package javafx.scene.media;

import java.io.IOException;
import java.io.InputStream;

/**
 * This class is used to provide media data to a {@code Media} object.
 */
public class MediaInputStream {
    
    /**
     * Enumeration of media stream types.
     */
    public enum StreamType {
        /**
         * Auto detect stream type.
         */
        AUTO_DETECT,
        /**
         * MPEG-1, 2, 2.5 raw audio stream possibly with ID3 metadata v2.3 or v2.4.
         */
        MP3,
        /**
         * MPEG-4 Part 14.
         */
        MP4
    };
    
    private InputStream inputStream = null;
    private StreamType streamType = StreamType.AUTO_DETECT;
    private long length = -1;
    private boolean enableProgressBuffer = true;
    
    /**
     * Constructs a <code>MediaInputStream</code> instance.
     */
    public MediaInputStream() {        
    }
    
    /**
     * Constructs a <code>MediaInputStream</code> instance with media data read from the specified input stream.
     * 
     * @param inputStream the stream from which to read media data.
     * @param streamType the type of media data. Use <code>StreamType.AUTO_DETECT</code> or <code>null</code> for auto detect stream type.
     * @param length the length of entire media data;
     * 
     * @throws NullPointerException if the InputStream is <code>null</code>.
     */
    public MediaInputStream(InputStream inputStream, StreamType streamType, long length) {
        if (inputStream == null) {
            throw new NullPointerException();
        }
        
        this.inputStream = inputStream;
        this.streamType = streamType;
        this.length = length;        
    }
    
    /**
     * Get stream type. Default value is <code>StreamType.AUTO_DETECT</code>.
     * 
     * @return the stream type of media data.
     */    
    public final StreamType getStreamType() {
        return streamType;
    }
        
    /**
     * Get length of entire media data. Default value is -1.
     * 
     * @return the length of entire media data.
     */
    public final long getLength() {
        return length;
    }
    
    /**
     * Get whether to enable progress buffer internally or not. Default value is <code>true</code>.
     * {@link MediaInputStream.seek} should be implemented if enableProgressBuffer() will return false.
     */
    public final boolean enableProgressBuffer() {
        return enableProgressBuffer;
    }
    
    /**
     * Read media data.
     * This function can block, if data is not yet available.
     * 
     * @param data the buffer into which the data is read.
     * 
     * @return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
     */
    public int read(byte[] data) throws IOException {
        return inputStream.read(data);
    }
    
    /**
     * Read media data from specified position.
     * This function can block, if data is not yet available.
     * Implement this method if you need advanced functionality such as metadata support.
     * 
     * @param data the buffer into which the data is read.
     * @param position the byte position from which the data should be read.
     * 
     * @return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
     */
    public synchronized int read(byte[] data, long position) throws IOException {
        return -1;
    }
    
    /**
     * Seek media stream to new position.
     * This function should not block. Instead block read if media data is not yet available.
     * 
     * @param position seek position.
     * 
     * @return true if seek was performed or false if seek failed.
     */
    public boolean seek(long position) throws IOException {
        return false;
    }
    
    /**
     * Called when we no longer will request data. All blocked calls such as read() should be unblocked.
     */
    public void close() throws IOException {
        if (inputStream != null) {
            inputStream.close();
            inputStream = null;
        }
    }
    
    /**
     * Set stream type.
     * 
     * @param streamType the stream type of media data.
     */
    protected final void setStreamType(StreamType streamType) {
        this.streamType = streamType;
    }    
    
    /**
     * Set whether to enable progress buffer internally or not.
     * 
     * @param enableProgressBuffer indicates whether to enable progress buffer or not.
     */
    protected final void setEnableProgressBuffer(boolean enableProgressBuffer) {
        this.enableProgressBuffer = enableProgressBuffer;
    }
    
    /**
     * Set length of entire media data.
     * 
     * @param length the length of entire media data.
     */
    protected final void setLength(long length) {
        this.length = length;
    }
}