/*
 * Copyright 2011 Jon S Akhtar (Sylvanaar)
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.sylvanaar.idea.Lua.lang.psi.dataFlow.reachingDefs;

import com.sylvanaar.idea.Lua.lang.psi.dataFlow.Semilattice;
import gnu.trove.TIntHashSet;
import gnu.trove.TIntObjectHashMap;
import gnu.trove.TIntObjectProcedure;

import java.util.ArrayList;

/**
 * @author ven
 */
public class ReachingDefinitionsSemilattice implements Semilattice<TIntObjectHashMap<TIntHashSet>> {
  public TIntObjectHashMap<TIntHashSet> join(ArrayList<TIntObjectHashMap<TIntHashSet>> ins) {
    if (ins.isEmpty()) return new TIntObjectHashMap<TIntHashSet>();

    TIntObjectHashMap<TIntHashSet> result = new TIntObjectHashMap<TIntHashSet>();
    for (TIntObjectHashMap<TIntHashSet> map : ins) {
      merge(result, map);
    }

    return result;
  }

  private void merge(final TIntObjectHashMap<TIntHashSet> result, TIntObjectHashMap<TIntHashSet> map2) {
    map2.forEachEntry(new TIntObjectProcedure<TIntHashSet>() {
      public boolean execute(int num, TIntHashSet defs) {
        TIntHashSet defs2 = result.get(num);
        if (defs2 == null) {
          defs2 = new TIntHashSet(defs.toArray());
          result.put(num, defs2);
        } else {
          defs2.addAll(defs.toArray());
        }

        return true;
      }
    });
  }

  public boolean eq(final TIntObjectHashMap<TIntHashSet> m1, final TIntObjectHashMap<TIntHashSet> m2) {
    if (m1.size() != m2.size()) return false;

    return m1.forEachEntry(new TIntObjectProcedure<TIntHashSet>() {
      public boolean execute(int num, TIntHashSet defs1) {
        final TIntHashSet defs2 = m2.get(num);
        return defs2 != null && defs2.equals(defs1);
      }
    });
  }
}