src/com/plusminus/craft/MineCraftEnvironment.java

package com.plusminus.craft;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

import sun.security.action.GetBooleanAction;

/***
 * Utility class which has convenience methods to access the
 * files of the current minecraft installation
 * @author Vincent Vollers
 */
public class MineCraftEnvironment {
	public static enum OS {XP, Vista, MacOS, Linux, NotSupported};
	public static OS os; 
	public static File baseDir;
	
	static {
		String os = System.getProperty( "os.name" );
		HashMap<String,OS> osData = new HashMap<String,OS>();
		/*  Full list of os.name strings
		    AIX
			Digital Unix
			FreeBSD
			HP UX
			Irix
			Linux
			Mac OS
			Mac OS X
			MPE/iX
			Netware 4.11
			OS/2
			Solaris
			Windows 2000
			Windows 7
			Windows 95
			Windows 98
			Windows NT
			Windows Vista
			Windows XP
		 */
		osData.put("FreeBSD", 	OS.Linux);
		osData.put("HP UX", 	OS.Linux);
		osData.put("Linux", 	OS.Linux);
		osData.put("Mac OS", 	OS.MacOS);
		osData.put("Mac OS X", 	OS.MacOS);
		osData.put("Windows", 	OS.XP);
		osData.put("Windows 7", OS.Vista);
		osData.put("Windows XP", OS.XP);
		osData.put("Windows 2003", OS.XP);
		osData.put("Windows 2000", OS.XP);
		osData.put("Windows Vista", OS.Vista);
		
		if(!osData.containsKey(os)) {
			MineCraftEnvironment.os = OS.NotSupported;
		} else {
			MineCraftEnvironment.os = osData.get(os);
		}
		
		switch(MineCraftEnvironment.os) {
			case Vista:
				MineCraftEnvironment.baseDir = new File(System.getenv("APPDATA"), ".minecraft");
				break;
			case Linux:
				MineCraftEnvironment.baseDir = new File(System.getProperty("user.home"), ".minecraft"); // untested
				break;
			case XP:
				MineCraftEnvironment.baseDir = new File(System.getenv("APPDATA"), ".minecraft"); // untested
				break;
			case MacOS:
				// damn macs ;p
				File dotMinecraftEnv = new File(System.getProperty("user.home"), "Library/Application Support/.minecraft");
				if(dotMinecraftEnv.exists()) {
					MineCraftEnvironment.baseDir = dotMinecraftEnv;
				} else {
					MineCraftEnvironment.baseDir = new File(System.getProperty("user.home"), "Library/Application Support/minecraft"); // untested
				}
				break;
			default:
				MineCraftEnvironment.baseDir = null;
		}
		System.out.println(MineCraftEnvironment.baseDir.getAbsolutePath());
	}
	
	/***
	 * Returns a list of integers corresponding to available worlds
	 * @return
	 */
	public static ArrayList<Integer> getAvailableWorlds() {
		ArrayList<Integer> worlds = new ArrayList<Integer>();
		for(int i=0;i<10;i++) {
			File worldDir = getWorldDirectory(i);
			if(worldDir.exists() && worldDir.canRead()) {
				worlds.add(i);
			}
		}
		return worlds;
	}
	
	/***
	 * Returns a file handle to a chunk file in a world
	 * @param world
	 * @param x
	 * @param z
	 * @return
	 */
	public static File getChunkFile(int world, int x, int z) {
		int xx = x % 64;
		if(xx<0) xx = 64+xx;
		int zz = z % 64;
		if(zz<0) zz = 64+zz;
		String firstFolder 		= Integer.toString(xx, 36);
		String secondFolder 	= Integer.toString(zz, 36);
		String filename 		= "c." + Integer.toString(x, 36) + "." + Integer.toString(z, 36) + ".dat";
		return new File(getWorldDirectory(world), firstFolder + "/" + secondFolder + "/" + filename);
	}
	
	/***
	 * Returns a file handle to a base world directory
	 * @param world
	 * @return
	 */
	public static File getWorldDirectory(int world) {
		return new File(baseDir, "saves/World" + world);
	}
	
	/***
	 * Returns a file handle to the base minecraft directory
	 * @return
	 */
	public static File getMinecraftDirectory() {
		return MineCraftEnvironment.baseDir;
	}
	
	/***
	 * Returns a stream to the texture data (overrides in the directory are handled)
	 * @return
	 */
	public static InputStream getMinecraftTextureData() {
		return getMinecraftFile("terrain.png");
	}
	
	/***
	 * Returns a stream to the font data (overrides in the directory are handled)
	 * @return
	 */
	public static InputStream getMinecraftFontData() {
		return getMinecraftFile("default.png");
	}
	
	/***
	 * Attempts to create a bufferedImage for a stream
	 * @param i
	 * @return
	 */
	private static BufferedImage buildImageFromInput(InputStream i) {
		try {
			return ImageIO.read(i);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
	}
	
	/***
	 * Attempts to create a bufferedImage containing the texture sprite sheet
	 * @return
	 */
	public static BufferedImage getMinecraftTexture() {
		return buildImageFromInput(getMinecraftTextureData());
	}
	
	/***
	 * Attempts to create a bufferedImage containing the font
	 * @return
	 */
	public static BufferedImage getMinecraftFont() {
		return buildImageFromInput(getMinecraftFontData());
	}
	
	/***
	 * Creates an Inputstream to a file in the bin/ directory in the minecraft directory.
	 * This handles overrides. If a file exists in the bin/ directory it will load that.
	 * Otherwise it will look in the .jar file of minecraft
	 * @param fileName
	 * @return
	 */
	public static InputStream getMinecraftFile(String fileName){
		File overrideFile = new File(baseDir, "bin/" + fileName);

		if(overrideFile.exists()) {
			try {
				return new FileInputStream(overrideFile);
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				return null;
			}
		}
		
		File minecraftDataFile = new File(baseDir, "bin/minecraft.jar");
		if(!minecraftDataFile.exists()) {
			return null;
		}
		try {
			JarFile jf = new JarFile(minecraftDataFile);
			ZipEntry zipEntry = jf.getEntry(fileName);
			if(zipEntry == null) {
				return null;
			}
			return jf.getInputStream(zipEntry);
		} catch (IOException e) {
			System.out.println(e.toString());
			return null;
		}
	}
}