/*

  * #%L

  * CreateIndexCommand.java - mongodb-async-driver - Allanbank Consulting, Inc.

  * %%

  * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.

  * %%

  * 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.

  * #L%

  */

 package com.allanbank.mongodb.client.message;

 import com.allanbank.mongodb.ReadPreference;

 import com.allanbank.mongodb.Version;

 import com.allanbank.mongodb.bson.Document;

 import com.allanbank.mongodb.bson.DocumentAssignable;

 import com.allanbank.mongodb.bson.Element;

 import com.allanbank.mongodb.bson.NumericElement;

 import com.allanbank.mongodb.bson.builder.BuilderFactory;

 import com.allanbank.mongodb.bson.builder.DocumentBuilder;

 import com.allanbank.mongodb.client.VersionRange;

 /**

  * Helper class to make generating a {@code createIndexes} command easier.

  * 

  * @see <a

  *      href="http://docs.mongodb.org/manual/reference/command/createIndexes">createIndexes

  *      reference manual.</a>

  * @api.no This class is <b>NOT</b> part of the drivers API. This class may be

  *         mutated in incompatible ways between any two releases of the driver.

  * @copyright 2014, Allanbank Consulting, Inc., All Rights Reserved

  */

 public class CreateIndexCommand extends Command {

     /**

      * The first version of MongoDB to support the {@code createIndexes}

      * command.

      */

     public static final Version REQUIRED_VERSION = Version.VERSION_2_6;

     /** The required server version range for the {@code createIndexes} command. */

     public static final VersionRange REQUIRED_VERSION_RANGE = VersionRange

             .minimum(REQUIRED_VERSION);

     /**

      * Generates a name for the index based on the keys.

      * 

      * @param keys

      *            The keys for the index.

      * @return The name for the index.

      */

     public static String buildIndexName(final Element... keys) {

         final StringBuilder nameBuilder = new StringBuilder();

         for (final Element key : keys) {

             if (nameBuilder.length() > 0) {

                 nameBuilder.append('_');

             }

             nameBuilder.append(key.getName().replace(' ', '_'));

             nameBuilder.append("_");

             if (key instanceof NumericElement) {

                 nameBuilder.append(((NumericElement) key).getIntValue());

             }

             else {

                 nameBuilder.append(key.getValueAsString());

             }

         }

         return nameBuilder.toString();

     }

     /**

      * Constructs the {@code createIndexes} command.

      * 

      * @param collectionName

      *            The name of the collection the command is using. This should

      *            be the real collection and not

      *            {@link Command#COMMAND_COLLECTION $cmd}.

      * @param keys

      *            The index keys for the index.

      * @param indexName

      *            The name of the index.

      * @param options

      *            Options for the index. May be <code>null</code>.

      * @return The {@code createIndexes} command.

      */

     private static Document buildCommand(final String collectionName,

             final Element[] keys, final String indexName,

             final DocumentAssignable options) {

         final DocumentBuilder builder = BuilderFactory.start();

         builder.add("createIndexes", collectionName);

         final DocumentBuilder index = builder.pushArray("indexes").push();

         final DocumentBuilder keysDoc = index.push("key");

         for (final Element key : keys) {

             keysDoc.add(key);

         }

         index.add("name", indexName == null ? buildIndexName(keys) : indexName);

         if (options != null) {

             for (final Element option : options.asDocument()) {

                 index.add(option);

             }

         }

         return builder.build();

     }

     /**

      * Create a new CreateIndexCommand.

      * 

      * @param databaseName

      *            The name of the database.

      * @param collectionName

      *            The name of the collection the command is using. This should

      *            be the real collection and not

      *            {@link Command#COMMAND_COLLECTION $cmd}.

      * @param keys

      *            The index keys for the index.

      * @param indexName

      *            The name of the index.

      * @param options

      *            Options for the index. May be <code>null</code>.

      */

     public CreateIndexCommand(final String databaseName,

             final String collectionName, final Element[] keys,

             final String indexName, final DocumentAssignable options) {

         super(databaseName, collectionName, buildCommand(collectionName, keys,

                 indexName, options), ReadPreference.PRIMARY,

                 REQUIRED_VERSION_RANGE);

     }

     /**

      * Determines if the passed object is of this same type as this object and

      * if so that its fields are equal.

      * 

      * @param object

      *            The object to compare to.

      * 

      * @see java.lang.Object#equals(java.lang.Object)

      */

     @Override

     public boolean equals(final Object object) {

         boolean result = false;

         if (this == object) {

             result = true;

         }

         else if ((object != null) && (getClass() == object.getClass())) {

             result = super.equals(object);

         }

         return result;

     }

     /**

      * Computes a reasonable hash code.

      * 

      * @return The hash code value.

      */

     @Override

     public int hashCode() {

         int result = 1;

         result = (31 * result) + super.hashCode();

         return result;

     }

 }