/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware;

import android.os.ParcelFileDescriptor;

import java.io.FileDescriptor;
import java.io.IOException;

import java.nio.ByteBuffer;

@hide
/**
 * @hide
 */
public class SerialPort {

    private static final String TAG = "SerialPort";

    // used by the JNI code
    private int mNativeContext;
    private final String mName;
    private ParcelFileDescriptor mFileDescriptor;

    
SerialPort should only be instantiated by SerialManager
@hide
/**
     * SerialPort should only be instantiated by SerialManager
     * @hide
     */
    public SerialPort(String name) {
        mName = name;
    }

    
SerialPort should only be instantiated by SerialManager
Speed must be one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
19200, 38400, 57600, 115200, 230400, 460800, 500000, 576000, 921600, 1000000, 1152000,
1500000, 2000000, 2500000, 3000000, 3500000, 4000000
@hide
/**
     * SerialPort should only be instantiated by SerialManager
     * Speed must be one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
     * 19200, 38400, 57600, 115200, 230400, 460800, 500000, 576000, 921600, 1000000, 1152000,
     * 1500000, 2000000, 2500000, 3000000, 3500000, 4000000
     *
     * @hide
     */
    public void open(ParcelFileDescriptor pfd, int speed) throws IOException {
        native_open(pfd.getFileDescriptor(), speed);
        mFileDescriptor = pfd;
    }

    
Closes the serial port
/**
     * Closes the serial port
     */
    public void close() throws IOException {
        if (mFileDescriptor != null) {
            mFileDescriptor.close();
            mFileDescriptor = null;
        }
        native_close();
    }

    
Returns the name of the serial port
Returns:
the serial port's name/**
     * Returns the name of the serial port
     *
     * @return the serial port's name
     */
    public String getName() {
        return mName;
    }

    
Reads data into the provided buffer. Note that the value returned by Buffer.position() on this buffer is unchanged after a call to this method. 
Params:
buffer – to read into
Returns:
number of bytes read/**
     * Reads data into the provided buffer.
     * Note that the value returned by {@link java.nio.Buffer#position()} on this buffer is
     * unchanged after a call to this method.
     *
     * @param buffer to read into
     * @return number of bytes read
     */
    public int read(ByteBuffer buffer) throws IOException {
        if (buffer.isDirect()) {
            return native_read_direct(buffer, buffer.remaining());
        } else if (buffer.hasArray()) {
            return native_read_array(buffer.array(), buffer.remaining());
        } else {
            throw new IllegalArgumentException("buffer is not direct and has no array");
        }
    }

    
Writes data from provided buffer. Note that the value returned by Buffer.position() on this buffer is unchanged after a call to this method. 
Params:
buffer – to write
length – number of bytes to write/**
     * Writes data from provided buffer.
     * Note that the value returned by {@link java.nio.Buffer#position()} on this buffer is
     * unchanged after a call to this method.
     *
     * @param buffer to write
     * @param length number of bytes to write
     */
    public void write(ByteBuffer buffer, int length) throws IOException {
        if (buffer.isDirect()) {
            native_write_direct(buffer, length);
        } else if (buffer.hasArray()) {
            native_write_array(buffer.array(), length);
        } else {
            throw new IllegalArgumentException("buffer is not direct and has no array");
        }
    }

    
Sends a stream of zero valued bits for 0.25 to 0.5 seconds
/**
     * Sends a stream of zero valued bits for 0.25 to 0.5 seconds
     */
    public void sendBreak() {
        native_send_break();
    }

    private native void native_open(FileDescriptor pfd, int speed) throws IOException;
    private native void native_close();
    private native int native_read_array(byte[] buffer, int length) throws IOException;
    private native int native_read_direct(ByteBuffer buffer, int length) throws IOException;
    private native void native_write_array(byte[] buffer, int length) throws IOException;
    private native void native_write_direct(ByteBuffer buffer, int length) throws IOException;
    private native void native_send_break();
}