/*
 * 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.
 *
 * This file is a derivative of code released under the terms listed below.
 *
 */
/*
 * Copyright (c) 2009-2012,
 *
 * <p>Galois, Inc. (Aaron Tomb <atomb@galois.com>, Rogan Creswick <creswick@galois.com>, Adam
 * Foltzer <acfoltzer@galois.com>) Steve Suh <suhsteve@gmail.com>
 *
 * <p>All rights reserved.
 *
 * <p>Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * <p>1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 *
 * <p>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.
 *
 * <p>3. The names of the contributors may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * <p>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;

import com.ibm.wala.dataflow.IFDS.TabulationResult;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.callgraph.propagation.PointerKey;
import com.ibm.wala.ipa.cfg.BasicBlockInContext;
import com.ibm.wala.ssa.analysis.IExplodedBasicBlock;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.intset.OrdinalSet;
import java.util.Collections;
import java.util.Set;
import org.scandroid.domain.CodeElement;
import org.scandroid.domain.DomainElement;
import org.scandroid.domain.IFDSTaintDomain;
import org.scandroid.domain.LocalElement;
import org.scandroid.flow.types.FlowType;
import org.scandroid.util.CGAnalysisContext;

public class LocalSinkPoint implements ISinkPoint {

  private final BasicBlockInContext<IExplodedBasicBlock> block;
  private final int ssaVal;
  private final FlowType<IExplodedBasicBlock> sinkFlow;

  public LocalSinkPoint(
      BasicBlockInContext<IExplodedBasicBlock> block,
      int ssaVal,
      FlowType<IExplodedBasicBlock> sinkFlow) {
    this.block = block;
    this.ssaVal = ssaVal;
    this.sinkFlow = sinkFlow;
  }

  @SuppressWarnings("unchecked")
  @Override
  public Set<FlowType<IExplodedBasicBlock>> findSources(
      CGAnalysisContext<IExplodedBasicBlock> ctx,
      TabulationResult<BasicBlockInContext<IExplodedBasicBlock>, CGNode, DomainElement> flowResult,
      IFDSTaintDomain<IExplodedBasicBlock> domain) {
    Set<FlowType<IExplodedBasicBlock>> sources = HashSetFactory.make();

    final CodeElement localElt = new LocalElement(ssaVal);
    Set<CodeElement> elts = HashSetFactory.make(Collections.singleton(localElt));

    final CGNode node = block.getNode();
    PointerKey pk = ctx.pa.getHeapModel().getPointerKeyForLocal(node, ssaVal);
    OrdinalSet<InstanceKey> iks = ctx.pa.getPointsToSet(pk);

    for (InstanceKey ik : iks) {
      elts.addAll(ctx.codeElementsForInstanceKey(ik));
    }

    for (CodeElement elt : elts) {
      for (DomainElement de : domain.getPossibleElements(elt)) {
        if (flowResult.getResult(block).contains(domain.getMappedIndex(de))) {
          sources.add(de.taintSource);
        }
      }
    }
    return sources;
  }

  @Override
  public FlowType<IExplodedBasicBlock> getFlow() {
    return sinkFlow;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((block == null) ? 0 : block.hashCode());
    result = prime * result + ((sinkFlow == null) ? 0 : sinkFlow.hashCode());
    result = prime * result + ssaVal;
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) return true;
    if (obj == null) return false;
    if (getClass() != obj.getClass()) return false;
    LocalSinkPoint other = (LocalSinkPoint) obj;
    if (block == null) {
      if (other.block != null) return false;
    } else if (!block.equals(other.block)) return false;
    if (sinkFlow == null) {
      if (other.sinkFlow != null) return false;
    } else if (!sinkFlow.equals(other.sinkFlow)) return false;
    if (ssaVal != other.ssaVal) return false;
    return true;
  }

  @Override
  public String toString() {
    return "SinkPoint [block=" + block + ", ssaVal=" + ssaVal + ", sinkFlow=" + sinkFlow + ']';
  }
}
