import javax.microedition.io.*;
import java.io.*;

/**
 * 該類描述了藍牙連接，提供了發送/接收數據的功能。
 */
public class BTConnection implements Runnable {
    //
    private GobangMIDlet midlet;
    private StreamConnection sconn; //流連接
    private DataOutputStream dos;   //數據輸出流，用于發送數據
    private DataInputStream dis;    //數據輸入流，用于接收數據
    private boolean connected;      //是否連接
    private Thread sendThread;      //發送數據線程
    private Thread receiveThread;   //接收數據線程
    private int[] sendData; //發送數據緩存區
    
    //構造方法，創建藍牙連接對象
    public BTConnection(GobangMIDlet midlet, StreamConnection sconn) throws IOException {
        this.midlet = midlet;
        this.sconn = sconn;
        dos = sconn.openDataOutputStream();
        dis = sconn.openDataInputStream();
        sendData = new int[2];
        connected = true;
        
        //創建并啟動接收\發送數據線程
        receiveThread = new Thread(this);
        sendThread = new Thread(this);
        receiveThread.start();
        sendThread.start();
    }
    
    //發送數據
    public void send(final int x, final int y) {
        sendData[0] = x;
        sendData[1] = y;
        
        synchronized(this) {
            notifyAll();    //通知發送線程發送緩沖區中的數據
        }
    }
    
    //關閉連接
    public void close() {
        if(connected) {
            try {
                connected = false;
                dos.close();
                dos = null;
                dis.close();
                dis = null;
                sconn.close();
                sconn = null;
                synchronized(this) {
                    notifyAll();
                }
            }
            catch(IOException ioe) {
                
            }
        }
    }
    
    //接收/發送數據線程執行體
    public void run() {
        while(connected) {
            try {
                //發送數據線程
                if(Thread.currentThread() == sendThread) {
                    synchronized(this) {
                        try {
                            wait(); //等待通知
                        }
                        catch(InterruptedException ie) {
                            System.out.println("ie = " + ie);
                        }
                    }
                    if(dos != null) {
                        dos.writeInt(sendData[0]);
                        dos.writeInt(sendData[1]);
                    }
                }
                //接收數據線程
                else if(Thread.currentThread() == receiveThread) {
                    if(dis != null) {
                        //讀取數據，如果流中沒有數據，該方法將阻塞當前線程。
                        int x = dis.readInt();
                        int y = dis.readInt();
                        midlet.otherPlay(x, y); //對方下子
                    }
                }
            }
            catch(IOException ioe) {
                close();
                midlet.release();
            }
        }
    }
}