/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hadoop.hive.serde2.lazy.objectinspector.primitive;

import java.util.ArrayList;
import java.util.HashMap;

import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;

/**
 * LazyPrimitiveObjectInspectorFactory is the primary way to create new
 * ObjectInspector instances.
 *
 * SerDe classes should call the static functions in this library to create an
 * ObjectInspector to return to the caller of SerDe2.getObjectInspector().
 *
 * The reason of having caches here is that ObjectInspector is because
 * ObjectInspectors do not have an internal state - so ObjectInspectors with the
 * same construction parameters should result in exactly the same
 * ObjectInspector.
 */
public final class LazyPrimitiveObjectInspectorFactory {

  public static final LazyBooleanObjectInspector LAZY_BOOLEAN_OBJECT_INSPECTOR =
      new LazyBooleanObjectInspector();
  public static final LazyByteObjectInspector LAZY_BYTE_OBJECT_INSPECTOR =
      new LazyByteObjectInspector();
  public static final LazyShortObjectInspector LAZY_SHORT_OBJECT_INSPECTOR =
      new LazyShortObjectInspector();
  public static final LazyIntObjectInspector LAZY_INT_OBJECT_INSPECTOR =
      new LazyIntObjectInspector();
  public static final LazyLongObjectInspector LAZY_LONG_OBJECT_INSPECTOR =
      new LazyLongObjectInspector();
  public static final LazyFloatObjectInspector LAZY_FLOAT_OBJECT_INSPECTOR =
      new LazyFloatObjectInspector();
  public static final LazyDoubleObjectInspector LAZY_DOUBLE_OBJECT_INSPECTOR =
      new LazyDoubleObjectInspector();
  public static final LazyVoidObjectInspector LAZY_VOID_OBJECT_INSPECTOR =
      new LazyVoidObjectInspector();
  public static final LazyDateObjectInspector LAZY_DATE_OBJECT_INSPECTOR =
      new LazyDateObjectInspector();
  public static final LazyTimestampObjectInspector LAZY_TIMESTAMP_OBJECT_INSPECTOR =
      new LazyTimestampObjectInspector();
  public static final LazyBinaryObjectInspector LAZY_BINARY_OBJECT_INSPECTOR =
      new LazyBinaryObjectInspector();

  static HashMap<ArrayList<Object>, LazyStringObjectInspector> cachedLazyStringObjectInspector =
      new HashMap<ArrayList<Object>, LazyStringObjectInspector>();

  public static LazyStringObjectInspector getLazyStringObjectInspector(
      boolean escaped, byte escapeChar) {
    ArrayList<Object> signature = new ArrayList<Object>();
    signature.add(Boolean.valueOf(escaped));
    signature.add(Byte.valueOf(escapeChar));
    LazyStringObjectInspector result = cachedLazyStringObjectInspector
        .get(signature);
    if (result == null) {
      result = new LazyStringObjectInspector(escaped, escapeChar);
      cachedLazyStringObjectInspector.put(signature, result);
    }
    return result;
  }

  public static AbstractPrimitiveLazyObjectInspector<?> getLazyObjectInspector(
      PrimitiveCategory primitiveCategory, boolean escaped, byte escapeChar) {

    switch (primitiveCategory) {
    case BOOLEAN:
      return LAZY_BOOLEAN_OBJECT_INSPECTOR;
    case BYTE:
      return LAZY_BYTE_OBJECT_INSPECTOR;
    case SHORT:
      return LAZY_SHORT_OBJECT_INSPECTOR;
    case INT:
      return LAZY_INT_OBJECT_INSPECTOR;
    case LONG:
      return LAZY_LONG_OBJECT_INSPECTOR;
    case FLOAT:
      return LAZY_FLOAT_OBJECT_INSPECTOR;
    case DOUBLE:
      return LAZY_DOUBLE_OBJECT_INSPECTOR;
    case STRING:
      return getLazyStringObjectInspector(escaped, escapeChar);
    case BINARY:
      return LAZY_BINARY_OBJECT_INSPECTOR;
    case VOID:
      return LAZY_VOID_OBJECT_INSPECTOR;
    case DATE:
      return LAZY_DATE_OBJECT_INSPECTOR;
    case TIMESTAMP:
      return LAZY_TIMESTAMP_OBJECT_INSPECTOR;
    default:
      throw new RuntimeException("Internal error: Cannot find ObjectInspector "
          + " for " + primitiveCategory);
    }
  }

  private LazyPrimitiveObjectInspectorFactory() {
    // prevent instantiation
  }

}