/*
 * Copyright (c) 2003-2004 Christopher Lenz and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: CssStructureCreator.java,v 1.1 2004-09-02 18:11:49 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.ui.internal.compare;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;

import net.sourceforge.phpeclipse.core.model.ISourceReference;
import net.sourceforge.phpeclipse.css.core.internal.parser.DefaultCssParser;
import net.sourceforge.phpeclipse.css.core.internal.text.CssTextUtils;
import net.sourceforge.phpeclipse.css.core.model.IAtRule;
import net.sourceforge.phpeclipse.css.core.model.IDeclaration;
import net.sourceforge.phpeclipse.css.core.model.IRule;
import net.sourceforge.phpeclipse.css.core.model.IStyleRule;
import net.sourceforge.phpeclipse.css.core.parser.ICssParser;
import net.sourceforge.phpeclipse.css.core.parser.LexicalErrorException;
import net.sourceforge.phpeclipse.css.core.parser.SyntaxErrorException;
import net.sourceforge.phpeclipse.css.ui.CssUI;
import net.sourceforge.phpeclipse.css.ui.internal.CssUIMessages;
import net.sourceforge.phpeclipse.css.ui.text.CssTextTools;

import org.eclipse.compare.IStreamContentAccessor;
import org.eclipse.compare.internal.DocumentManager;
import org.eclipse.compare.structuremergeviewer.IStructureComparator;
import org.eclipse.compare.structuremergeviewer.IStructureCreator;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;

/**
 * TODO Check why the root node is not being displayed
 */
public class CssStructureCreator implements IStructureCreator {

	// IStructureCreator Implementation ----------------------------------------

	/*
	 * @see IStructureCreator#getName()
	 */
	public String getName() {
		return CssUIMessages.getString(
			"CssStructureViewer.title"); //$NON-NLS-1$
	}

	/*
	 * @see IStructureCreator#getStructure(Object)
	 */
	public IStructureComparator getStructure(final Object input) {
		IDocument doc = DocumentManager.get(input);
		if (doc == null) {
			if (input instanceof IStreamContentAccessor) {
				doc = createDocument((IStreamContentAccessor) input);
			}
		}
		if (doc != null) {
			CssNode node = new CssNode(doc);
			ICssParser parser = new DefaultCssParser();
			parser.setSource(doc);
			try {
				IRule[] rules = parser.parseRules(null);
				for (int i = 0; i < rules.length; i++) {
					node.addChild(createNode(node, rules[i], new HashMap()));
				}
			} catch (LexicalErrorException e) {
				// just return null
			} catch (SyntaxErrorException e) {
				// just return null
			}
			return node;
		}
		return null;
	}

	/*
	 * @see IStructureCreator#locate(Object, Object)
	 */
	public IStructureComparator locate(Object path, Object input) {
		// TODO Find out what locate() is about and implement the functionality
		return null;
	}

	/*
	 * @see IStructureCreator#getContents(Object, boolean)
	 */
	public String getContents(Object node, boolean ignoreWhitespace) {
		if (node instanceof CssNode) {
			CssNode cssNode = (CssNode) node;
			int ch;
			InputStream in = null;
			try {
				StringBuffer buf = new StringBuffer();
				in = cssNode.getContents();
				while ((ch = in.read()) != -1) {
					if (!ignoreWhitespace
					 || !CssTextUtils.isCssWhitespace((char) ch)) {
						buf.append((char) ch);
					}
				}
				return buf.toString();
			} catch (IOException e) {
				// just return an empty string
			} finally {
				if (in != null) {
					try {
						in.close();
					} catch (IOException e1) {
						// ignore
					}
				}
			}
		}
		return ""; //$NON-NLS-1$
	}

	/*
	 * @see IStructureCreator#save(IStructureComparator, Object)
	 */
	public void save(IStructureComparator node, Object input) {
		// TODO Find out what save() is about and implement the functionality
	}

	// Private Methods ---------------------------------------------------------

	private IDocument createDocument(IStreamContentAccessor content) {
		IDocument document = null;
		InputStreamReader in = null;
		try {
			in = new InputStreamReader(content.getContents());
			StringBuffer buf = new StringBuffer();
			int ch;
			while ((ch = in.read()) != -1) {
				buf.append((char) ch);
			}
			document = new Document(buf.toString());
			DocumentManager.put(content, document);
			CssTextTools tools = CssUI.getDefault().getTextTools();
			tools.setupDocument(document);
		} catch (CoreException e) {
			CssUI.log(e);
		} catch (IOException e) {
			CssUI.log(e);
		} finally {
			if (in != null) {
				try {
					in.close();
				} catch (IOException e) {
					// ignore
				}
			}
		}
		return document;
	}

	private CssNode createNode(CssNode parent, IRule rule, Map names) {
		int typeCode = -1;
		String name = ""; //$NON-NLS-1$
		if (rule instanceof IAtRule) {
			IAtRule atRule = (IAtRule) rule;
			typeCode = CssNode.AT_RULE;
			ISourceReference atKeyword = atRule.getName();
			if (atKeyword != null) {
				name = atKeyword.getSource();
			}
		} else if (rule instanceof IStyleRule) {
			IStyleRule styleRule = (IStyleRule) rule;
			typeCode = CssNode.STYLE_RULE;
			ISourceReference selector = styleRule.getSelector();
			if (selector != null) {
				name = selector.getSource();
			}
		}
		String id = name;
		if (names.containsKey(name)) {
			Integer count = (Integer) names.get(name);
			id += count.toString();
			names.put(name, new Integer(count.intValue() + 1));
		} else {
			names.put(name, new Integer(0));
		}
		IRegion region = rule.getSourceRegion();
		CssNode node = new CssNode(parent, typeCode, id, name,
			region.getOffset(), region.getLength());
		IRule[] children = rule.getChildren();
		if (children.length > 0) {
			Map ruleNames = new HashMap();
			for (int i = 0; i < children.length; i++) {
				node.addChild(createNode(node, children[i], ruleNames));
			}
		}
		IDeclaration[] properties = rule.getDeclarations();
		if (properties.length > 0) {
			Map propertyNames = new HashMap();
			for (int i = 0; i < properties.length; i++) {
				node.addChild(createNode(node, properties[i], propertyNames));
			}
		}
		return node;
	}

	private CssNode createNode(CssNode parent, IDeclaration declaration,
		Map names) {
		String name = ""; //$NON-NLS-1$
		ISourceReference property = declaration.getProperty();
		if (property != null) {
			name = property.getSource();
		}
		String id = name;
		if (names.containsKey(name)) {
			Integer count = (Integer) names.get(name);
			id += count.toString();
			names.put(name, new Integer(count.intValue() + 1));
		} else {
			names.put(name, new Integer(0));
		}
		IRegion region = declaration.getSourceRegion();
		return new CssNode(parent, CssNode.DECLARATION, id, name,
			region.getOffset(), region.getLength());
	}

}