/**

  * 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.services.dynamodbv2.model.AttributeValue;

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

 import com.google.common.base.Joiner;

 import com.google.common.collect.ImmutableMap;

 import com.jcabi.aspects.Immutable;

 import com.jcabi.aspects.Loggable;

 import com.jcabi.immutable.ArrayMap;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.Map;

 import java.util.Set;

 import java.util.concurrent.ConcurrentHashMap;

 import java.util.concurrent.ConcurrentMap;

 import lombok.EqualsAndHashCode;

 /**

  * DynamoDB item attributes.

  *

  * <p>It's a convenient immutable builder of a map of attribute values for

  * DynamoDB put operation. Use it like this:

  *

  * <pre>Map&lt;String, AttributeValue&gt; attributes = new Attributes()

  *   .with("hash", "some value")

  *   .with("range", 12345);

  * </pre>

  *

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

  * @version $Id: 26ba78e0b53155a9093056ee342f2d341bd7bff0 $

  * @since 0.1

  */

 @Immutable

 @Loggable(Loggable.DEBUG)

 @EqualsAndHashCode(of = "attrs")

 @SuppressWarnings

     (

         {

             "PMD.TooManyMethods",

             "PMD.AvoidInstantiatingObjectsInLoops"

         }

     )

 public final class Attributes implements Map<String, AttributeValue> {

     /**

      * Encapsulated attributes.

      */

     private final transient ArrayMap<String, AttributeValue> attrs;

     /**

      * Private ctor.

      */

     public Attributes() {

         this(new ArrayMap<String, AttributeValue>());

     }

     /**

      * Private ctor.

      * @param map Map of them

      */

     public Attributes(final Map<String, AttributeValue> map) {

         this.attrs = new ArrayMap<String, AttributeValue>(map);

     }

     /**

      * With this attribute.

      * @param name Attribute name

      * @param value The value

      * @return Attributes

      */

     public Attributes with(final String name, final AttributeValue value) {

         return new Attributes(this.attrs.with(name, value));

     }

     /**

      * With these attributes.

      * @param map Attributes to add

      * @return Attributes

      */

     public Attributes with(final Map<String, AttributeValue> map) {

         final ConcurrentMap<String, AttributeValue> attribs =

             new ConcurrentHashMap<String, AttributeValue>(map.size());

         for (final Map.Entry<String, AttributeValue> entry : map.entrySet()) {

             attribs.put(entry.getKey(), entry.getValue());

         }

         return new Attributes(this.attrs.with(attribs));

     }

     /**

      * Convert them to a map of expected values.

      * @return Expected values

      */

     public Map<String, ExpectedAttributeValue> asKeys() {

         final ImmutableMap.Builder<String, ExpectedAttributeValue> map =

             new ImmutableMap.Builder<String, ExpectedAttributeValue>();

         for (final Map.Entry<String, AttributeValue> attr

             : this.attrs.entrySet()) {

             map.put(

                 attr.getKey(),

                 new ExpectedAttributeValue(attr.getValue())

             );

         }

         return map.build();

     }

     /**

      * With this attribute.

      * @param name Attribute name

      * @param value The value

      * @return Attributes

      * @

      */

     public Attributes with(final String name, final Object value) {

         final AttributeValue attr;

         if (value instanceof Long || value instanceof Integer) {

             attr = new AttributeValue().withN(value.toString());

         } else {

             attr = new AttributeValue(value.toString());

         }

         return this.with(name, attr);

     }

     /**

      * Filter out all keys except provided ones.

      * @param keys Keys to leave in the map

      * @return Attributes

      */

     public Attributes only(final Iterable<String> keys) {

         final ImmutableMap.Builder<String, AttributeValue> map =

             new ImmutableMap.Builder<String, AttributeValue>();

         final Collection<String> hash = new HashSet<String>(0);

         for (final String key : keys) {

             hash.add(key);

         }

         for (final Map.Entry<String, AttributeValue> entry : this.entrySet()) {

             if (hash.contains(entry.getKey())) {

                 map.put(

                     entry.getKey(),

                     entry.getValue()

                 );

             }

         }

         return new Attributes(map.build());

     }

     @Override

     public String toString() {

         final Collection<String> terms =

             new ArrayList<String>(this.attrs.size());

         for (final Map.Entry<String, AttributeValue> attr

             : this.attrs.entrySet()) {

             terms.add(

                 String.format(

                     "%s=%s",

                     attr.getKey(),

                     attr.getValue()

                 )

             );

         }

         return Joiner.on("; ").join(terms);

     }

     @Override

     public int size() {

         return this.attrs.size();

     }

     @Override

     public boolean isEmpty() {

         return this.attrs.isEmpty();

     }

     @Override

     public boolean containsKey(final Object key) {

         return this.attrs.containsKey(key.toString());

     }

     @Override

     public boolean containsValue(final Object value) {

         return this.attrs.containsValue(value);

     }

     @Override

     public AttributeValue get(final Object key) {

         return this.attrs.get(key.toString());

     }

     @Override

     public Set<String> keySet() {

         return this.attrs.keySet();

     }

     @Override

     public Collection<AttributeValue> values() {

         return this.attrs.values();

     }

     @Override

     public Set<Map.Entry<String, AttributeValue>> entrySet() {

         return this.attrs.entrySet();

     }

     @Override

     public AttributeValue put(final String key, final AttributeValue value) {

         throw new UnsupportedOperationException(

             "Attributes class is immutable, can't do #put()"

         );

     }

     @Override

     public AttributeValue remove(final Object key) {

         throw new UnsupportedOperationException(

             "Attributes class is immutable, can't do #remove()"

         );

     }

     @Override

     public void putAll(

         final Map<? extends String, ? extends AttributeValue> map) {

         throw new UnsupportedOperationException(

             "Attributes class is immutable, can't do #putAll()"

         );

     }

     @Override

     public void clear() {

         throw new UnsupportedOperationException(

             "Attributes class is immutable, can't do #clear()"

         );

     }

 }