            if (str.Length != sendLen) isSuccessful = false;
        }

        socket.Close();

        if (isSuccessful) { return true; }
        else { return false; }
    }

    /// <summary>
    /// 异步发送字符串
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="stringArray">字符串数组</param>
    /// <returns>是否成功</returns>
    public async static ValueTask<bool> SendStringAsync(IPEndPoint endPoint, string[] stringArray)
    {
        return await Task.Run(() => { return SendString(endPoint, stringArray); });
    }

    /// <summary>
    /// 发送二进制字节
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="buf">二进制字节</param>
    /// <returns>是否成功</returns>
    public static bool SendBytes(IPEndPoint endPoint, byte[] buf)
    {
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        var sendLen = socket.SendTo(buf, endPoint);
        socket.Close();

        logger.Debug($"UDP socket send bytes to device {endPoint.Address.ToString()}:{endPoint.Port.ToString()}:");
        logger.Debug($"  Original Data: {BitConverter.ToString(buf).Replace("-", " ")}");

        if (sendLen == buf.Length) { return true; }
        else { return false; }
    }

    /// <summary>
    /// 异步发送二进制字节
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="buf">二进制字节</param>
    /// <returns>是否成功</returns>
    public async static ValueTask<bool> SendBytesAsync(IPEndPoint endPoint, byte[] buf)
    {
        return await Task.Run(() => { return SendBytes(endPoint, buf); });
    }

    /// <summary>
    /// 发送地址包
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="pkg">地址包</param>
    /// <returns>是否成功</returns>
    public static bool SendAddrPack(IPEndPoint endPoint, WebProtocol.SendAddrPackage pkg)
    {
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        var sendBytes = pkg.ToBytes();
        var sendLen = socket.SendTo(sendBytes, endPoint);
        socket.Close();

        logger.Debug($"UDP socket send address package to device {endPoint.Address.ToString()}:{endPoint.Port.ToString()}:");
        logger.Debug($"  Original Data: {BitConverter.ToString(pkg.ToBytes()).Replace("-", " ")}");
        logger.Debug($"  Decoded  Data: {pkg.ToString()}");

        if (sendLen == sendBytes.Length) { return true; }
        else { return false; }
    }

    /// <summary>
    /// 异步发送地址包
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="pkg">地址包</param>
    /// <returns>是否成功</returns>
    public async static ValueTask<bool> SendAddrPackAsync(IPEndPoint endPoint, WebProtocol.SendAddrPackage pkg)
    {
        return await Task.Run(() => { return SendAddrPack(endPoint, pkg); });
    }


    /// <summary>
    /// 发送数据包
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="pkg">数据包</param>
    /// <returns>是否成功</returns>
    public static bool SendDataPack(IPEndPoint endPoint, WebProtocol.SendDataPackage pkg)
    {
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        var sendBytes = pkg.ToBytes();
        var sendLen = socket.SendTo(sendBytes, endPoint);
        socket.Close();

        logger.Debug($"UDP socket send data package to device {endPoint.Address.ToString()}:{endPoint.Port.ToString()}:");
        logger.Debug($"  Original Data: {BitConverter.ToString(pkg.ToBytes()).Replace("-", " ")}");

        if (sendLen == sendBytes.Length) { return true; }
        else { return false; }
    }

    /// <summary>
    /// 异步发送数据包
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="pkg">数据包</param>
    /// <returns>是否成功</returns>
    public async static ValueTask<bool> SendDataPackAsync(IPEndPoint endPoint, WebProtocol.SendDataPackage pkg)
    {
        return await Task.Run(() => { return SendDataPack(endPoint, pkg); });
    }

    /// <summary>
    /// 发送字符串到本地
    /// </summary>
    /// <param name="port">端口</param>
    /// <param name="stringArray">字符串数组</param>
    /// <returns>是否成功</returns>
    public static bool SendStringLocalHost(int port, string[] stringArray)
    {
        return SendString(new IPEndPoint(localhost, port), stringArray);
    }

