package com.zcsoft.opc;

/**
 * <p>Title: 現場總線通訊 </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2005－2006</p>
 * <p>Company: Zhicheng Software&Service Co. Ltd.</p>
 * @author 蔣智湘
 * @version 1.0
 */
import java.util.*;
import java.net.*;
import java.io.*;

/**
 * 同OPC控制中心應用程序（OpcCtrl.exe）進行控制通訊的連接類
 * 使用方法示例：
 * <pre>
 *    OpcConnector oc = new OpcConnector();
 *    oc.setProtocol("S7");
 *    oc.setTopic("demo");
 *    Item item1 = new Item();
 *    item1.setID("DB101,DBB1,1");
 *    Item item2 = new Item();
 *    item2.setID("DB101,DBB2,1");
 *    ...
 *    ItemGroup ig1 = new ItemGroup();
 *    ig1.setName("grp1");
 *    ig1.addItem(item1);
 *    ig1.addItem(item2);
 *    ...
 *    oc.addGroup(ig1);
 *    ...
 *    oc.connect();
 * </pre>
 * 當前版本支持的最大加入的變量組的個數上限為32765。對于組上的變量個數的上限也是32765。
 *
 */
public class OpcConnector implements Runnable, CommandSent
{

	/** 通信協議，如S7。該屬性值將作為實際變量名的一部分 */
	private String protocol;
	/** 通信主題，或應用程序名。該屬性值將作為實際變量名的一部分 */
	private String topic;
	/** 是否已經同OPC控制中心建立好了連接 */
	private boolean connected = false;
	/** 所有數據項組的集合 */
	private List groups = new ArrayList(6);
	/** OPC控制中心程序所在機器的IP地址 */
	private InetAddress hostRequest;
	/** OPC控制中心程序接收控制請求的TCP端口 */
	private int portRequest = 8089;
	/** 接收UDP報文的線程 */
	private Thread threadRcv;
	/** 接收OPC控制中心程序發送過來的UDP報文的套接字 */
	private DatagramSocket socketRcvUDP;

	/**
	 * 構造一個在8087端口上監聽UDP報文的實例
	 */
	public OpcConnector() throws SocketException
	{
		this(8087);
	}

	/**
	 *
	 * @param portReceive 該實例使用哪個本機端口接收控制中心發送過來的UDP通知報文
	 */
	public OpcConnector(int portReceive) throws SocketException
	{
		socketRcvUDP = new DatagramSocket(portReceive);
		threadRcv = new Thread(this);
		threadRcv.start();
	}

	public void run()
	{
		byte[] buffer;
		try
		{
			buffer = new byte[Math.min(4096, socketRcvUDP.getReceiveBufferSize())];
		}
		catch (SocketException ex)
		{
			ex.printStackTrace();
			return;
		}
		while (true)
		{
			try
			{
				DatagramPacket dp = new DatagramPacket(buffer, buffer.length);
				socketRcvUDP.receive(dp);
				int readed = dp.getLength();
				int offset = dp.getOffset();
				byte[] data = dp.getData();
				byte firstByte = data[offset++];
				if (firstByte == 'C')//最頻繁出現的數值變化通知
				{
					dataChanged(data, offset, readed - 1);
				}
				else if (firstByte == 'W')//異步寫完成
				{
					writeCompleted(data, offset, readed - 1);
				}
				else if (firstByte == 'R')//異步讀完成
				{
					dataChanged(data, offset, readed - 1);
				}
				else if(firstByte == 'E'//OPC控制中心退出
					&&	bytesABeginWithB(data, offset, new byte[]{'x', 'i', 't'}))
				{
					connected = false;
				}
				else if(firstByte == 'S'//OPC控制中心重新啟動了，就再連上它
					&&	bytesABeginWithB(data, offset, new byte[]{'t', 'a', 'r', 't', 'u', 'p'}))
				{
					try
					{
						connectGroups(groups.size(), true);
					}
					catch (IOException ex)
					{
						ex.printStackTrace();
					}
				}
				else if (firstByte == 'N')//異步操作取消執行完成通知
				{
				}
				else
				{
					System.err.println("Unknown packet");
				}
			}
			catch (IOException ex)
			{
				System.err.println(ex);
				break;
			}
			catch (Exception ex)
			{
				ex.printStackTrace();
			}
		}
		threadRcv = null;
	}

	/**
	 * 判定字節數組A的前B.length各字節同字節數組B的對應字節相同
	 */
	static boolean bytesABeginWithB(byte[] A, int offset, byte[] B)
	{
		if (A.length - offset < B.length) return false;
		for (int i = 0; i < B.length; i++)
		{
			if (A[offset + i] != B[i]) return false;
		}
	  return true;
	}

	public void setProtocol(String protocol)
	{
		checkStatus();
		this.protocol = protocol;
	}

	public void setTopic(String topic)
	{
		checkStatus();
		this.topic = topic;
	}

	/**
	 * 在連接前添加一個變量值實例。
	 *
	 * @param aGroup 不為null的ItemGroup實例
	 */
	public final void addGroup(ItemGroup aGroup)
	{
		checkStatus();
		aGroup.cmdSentHook = this;
		this.groups.add(aGroup);
	}

	private void checkStatus() throws IllegalStateException
	{
		if (connected)
		{
			throw new IllegalStateException("connected");
		}
	}

