/*
 * Bytecode Analysis Framework
 * Copyright (C) 2005, University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package edu.umd.cs.findbugs.ba.ca;

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

public class CallList {
	private boolean isTop, isBottom;
	private ArrayList<Call> callList;

	public CallList() {
		this.callList = new ArrayList<Call>();
	}

	public boolean isValid() {
		return !(isTop() || isBottom());
	}

	public Iterator<Call> callIterator() {
		return callList.iterator();
	}

	public boolean isTop() {
		return isTop;
	}

	public boolean isBottom() {
		return isBottom;
	}

	public void setTop() {
		this.isTop = true;
		this.isBottom = false;
		this.callList.clear();
	}

	public void setBottom() {
		this.isTop = false;
		this.isBottom = true;
		this.callList.clear();
	}

	public void clear() {
		this.isTop = this.isBottom = false;
		this.callList.clear();
	}

	public void add(Call call) {
		callList.add(call);
	}

	public int size() {
		return callList.size();
	}

	public Call get(int index) {
		return callList.get(index);
	}

	public void copyFrom(CallList other) {
		this.isTop = other.isTop;
		this.isBottom = other.isBottom;
		this.callList.clear();
		this.callList.addAll(other.callList);
	}

	public static CallList merge(CallList a, CallList b) {
		CallList result = new CallList();

		if (a.isBottom || b.isBottom) {
			result.isBottom = true;
		} else if (a.isTop) {
			result.copyFrom(b);
		} else if (b.isTop) {
			result.copyFrom(a);
		} else {
			// Result is the common prefix
			int len = Math.min(a.size(), b.size());
			for (int i = 0; i < len; ++i) {
				if (!a.get(i).equals(b.get(i)))
					break;
				result.add(a.get(i));
			}
		}
		return result;
	}


	@Override
		 public boolean equals(Object obj) {
		if (obj == null || obj.getClass() != this.getClass())
			return false;
		CallList other = (CallList) obj;
		return this.callList.equals(other.callList);
	}


	@Override
		 public int hashCode() {
		return callList.hashCode();
	}

	@Override
	public String toString() {
		StringBuilder buf = new StringBuilder();
		for (Call call : callList) {
			if (buf.length() > 0)
				buf.append(',');
			buf.append(call.getMethodName());
		}
		return buf.toString();
	}
}