package slim.util;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import slim.engine.Image2D;
import slim.engine.SlimException;

/**
 * A small SpriteSheet utility based on Properties files. Format:
 * <pre>
 *     #my sprite sheet... 
 *     #4 comma-separated ints per key; white space ignored
 *     char1 = 0, 0, 32, 32
 *     char2 = 32, 32, 32, 32
 *     hud = 50, 55, 100, 150
 * </pre>
 * 
 * @author davedes
 */
public class SimpleSpriteSheet {
   
   private HashMap<String, Image2D> sprites = new HashMap<String, Image2D>();
   private Image2D sheet;
   
   public SimpleSpriteSheet(URL sheetDef, Image2D sheetImage) throws SlimException {
      this.sheet = sheetImage;
      Properties p;
      try {
         InputStream in = sheetDef.openStream();
         p = new Properties();
         p.load(in);
         in.close();
      } catch (IOException e) {
         throw new SlimException("error loading sprite sheet "+e.getMessage(), e);
      }
      sprites = new HashMap<String, Image2D>();
      for (Map.Entry<Object, Object> e : p.entrySet()) {
         String k = String.valueOf(e.getKey());
         Object v = e.getValue();
         String[] s = v!=null ? v.toString().trim().split(",") : null; 
         sprites.put(k, toimg(k, s));
      }
   }
   
   private Image2D toimg(String key, String[] s) throws SlimException {
      if (s==null || s.length<4)
         throw new SlimException("invalid value for key "+key);
      try { 
         int x = Integer.parseInt(s[0].trim());
         int y = Integer.parseInt(s[1].trim());
         int w = Integer.parseInt(s[2].trim());
         int h = Integer.parseInt(s[3].trim());
         return sheet.getSubImage(x, y, w+1, h+1);
      } catch (NumberFormatException e) {
         throw new SlimException("invalid int values for key "+key+" "+Arrays.toString(s));
      }
   }
   
   public int size() {
      return sprites.size();
   }

   public Image2D getSprite(String key) {
      return sprites.get(key);
   }
   
   public HashMap<String, Image2D> sprites() {
      return sprites;
   }
}