/*
 *
 * Copyright (c) 2009-2012,
 *
 *  Steve Suh           <suhsteve@gmail.com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The names of the contributors may not be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *
 */

package org.scandroid.flow.types;

import com.ibm.wala.ipa.cfg.BasicBlockInContext;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.ssa.SSAInvokeInstruction;
import com.ibm.wala.ssa.analysis.IExplodedBasicBlock;

/** A flow to or from the parameter of a method. This can represent formal
 * parameters of methods being analyzed, or actual parameters of methods
 * being called. In the former case, the associated block is the entry
 * block of the method. In the latter case, the block is the block containing
 * the invoke instruction.
 *
 * @author atomb
 *
 * @param <E>
 */
public class ParameterFlow <E extends ISSABasicBlock> extends FlowType<E> {

    private final int argNum;
    
    public ParameterFlow(BasicBlockInContext<E> block, 
            int argNum, boolean source) {
        super(block, source);
    	this.argNum = argNum;
    }
    
    public int getArgNum() {
        return argNum;
    }
    
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = super.hashCode();
        result = prime * result + argNum;
        return result;
    }
    
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (!super.equals(obj))
            return false;
        if (getClass() != obj.getClass())
            return false;
        @SuppressWarnings("unchecked")
        ParameterFlow<E> other = (ParameterFlow<E>) obj;
        if (argNum != other.argNum)
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "ParameterFlow( argNum="+argNum+" "+super.toString()+")";
    }

    @Override
    public String descString() {
        String s = "arg(" + argNum + ")";
        if(!getBlock().isEntryBlock()) {
            SSAInvokeInstruction inv = (SSAInvokeInstruction) ((IExplodedBasicBlock) getBlock().getDelegate()).getInstruction();
            s = s + ":" + inv.getDeclaredTarget().getSignature();
        }
        return s;
    }

	@Override
	public <R> R visit(FlowTypeVisitor<E, R> v) {
		return v.visitParameterFlow(this);
	}
}
