using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO.Ports;

namespace Mesnac.Communication
{
    /// <summary>
    /// 串口通讯服务类
    /// </summary>
    public class SerialPortService
    {
        #region 单例实现

        private static SerialPortService instance = null;
        private Dictionary<int, SerialPort> _dicSerialPort = null;  //保存串口对象的集合

        private SerialPortService() 
        {
            if (this._dicSerialPort == null)
            {
                this._dicSerialPort = new Dictionary<int, SerialPort>();
            }
        }

        public static SerialPortService Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new SerialPortService();
                }
                return instance;
            }
        }

        #endregion
        
        #region 获取串口对象

        /// <summary>
        /// 获取串口对象
        /// </summary>
        /// <param name="portName">串口名称</param>
        /// <param name="baudRate">波特率</param>
        /// <returns>返可用的串口对象</returns>
        public SerialPort GetSerialPort(string portName, int baudRate)
        {
            SerialPort currSerialPort = null;
            foreach (SerialPort sp in this._dicSerialPort.Values)
            {
                if (sp.PortName == portName && sp.BaudRate == baudRate)
                {
                    currSerialPort = sp;
                    break;
                }
            }
            if (currSerialPort == null)
            {
                currSerialPort = new SerialPort();
                currSerialPort.PortName = portName;
                currSerialPort.BaudRate = baudRate;
                currSerialPort.Encoding = System.Text.Encoding.Default;
                this._dicSerialPort.Add(currSerialPort.GetHashCode(), currSerialPort);
            }
            try
            {
                if (currSerialPort.IsOpen)
                {
                    currSerialPort.Close();
                    currSerialPort.Open();
                }
                else
                {
                    currSerialPort.Open();
                }
            }
            catch (Exception ex)
            {
                ICSharpCode.Core.LoggingService.Warn(String.Format("串口{0}关闭或打开失败，重新创建串口对象!", portName));
                this._dicSerialPort.Remove(currSerialPort.GetHashCode());
                currSerialPort = new SerialPort();
                currSerialPort.PortName = portName;
                currSerialPort.BaudRate = baudRate;
                currSerialPort.Encoding = System.Text.Encoding.Default;
                this._dicSerialPort.Add(currSerialPort.GetHashCode(), currSerialPort);
                currSerialPort.Open();
            }
            return currSerialPort;
        }

        #endregion
    }
}