    /// <summary>
    /// 循环发送字符串到本地
    /// </summary>
    /// <param name="times">发送总次数</param>
    /// <param name="sleepMilliSeconds">间隔时间</param>
    /// <param name="port">端口</param>
    /// <param name="stringArray">字符串数组</param>
    /// <returns>是否成功</returns>
    public static bool CycleSendStringLocalHost(int times, int sleepMilliSeconds, int port, string[] stringArray)
    {
        var isSuccessful = true;

        while (times-- >= 0)
        {
            isSuccessful = SendStringLocalHost(port, stringArray);
            if (!isSuccessful) break;

            Thread.Sleep(sleepMilliSeconds);
        }

        return isSuccessful;
    }

    /// <summary>
    /// 读取设备地址数据
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>读取结果，包含接收到的数据包</returns>
    public static async ValueTask<Result<RecvDataPackage>> ReadAddr(
            IPEndPoint endPoint, int taskID, uint devAddr, int timeout = 1000)
    {
        var ret = false;
        var opts = new SendAddrPackOptions();

        opts.BurstType = BurstType.FixedBurst;
        opts.BurstLength = 0;
        opts.CommandID = Convert.ToByte(taskID);
        opts.Address = devAddr;

        // Read Jtag State Register
        opts.IsWrite = false;
        ret = await UDPClientPool.SendAddrPackAsync(endPoint, new SendAddrPackage(opts));
        if (!ret) return new(new Exception("Send Address Package Failed!"));

        // Wait for Read Ack
        if (!MsgBus.IsRunning)
            return new(new Exception("Message Bus not Working!"));

        var retPack = await MsgBus.UDPServer.WaitForDataAsync(
                endPoint.Address.ToString(), taskID, endPoint.Port, timeout);
        if (!retPack.IsSuccessful) return new(retPack.Error);
        else if (!retPack.Value.IsSuccessful)
            return new(new Exception("Send address package failed"));

        var retPackOpts = retPack.Value.Options;
        if (retPackOpts.Data is null)
            return new(new Exception($"Data is Null, package: {retPackOpts.ToString()}"));

        return retPack;
    }

    /// <summary>
    /// 读取设备地址数据并校验结果
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="result">期望的结果值</param>
    /// <param name="resultMask">结果掩码，用于位校验</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>校验结果，true表示数据匹配期望值</returns>
    public static async ValueTask<Result<bool>> ReadAddr(
            IPEndPoint endPoint, int taskID, uint devAddr, UInt32 result, UInt32 resultMask, int timeout = 1000)
    {
        var address = endPoint.Address.ToString();

        var ret = await ReadAddr(endPoint, taskID, devAddr, timeout);
        if (!ret.IsSuccessful) return new(ret.Error);
        if (!ret.Value.IsSuccessful)
            return new(new Exception($"Read device {address} address {devAddr} failed"));

        var retData = ret.Value.Options.Data;
        if (retData is null)
            return new(new Exception($"Device {address} receive none"));
        if (retData.Length != 4)
            return new(new Exception(
                $"Device {address} receive data is {retData.Length} bytes instead of 4 bytes"));

        // Check result
        try
        {
            var retCode = Convert.ToUInt32(Common.Number.BytesToUInt64(retData).Value);
            return Common.Number.BitsCheck(retCode, result, resultMask);
        }
        catch (Exception error)
        {
            return new(error);
        }
    }

