/*
 * Copyright 2008 Wishnu Prasetya.
 *
 * This file is part of T2.
 * T2 is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License (GPL) as published by the
 * Free Software Foundation; either version 3 of the License, or any
 * later version.
 * 
 * T2 is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * A copy of the GNU General Public License can be found in T2 distribution.
 * If it is missing, see http://www.gnu.org/licenses.
 */
package t2ext.weaver;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import t2ext.util.FileCopy;
import t2ext.util.InfoFile;
import t2ext.util.Util;
import t2ext.weaver.utils.Template;
import t2ext.xml.XMLBuilder;

/**
 * FIXME when the classInfo.xml contains whitespace the getChildNodes() calls
 *       return more results than normally. Some of which are unexpected.
 * 
 * @author Maaike Gerritsen
 */
public class WeaverCreator {
	Element _classInfo;

	public void createWeaver() {
		Document doc = (new XMLBuilder()).readXMLFile(FileCopy.TEMP_DIR+"classInfo.xml");
		NodeList list = doc.getChildNodes();
		_classInfo = (Element) list.item(0);
		StringBuilder total = new StringBuilder();
		total.append(Template.getPackage());
		total.append(Template.getImports());
		total.append(Template.getClassOpener());
		total.append(Template.getFieldAuxMethods());
		total.append("\n");
		total.append(Template.getInitialisationPointCut(getClassName()));
		total = appendPointCuts(total);
		total.append(Template.getInitialisationAdvice());
		total.append(Template.getCloseBracket());
		writeToFile(total.toString());
	}

	private StringBuilder appendPointCuts(StringBuilder total) {
		NodeList methods = _classInfo.getChildNodes();
		InfoFile infoFile = InfoFile.load();
		int id = 0;
		for(int i=0;i<methods.getLength();i++) {
			if(!methods.item(i).getNodeName().equals("method"))
				continue;
			Element method = (Element) methods.item(i);
			String methodName = createMethodName(method);
			boolean endMethod = getEndMethod(infoFile.endMethods, methodName);
			total.append(Template.getPointCut(methodName, id));
			if (endMethod) {
				total.append(Template.getAroundPointcut(methodName, id));
				total.append(Template.getAroundAdvice(methodName, id));
			}
			String smallName = createSmallBranchName(method);
			total.append(Template.getBeforeAdvice(smallName, id, endMethod));
			total.append(Template.getAfterAdvice(smallName, id, endMethod));
			id++;
			String branchMethodName = createBranchMethodName(method);
			total.append(Template.getPointCut(branchMethodName, id));
			total.append(Template.getAdvice(methodName, smallName, id, endMethod));
			id++;
		}
		return total;
	}

	private boolean getEndMethod(boolean endMethods, String methodName) {
		return endMethods && !methodName.contains("_spec");
	}

	private String createBranchMethodName(Element method) {
		StringBuilder builder = new StringBuilder();
		builder.append(getClassName());
		builder.append(".");
		builder.append(createSmallBranchName(method));
		builder.append("*()");
		return builder.toString();
	}

	private String createSmallBranchName(Element method) {
		StringBuilder builder = new StringBuilder();
		builder.append("aux_");
		builder.append(method.getAttribute("name").toString());
		builder.append("_");
		
		StringBuilder args = new StringBuilder();
		int argcount = 0;
		NodeList arguments = method.getChildNodes();
		for(int i=0;i<arguments.getLength();i++) {
			if(!arguments.item(i).getNodeName().equals("argument"))
				continue;
			argcount++;
			Element arg = (Element) arguments.item(i);
			String value = arg.getAttribute("name").toString();
			value = Util.replaceIllegalChars(value);
			args.append(value);
		}
		builder.append(argcount);
		builder.append(args);
		return builder.toString();
	}
	
	private String createMethodName(Element method) {
		StringBuilder builder = new StringBuilder();
		builder.append(getClassName());
		builder.append(".");
		builder.append(method.getAttribute("name").toString());
		builder.append("(");
		NodeList children = method.getChildNodes();
		String name = "";
		for(int i=0;i<children.getLength();i++) {
			if(!children.item(i).getNodeName().equals("argument"))
				continue;
			Element argument = (Element) children.item(i);
			name = name + argument.getAttribute("name").toString() + ",";
		}
		if (name.length() > 0) {
			name = name.substring(0, name.length() - 1);
			builder.append(name);
		}
		builder.append(")");
		return builder.toString();
	}

	private String getClassName() {
		return _classInfo.getAttribute("name").toString();
	}

	private void writeToFile(String total) {
		// TODO paths?
		File weaverDir = new File(FileCopy.TEMP_DIR+"t2ext/weaver");
		if (weaverDir.mkdirs()) {
			File file = new File(weaverDir.getAbsolutePath() + "/Weaver.aj");
			System.out.println("Writing aspect "+file);
			try {
				FileOutputStream fStream = new FileOutputStream(file);
				BufferedOutputStream out = new BufferedOutputStream(fStream);
				out.write(total.getBytes());
				out.flush();
				out.close();
			} catch(IOException e) {
				System.out.println("Failed to write to "+file);
				e.printStackTrace();
				System.exit(1);
			}
		}
		else {
			System.out.println("Failed to create "+weaverDir);
			System.exit(1);
		}
	}

}