/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package alterrs.asm.optimizer;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;

import alterrs.asm.ClassReader;
import alterrs.asm.ClassWriter;
import alterrs.asm.commons.Remapper;
import alterrs.asm.commons.SimpleRemapper;

/**
 * A class file shrinker utility.
 * 
 * @author Eric Bruneton
 * @author Eugene Kuleshov
 */
public class Shrinker {

	static final Properties MAPPING = new Properties();

	public static void main(final String[] args) throws IOException {
		int n = args.length - 1;
		for (int i = 0; i < n - 1; ++i) {
			MAPPING.load(new FileInputStream(args[i]));
		}
		final Set unused = new HashSet(MAPPING.keySet());

		File f = new File(args[n - 1]);
		File d = new File(args[n]);

		optimize(f, d, new SimpleRemapper(MAPPING) {
			public String map(String key) {
				String s = super.map(key);
				if (s != null) {
					unused.remove(key);
				}
				return s;
			}
		});

		Iterator i = unused.iterator();
		while (i.hasNext()) {
			String s = (String) i.next();
			if (!s.endsWith("/remove")) {
				System.out.println("INFO: unused mapping " + s);
			}
		}
	}

	static void optimize(final File f, final File d, final Remapper remapper)
			throws IOException {
		if (f.isDirectory()) {
			File[] files = f.listFiles();
			for (int i = 0; i < files.length; ++i) {
				optimize(files[i], d, remapper);
			}
		} else if (f.getName().endsWith(".class")) {
			ConstantPool cp = new ConstantPool();
			ClassReader cr = new ClassReader(new FileInputStream(f));
			ClassWriter cw = new ClassWriter(0);
			ClassConstantsCollector ccc = new ClassConstantsCollector(cw, cp);
			ClassOptimizer co = new ClassOptimizer(ccc, remapper);
			cr.accept(co, ClassReader.SKIP_DEBUG);

			Set constants = new TreeSet(new ConstantComparator());
			constants.addAll(cp.values());

			cr = new ClassReader(cw.toByteArray());
			cw = new ClassWriter(0);
			Iterator i = constants.iterator();
			while (i.hasNext()) {
				Constant c = (Constant) i.next();
				c.write(cw);
			}
			cr.accept(cw, ClassReader.SKIP_DEBUG);

			if (MAPPING.getProperty(cr.getClassName() + "/remove") != null) {
				return;
			}
			String n = remapper.mapType(cr.getClassName());
			File g = new File(d, n + ".class");
			if (!g.exists() || g.lastModified() < f.lastModified()) {
				g.getParentFile().mkdirs();
				OutputStream os = new FileOutputStream(g);
				os.write(cw.toByteArray());
				os.close();
			}
		}
	}

	static class ConstantComparator implements Comparator {

		public int compare(final Object o1, final Object o2) {
			Constant c1 = (Constant) o1;
			Constant c2 = (Constant) o2;
			int d = getSort(c1) - getSort(c2);
			if (d == 0) {
				switch (c1.type) {
				case 'I':
					return new Integer(c1.intVal).compareTo(new Integer(
							c2.intVal));
				case 'J':
					return new Long(c1.longVal).compareTo(new Long(c2.longVal));
				case 'F':
					return new Float(c1.floatVal).compareTo(new Float(
							c2.floatVal));
				case 'D':
					return new Double(c1.doubleVal).compareTo(new Double(
							c2.doubleVal));
				case 's':
				case 'S':
				case 'C':
					return c1.strVal1.compareTo(c2.strVal1);
				case 'T':
					d = c1.strVal1.compareTo(c2.strVal1);
					if (d == 0) {
						d = c1.strVal2.compareTo(c2.strVal2);
					}
					break;
				default:
					d = c1.strVal1.compareTo(c2.strVal1);
					if (d == 0) {
						d = c1.strVal2.compareTo(c2.strVal2);
						if (d == 0) {
							d = c1.strVal3.compareTo(c2.strVal3);
						}
					}
				}
			}
			return d;
		}

		private static int getSort(final Constant c) {
			switch (c.type) {
			case 'I':
				return 0;
			case 'J':
				return 1;
			case 'F':
				return 2;
			case 'D':
				return 3;
			case 's':
				return 4;
			case 'S':
				return 5;
			case 'C':
				return 6;
			case 'T':
				return 7;
			case 'G':
				return 8;
			case 'M':
				return 9;
			default:
				return 10;
			}
		}
	}
}
