/*
 * Copyright 2010-2012 Luca Garulli (l.garulli--at--orientechnologies.com)
 *
 * 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.orientechnologies.orient.core.sql.operator;

import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.orientechnologies.orient.core.command.OCommandContext;
import com.orientechnologies.orient.core.db.record.OIdentifiable;
import com.orientechnologies.orient.core.id.ORID;
import com.orientechnologies.orient.core.index.OCompositeIndexDefinition;
import com.orientechnologies.orient.core.index.OIndex;
import com.orientechnologies.orient.core.index.OIndexDefinition;
import com.orientechnologies.orient.core.index.OIndexDefinitionMultiValue;
import com.orientechnologies.orient.core.index.OIndexInternal;
import com.orientechnologies.orient.core.record.impl.ODocument;
import com.orientechnologies.orient.core.sql.filter.OSQLFilterCondition;

/**
 * CONTAINS operator.
 * 
 * @author Luca Garulli
 * 
 */
public class OQueryOperatorContains extends OQueryOperatorEqualityNotNulls {

  public OQueryOperatorContains() {
    super("CONTAINS", 5, false);
  }

  @Override
  @SuppressWarnings("unchecked")
  protected boolean evaluateExpression(final OIdentifiable iRecord, final OSQLFilterCondition iCondition, final Object iLeft,
      final Object iRight, OCommandContext iContext) {
    final OSQLFilterCondition condition;
    if (iCondition.getLeft() instanceof OSQLFilterCondition)
      condition = (OSQLFilterCondition) iCondition.getLeft();
    else if (iCondition.getRight() instanceof OSQLFilterCondition)
      condition = (OSQLFilterCondition) iCondition.getRight();
    else
      condition = null;

    if (iLeft instanceof Iterable<?>) {

      final Iterable<Object> iterable = (Iterable<Object>) iLeft;

      if (condition != null) {
        // CHECK AGAINST A CONDITION
        for (final Object o : iterable) {
          final OIdentifiable id;
          if (o instanceof OIdentifiable)
            id = (OIdentifiable) o;
          else if (o instanceof Map<?, ?>) {
            final Iterator<Object> iter = ((Map<?, Object>) o).values().iterator();
            final Object v = iter.hasNext() ? iter.next() : null;
            if (v instanceof OIdentifiable)
              id = (OIdentifiable) v;
            else
              // TRANSFORM THE ENTIRE MAP IN A DOCUMENT. PROBABLY HAS BEEN IMPORTED FROM JSON
              id = new ODocument((Map) o);

          } else if (o instanceof Iterable<?>) {
            final Iterator<OIdentifiable> iter = ((Iterable<OIdentifiable>) o).iterator();
            id = iter.hasNext() ? iter.next() : null;
          } else
            continue;

          if ((Boolean) condition.evaluate(id, null, iContext) == Boolean.TRUE)
            return true;
        }
      } else {
        // CHECK AGAINST A SINGLE VALUE
        for (final Object o : iterable) {
          if (OQueryOperatorEquals.equals(iRight, o))
            return true;
        }
      }
    } else if (iRight instanceof Iterable<?>) {

      // CHECK AGAINST A CONDITION
      final Iterable<OIdentifiable> iterable = (Iterable<OIdentifiable>) iRight;

      if (condition != null) {
        for (final OIdentifiable o : iterable) {
          if ((Boolean) condition.evaluate(o, null, iContext) == Boolean.TRUE)
            return true;
        }
      } else {
        // CHECK AGAINST A SINGLE VALUE
        for (final Object o : iterable) {
          if (OQueryOperatorEquals.equals(iLeft, o))
            return true;
        }
      }
    }
    return false;
  }

  @Override
  public OIndexReuseType getIndexReuseType(final Object iLeft, final Object iRight) {
    if (!(iLeft instanceof OSQLFilterCondition) && !(iRight instanceof OSQLFilterCondition))
      return OIndexReuseType.INDEX_METHOD;

    return OIndexReuseType.NO_INDEX;
  }

  @Override
  public Object executeIndexQuery(OCommandContext iContext, OIndex<?> index, List<Object> keyParams, boolean ascSortOrder,
      IndexResultListener resultListener, int fetchLimit) {
    final OIndexDefinition indexDefinition = index.getDefinition();

    final OIndexInternal<?> internalIndex = index.getInternal();
    if (!internalIndex.canBeUsedInEqualityOperators())
      return null;

    final Object result;

    if (indexDefinition.getParamCount() == 1) {
      final Object key;
      if (indexDefinition instanceof OIndexDefinitionMultiValue)
        key = ((OIndexDefinitionMultiValue) indexDefinition).createSingleValue(keyParams.get(0));
      else
        key = indexDefinition.createValue(keyParams);

      if (key == null)
        return null;

      final Object indexResult;

      indexResult = index.get(key);

      result = convertIndexResult(indexResult);
    } else {
      // in case of composite keys several items can be returned in case of we perform search
      // using part of composite key stored in index.

      final OCompositeIndexDefinition compositeIndexDefinition = (OCompositeIndexDefinition) indexDefinition;

      final Object keyOne = compositeIndexDefinition.createSingleValue(keyParams);

      if (keyOne == null)
        return null;

      final Object keyTwo = compositeIndexDefinition.createSingleValue(keyParams);
      if (internalIndex.hasRangeQuerySupport()) {
        if (resultListener != null) {
          index.getValuesBetween(keyOne, true, keyTwo, true, ascSortOrder, resultListener);
          result = resultListener.getResult();
        } else
          result = index.getValuesBetween(keyOne, true, keyTwo, true, ascSortOrder);
      } else {
        int indexParamCount = indexDefinition.getParamCount();
        if (indexParamCount == keyParams.size()) {
          final Object indexResult;
          indexResult = index.get(keyOne);

          result = convertIndexResult(indexResult);
        } else
          return null;
      }
    }

    updateProfiler(iContext, index, keyParams, indexDefinition);
    return result;
  }

  private Object convertIndexResult(Object indexResult) {
    Object result;
    if (indexResult instanceof Collection)
      result = (Collection<?>) indexResult;
    else if (indexResult == null)
      result = Collections.emptyList();
    else
      result = Collections.singletonList((OIdentifiable) indexResult);
    return result;
  }

  @Override
  public ORID getBeginRidRange(Object iLeft, Object iRight) {
    return null;
  }

  @Override
  public ORID getEndRidRange(Object iLeft, Object iRight) {
    return null;
  }

}
