/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.video;

import java.io.Closeable;
import java.util.Iterator;

import org.openimaj.image.Image;

/**
 * Abstract base class for videos.
 * 
 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * @author David Dupplaw (dpd@ecs.soton.ac.uk)
 * 
 * @param <T>
 *            the image type of the frames
 */
public abstract class Video<T extends Image<?, T>> implements Iterable<T>, Closeable
{
        /** The number of frames per second */
        // protected double fps = -1;

        /** The current frame being displayed */
        protected int currentFrame;

        /**
         * Get the next frame. Increments the frame counter by 1.
         * 
         * @return the next frame
         */
        public abstract T getNextFrame();

        /**
         * Get the current frame
         * 
         * @return the current frame
         */
        public abstract T getCurrentFrame();

        /**
         * Get the width of the video frame
         * 
         * @return the width of the video frame.
         */
        public abstract int getWidth();

        /**
         * Get the height of the video frame.
         * 
         * @return the height of the video frame.
         */
        public abstract int getHeight();

        /**
         * Get the timestamp of the current frame in milliseconds
         * 
         * @return the time stamp in milliseconds
         */
        public abstract long getTimeStamp();

        // /**
        // * Determine how many milliseconds each frame needs
        // * to be displayed for
        // *
        // * @return the time to show each frame in ms
        // */
        // public long getMilliPerFrame()
        // {
        // if(this.getFPS() < 0) return 1;
        // return (long) (1000 * (1.0/this.getFPS()));
        // }
        //
        /**
         * Get the frame rate
         * 
         * @return the frame rate
         */
        public abstract double getFPS();

        // /**
        // * Set the frame rate
        // *
        // * @return the frame rate
        // */
        // public void setFPS(double fps)
        // {
        // this.fps = fps;
        // }

        /**
         * Get the index of the current frame
         * 
         * @return the current frame index
         */
        public synchronized int getCurrentFrameIndex()
        {
                return currentFrame;
        }

        /**
         * Set the current frame index (i.e. skips to a certain frame). If your
         * video subclass can implement this in a cleverer way, then override this
         * method, otherwise this method will simply grab frames until it gets to
         * the given frame index. This method is naive and may take some time as
         * each frame will be decoded by the video decoder.
         * 
         * @param newFrame
         *            the new index
         */
        public synchronized void setCurrentFrameIndex(long newFrame)
        {
                // We're already at the frame?
                if (this.currentFrame == newFrame)
                        return;

                // If we're ahread of where we want to be
                if (this.currentFrame > newFrame)
                {
                        this.reset();
                }

                // Grab frames until we read the new frame counter
                // (or until the getNextFrame() method returns null)
                while (this.currentFrame < newFrame && getNextFrame() != null)
                        ;
        }

        /**
         * Seek the video to a given timestamp in SECONDS. Many videos (including
         * cameras etc.) will have no ability to seek so by default this function
         * does nothing.
         * 
         * @param timestamp
         */
        public void seek(double timestamp) {

        }

        /**
         * Returns whether this video has another frame to provide.
         * 
         * @return Whether the video has another frame available
         */
        public abstract boolean hasNextFrame();

        /**
         * Return the number of frames in the whole video. If the video is a live
         * stream, then this method should return -1.
         * 
         * @return the number of frames in the whole video or -1 if unknown
         */
        public abstract long countFrames();

        /**
         * Reset the video - putting the frame counter back to the start.
         */
        public abstract void reset();

        @Override
        public Iterator<T> iterator() {
                return new VideoIterator<T>(this);
        }

        /**
         * Close the video object
         */
        @Override
        public void close() {

        }
}