    /// <summary>
    /// 读取设备地址数据并等待直到结果匹配或超时
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="result">期望的结果值</param>
    /// <param name="resultMask">结果掩码，用于位校验</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>校验结果，true表示在超时前数据匹配期望值</returns>
    public static async ValueTask<Result<bool>> ReadAddrWithWait(
            IPEndPoint endPoint, int taskID, uint devAddr, UInt32 result, UInt32 resultMask, int timeout = 1000)
    {
        var address = endPoint.Address.ToString();

        var startTime = DateTime.Now;
        while (true)
        {
            var elapsed = DateTime.Now - startTime;
            if (elapsed >= TimeSpan.FromMilliseconds(timeout)) break;
            var timeleft = TimeSpan.FromMilliseconds(timeout) - elapsed;

            try
            {
                var ret = await ReadAddr(endPoint, taskID, devAddr, Convert.ToInt32(timeleft.TotalMilliseconds));
                if (!ret.IsSuccessful) return new(ret.Error);
                if (!ret.Value.IsSuccessful)
                    return new(new Exception($"Read device {address} address {devAddr} failed"));

                var retData = ret.Value.Options.Data;
                if (retData is null)
                    return new(new Exception($"Device {address} receive none"));
                if (retData.Length != 4)
                    return new(new Exception(
                        $"Device {address} receive data is {retData.Length} bytes instead of 4 bytes"));

                // Check result
                var retCode = Convert.ToUInt32(Common.Number.BytesToUInt64(retData).Value);
                if (Common.Number.BitsCheck(retCode, result, resultMask)) return true;
            }
            catch (Exception error)
            {
                return new(error);
            }
        }

        return false;
    }

    /// <summary>
    /// 从设备地址读取字节数组数据（支持大数据量分段传输）
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="dataLength">要读取的数据长度（字节）</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>读取结果，包含接收到的字节数组</returns>
    public static async ValueTask<Result<byte[]>> ReadAddrBytes(
        IPEndPoint endPoint, int taskID, UInt32 devAddr, int dataLength, int timeout = 1000)
    {
        var ret = false;
        var opts = new SendAddrPackOptions();
        var resultData = new List<byte>();

        opts.BurstType = BurstType.FixedBurst;
        opts.CommandID = Convert.ToByte(taskID);
        opts.IsWrite = false;

        // Check Msg Bus
        if (!MsgBus.IsRunning)
            return new(new Exception("Message bus not working!"));

        // Calculate read times and segments
        var max4BytesPerRead = 0x80; // 1024 bytes per read
        var rest4Bytes = dataLength % max4BytesPerRead;
        var readTimes = (rest4Bytes != 0) ?
            (dataLength / max4BytesPerRead + 1) :
            (dataLength / max4BytesPerRead);

        for (var i = 0; i < readTimes; i++)
        {
            // Calculate current segment size
            var isLastSegment = i == readTimes - 1;
            var currentSegmentSize = (isLastSegment && rest4Bytes != 0) ? rest4Bytes : max4BytesPerRead;

            // Set burst length (in 32-bit words)
            opts.BurstLength = (byte)(currentSegmentSize - 1);

            // Update address for current segment
            opts.Address = devAddr + (uint)(i * max4BytesPerRead);

            // Send read address package
            ret = await UDPClientPool.SendAddrPackAsync(endPoint, new SendAddrPackage(opts));
            if (!ret) return new(new Exception($"Send address package failed at segment {i}!"));

            // Wait for data response
            var retPack = await MsgBus.UDPServer.WaitForDataAsync(
                endPoint.Address.ToString(), taskID, endPoint.Port, timeout);
            if (!retPack.IsSuccessful) return new(retPack.Error);

            if (!retPack.Value.IsSuccessful)
                return new(new Exception($"Read address package failed at segment {i}"));

            var retPackOpts = retPack.Value.Options;
            if (retPackOpts.Data is null)
                return new(new Exception($"Data is null at segment {i}, package: {retPackOpts.ToString()}"));

            // Validate received data length
            if (retPackOpts.Data.Length != currentSegmentSize * 4)
                return new(new Exception($"Expected {currentSegmentSize * 4} bytes but received {retPackOpts.Data.Length} bytes at segment {i}"));

            // Add received data to result
            resultData.AddRange(retPackOpts.Data);
        }

