/*

  * #%L

  * Update.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 java.io.IOException;

 import com.allanbank.mongodb.ReadPreference;

 import com.allanbank.mongodb.bson.Document;

 import com.allanbank.mongodb.bson.io.BsonInputStream;

 import com.allanbank.mongodb.bson.io.BsonOutputStream;

 import com.allanbank.mongodb.bson.io.BufferingBsonOutputStream;

 import com.allanbank.mongodb.bson.io.StringEncoder;

 import com.allanbank.mongodb.client.Message;

 import com.allanbank.mongodb.client.Operation;

 import com.allanbank.mongodb.error.DocumentToLargeException;

 /**

  * Message to apply an <a href=

  * "http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol#MongoWireProtocol-OPUPDATE"

  * >update</a> to a document.

  * 

  * <pre>

  * <code>

  * struct OP_UPDATE {

  *     MsgHeader header;             // standard message header

  *     int32     ZERO;               // 0 - reserved for future use

  *     cstring   fullCollectionName; // "dbname.collectionname"

  *     int32     flags;              // bit vector. see below

  *     document  selector;           // the query to select the document

  *     document  update;             // specification of the update to perform

  * }

  * </code>

  * </pre>

  * 

  * 

  * @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 2011-2013, Allanbank Consulting, Inc., All Rights Reserved

  */

 public class Update extends AbstractMessage {

     /** Flag bit for a multi-update. */

     public static final int MULTIUPDATE_FLAG_BIT = 0x02;

     /** Flag bit for an upsert. */

     public static final int UPSERT_FLAG_BIT = 0x01;

     /**

      * If true then all documents matching the query should be updated,

      * otherwise only the first document should be updated.

      */

     private final boolean myMultiUpdate;

     /** The query to select the document to update. */

     private final Document myQuery;

     /** The updates to apply to the selected document(s). */

     private final Document myUpdate;

     /**

      * If true then a document should be inserted if none match the query

      * criteria.

      */

     private final boolean myUpsert;

     /**

      * Creates a new Update.

      * 

      * @param in

      *            The input stream to read the update message from.

      * @throws IOException

      *             On an error reading the update message.

      */

     public Update(final BsonInputStream in) throws IOException {

         in.readInt(); // 0 - reserved.

         init(in.readCString());

         final int flags = in.readInt();

         myQuery = in.readDocument();

         myUpdate = in.readDocument();

         myUpsert = (flags & UPSERT_FLAG_BIT) == UPSERT_FLAG_BIT;

         myMultiUpdate = (flags & MULTIUPDATE_FLAG_BIT) == MULTIUPDATE_FLAG_BIT;

     }

     /**

      * Creates a new Update.

      * 

      * @param databaseName

      *            The name of the database.

      * @param collectionName

      *            The name of the collection.

      * @param query

      *            The query to select the document to update.

      * @param update

      *            The updates to apply to the selected document(s).

      * @param multiUpdate

      *            If true then all documents matching the query should be

      *            updated, otherwise only the first document should be updated.

      * @param upsert

      *            If true then a document should be inserted if none match the

      *            query criteria.

      */

     public Update(final String databaseName, final String collectionName,

             final Document query, final Document update,

             final boolean multiUpdate, final boolean upsert) {

         super(databaseName, collectionName, ReadPreference.PRIMARY);

         myQuery = query;

         myUpdate = update;

         myMultiUpdate = multiUpdate;

         myUpsert = upsert;

     }

     /**

      * 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())) {

             final Update other = (Update) object;

             result = super.equals(object)

                     && (myMultiUpdate == other.myMultiUpdate)

                     && (myUpsert == other.myUpsert)

                     && myUpdate.equals(other.myUpdate)

                     && myQuery.equals(other.myQuery);

         }

         return result;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the name of the operation: "UPDATE".

      * </p>

      */

     @Override

     public String getOperationName() {

         return Operation.UPDATE.name();

     }

     /**

      * Returns the query to select the document to update.

