/* $Id$
 * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
 * For details on use and redistribution please refer to the
 * LICENSE file included with these sources."
 */

package org.apache.fop.image;

// Java
import java.util.Hashtable;
import java.net.URL;

// FOP
import org.apache.fop.datatypes.ColorSpace;
import org.apache.fop.pdf.PDFColor;
import org.apache.fop.pdf.PDFFilter;
import org.apache.fop.image.analyser.ImageReaderFactory;
import org.apache.fop.image.analyser.ImageReader;

/**
 * Base class to implement the FopImage interface.
 * @author Eric SCHAEFFER
 * @see FopImage
 */
public abstract class AbstractFopImage implements FopImage {
  /**
   * Image width (in pixel).
   */
  protected int m_width = 0;
  /**
   * Image height (in pixel).
   */
  protected int m_height = 0;
  /**
   * Image URL.
   */
  protected URL m_href = null;
  /**
   * ImageReader object (to obtain image header informations).
   */
  protected ImageReader m_imageReader = null;
  /**
   * Image color space (org.apache.fop.datatypes.ColorSpace).
   */
  protected ColorSpace m_colorSpace = null;
  /**
   * Bits per pixel.
   */
  protected int m_bitsPerPixel = 0;
  /**
   * Image data (uncompressed).
   */
  protected byte[] m_bitmaps = null;
  /**
   * Image data size.
   */
  protected int m_bitmapsSize = 0;
  /**
   * Image transparency.
   */
  protected boolean m_isTransparent = false;
  /**
   * Transparent color (org.apache.fop.pdf.PDFColor).
   */
  protected PDFColor m_transparentColor = null;

  /**
   * Constructor.
   * Construct a new FopImage object and initialize its default properties:
   * <UL>
   *  <LI>image width
   *  <LI>image height
   * </UL>
   * The image data isn't kept in memory.
   * @param href image URL
   * @return a new FopImage object
   * @exception FopImageException an error occured during initialization
   */
  public AbstractFopImage(URL href) throws FopImageException {
    this.m_href = href;
    try {
      this.m_imageReader = ImageReaderFactory.Make(this.m_href.toExternalForm(), this.m_href.openStream());
    } catch (Exception e) {
      throw new FopImageException(e.getMessage());
    }
    this.m_width = this.m_imageReader.getWidth();
    this.m_height = this.m_imageReader.getHeight();
  }

  /**
    * Constructor.
    * Construct a new FopImage object and initialize its default properties:
    * <UL>
    *  <LI>image width
    *  <LI>image height
    * </UL>
    * The image data isn't kept in memory.
    * @param href image URL
    *        imgReader ImageReader object
    * @return a new FopImage object
    * @exception FopImageException an error occured during initialization
    */
  public AbstractFopImage(URL href, ImageReader imgReader)
	throws FopImageException {
    this.m_href = href;
    this.m_imageReader = imgReader;
    this.m_width = this.m_imageReader.getWidth();
    this.m_height = this.m_imageReader.getHeight();
  }

  /**
   * Load image data and initialize its properties.
   * Subclasses need to implement this method.
   * @exception FopImageException an error occured during loading
   */
  abstract protected void loadImage() throws FopImageException;

  /**
   * Return the image URL.
   * @return the image URL (as String)
   */
  public String getURL() {
    return this.m_href.toString();
  }

  /**
   * Return the image width.
   * @return the image width
   * @exception FopImageException an error occured during property retriaval
   */
  public int getWidth() throws FopImageException {
    if (this.m_width == 0)
      this.loadImage();

    return this.m_width;
  }

  /**
   * Return the image height.
   * @return the image height
   * @exception FopImageException an error occured during property retriaval
   */
  public int getHeight() throws FopImageException {
    if (this.m_height == 0)
      this.loadImage();

    return this.m_height;
  }

  /**
   * Return the image color space.
   * @return the image color space (org.apache.fop.datatypes.ColorSpace)
   * @exception FopImageException an error occured during property retriaval
   */
  public ColorSpace getColorSpace() throws FopImageException {
    if (this.m_colorSpace == null)
      this.loadImage();

    return this.m_colorSpace;
  }

  /**
   * Return the number of bits per pixel.
   * @return number of bits per pixel
   * @exception FopImageException an error occured during property retriaval
   */
  public int getBitsPerPixel() throws FopImageException {
    if (this.m_bitsPerPixel == 0)
      this.loadImage();

    return this.m_bitsPerPixel;
  }

  /**
   * Return the image transparency.
   * @return true if the image is transparent
   * @exception FopImageException an error occured during property retriaval
   */
  public boolean isTransparent() throws FopImageException {
    return this.m_isTransparent;
  }

  /**
   * Return the transparent color.
   * @return the transparent color (org.apache.fop.pdf.PDFColor)
   * @exception FopImageException an error occured during property retriaval
   */
  public PDFColor getTransparentColor() throws FopImageException {
    return this.m_transparentColor;
  }

  /**
   * Return the image data (uncompressed).
   * @return the image data
   * @exception FopImageException an error occured during loading
   */
  public byte[] getBitmaps() throws FopImageException {
    if (this.m_bitmaps == null)
      this.loadImage();

    return this.m_bitmaps;
  }

  /**
   * Return the image data size (uncompressed).
   * @return the image data size
   * @exception FopImageException an error occured during loading
   */
  public int getBitmapsSize() throws FopImageException {
    if (this.m_bitmapsSize == 0)
      this.loadImage();

    return this.m_bitmapsSize;
  }

  /**
   * Return the original image data (compressed).
   * @return the original image data
   * @exception FopImageException an error occured during loading
   */
  public byte[] getRessourceBytes() throws FopImageException {
    return null;
  }

  /**
   * Return the original image data size (compressed).
   * @return the original image data size
   * @exception FopImageException an error occured during loading
   */
  public int getRessourceBytesSize() throws FopImageException {
    return 0;
  }

  /**
   * Return the original image compression type.
   * @return the original image compression type (org.apache.fop.pdf.PDFFilter)
   * @exception FopImageException an error occured during loading
   */
  public PDFFilter getPDFFilter() throws FopImageException {
    return null;
  }

  /**
   * Free all ressource.
   */
  public void close() {
    /* For the moment, only release the bitmaps (image areas
       can share the same FopImage object)
       Thus, even if it had been called, other properties
       are still available.
       */
    //this.m_width = 0;
    //this.m_height = 0;
    //this.m_href = null;
    //this.m_colorSpace = null;
    //this.m_bitsPerPixel = 0;
    this.m_bitmaps = null;
    this.m_bitmapsSize = 0;
    //this.m_isTransparent = false;
    //this.m_transparentColor = null;
  }
}