        // Validate total data length
        if (resultData.Count != dataLength * 4)
            return new(new Exception($"Expected total {dataLength * 4} bytes but received {resultData.Count} bytes"));

        return resultData.ToArray();
    }


    /// <summary>
    /// 向设备地址写入32位数据
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="data">要写入的32位数据</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>写入结果，true表示写入成功</returns>
    public static async ValueTask<Result<bool>> WriteAddr(
            IPEndPoint endPoint, int taskID, UInt32 devAddr, UInt32 data, int timeout = 1000)
    {
        var ret = false;
        var opts = new SendAddrPackOptions();

        opts.BurstType = BurstType.FixedBurst;
        opts.BurstLength = 0;
        opts.CommandID = Convert.ToByte(taskID);
        opts.Address = devAddr;

        // Write Jtag State Register
        opts.IsWrite = true;
        ret = await UDPClientPool.SendAddrPackAsync(endPoint, new SendAddrPackage(opts));
        if (!ret) return new(new Exception("Send 1st address package failed!"));
        // Send Data Package
        ret = await UDPClientPool.SendDataPackAsync(endPoint,
                new SendDataPackage(Common.Number.NumberToBytes(data, 4).Value));
        if (!ret) return new(new Exception("Send data package failed!"));

        // Check Msg Bus
        if (!MsgBus.IsRunning)
            return new(new Exception("Message bus not working!"));

        // Wait for Write Ack
        var udpWriteAck = await MsgBus.UDPServer.WaitForAckAsync(
                endPoint.Address.ToString(), taskID, endPoint.Port, timeout);
        if (!udpWriteAck.IsSuccessful) return new(udpWriteAck.Error);

        return udpWriteAck.Value.IsSuccessful;
    }

    /// <summary>
    /// 向设备地址写入字节数组数据（支持大数据量分段传输）
    /// </summary>
    /// <param name="endPoint">IP端点（IP地址与端口）</param>
    /// <param name="taskID">任务ID</param>
    /// <param name="devAddr">设备地址</param>
    /// <param name="dataArray">要写入的字节数组</param>
    /// <param name="timeout">超时时间（毫秒）</param>
    /// <returns>写入结果，true表示写入成功</returns>
    public static async ValueTask<Result<bool>> WriteAddr(
        IPEndPoint endPoint, int taskID, UInt32 devAddr, byte[] dataArray, int timeout = 1000)
    {
        var ret = false;
        var opts = new SendAddrPackOptions();


        opts.BurstType = BurstType.FixedBurst;
        opts.CommandID = Convert.ToByte(taskID);
        opts.Address = devAddr;

        // Check Msg Bus
        if (!MsgBus.IsRunning)
            return new(new Exception("Message bus not working!"));

        opts.IsWrite = true;
        var hasRest = dataArray.Length % (256 * (32 / 8)) != 0;
        var writeTimes = hasRest ?
            dataArray.Length / (256 * (32 / 8)) + 1 :
            dataArray.Length / (256 * (32 / 8));
        for (var i = 0; i < writeTimes; i++)
        {
            // Sperate Data Array
            var isLastData = i == writeTimes - 1;
            var sendDataArray =
                isLastData ?
                dataArray[(i * (256 * (32 / 8)))..] :
                dataArray[(i * (256 * (32 / 8)))..((i + 1) * (256 * (32 / 8)))];

            // Write Jtag State Register
            opts.BurstLength = ((byte)(sendDataArray.Length / 4 - 1));
            ret = await UDPClientPool.SendAddrPackAsync(endPoint, new SendAddrPackage(opts));
            if (!ret) return new(new Exception("Send 1st address package failed!"));

            // Send Data Package
            ret = await UDPClientPool.SendDataPackAsync(endPoint, new SendDataPackage(sendDataArray));
            if (!ret) return new(new Exception("Send data package failed!"));

            // Wait for Write Ack
            var udpWriteAck = await MsgBus.UDPServer.WaitForAckAsync(endPoint.Address.ToString(), taskID, endPoint.Port, timeout);
            if (!udpWriteAck.IsSuccessful) return new(udpWriteAck.Error);

            if (!udpWriteAck.Value.IsSuccessful)
                return false;
        }

        return true;
    }
}