package com.c2kernel.gui;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Hashtable;

import javax.swing.ImageIcon;

import com.c2kernel.common.ObjectNotFoundException;
import com.c2kernel.process.Gateway;
import com.c2kernel.utils.Logger;

public class ImageLoader {

    static private Hashtable<String, ImageIcon> imgCache = new Hashtable<String, ImageIcon>();
    static public final ImageIcon nullImg = new ImageIcon(new byte[] { 0 });
    static private final ArrayList<String> reportedMissingIcons = new ArrayList<String>();

    /**
     * Gets an image from the resource directories
     *
     * @param resName - filename after resources/images
     * @return
     */
    static public ImageIcon findImage(String resName) {
        try {
        	for (String ns : Gateway.getResource().getModuleBaseURLs().keySet()) {
        		try {
        			return getImage(ns, resName);
        		} catch (ObjectNotFoundException ex) { }
			}
            return getImage(null, resName);
        } catch (ObjectNotFoundException ex) {
        	if (!reportedMissingIcons.contains(resName)) {
        		Logger.warning("Image '"+resName+"' not found. Using null icon");
        		reportedMissingIcons.add(resName);
        	}
            return nullImg;
        }
    }

    static public ImageIcon getImage(String ns, String resName) throws ObjectNotFoundException {
        if (resName == null)
            return nullImg;

        if (imgCache.containsKey(ns+'/'+resName)) {
            return imgCache.get(ns+'/'+resName);
        }

        URL imgLocation = null;
        if (ns == null) 
        	try {
        		imgLocation = Gateway.getResource().getKernelResourceURL("images/"+resName);
        	} catch (MalformedURLException ex) { }
        else
        	try {
        		imgLocation = Gateway.getResource().getModuleResourceURL(ns, "images/"+resName);
        	} catch (MalformedURLException ex) { }
        
        if (imgLocation!= null) {
        	ImageIcon newImg = new ImageIcon(imgLocation);

        	if (newImg.getIconHeight() > -1) {
        		imgCache.put(ns+'/'+resName, newImg);
                Logger.msg(3, "Loaded "+resName+" "+newImg.getIconWidth()+"x"+newImg.getIconHeight());
                return newImg;
        	}
        }
        throw new ObjectNotFoundException();
    }

}