using System;
using System.Diagnostics;

namespace Bro.Common.Link
{
    /// <summary>
    /// 设备的连接基类
    /// </summary>
    public abstract class LinkBase
    {
        // 默认保存数据缓存长度
        public const int        DFT_BUFF_LEN    = 4096;

        // 连接对象接收缓存大小
        public const int        DFT_SEND_BUFF_LEN   = 4096;
        // 连接对象发送缓存大小
        public const int        DFT_RECV_BUFF_LEN   = 4096;

        // 连接描述
        public string   Desp { get;set;}
        // 初始化状态
        public bool     IsInit { get;set; }
        // 连接状态
        public bool     IsConn { get;set;}
        // 接收缓存长度
        public int      BufferLen { get;set;}
        // 接收缓存大小
        public int      SendBuffLen { get;set;}
        // 发送缓存大小
        public int      RecvBuffLen { get;set;}

        // 接收缓存
        protected byte[] rcvBuf = null;

        // 连接状态
        public LinkBase()
        {
            Desp        = this.GetType().Name;
            IsInit      = false;
            IsConn      = false;
            SendBuffLen = DFT_SEND_BUFF_LEN;
            RecvBuffLen = DFT_RECV_BUFF_LEN;
            BufferLen   = DFT_BUFF_LEN;

        }

        /// <summary>
        /// 连接初始化
        /// </summary>
        /// <returns></returns>
        public virtual bool Init()
        {
            if ( IsInit )
            {
                return true;
            }

            try
            {
                rcvBuf = new byte[BufferLen];

                return true;
            }
            catch(Exception ex)
            {
                Trace.TraceError("Link:{0} Init fail, ex:{1}-{2}", this.Desp, ex.Message, ex.StackTrace);
            }

            return false;
        }

        /// <summary>
        /// 打开连接
        /// </summary>
        /// <returns></returns>
        public abstract bool Open();

        /// <summary>
        /// 关闭连接
        /// </summary>
        public abstract void Close();

        /// <summary>
        /// 销毁
        /// </summary>
        public abstract void Fnit();

        /// <summary>
        /// 接收数据
        /// </summary>
        /// <param name="rcvBuf"></param>
        /// <param name="offset"></param>
        /// <returns></returns>
        public abstract int Recv(byte[] rcvBuf, int offset);

        /// <summary>
        /// 发送数据
        /// </summary>
        /// <param name="sndBuf"></param>
        /// <returns></returns>
        public abstract bool Send(byte[] sndBuf, int offset, int len);

    }


}