using LJLib.Net.SPI.Client;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;

namespace LJLib.Client
{
    public sealed class LJClientPool : ILJClient
    {
        private const int DEFAULT_RETRY_COUNT = 1;

        private LJClientCreator _creator;
        private ILJClient[] _clients;
        private bool[] _client_states;
        private object _syncRoot = new object();

        public LJClientPool(LJClientCreator creator, int size)
        {
            _creator = creator;
            _clients = new ILJClient[size];
            _client_states = new bool[size];
            for (int i = 0; i < size; i++)
            {
                _clients[i] = null;
                _client_states[i] = false;
            }
        }
        public string DoExcute(string apiName, string requestJSON)
        {
            int i;
            do
            {
                lock (_syncRoot)
                {
                    for (i = 0; i < _client_states.Length; i++)
                    {
                        if (!_client_states[i])
                        {
                            _client_states[i] = true;
                            break;
                        }
                    }
                }
                if (i >= _client_states.Length)
                {
                    Thread.Sleep(100);
                }
            } while (i >= _client_states.Length);

            try
            {
                int retry = 0;
                string rslt = null;
                while (retry <= DEFAULT_RETRY_COUNT)
                {
                    try
                    {
                        if (_clients[i] == null)
                        {
                            _clients[i] = _creator.newClient();
                        }
                        rslt = _clients[i].DoExcute(apiName, requestJSON);
                        break;
                    }
                    catch (Exception e)
                    {
                        Trace.Write(e.ToString());
                        if (_clients[i] != null)
                        {
                            _clients[i].Dispose();
                            _clients[i] = null;
                        }
                        ++retry;
                        if (retry > DEFAULT_RETRY_COUNT)
                        {
                            throw e;//大于重试次数时异常重抛
                        }
                    }
                }
                return rslt;
            }
            catch (Exception ex)
            {
                Trace.Write(ex.ToString());
                return ex.ToString();
            }
            finally
            {
                _client_states[i] = false;
            }
        }

        public void Beat()
        {
            for (int i = 0; i < _client_states.Length; i++)
            {
                lock (_syncRoot)
                {
                    if (_client_states[i])
                    {
                        continue;
                    }
                    _client_states[i] = true;
                }
                try
                {
                    //空实例无须心跳
                    if (_clients[i] != null)
                    {
                        _clients[i].Beat();
                    }
                }
                catch (Exception e)
                {
                    _clients[i].Dispose();
                    _clients[i] = null;
                    Trace.Write("连接池请求异常" + e.ToString());
                }
                finally
                {
                    _client_states[i] = false;
                }
            }
        }

        public void Dispose()
        {
            for (int i = 0; i < _clients.Length; i++)
            {
                if (_clients[i] != null)
                {
                    _clients[i].Dispose();
                    _clients[i] = null;
                }
            }
        }

    }
}