package stdlib;
/* ***********************************************************************
 *  Compilation:  javac Picture.java
 *  Execution:    java Picture imagename
 *
 *  Data type for manipulating individual pixels of an image. The original
 *  image can be read from a file in jpg, gif, or png format, or the
 *  user can create a blank image of a given size. Includes methods for
 *  displaying the image in a window on the screen or saving to a file.
 *
 *  % java Picture mandrill.jpg
 *
 *  Remarks
 *  -------
 *   - pixel (x, y) is column x and row y, where (0, 0) is upper left
 *
 *   - see also GrayPicture.java for a grayscale version
 *
 *************************************************************************/

import java.awt.Color;
import java.awt.FileDialog;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.KeyStroke;
import javax.swing.WindowConstants;


/**
 *  This class provides methods for manipulating individual pixels of
 *  an image. The original image can be read from a file in JPEG, GIF,
 *  or PNG format, or the user can create a blank image of a given size.
 *  This class includes methods for displaying the image in a window on
 *  the screen or saving to a file.
 *  <p>
 *  By default, pixel (x, y) is column x, row y, where (0, 0) is upper left.
 *  The method setOriginLowerLeft() change the origin to the lower left.
 *  <p>
 *  For additional documentation, see
 *  <a href="http://introcs.cs.princeton.edu/31datatype">Section 3.1</a> of
 *  <i>Introduction to Programming in Java: An Interdisciplinary Approach</i>
 *  by Robert Sedgewick and Kevin Wayne.
 */
public final class Picture implements ActionListener {
  private BufferedImage image;               // the rasterized image
  private JFrame frame;                      // on-screen view
  private String filename;                   // name of file
  private boolean isOriginUpperLeft = true;  // location of origin
  private final int width, height;           // width and height

  /**
   * Create a blank w-by-h picture, where each pixel is black.
   */
  public Picture(int w, int h) {
    width = w;
    height = h;
    image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    // set to TYPE_INT_ARGB to support transparency
    filename = w + "-by-" + h;
  }

  /**
   * Copy constructor.
   */
  public Picture(Picture pic) {
    width = pic.width();
    height = pic.height();
    image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    filename = pic.filename;
    for (int i = 0; i < width(); i++)
      for (int j = 0; j < height(); j++)
        image.setRGB(i, j, pic.get(i, j).getRGB());
  }

  /**
   * Create a picture by reading in a .png, .gif, or .jpg from
   * the given filename or URL name.
   */
  public Picture(String filename) {
    this.filename = filename;
    try {
      // try to read from file in working directory
      File file = new File(filename);
      if (file.isFile()) {
        image = ImageIO.read(file);
      }

      // now try to read from file in same directory as this .class file
      else {
        URL url = getClass().getResource(filename);
        if (url == null) { url = new URL(filename); }
        image = ImageIO.read(url);
      }
      width  = image.getWidth(null);
      height = image.getHeight(null);
    }
    catch (IOException e) {
      // e.printStackTrace();
      throw new RuntimeException("Could not open file: " + filename);
    }
  }

  /**
   * Create a picture by reading in a .png, .gif, or .jpg from a File.
   */
  public Picture(File file) {
    try { image = ImageIO.read(file); }
    catch (IOException e) {
      e.printStackTrace();
      throw new RuntimeException("Could not open file: " + file);
    }
    if (image == null) {
      throw new RuntimeException("Invalid image file: " + file);
    }
    width  = image.getWidth(null);
    height = image.getHeight(null);
    filename = file.getName();
  }

  /**
   * Return a JLabel containing this Picture, for embedding in a JPanel,
   * JFrame or other GUI widget.
   */
  public JLabel getJLabel() {
    if (image == null) { return null; }         // no image available
    ImageIcon icon = new ImageIcon(image);
    return new JLabel(icon);
  }

  /**
   * Set the origin to be the upper left pixel.
   */
  public void setOriginUpperLeft() {
    isOriginUpperLeft = true;
  }

  /**
   * Set the origin to be the lower left pixel.
   */
  public void setOriginLowerLeft() {
    isOriginUpperLeft = false;
  }

  /**
   * Display the picture in a window on the screen.
   */
  public void show() {

    // create the GUI for viewing the image if needed
    if (frame == null) {
      frame = new JFrame();

      JMenuBar menuBar = new JMenuBar();
      JMenu menu = new JMenu("File");
      menuBar.add(menu);
      JMenuItem menuItem1 = new JMenuItem(" Save...   ");
      menuItem1.addActionListener(this);
      menuItem1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
          Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
      menu.add(menuItem1);
      frame.setJMenuBar(menuBar);



      frame.setContentPane(getJLabel());
      // frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);        // closes all windows
      frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);      // closes only current window
      frame.setTitle(filename);
      frame.setResizable(false);
      frame.pack();
      frame.setVisible(true);
    }

    // draw
    frame.repaint();
  }

  /**
   * Return the height of the picture in pixels.
   */
  public int height() {
    return height;
  }

  /**
   * Return the width of the picture in pixels.
   */
  public int width() {
    return width;
  }

  /**
   * Return the color of pixel (i, j).
   */
  public Color get(int i, int j) {
    if (isOriginUpperLeft) return new Color(image.getRGB(i, j));
    else                   return new Color(image.getRGB(i, height - j - 1));
  }

  /**
   * Set the color of pixel (i, j) to c.
   */
  public void set(int i, int j, Color c) {
    if (c == null) { throw new RuntimeException("can't set Color to null"); }
    if (isOriginUpperLeft) image.setRGB(i, j, c.getRGB());
    else                   image.setRGB(i, height - j - 1, c.getRGB());
  }

  /**
   * Is this Picture equal to obj?
   */
  public boolean equals(Object obj) {
    if (obj == this) return true;
    if (obj == null) return false;
    if (obj.getClass() != this.getClass()) return false;
    Picture that = (Picture) obj;
    if (this.width()  != that.width())  return false;
    if (this.height() != that.height()) return false;
    for (int x = 0; x < width(); x++)
      for (int y = 0; y < height(); y++)
        if (!this.get(x, y).equals(that.get(x, y))) return false;
    return true;
  }


  /**
   * Save the picture to a file in a standard image format.
   * The filetype must be .png or .jpg.
   */
  public void save(String name) {
    save(new File(name));
  }

  /**
   * Save the picture to a file in a standard image format.
   */
  public void save(File file) {
    this.filename = file.getName();
    if (frame != null) { frame.setTitle(filename); }
    String suffix = filename.substring(filename.lastIndexOf('.') + 1);
    suffix = suffix.toLowerCase();
    if (suffix.equals("jpg") || suffix.equals("png")) {
      try { ImageIO.write(image, suffix, file); }
      catch (IOException e) { e.printStackTrace(); }
    }
    else {
      System.out.println("Error: filename must end in .jpg or .png");
    }
  }

  /**
   * Opens a save dialog box when the user selects "Save As" from the menu.
   */
  public void actionPerformed(ActionEvent e) {
    FileDialog chooser = new FileDialog(frame,
        "Use a .png or .jpg extension", FileDialog.SAVE);
    chooser.setVisible(true);
    if (chooser.getFile() != null) {
      save(chooser.getDirectory() + File.separator + chooser.getFile());
    }
  }


  /**
   * Test client. Reads a picture specified by the command-line argument,
   * and shows it in a window on the screen.
   */
  public static void main(String[] args) {
    Picture pic = new Picture(args[0]);
    System.out.format("%d-by-%d\n", pic.width(), pic.height());
    pic.show();
  }

}