/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Zend Technologies - adapt for PHP refactoring
 *******************************************************************************/
package org.eclipse.php.refactoring.core.code.flow;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.runtime.Assert;
import org.eclipse.php.core.ast.nodes.ITypeBinding;
import org.eclipse.php.core.ast.nodes.IVariableBinding;
import org.eclipse.php.core.ast.nodes.TryStatement;

public class FlowContext {

	private static class Enum {
	}

	public static final Enum MERGE = new Enum();
	public static final Enum ARGUMENTS = new Enum();
	public static final Enum RETURN_VALUES = new Enum();

	private int fStart;
	private int fLength;
	private boolean fConsiderAccessMode;
	private boolean fLoopReentranceMode;
	private Enum fComputeMode;
	private IVariableBinding[] fLocals;
	private List fExceptionStack;

	private static final List EMPTY_CATCH_CLAUSE = new ArrayList(0);

	public FlowContext(int start, int length) {
		fStart = start;
		fLength = length;
		fExceptionStack = new ArrayList(3);
	}

	public void setConsiderAccessMode(boolean b) {
		fConsiderAccessMode = b;
	}

	public void setComputeMode(Enum mode) {
		fComputeMode = mode;
	}

	void setLoopReentranceMode(boolean b) {
		fLoopReentranceMode = b;
	}

	int getArrayLength() {
		return fLength;
	}

	int getStartingIndex() {
		return fStart;
	}

	boolean considerAccessMode() {
		return fConsiderAccessMode;
	}

	boolean isLoopReentranceMode() {
		return fLoopReentranceMode;
	}

	boolean computeMerge() {
		return fComputeMode == MERGE;
	}

	boolean computeArguments() {
		return fComputeMode == ARGUMENTS;
	}

	boolean computeReturnValues() {
		return fComputeMode == RETURN_VALUES;
	}

	public IVariableBinding getLocalFromId(int id) {
		return getLocalFromIndex(id - fStart);
	}

	public IVariableBinding getLocalFromIndex(int index) {
		if (fLocals == null || index > fLocals.length)
			return null;
		return fLocals[index];
	}

	public int getIndexFromLocal(IVariableBinding local) {
		if (fLocals == null)
			return -1;
		for (int i = 0; i < fLocals.length; i++) {
			if (fLocals[i] == local)
				return i;
		}
		return -1;
	}

	void manageLocal(IVariableBinding local) {
		if (fLocals == null)
			fLocals = new IVariableBinding[fLength];
		fLocals[local.getVariableId() - fStart] = local;
	}

	// ---- Exception handling
	// --------------------------------------------------------

	void pushExcptions(TryStatement node) {
		List catchClauses = node.catchClauses();
		if (catchClauses == null)
			catchClauses = EMPTY_CATCH_CLAUSE;
		fExceptionStack.add(catchClauses);
	}

	void popExceptions() {
		Assert.isTrue(fExceptionStack.size() > 0);
		fExceptionStack.remove(fExceptionStack.size() - 1);
	}

	// TODO resolve exceptions binding
	boolean isExceptionCaught(ITypeBinding excpetionType) {
		for (Iterator exceptions = fExceptionStack.iterator(); exceptions.hasNext();) {
			for (Iterator catchClauses = ((List) exceptions.next()).iterator(); catchClauses.hasNext();) {
				// Expression catchedException = ((CatchClause) catchClauses
				// .next()).getClassName();
				// IVariableBinding binding= catchedException.resolveBinding();
				// if (binding == null)
				// continue;
				// ITypeBinding catchedType= binding.getType();
				// while (catchedType != null) {
				// if (catchedType == excpetionType)
				// return true;
				// catchedType= catchedType.getSuperclass();
				// }
			}
		}
		return false;
	}
}