/*
 * Copyright (c) 2002 - 2006 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 com.ibm.wala.cast.ipa.callgraph;

import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IClassLoader;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.classLoader.Language;
import com.ibm.wala.core.util.strings.Atom;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.Context;
import com.ibm.wala.ipa.callgraph.ContextSelector;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.types.ClassLoaderReference;
import com.ibm.wala.types.Descriptor;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.types.TypeName;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.intset.IntSet;
import java.util.Set;

public class MiscellaneousHacksContextSelector implements ContextSelector {

  private final Set<MethodReference> methodsToSpecialize;

  private final ContextSelector specialPolicy;

  private final ContextSelector basePolicy;

  public MiscellaneousHacksContextSelector(
      ContextSelector special, ContextSelector base, IClassHierarchy cha, String[][] descriptors) {
    basePolicy = base;
    specialPolicy = special;
    methodsToSpecialize = HashSetFactory.make();
    for (String[] descr : descriptors) {
      switch (descr.length) {

          // loader name, loader language, classname, method name, method descr
        case 5:
          {
            ClassLoaderReference clr =
                cha.getScope().getLoader(Atom.findOrCreateUnicodeAtom(descr[0]));
            IClassLoader loader = cha.getLoader(clr);
            MethodReference ref =
                MethodReference.findOrCreate(
                    TypeReference.findOrCreate(clr, TypeName.string2TypeName(descr[2])),
                    Atom.findOrCreateUnicodeAtom(descr[3]),
                    Descriptor.findOrCreateUTF8(loader.getLanguage(), descr[4]));

            if (cha.resolveMethod(ref) != null) {
              methodsToSpecialize.add(cha.resolveMethod(ref).getReference());
            } else {
              methodsToSpecialize.add(ref);
            }
            break;
          }

          // classname, method name, method descr
        case 3:
          {
            MethodReference ref =
                MethodReference.findOrCreate(
                    TypeReference.findOrCreate(
                        ClassLoaderReference.Application, TypeName.string2TypeName(descr[0])),
                    Atom.findOrCreateUnicodeAtom(descr[1]),
                    Descriptor.findOrCreateUTF8(Language.JAVA, descr[2]));

            methodsToSpecialize.add(cha.resolveMethod(ref).getReference());
            break;
          }

          // loader name, classname, meaning all methods of that class
        case 2:
          {
            IClass klass =
                cha.lookupClass(
                    TypeReference.findOrCreate(
                        new ClassLoaderReference(
                            Atom.findOrCreateUnicodeAtom(descr[0]),
                            ClassLoaderReference.Java,
                            null),
                        TypeName.string2TypeName(descr[1])));

            for (IMethod M : klass.getDeclaredMethods()) {
              methodsToSpecialize.add(M.getReference());
            }

            break;
          }

          // classname, meaning all methods of that class
        case 1:
          {
            IClass klass =
                cha.lookupClass(
                    TypeReference.findOrCreate(
                        ClassLoaderReference.Application, TypeName.string2TypeName(descr[0])));

            for (IMethod M : klass.getDeclaredMethods()) {
              methodsToSpecialize.add(M.getReference());
            }

            break;
          }

        default:
          Assertions.UNREACHABLE();
      }
    }

    System.err.println(("hacking context selector for methods " + methodsToSpecialize));
  }

  @Override
  public Context getCalleeTarget(
      CGNode caller, CallSiteReference site, IMethod callee, InstanceKey[] receiver) {
    if (methodsToSpecialize.contains(site.getDeclaredTarget())
        || methodsToSpecialize.contains(callee.getReference())) {
      return specialPolicy.getCalleeTarget(caller, site, callee, receiver);
    } else {
      return basePolicy.getCalleeTarget(caller, site, callee, receiver);
    }
  }

  @Override
  public IntSet getRelevantParameters(CGNode caller, CallSiteReference site) {
    return specialPolicy
        .getRelevantParameters(caller, site)
        .union(basePolicy.getRelevantParameters(caller, site));
  }
}
