package yaokong;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class BaseStationCommandSender extends WaitForAck {

    public BaseStationCommandSender(InputStream inputStream, OutputStream outputStream) {
        super(inputStream, outputStream);
    }

    // 发送基站经纬度和方向信息至设备
    public boolean sendBaseStationCommand(double latitude, double longitude,
                                          char latDirection, char lonDirection) throws IOException {
        ByteBuffer buffer = ByteBuffer.allocate(2 + 1 + 2 + 2 + 32 + 2 + 1);
        buffer.order(ByteOrder.LITTLE_ENDIAN);
        
        // 帧头
        buffer.put(BluetoothProtocol.FRAME_HEADER);
        // 指令类型
        buffer.put(BluetoothProtocol.CMD_BASE_STATION);
        // 数据长度
        buffer.putShort((short) 32);
        // 序列号
        buffer.putShort((short) BluetoothProtocol.getNextSequence());
        // 纬度
        buffer.putDouble(latitude);
        // 经度
        buffer.putDouble(longitude);
        // 方向
        buffer.put((byte) latDirection);
        buffer.put((byte) lonDirection);
        // 保留字段（14字节）
        for (int i = 0; i < 14; i++) {
            buffer.put((byte) 0x00);
        }
        
        // 计算CRC16
        byte[] dataForCRC = new byte[1 + 2 + 2 + 32];
        System.arraycopy(buffer.array(), 2, dataForCRC, 0, dataForCRC.length);
        int crc = CRC16.calculateCRC16(dataForCRC, 0, dataForCRC.length);
        buffer.putShort((short) crc);
        
        // 帧尾
        buffer.put(BluetoothProtocol.FRAME_FOOTER);
        
        outputStream.write(buffer.array());
        outputStream.flush();
        
        return waitForAck(BluetoothProtocol.CMD_BASE_STATION);
    }
}