/*
 * 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>) Adam Fuchs <afuchs@cs.umd.edu> Avik Chaudhuri <avik@cs.umd.edu>
 * 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 static util.MyLogger.LogLevel.DEBUG;

import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.dataflow.IFDS.ISupergraph;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.callgraph.propagation.PointerAnalysis;
import com.ibm.wala.ipa.cfg.BasicBlockInContext;
import com.ibm.wala.ipa.cha.ClassHierarchy;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSAInvokeInstruction;
import com.ibm.wala.util.collections.HashMapFactory;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.scandroid.domain.CodeElement;
import org.scandroid.flow.types.FlowType;
import org.scandroid.spec.CallArgSourceSpec;
import org.scandroid.spec.CallRetSourceSpec;
import org.scandroid.spec.EntryArgSourceSpec;
import org.scandroid.spec.ISpecs;
import org.scandroid.spec.SourceSpec;
import org.scandroid.spec.StaticFieldSourceSpec;
import org.scandroid.util.CGAnalysisContext;

@SuppressWarnings("rawtypes")
public class InflowAnalysis {

  @SuppressWarnings("unchecked")
  public static <E extends ISSABasicBlock> void addDomainElements(
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap,
      BasicBlockInContext<E> block,
      FlowType taintType,
      Set<CodeElement> newElements) {
    Map<FlowType<E>, Set<CodeElement>> blockMap =
        taintMap.computeIfAbsent(block, k -> new HashMap<>());

    Set<CodeElement> elements = blockMap.computeIfAbsent(taintType, k -> new HashSet<>());
    elements.addAll(newElements);
  }

  public static <E extends ISSABasicBlock> void addDomainElement(
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap,
      BasicBlockInContext<E> block,
      FlowType taintType,
      CodeElement element) {

    final Set<CodeElement> elements = Collections.singleton(element);
    addDomainElements(taintMap, block, taintType, elements);
  }

  private static <E extends ISSABasicBlock> void processInputSource(
      CGAnalysisContext<E> ctx,
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap,
      SourceSpec ss,
      CallGraph cg,
      ISupergraph<BasicBlockInContext<E>, CGNode> graph,
      ClassHierarchy cha,
      PointerAnalysis<InstanceKey> pa) {
    int[] newArgNums;
    for (IMethod im : ss.getNamePattern().getPossibleTargets(cha)) {
      newArgNums =
          (ss.getArgNums() == null)
              ? SourceSpec.getNewArgNums(
                  (im.isStatic()) ? im.getNumberOfParameters() : im.getNumberOfParameters() - 1)
              : ss.getArgNums();
      for (CGNode node : cg.getNodes(im.getReference())) {
        BasicBlockInContext<E>[] entriesForProcedure = graph.getEntriesForProcedure(node);
        if (entriesForProcedure == null || 0 == entriesForProcedure.length) {
          continue;
        }

        for (BasicBlockInContext<E> bb : entriesForProcedure) {
          ss.addDomainElements(ctx, taintMap, im, bb, null, newArgNums, graph, pa, cg);
        }
      }
    }
  }

  private static <E extends ISSABasicBlock> void processStaticFieldSource(
      CGAnalysisContext<E> ctx,
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap,
      StaticFieldSourceSpec ss,
      CallGraph cg,
      ISupergraph<BasicBlockInContext<E>, CGNode> graph,
      PointerAnalysis<InstanceKey> pa) {
    // get the first block:
    BasicBlockInContext<E> bb = null;
    for (CGNode n : cg.getEntrypointNodes()) {
      bb = graph.getEntriesForProcedure(n)[0];
    }

    assert bb != null : "Could not find entry basic block.";

    ss.addDomainElements(ctx, taintMap, bb.getMethod(), bb, null, null, graph, pa, cg);
  }

  private static <E extends ISSABasicBlock> void processFunctionCalls(
      CGAnalysisContext<E> ctx,
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap,
      ArrayList<SourceSpec> ssAL,
      ISupergraph<BasicBlockInContext<E>, CGNode> graph,
      PointerAnalysis<InstanceKey> pa,
      ClassHierarchy cha,
      CallGraph cg) {
    Collection<IMethod> targets = new HashSet<>();
    ArrayList<Collection<IMethod>> targetList = new ArrayList<>();

    for (SourceSpec sourceSpec : ssAL) {
      Collection<IMethod> tempList = sourceSpec.getNamePattern().getPossibleTargets(cha);
      targets.addAll(tempList);
      targetList.add(tempList);
    }

    for (BasicBlockInContext<E> block : graph) {

      for (SSAInstruction inst : block) {
        if (!(inst instanceof SSAInvokeInstruction)) {
          continue;
        }

        SSAInvokeInstruction invInst = (SSAInvokeInstruction) inst;
        for (IMethod target : cha.getPossibleTargets(invInst.getDeclaredTarget())) {
          if (targets.contains(target)) {
            for (int i = 0; i < targetList.size(); i++) {
              if (targetList.get(i).contains(target)) {

                int[] argNums = ssAL.get(i).getArgNums();
                argNums =
                    (argNums == null)
                        ? SourceSpec.getNewArgNums(
                            (target.isStatic())
                                ? target.getNumberOfParameters()
                                : target.getNumberOfParameters() - 1)
                        : argNums;

                ssAL.get(i)
                    .addDomainElements(
                        ctx, taintMap, target, block, invInst, argNums, graph, pa, cg);
              }
            }
          }
        }
      }
    }
  }

  public static <E extends ISSABasicBlock>
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> analyze(
          CGAnalysisContext<E> analysisContext, ISpecs s) {
    return analyze(
        analysisContext,
        analysisContext.cg,
        analysisContext.getClassHierarchy(),
        analysisContext.graph,
        analysisContext.pa,
        s);
  }

  public static <E extends ISSABasicBlock>
      Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> analyze(
          CGAnalysisContext<E> ctx,
          CallGraph cg,
          ClassHierarchy cha,
          ISupergraph<BasicBlockInContext<E>, CGNode> graph,
          PointerAnalysis<InstanceKey> pa,
          ISpecs s) {

    Map<BasicBlockInContext<E>, Map<FlowType<E>, Set<CodeElement>>> taintMap =
        HashMapFactory.make();

    SourceSpec[] ss = s.getSourceSpecs();

    ArrayList<SourceSpec> ssAL = new ArrayList<>();
    for (SourceSpec element : ss) {
      if (element instanceof EntryArgSourceSpec)
        processInputSource(ctx, taintMap, element, cg, graph, cha, pa);
      else if (element instanceof CallRetSourceSpec || element instanceof CallArgSourceSpec)
        ssAL.add(element);
      else if (element instanceof StaticFieldSourceSpec) {
        processStaticFieldSource(ctx, taintMap, (StaticFieldSourceSpec) element, cg, graph, pa);
      } else throw new UnsupportedOperationException("Unrecognized SourceSpec");
    }
    if (!ssAL.isEmpty()) processFunctionCalls(ctx, taintMap, ssAL, graph, pa, cha, cg);

    return taintMap;
  }
}
