/*******************************************************************************
 * Copyright (c) 2013 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.cast.ipa.callgraph.ScopeMappingInstanceKeys.ScopeMappingInstanceKey;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.Context;
import com.ibm.wala.ipa.callgraph.ContextItem;
import com.ibm.wala.ipa.callgraph.ContextKey;
import com.ibm.wala.ipa.callgraph.ContextSelector;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.ipa.summaries.SummarizedMethod;
import com.ibm.wala.util.intset.IntSet;
import com.ibm.wala.util.intset.IntSetUtil;

public class ScopeMappingKeysContextSelector implements ContextSelector {

  public static final ContextKey scopeKey = new ContextKey() {
    public String toString() {
      return "SCOPE KEY";
    }
  };

  public static class ScopeMappingContext implements Context {
    private final Context base;
    private final ScopeMappingInstanceKey key;

    private ScopeMappingContext(Context base, ScopeMappingInstanceKey key) {
      this.base = base;
      this.key = key;
    }

    public ContextItem get(ContextKey name) {
      if (scopeKey.equals(name)) {
        return key;
      } else {
        return base.get(name);
      }
    }

    private int hashcode = -1;

    public int hashCode() {
      if (hashcode == -1) {
        hashcode = base.hashCode() * key.hashCode();
      }
      return hashcode;
    }

    public String toString() {
      return "context for " + key;
    }

    public boolean equals(Object o) {
      return (o instanceof ScopeMappingContext) && key.equals(((ScopeMappingContext) o).key)
          && base.equals(((ScopeMappingContext) o).base);
    }
  }

  private final ContextSelector base;

  public ScopeMappingKeysContextSelector(ContextSelector base) {
    this.base = base;
  }

  public Context getCalleeTarget(CGNode caller, CallSiteReference site, IMethod callee, InstanceKey[] receiver) {
    Context bc = base.getCalleeTarget(caller, site, callee, receiver);
    if (callee instanceof SummarizedMethod) {
      final String calleeName = callee.getReference().toString();
      if (calleeName.equals("< JavaScriptLoader, LArray, ctor()LRoot; >")
          || calleeName.equals("< JavaScriptLoader, LObject, ctor()LRoot; >")) {
        return bc;
      }
    }
    if (receiver[0] instanceof ScopeMappingInstanceKey) {
      final ScopeMappingInstanceKey smik = (ScopeMappingInstanceKey) receiver[0];
      final ScopeMappingContext scopeMappingContext = new ScopeMappingContext(bc, smik);
      return scopeMappingContext;
    } else {
      return bc;
    }
  }

  private static final IntSet thisParameter = IntSetUtil.make(new int[] { 0 });

  public IntSet getRelevantParameters(CGNode caller, CallSiteReference site) {
    return thisParameter;
  }

}