package cse1030;

import java.awt.MediaTracker;
import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.swing.ImageIcon;

/**
 * A model for the image viewer app. The model represents a sequence of
 * images. It supports traversal through the sequence of images by providing
 * methods for getting the previous image in the sequence, the current image
 * in the sequence, and the next image in the sequence. Images
 * 
 * @author CSE1030Z
 *
 */
public class ViewerModel {
  private static final ImageIcon EMPTY_IMAGE = new ImageIcon();

  private int currentImageIndex;     // the index in this.images for the current image
  private List<ImageIcon> images;    // the images

  /**
   * Create the model.
   */
  public ViewerModel() {
    /*
    You need to implement:

    set the current image index to -1 to indicate that there are no images
    create a new empty list of images
    */


  }

  /**
   * Get the current image in the model. Returns an empty image if the model has no images.
   * 
   * @return the current image if the model has one or more images, or an empty
   *         image otherwise
   */
  public ImageIcon getCurrentImage() {
    /*
    You need to implement:

    if there are no images in the model
      return an empty image
    else
      return the current image
    */


  }

  /**
   * Get the next image in the model and makes the next image the current image.
   * Returns the current image if the current image is the last image in the
   * model. Returns an empty image if the model has no images.
   * 
   * @return the next image in the model 
   */
  public ImageIcon getNextImage() {
    /*
    You need to implement:

    if there are no images in the model
      return an empty image
    else if the current image is the last image
      return the current image
    else
      increase the current image index by 1, and
      return the current image
    */


  }

  /**
   * Get the previous image in the model and makes the previous image the current image.
   * Returns the current image if the current image is the first image in the
   * model. Returns an empty image if the model has no images.
   * 
   * @return the previous image in the model
   */
  public ImageIcon getPreviousImage() {
    /*
    You need to implement:

    if there are no images in the model
      return an empty image
    else if the current image is the first image
      return the current image
    else
      decrease the current image index by 1, and
      return the current image
    */


  }

  /**
   * Clear the images held by the model.
   */
  public void clearImages() {
    /*
    You need to implement:

    set the current image index to -1 to indicate that there are no images
    clear the list of images
    */

    
  }
  


  /**
   * Read an array of image files into the model. The images are added to the end
   * of the sequence of images in the model. Image file formats supported
   * include JPEG, PNG, and GIF.
   * 
   * @param files an array of <code>File</code> references to open
   */
  public void openImages(File[] files) {
    List<ImageIcon> icons = new ArrayList<ImageIcon>();
    for (File f : files) {
      ImageIcon icon = new ImageIcon(f.getAbsolutePath());
      if (icon.getImageLoadStatus() == MediaTracker.COMPLETE) {
        icons.add(icon);
      }
    }
    if (this.currentImageIndex < 0 && icons.size() > 0) {
      this.currentImageIndex = 0;
    }
    this.images.addAll(icons);
  }

}