/**

  * Copyright (c) 2012-2014, 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.simpledb;

 import com.amazonaws.auth.BasicAWSCredentials;

 import com.amazonaws.regions.RegionUtils;

 import com.amazonaws.regions.Regions;

 import com.amazonaws.services.simpledb.AmazonSimpleDB;

 import com.amazonaws.services.simpledb.AmazonSimpleDBClient;

 import com.jcabi.aspects.Immutable;

 import com.jcabi.aspects.Loggable;

 import javax.validation.constraints.NotNull;

 import lombok.EqualsAndHashCode;

 import org.apache.commons.lang3.Validate;

 /**

  * Amazon SimpleDB credentials.

  *

  * <p>It is recommended to use {@link Credentials.Simple} in most cases.

  *

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

  * @version $Id$

  * @since 0.1

  */

 @Immutable

 public interface Credentials {

     /**

      * Test credentials, for unit testing mostly.

      */

     Credentials TEST = new Credentials.Simple(

         "AAAAAAAAAAAAAAAAAAAA",

         "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"

     );

     /**

      * Build AWS client.

      *

      * <p>Don't forget to shut it down after use,

      * using {@link AmazonSimpleDB#shutdown()}.

      *

      * @return Amazon Dynamo DB client

      */

     @NotNull

     AmazonSimpleDB aws();

     /**

      * Simple implementation.

      */

     @Immutable

     @Loggable(Loggable.DEBUG)

     @EqualsAndHashCode(of = { "key", "secret", "region" })

     final class Simple implements Credentials {

         /**

          * AWS key.

          */

         private final transient String key;

         /**

          * AWS secret.

          */

         private final transient String secret;

         /**

          * Region name.

          */

         private final transient String region;

         /**

          * Public ctor, with "us-east-1" region.

          * @param akey AWS key

          * @param scrt Secret

          */

         public Simple(@NotNull final String akey, @NotNull final String scrt) {

             this(akey, scrt, Regions.US_EAST_1.getName());

         }

         /**

          * Public ctor.

          * @param akey AWS key

          * @param scrt Secret

          * @param reg Region

          */

         public Simple(

             @NotNull(message = "AWS key can't be NULL") final String akey,

             @NotNull(message = "AWS secret can't be NULL") final String scrt,

             @NotNull(message = "AWS region can't be NULL") final String reg) {

             Validate.matchesPattern(

                 akey, "[A-Z0-9]{20}",

                 "Invalid AWS key '%s'", akey

             );

             this.key = akey;

             Validate.matchesPattern(

                 scrt, "[a-zA-Z0-9+/=]{40}",

                 "Invalid AWS secret key '%s'", scrt

             );

             this.secret = scrt;

             Validate.matchesPattern(

                 reg, "[-a-z0-9]+",

                 "Invalid AWS region name '%s'", reg

             );

             this.region = reg;

         }

         /**

          * {@inheritDoc}

          */

         @Override

         public String toString() {

             return String.format("%s/%s", this.region, this.key);

         }

         /**

          * {@inheritDoc}

          */

         @Override

         @NotNull

         public AmazonSimpleDB aws() {

             final AmazonSimpleDB aws = new AmazonSimpleDBClient(

                 new BasicAWSCredentials(this.key, this.secret)

             );

             final com.amazonaws.regions.Region reg =

                 RegionUtils.getRegion(this.region);

             Validate.notNull(reg, "Failed to find region '%s'", this.region);

             aws.setRegion(reg);

             return aws;

         }

     }

     /**

      * Assumed AWS IAM role.

      *

      * @see <a href="http://docs.aws.amazon.com/IAM/latest/UserGuide/role-usecase-ec2app.html">Granting Applications that Run on Amazon EC2 Instances Access to AWS Resources</a>

      */

     @Immutable

     @Loggable(Loggable.DEBUG)

     @EqualsAndHashCode(of = "region")

     final class Assumed implements Credentials {

         /**

          * Region name.

          */

         private final transient String region;

         /**

          * Public ctor.

          */

         public Assumed() {

             this(Regions.US_EAST_1.getName());

         }

         /**

          * Public ctor.

          * @param reg Region

          */

         public Assumed(@NotNull(message = "SimpleDB region can't be NULL")

             final String reg) {

             Validate.matchesPattern(

                 reg, "[-0-9a-z]+",

                 "Invalid AWS region name: '%s'", reg

             );

             this.region = reg;

         }

         /**

          * {@inheritDoc}

          */

         @Override

         public String toString() {

             return this.region;

         }

         /**

          * {@inheritDoc}

          */

         @Override

         @NotNull

         public AmazonSimpleDB aws() {

             final AmazonSimpleDB aws = new AmazonSimpleDBClient();

             final com.amazonaws.regions.Region reg =

                 RegionUtils.getRegion(this.region);

             Validate.notNull(reg, "Failed to detect region '%s'", this.region);

             aws.setRegion(reg);

             return aws;

         }

     }

     /**

      * With explicitly specified endpoint.

      */

     @Immutable

     @Loggable(Loggable.DEBUG)

     @EqualsAndHashCode(of = { "origin", "endpoint" })

     final class Direct implements Credentials {

         /**

          * Original credentials.

          */

         private final transient Credentials origin;

         /**

          * Endpoint.

          */

         private final transient String endpoint;

         /**

          * Public ctor.

          * @param creds Original credentials

          * @param pnt Endpoint

          */

         public Direct(

             @NotNull(message = "credentials is NULL") final Credentials creds,

             @NotNull(message = "end point can't be NULL") final String pnt) {

             this.origin = creds;

             this.endpoint = pnt;

         }

         /**

          * Public ctor.

          * @param creds Original credentials

          * @param port Port number for localhost

          */

         public Direct(@NotNull final Credentials creds, final int port) {

             this(creds, String.format("http://localhost:%d", port));

         }

         /**

          * {@inheritDoc}

          */

         @Override

         public String toString() {

             return String.format("%s at %s", this.origin, this.endpoint);

         }

         /**

          * {@inheritDoc}

          */

         @Override

         @NotNull

         public AmazonSimpleDB aws() {

             final AmazonSimpleDB aws = this.origin.aws();

             aws.setEndpoint(this.endpoint);

             return aws;

         }

     }

 }