/**
    * Copyright (c) 2014, stateful.co
    * 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 stateful.co 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 co.stateful.core;
  
  import co.stateful.spi.Counters;
  import co.stateful.spi.Locks;
  import co.stateful.spi.User;
  import com.google.common.base.Joiner;
  import com.google.common.base.Splitter;
  import com.google.common.collect.Iterables;
  import com.jcabi.aspects.Cacheable;
  import com.jcabi.aspects.Immutable;
  import com.jcabi.aspects.Loggable;
  import com.jcabi.aspects.Tv;
  import com.jcabi.dynamo.Attributes;
  import com.jcabi.dynamo.Conditions;
  import com.jcabi.dynamo.Credentials;
  import com.jcabi.dynamo.Item;
  import com.jcabi.dynamo.QueryValve;
  import com.jcabi.dynamo.Region;
  import com.jcabi.manifests.Manifests;
  import com.jcabi.urn.URN;
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.Locale;
  import java.util.concurrent.TimeUnit;
  import lombok.EqualsAndHashCode;
  import lombok.ToString;
  import org.apache.commons.codec.digest.DigestUtils;
  import org.apache.commons.lang3.RandomStringUtils;
  
  /**
   * Default user.
   *
   * @author Yegor Bugayenko (yegor@tpc2.com)
   * @version $Id$
   * @checkstyle ClassDataAbstractionCouplingCheck (500 lines)
   */
  @Immutable
  @ToString
  @EqualsAndHashCode(of = "name")
  @Loggable(Loggable.DEBUG)
  final class DefaultUser implements User {
  
      /**
       * Table name.
       */
      public static final String TOKENS = "tokens";
  
      /**
       * Hash.
       */
      public static final String HASH = "urn";
  
      /**
       * Token attribute.
       */
      public static final String ATTR_TOKEN = "token";
  
      /**
       * Name of the user.
       */
      private final transient URN name;
  
      /**
       * Region.
       */
      private final transient Region region;
  
      /**
       * Ctor.
       * @param urn Name of it
      */
     DefaultUser(final URN urn) {
         this.name = urn;
         final String key = Manifests.read("Stateful-DynamoKey");
         Credentials creds = new Credentials.Simple(
             key,
             Manifests.read("Stateful-DynamoSecret")
         );
         if ("AAAAABBBBBAAAAABBBBB".equals(key)) {
             creds = new Credentials.Direct(
                 creds, Integer.parseInt(System.getProperty("dynamo.port"))
             );
         }
         this.region = new Region.Prefixed(
             new Region.Simple(creds),
             Manifests.read("Stateful-DynamoPrefix")
         );
     }
 
     @Override
     @Cacheable(forever = true)
     public boolean exists() {
         return this.region.table(DefaultUser.TOKENS)
             .frame().through(new QueryValve())
             .where(DefaultUser.HASH, Conditions.equalTo(this.name))
             .iterator().hasNext();
     }
 
     @Override
     @Cacheable(lifetime = 1, unit = TimeUnit.HOURS)
     public String token() throws IOException {
         final Iterator<Item> items = this.region.table(DefaultUser.TOKENS)
             .frame().through(new QueryValve())
             .where(DefaultUser.HASH, Conditions.equalTo(this.name))
             .iterator();
         final String token;
         if (items.hasNext()) {
             token = items.next().get(DefaultUser.ATTR_TOKEN).getS();
         } else {
             this.refresh();
             token = this.token();
         }
         return token;
     }
 
     @Override
     @Cacheable.FlushAfter
     public void refresh() throws IOException {
         this.region.table(DefaultUser.TOKENS).put(
             new Attributes()
                 .with(DefaultUser.HASH, this.name)
                 .with(
                     DefaultUser.ATTR_TOKEN,
                     Joiner.on('-').join(
                         Iterables.limit(
                             Splitter.fixedLength(Tv.FOUR).split(
                                 DigestUtils.md5Hex(
                                     RandomStringUtils.random(Tv.TEN)
                                 ).toUpperCase(Locale.ENGLISH)
                             ),
                             Tv.FOUR
                         )
                     )
                 )
         );
     }
 
     @Override
     @Cacheable(lifetime = 1, unit = TimeUnit.HOURS)
     public Counters counters() {
         return new DyCounters(this.region.table(DyCounters.TBL), this.name);
     }
 
     @Override
     public Locks locks() {
         return new DyLocks(this.region.table(DyLocks.TBL), this.name);
     }
 }