using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

public class BleUDP : MonoBehaviour
{
    public static BleUDP ins; //单例记录

    readonly string localIP = "127.0.0.1"; //本地IP
    readonly int myPort = 8001; //自身的注册端口
    readonly int targetPort = 8000; //发消息的目标端口
    Socket client; //UDP对象

    float noneMsgTime = 0; //多久没收到字节消息了
    Queue<byte[]> byteQueue = new Queue<byte[]>(); //接收信息的线程把字节信息放这里
    Queue<byte[]> byteMainQueue = new Queue<byte[]>(); //主线程从byteQueue中取出数据后放在这里，供主线程update使用

    public Action OnConnected;
    public Action OnConnectionFailed;
    public Action<byte[]> OnCharacteristicChanged;
    public Action OnScanEnded;

    [NonSerialized] public BluetoothStatusEnum bluetoothStatusEnum = BluetoothStatusEnum.Connect;

    void Awake()
    {
        if (ins)
        {
            Destroy(this.gameObject);
            return;
        }
        ins = this;
        DontDestroyOnLoad(this.gameObject);

        client = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        client.Bind(new IPEndPoint(IPAddress.Parse(localIP), myPort));
        Thread threadReciveMsg = new Thread(ReciveMsg);
        threadReciveMsg.Start();
    }

    void OnDestroy()
    {
        if (ins == this) ins = null;
        client.Close();
    }

    void Update()
    {
        lock (byteQueue)
        {
            while (byteQueue.Count > 0)
            {
                byteMainQueue.Enqueue(byteQueue.Dequeue());
            }
        }
        if (bluetoothStatusEnum == BluetoothStatusEnum.Connecting)
        {
            if (noneMsgTime > 5)
            {
                bluetoothStatusEnum = BluetoothStatusEnum.ConnectFail;
                EmitOnConnectionFailed();
                return;
            }
            else if (byteMainQueue.Count > 0)
            {
                bluetoothStatusEnum = BluetoothStatusEnum.ConnectSuccess;
                EmitOnConnected();
            }
        }
        else if (bluetoothStatusEnum == BluetoothStatusEnum.ConnectSuccess)
        {
            if (noneMsgTime > 5)
            {
                bluetoothStatusEnum = BluetoothStatusEnum.ConnectFail;
                EmitOnConnectionFailed();
            }
        }
        else
        {
            byteMainQueue.Clear();
            return;
        }
        if (byteMainQueue.Count == 0)
        {
            noneMsgTime += Time.deltaTime;
            return;
        }
        noneMsgTime = 0;
        while (byteMainQueue.Count > 0)
        {
            EmitOnCharacteristicChanged(byteMainQueue.Dequeue());
        }
    }

    public void SendMsg(string data)
    {
        Debug.LogWarning("sendMsgToBle: " + data);
        EndPoint point = new IPEndPoint(IPAddress.Parse(localIP), targetPort);
        client.SendTo(Encoding.UTF8.GetBytes(data), point);
    }

    void ReciveMsg()
    {
        while (true)
        {
            EndPoint point = new IPEndPoint(IPAddress.Any, 0);
            byte[] buffer = new byte[1024];
            int length = client.ReceiveFrom(buffer, ref point);
            if (!point.ToString().EndsWith(targetPort.ToString())) return;
            if (length <= 0) continue;
            byte[] bytes = new byte[length];
            Array.Copy(buffer, bytes, length);
            lock (byteQueue)
            {
                byteQueue.Enqueue(bytes);
            }
        }
    }

    public void ScanNearbyDevices()
    {
        EmitOnScanEnded();
    }

    public void Connect()
    {
        noneMsgTime = 0;
        bluetoothStatusEnum = BluetoothStatusEnum.Connecting;
        SendMsg("V");
    }

    public void Disconnect()
    {
        bluetoothStatusEnum = BluetoothStatusEnum.Connect;
    }

    void EmitOnConnected()
    {
        try
        {
            OnConnected?.Invoke();
        }
        catch (Exception) { }
    }

    void EmitOnConnectionFailed()
    {
        try
        {
            OnConnectionFailed?.Invoke();
        }
        catch (Exception) { }
    }

    void EmitOnCharacteristicChanged(byte[] bytes)
    {
        try
        {
            OnCharacteristicChanged?.Invoke(bytes);
        }
        catch (Exception) { }
    }

    void EmitOnScanEnded()
    {
        try
        {
            OnScanEnded?.Invoke();
        }
        catch (Exception) { }
    }
}