package com.dev.modbus;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

import com.base.ComBase;
import com.base.Crc16;


public class MyModBusRtu {
	public static final int BYTE_LEN = 7;
	
	public static final short CMD_TYPE_READ 			= 0x03;			//读保持寄存器

	public static final short CMD_TYPE_READ_INPUT 		= 0x04;			//读输入寄存器
	
	public static final short CMD_TYPE_WRITE_YC 		= 0x05;
	public static final short CMD_TYPE_WRITE_STD 		= 0x06;			//单点写入
	public static final short CMD_TYPE_WRITE_MULTY 		= 0x10;			//多点写入

	
	public int addr = 0xFF;			//设备地址
	public int Cmd;				//功能码
	public int reg_addr;		//寄存器地址
	public int reg_count;		//寄存器数量
	
	public int data_count;		//数据区字节数量
	
	public int result;			//返回操作结果
	
	public int crc;				//crc校验
	
	public int write_value;		//单点写入时的数值
	
	public MyModBusRtu() {
		
	}
	
	public MyModBusRtu(int Cmd,int reg_addr) {
		this.Cmd = Cmd;
		this.reg_addr = reg_addr;
	}
	
	public MyModBusRtu(int addr) {
		this.addr = addr;
	}
	
	
	public void mkBusRtu(int Cmd,int reg_addr) {
		this.Cmd = Cmd;
		this.reg_addr = reg_addr;
	}

	public void mkBusRtu(int Cmd,int reg_addr,int reg_count) {
		this.Cmd = Cmd;
		this.reg_addr = reg_addr;
		this.reg_count = reg_count;
	}
	
	public void mkBusRtu(int addr,int Cmd,int reg_addr,int reg_count) {
		this.addr = addr;
		this.Cmd = Cmd;
		this.reg_addr = reg_addr;
		this.reg_count = reg_count;
	}
	
	public void clear() {
		this.addr = 0;  			//设备地址
		this.Cmd = 0;				//功能码
		this.reg_addr = 0;			//寄存器地址
		this.reg_count = 0;			//寄存器数量
		
		this.data_count = 0;		//数据区字节数量
		this.result = 0;			//返回操作结果
	}

		/**
     * 	构造基础发送数据
     * @return
     */
    public ByteBuffer mkByteBuffer()
    {
        ByteBuffer bytebuffer = ByteBuffer.allocate(BYTE_LEN);
        bytebuffer.order(ByteOrder.BIG_ENDIAN);
        bytebuffer.position(0);
        bytebuffer.put(ComBase.changeIntToByte(addr));
        bytebuffer.put(ComBase.changeIntToByte(Cmd));
        bytebuffer.putShort(ComBase.changeIntToShort(reg_addr));
        
        if(CMD_TYPE_WRITE_STD == Cmd || CMD_TYPE_WRITE_YC == Cmd) {
        	
        }else if(CMD_TYPE_WRITE_MULTY == Cmd) {    
        	//多点写入时,每个寄存器4个字节
        	bytebuffer.putShort(ComBase.changeIntToShort(reg_count));
        	bytebuffer.put(ComBase.changeIntToByte(reg_count*4));
        } else {
        	bytebuffer.putShort(ComBase.changeIntToShort(reg_count));
        }
        bytebuffer.flip();
        return bytebuffer;
    }
	

	public boolean putByteBuffer(final ByteBuffer bf)
	{
		if(bf.limit() < BYTE_LEN)
			return false;

		ByteBuffer tmpbuf = bf;
		int crc0 = tmpbuf.getShort(bf.limit()-2) & 0xFFFF; 
	
		int crc1 = Crc16.CalCRC16(tmpbuf, bf.limit()-2) & 0xFFFF;
		if(crc0 != crc1) {
			System.err.println("CRC error  "+crc0+"==="+crc1);
			return false;
		}
		tmpbuf.position(0);
		
		this.addr = tmpbuf.get()&0xFF;  			//设备地址
		this.Cmd = tmpbuf.get()&0xFF;				//功能码
		
		if(CMD_TYPE_READ == this.Cmd) {
			this.data_count = tmpbuf.getShort()&0xFFFF;				
		}else if(CMD_TYPE_READ_INPUT == this.Cmd){
			this.data_count = tmpbuf.get()&0xFF;
		}else if(CMD_TYPE_WRITE_STD == this.Cmd || CMD_TYPE_WRITE_YC == this.Cmd || CMD_TYPE_WRITE_MULTY == this.Cmd){
			//设置时的返回结果			
			this.reg_addr = tmpbuf.getShort()&0xFFFF;			//寄存器地址
			this.result = tmpbuf.getShort()&0xFFFF;
		}
		
		tmpbuf.compact();
		tmpbuf.flip();
		
		return true;
	}
	
	public static void main(String[] args) {
		byte[] data = new byte[] {(byte) 0xa0 ,(byte)0xdd,0x6c ,0x23,0x26,0x16};
		ByteBuffer bf = ByteBuffer.allocate(data.length);
		bf.order(ByteOrder.BIG_ENDIAN);
		bf.put(data);
		System.out.println(Crc16.CalCRC16(bf, bf.limit())&0xFFFF);

		
		System.out.println(Crc16.CalCRC16(data, bf.limit())&0xFFFF);
	}
	
}