	/**
	 * 建立本實例同OPC控制中心之間的連接。
	 * @throws IOException 連接過程可能出現的套接字IO異常
	 */
	public void connect() throws IOException
	{
		if (this.topic == null)
		{
			throw new IllegalStateException("Not specify topic");
		}
		if (this.protocol == null)
		{
			throw new IllegalStateException("Not specify protocol");
		}
		int cntGroups = groups.size();
		if (cntGroups == 0)
		{
			throw new OpcException("none group");
		}

		ItemGroup ig;
		int groupIndex;
		//首先查詢組是否被加入
		TcpConnection conn = getConnection();
		conn.writeHeader("Q?" + DELIMETER + cntGroups);
		for (groupIndex = 0; groupIndex < cntGroups; groupIndex++)
		{
			ig = (ItemGroup)groups.get(groupIndex);
			conn.writeHeader(ig.getName());
		}
		//conn.flushHeanders();
		String hdr = conn.readHeader();
		int index = getResultCode(hdr);
		int cntGroupsNoFounded = 0;
		if (index == -1)
		{
			cntGroupsNoFounded = cntGroups;
		}
		else if (index == 0)
		{
			for (groupIndex = 0; (hdr = conn.readHeader()) != null && groupIndex < cntGroups; groupIndex++)
			{
				ig = (ItemGroup)groups.get(groupIndex);
				ig.index = index = Integer.parseInt(hdr);
//				debug(ig.getName() + "->index = " + index);
				if (index < 0)	++cntGroupsNoFounded;//累加未加入的組
				//else 記錄已經加入的組，準備調用刷新操作
			}
		}
		else
		{
			conn.close();
			throw new OpcException(hdr);
		}
		conn.close();

		//如果存在已經加入的組，則刷新變量值
		if (cntGroupsNoFounded != cntGroups)
		{
			refreshGroups();
		}

		//如果還有沒加入組，則嘗試加入
		if (cntGroupsNoFounded > 0)
		{
			connectGroups(cntGroupsNoFounded, false);
		}
		connected = true;
	}

	public TcpConnection getConnection() throws IOException
	{
		if (hostRequest == null) hostRequest = InetAddress.getByName(null);
		return new TcpConnection(hostRequest, portRequest);
	}

	/**
	 * 將變量組加到OPC控制中心
	 * @param cntGroupsToConnect 待連接的組的個數
	 * @param refresh 是否對那些已經確定索引值的組的索引值進行再確定
	 */
	void connectGroups(int cntGroupsToConnect, boolean refresh) throws IOException
	{
		TcpConnection conn = getConnection();
		String header;
		header = "AD" + DELIMETER + cntGroupsToConnect +  DELIMETER + this.socketRcvUDP.getLocalPort();
		conn.writeHeader(header);
		//System.out.println(header);
		String idPrefix = this.protocol + ":[" + this.topic + "]";
		Item item;
		int itemIndex, itemCount;
		int groupIndex, cntGroups = groups.size();
		ItemGroup ig;
		for (groupIndex = 0; groupIndex < cntGroups; groupIndex++)
		{
			ig = (ItemGroup)groups.get(groupIndex);
			if (!refresh && ig.index != -1) continue;
			itemCount = ig.itemCount();
			header = ig.getName() + DELIMETER + 'D'//(ig.isActive()?'A':'D')
			//只能在加入后單獨設定激活狀態才有效。不然在這個方法還沒有執行完成前，就收到了dataChanged報文
			//此時getGroupAt(int)很可能返回null
								+ DELIMETER + itemCount
								+ DELIMETER + ig.getUpdateRate();
			conn.writeHeader(header);
			//System.out.println("\t" + header);
			for (itemIndex = 0; itemIndex < itemCount; itemIndex++)
			{
				item = ig.getItem(itemIndex);
				header = idPrefix.concat(item.ID)
									  + DELIMETER + (item.active?'A':'D')
									  + DELIMETER + item.value.vt;
				conn.writeHeader(header);
				//System.out.println("\t\t" + header);
			}
		}
		//conn.flushHeanders();
		String hdr = conn.readHeader();
		if (getResultCode(hdr) != 0)
		{
			conn.close();
			throw new OpcException(hdr);
		}
		for (groupIndex = 0; groupIndex < cntGroups; groupIndex++)
		{
			ig = (ItemGroup)groups.get(groupIndex);
			if (!refresh && ig.index != -1) continue;
			hdr = conn.readHeader();
			if (hdr != null)
			{
				ig.index = Integer.parseInt(hdr);
//				debug(ig.getName() + ".index = " + ig.index);
			}
		}
		conn.close();
		//激活實際需要激活的變量組
		activateGroups();
	}


	void activateGroups() throws IOException
	{
		int groupIndex, cntGroups = groups.size();
		ItemGroup ig;
		TcpConnection conn = getConnection();
		conn.writeHeader("AC A" + DELIMETER + cntGroups);
		for (groupIndex = 0; groupIndex < cntGroups; groupIndex++)
		{
			ig = (ItemGroup)groups.get(groupIndex);
			if (ig.index >= 0 && ig.isActive())