/**

  * Copyright (c) 2012-2016, jcabi.com

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met: 1) Redistributions of source code must retain the above

  * copyright notice, this list of conditions and the following

  * disclaimer. 2) Redistributions in binary form must reproduce the above

  * copyright notice, this list of conditions and the following

  * disclaimer in the documentation and/or other materials provided

  * with the distribution. 3) Neither the name of the jcabi.com nor

  * the names of its contributors may be used to endorse or promote

  * products derived from this software without specific prior written

  * permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT

  * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

  * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

  * OF THE POSSIBILITY OF SUCH DAMAGE.

  */

 package com.jcabi.dynamo;

 import com.amazonaws.AmazonClientException;

 import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;

 import com.amazonaws.services.dynamodbv2.model.AttributeValue;

 import com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate;

 import com.amazonaws.services.dynamodbv2.model.GetItemRequest;

 import com.amazonaws.services.dynamodbv2.model.GetItemResult;

 import com.amazonaws.services.dynamodbv2.model.ReturnConsumedCapacity;

 import com.amazonaws.services.dynamodbv2.model.ReturnValue;

 import com.amazonaws.services.dynamodbv2.model.UpdateItemRequest;

 import com.amazonaws.services.dynamodbv2.model.UpdateItemResult;

 import com.jcabi.aspects.Immutable;

 import com.jcabi.aspects.Loggable;

 import com.jcabi.immutable.Array;

 import com.jcabi.log.Logger;

 import java.io.IOException;

 import java.util.Collections;

 import java.util.Locale;

 import java.util.Map;

 import java.util.NoSuchElementException;

 import lombok.EqualsAndHashCode;

 import lombok.ToString;

 /**

  * Single item/row in a DynamoDB table.

  *

  * @author Yegor Bugayenko (yegor@tpc2.com)

  * @version $Id: 1d2b6329f00902e790b31754d8332d955e3d2641 $

  * @since 0.1

  */

 @Immutable

 @Loggable(Loggable.DEBUG)

 @ToString

 @EqualsAndHashCode(of = { "credentials", "frm", "name", "attributes" })

 final class AwsItem implements Item {

     /**

      * AWS credentials.

      */

     private final transient Credentials credentials;

     /**

      * Frame.

      */

     private final transient AwsFrame frm;

     /**

      * Table name.

      */

     private final transient String name;

     /**

      * Pre-loaded attributes and their values.

      */

     private final transient Attributes attributes;

     /**

      * Table keys.

      */

     private final transient Array<String> keys;

     /**

      * Public ctor.

      * @param creds Credentials

      * @param frame Frame

      * @param table Table name

      * @param attrs Loaded already attributes with values

      * @param pks Keys of the table

      * @checkstyle ParameterNumber (5 lines)

      */

     AwsItem(final Credentials creds, final AwsFrame frame,

         final String table, final Attributes attrs,

         final Array<String> pks) {

         this.credentials = creds;

         this.frm = frame;

         this.name = table;

         this.attributes = attrs;

         this.keys = pks;

     }

     @Override

     public boolean has(final String attr) throws IOException {

         final String attrib = String.format(Locale.ENGLISH, attr);

         boolean has = this.attributes.containsKey(attrib);

         if (!has) {

             final AmazonDynamoDB aws = this.credentials.aws();

             try {

                 final GetItemRequest request = new GetItemRequest();

                 request.setTableName(this.name);

                 request.setAttributesToGet(Collections.singletonList(attr));

                 request.setKey(this.attributes.only(this.keys));

                 request.setReturnConsumedCapacity(ReturnConsumedCapacity.TOTAL);

                 request.setConsistentRead(true);

                 final long start = System.currentTimeMillis();

                 final GetItemResult result = aws.getItem(request);

                 has = result.getItem().get(attrib) != null;

                 Logger.info(

                     this, "#has('%s'): %B from DynamoDB, %s, in %[ms]s",

                     attr, has,

                     new PrintableConsumedCapacity(

                         result.getConsumedCapacity()

                     ).print(),

                     System.currentTimeMillis() - start

                 );

             } catch (final AmazonClientException ex) {

                 throw new IOException(

                     String.format(

                         "failed to check existence of \"%s\" at \"%s\" by %s",

                         attr, this.name, this.keys

                     ),

                     ex

                 );

             } finally {

                 aws.shutdown();

             }

         }

         return has;

     }

     @Override

     public AttributeValue get(final String attr) throws IOException {

         final String attrib = String.format(Locale.ENGLISH, attr);

         AttributeValue value = this.attributes.get(attrib);

         if (value == null) {

             final AmazonDynamoDB aws = this.credentials.aws();

             try {

                 final GetItemRequest request = new GetItemRequest();

                 request.setTableName(this.name);

                 request.setAttributesToGet(Collections.singletonList(attrib));

                 request.setKey(this.attributes.only(this.keys));

                 request.setReturnConsumedCapacity(ReturnConsumedCapacity.TOTAL);

                 request.setConsistentRead(true);

                 final long start = System.currentTimeMillis();

                 final GetItemResult result = aws.getItem(request);

                 value = result.getItem().get(attrib);

                 Logger.info(

                     this,

                     // @checkstyle LineLength (1 line)

                     "#get('%s'): loaded '%[text]s' from DynamoDB, %s, in %[ms]s",

                     attrib, value,

                     new PrintableConsumedCapacity(

                         result.getConsumedCapacity()

                     ).print(),

                     System.currentTimeMillis() - start

                 );

             } catch (final AmazonClientException ex) {

                 throw new IOException(

                     String.format(

                         "failed to get \"%s\" from \"%s\" by %s",

                         attr, this.name, this.keys

                     ),

                     ex

                 );

             } finally {

                 aws.shutdown();

             }

         }

         if (value == null) {

             throw new NoSuchElementException(

                 String.format("attribute \"%s\" not found", attr)

             );

         }

         return value;

     }

     @Override

     public Map<String, AttributeValue> put(final String attr,

         final AttributeValueUpdate value) throws IOException {

         return this.put(new AttributeUpdates().with(attr, value));

     }

     @Override

     public Map<String, AttributeValue> put(

         final Map<String, AttributeValueUpdate> attrs) throws IOException {

         final AmazonDynamoDB aws = this.credentials.aws();

         final Attributes expected = this.attributes.only(this.keys);

         try {

             final UpdateItemRequest request = new UpdateItemRequest()

                 .withTableName(this.name)

                 .withExpected(expected.asKeys())

                 .withKey(expected)

                 .withAttributeUpdates(attrs)

                 .withReturnConsumedCapacity(ReturnConsumedCapacity.TOTAL)

                 .withReturnValues(ReturnValue.UPDATED_NEW);

             final long start = System.currentTimeMillis();

             final UpdateItemResult result = aws.updateItem(request);

             Logger.info(

                 this, "#put('%s'): updated item to DynamoDB, %s, in %[ms]s",

                 attrs,

                 new PrintableConsumedCapacity(

                     result.getConsumedCapacity()

                 ).print(),

                 System.currentTimeMillis() - start

             );

             return result.getAttributes();

         } catch (final AmazonClientException ex) {

             throw new IOException(

                 String.format(

                     "failed to put %s into \"%s\" with %s",

                     attrs, this.name, this.keys

                 ),

                 ex

             );

         } finally {

             aws.shutdown();

         }

     }

     @Override

     public Frame frame() {

         return this.frm;

     }

 }