package android_serialport_api;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Google官方代码
 * 此类的作用为,JNI的调用,用来加载.so文件的
 * 获取串口输入输出流
 */
public class SerialPort {
    private FileDescriptor mFd;
    private FileInputStream mFileInputStream;
    private FileOutputStream mFileOutputStream;

    static {
        System.loadLibrary("serial_port");
    }

    public SerialPort(String devicePath, int baudRate, int flags) throws SecurityException {
        this(new File(devicePath), baudRate, flags);
    }

    private SerialPort(File device, int baudRate, int flags) throws SecurityException {
        if (!device.canRead() || !device.canWrite()) {
            try {
                Process su = Runtime.getRuntime().exec("/system/bin/su");
                String cmd = "chmod 666 " + device.getAbsolutePath() + "\n" + "exit\n";
                su.getOutputStream().write(cmd.getBytes());
                if ((su.waitFor() != 0) || !device.canRead() || !device.canWrite()) {
                    throw new RuntimeException("没有串口权限");
                }
            } catch (Exception e) {
                throw new RuntimeException("提权失败" + e.getMessage(), e);
            }
        }
        mFd = open(device.getAbsolutePath(), baudRate, flags);
        mFileInputStream = new FileInputStream(mFd);
        mFileOutputStream = new FileOutputStream(mFd);
    }

    public InputStream getInputStream() {
        return mFileInputStream;
    }

    public OutputStream getOutputStream() {
        return mFileOutputStream;
    }

    private native static FileDescriptor open(String path, int baudrate, int flags);

    public native void close();
}