/**********************************************************************
 * Copyright (c) 2007,2010 IBM Corporation.
 * 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
 *******************************************************************************/

package org.eclipse.ptp.pldt.mpi.analysis.cdt.graphs.impl;

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

import org.eclipse.cdt.core.dom.ast.IASTExpression;
import org.eclipse.cdt.core.dom.ast.IASTName;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IASTStatement;
import org.eclipse.ptp.pldt.mpi.analysis.cdt.graphs.IBlock;

/**
 * 
 * @author Yuan Zhang
 *
 */
public class Block implements IBlock {
	protected List<IBlock> succs_;
	protected List<IBlock> preds_;
	protected IBlock topNext_ = null;
	protected IBlock botNext_ = null;
	protected List<IBlock> DOM_ = null;
	protected List<IBlock> PDOM_ = null;
	
	protected static int counter = 0;
	protected int id;
	
	/** "type" tells the type of the content in this block. 
	 * A block with expr_type/stmt_type/label_type stores an 
	 * expression/statement/labelname, respectively. A block
	 * with continue_join_type is an empty block in a loop 
	 * joining regular flows and flows from continue statements.
	 * A block with exit_join_type is an empty block joining
	 * (1) two branches of an if statement (2) all leaving
	 * edges (through break or default statements) of a
	 * switch statement (3) the regular exit from a loop and
	 * irregular exits from break statements of this loop.  
	 */
	protected int type;
	public static final int expr_type = 1;
	public static final int stmt_type = 2;
	public static final int label_type = 3;
	public static final int continue_join_type = 4;
	public static final int exit_join_type = 5;
	
	protected IASTNode content_;
	
	/** The parent of a block storing a statement is the statement itself;
	 *  The parent of a block with a predicate expression is the corresponding
	 *  if/loop/switch statement;
	 *  The parent of a block with a label is the label statement;
	 *  The parent of a block with continue_join_type or exit_join_type
	 *  is the corresponding if/loop/switch statement;
	 */
	protected IASTStatement parent_;
	
	protected Hashtable<String,Object> attrs_;
	
	int color; // white = 0, gray = 1, black = 2
	
	public Block(){
		id = counter ++;
		type = 0;
		content_ = null;
		parent_ = null;
		blockInit();
	}

	public Block(IASTNode content, IASTStatement parent, int type){
		this();
		content_ = content;
		parent_ = parent;
		this.type = type;
		blockInit();
	}
	
	/** Short-cut constructor for stmt_type block */
	public Block(IASTStatement stmt){
		this(stmt, stmt, stmt_type);
	}
	
	/** Short-cut constructor for expr_type block */
	public Block(IASTExpression expr, IASTStatement parent){
		this(expr, parent, expr_type);
	}
	
	/** Short-cut constructor for label_type block */
	public Block(IASTName label){
		this(label, null, label_type);
	}
	
	protected void blockInit(){
		succs_ = new ArrayList<IBlock>();
		preds_ = new ArrayList<IBlock>();
		DOM_ = new ArrayList<IBlock>();
		PDOM_ = new ArrayList<IBlock>();
		attrs_ = new Hashtable<String,Object>();
	}

	public int getID(){
		return id;
	}
	
	public IASTNode getContent(){
		return content_;
	}
	
	public IASTStatement getParent(){
		return parent_;
	}
	public int getType() {return type;}

	public boolean search(IASTNode content, IASTStatement parent, int type){
		if(this.type != type) return false;
		if(type == stmt_type){
			if(content == content_) return true;
			else return false;
		}
		else if(type == label_type){
			if(content instanceof IASTName){
				IASTName name = (IASTName)content;
				IASTName labelName = (IASTName)content_;
				if(name.toString().equals(labelName.toString()))
					return true;
				else return false;
			}
			else return false;
		}
		else if(type == expr_type){
			if(content != null && content == content_) return true;
			if(content == null && content_ == null && parent_ == parent) 
				return true;
			else return false;
		}
		else if(type == continue_join_type || type == exit_join_type){
			if(content != null) return false;
			if(parent == parent_) return true;
			else return false;
		}
		else return false;
	}

	public boolean search(IASTExpression expr, IASTStatement parent){
		return search(expr, parent, expr_type);
	}
	
	public boolean search(IASTStatement stmt){
		return search(stmt, stmt, stmt_type);
	}
	
	public boolean search(IASTName label){
		return search(label, null, label_type);
	}
	
	public IBlock topNext() {
		return topNext_;
	}
	public IBlock getTopNext() {
		return topNext_;
	}
	public void setTopNext(IBlock b){
		topNext_ = b;
	}
	
	public IBlock botNext() {
		return botNext_;
	}
	public IBlock getBotNext() {
		return botNext_;
	}
	public void setBotNext(IBlock b){
		botNext_ = b;
	}
	
	public List<IBlock> getPreds() {
		return preds_;
	}

	public List<IBlock> getSuccs() {
		return succs_;
	}
	
	public List<IBlock> getDOM(){
		return DOM_;
	}
	
	public void setDOM(List<IBlock> set){
		DOM_ = set;
	}
	
	public List<IBlock> getPDOM(){
		return PDOM_;
	}
	
	public void setPDOM(List<IBlock> set){
		PDOM_ = set;
	}

	public void setAttr(String name, Object attr){
		attrs_.put(name, attr);
	}
	
	public Object getAttr(String name){
		return attrs_.get(name);
	}
	
	/**
	 * Print IBlock information, include id, content (type & raw signature), and successors
	 */
	public void print(){
		System.out.println(toString());
	}
	public String toString(){
		StringBuffer buf = new StringBuffer();
		buf.append("Block " + id + ": "); //$NON-NLS-1$ //$NON-NLS-2$
		IASTNode content = getContent();
		if(content != null) {
			String type=content.toString(); // a.b.c.Name@abcd
			type = type.substring(type.lastIndexOf('.')+1);  // Name@abcd
			type=type.substring(0,type.indexOf('@'));
			buf.append("  "+type+"  "+content.getRawSignature()+"\n"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		}
		else {
			buf.append("  Empty block"); //$NON-NLS-1$
			buf.append("\n"); //$NON-NLS-1$
		}
		buf.append("  flows to: "); //$NON-NLS-1$
		for(Iterator<IBlock> i = succs_.iterator(); i.hasNext();){
			buf.append(i.next().getID() + ", "); //$NON-NLS-1$
		}
		buf.append(" \n"); //$NON-NLS-1$
		/*
		System.out.print("Dominator: ");
		for(Iterator i = DOM_.iterator(); i.hasNext();){
			Block dom = (Block)i.next();
			System.out.print(dom.getID() + ", ");
		}
		System.out.println(" ");
		*/
		return buf.toString();
	}
}