      * 

      * @return The query to select the document to update.

      */

     public Document getQuery() {

         return myQuery;

     }

     /**

      * Returns the updates to apply to the selected document(s).

      * 

      * @return The updates to apply to the selected document(s).

      */

     public Document getUpdate() {

         return myUpdate;

     }

     /**

      * Computes a reasonable hash code.

      * 

      * @return The hash code value.

      */

     @Override

     public int hashCode() {

         int result = 1;

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

         result = (31 * result) + (myMultiUpdate ? 1 : 3);

         result = (31 * result) + (myUpsert ? 1 : 3);

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

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

         return result;

     }

     /**

      * Returns true if all documents matching the query should be updated,

      * otherwise only the first document should be updated.

      * 

      * @return True if all documents matching the query should be updated,

      *         otherwise only the first document should be updated.

      */

     public boolean isMultiUpdate() {

         return myMultiUpdate;

     }

     /**

      * Returns true if the document should be inserted if none match the query

      * criteria.

      * 

      * @return True if the document should be inserted if none match the query

      *         criteria.

      */

     public boolean isUpsert() {

         return myUpsert;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the size of the {@link Query}.

      * </p>

      */

     @Override

     public int size() {

         int size = HEADER_SIZE + 10; // See below.

         // size += 4; // 0 - reserved.

         size += StringEncoder.utf8Size(myDatabaseName);

         // size += 1; // StringEncoder.utf8Size(".");

         size += StringEncoder.utf8Size(myCollectionName);

         // size += 1; // \0 on the CString.

         // size += 4; // flags

         size += myQuery.size();

         size += myUpdate.size();

         return size;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to ensure the inserted documents are not too large in

      * aggregate.

      * </p>

      */

     @Override

     public void validateSize(final int maxDocumentSize)

             throws DocumentToLargeException {

         final long querySize = (myQuery != null) ? myQuery.size() : 0;

         if (maxDocumentSize < querySize) {

             throw new DocumentToLargeException((int) querySize,

                     maxDocumentSize, myQuery);

         }

         final long updateSize = (myUpdate != null) ? myUpdate.size() : 0;

         if (maxDocumentSize < updateSize) {

             throw new DocumentToLargeException((int) updateSize,

                     maxDocumentSize, myUpdate);

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to write the update message.

      * </p>

      * 

      * @see Message#write(int, BsonOutputStream)

      */

     @Override

     public void write(final int messageId, final BsonOutputStream out)

             throws IOException {

         final int flags = computeFlags();

         int size = HEADER_SIZE;

         size += 4; // 0 - reserved.

         size += out.sizeOfCString(myDatabaseName, ".", myCollectionName);

         size += 4; // flags

         size += myQuery.size();

         size += myUpdate.size();

         writeHeader(out, messageId, 0, Operation.UPDATE, size);

         out.writeInt(0);

         out.writeCString(myDatabaseName, ".", myCollectionName);

         out.writeInt(flags);

         out.writeDocument(myQuery);

         out.writeDocument(myUpdate);

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to write the update message.

      * </p>

      * 

      * @see Message#write(int, BsonOutputStream)

      */

     @Override

     public void write(final int messageId, final BufferingBsonOutputStream out)

             throws IOException {

         final int flags = computeFlags();

         final long start = writeHeader(out, messageId, 0, Operation.UPDATE);

         out.writeInt(0);

         out.writeCString(myDatabaseName, ".", myCollectionName);

         out.writeInt(flags);

         out.writeDocument(myQuery);

         out.writeDocument(myUpdate);

         finishHeader(out, start);

         out.flushBuffer();

     }

     /**

      * Computes the message flags bit field.

      * 

      * @return The message flags bit field.

      */

     private int computeFlags() {

         int flags = 0;

         if (myMultiUpdate) {

             flags += MULTIUPDATE_FLAG_BIT;

         }

         if (myUpsert) {

             flags += UPSERT_FLAG_BIT;

         }

         return flags;

     }

 }