/**

  * Copyright (c) 2013-2017, 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.github;

 import com.jcabi.aspects.Immutable;

 import com.jcabi.aspects.Loggable;

 import com.jcabi.http.Request;

 import java.io.IOException;

 import java.util.Iterator;

 import java.util.List;

 import javax.json.JsonArray;

 import javax.json.JsonObject;

 import lombok.EqualsAndHashCode;

 import lombok.ToString;

 /**

  * Commits comparison.

  * @author Alexander Sinyagin (sinyagin.alexander@gmail.com)

  * @version $Id: fa868ccf10c7be94588ca8cfbc93dfd442e43ad6 $

  */

 @Immutable

 @Loggable(Loggable.DEBUG)

 @EqualsAndHashCode(of = "request")

 final class RtCommitsComparison implements CommitsComparison {

     /**

      * RESTful request for the comparison.

      */

     private final transient Request request;

     /**

      * Parent repository.

      */

     private final transient Repo owner;

     /**

      * Ctor.

      * @param req Entry point of API

      * @param repo Repository

      * @param base SHA of a base commit

      * @param head SHA of a head commit

      * @checkstyle ParameterNumber (3 lines)

      */

     RtCommitsComparison(final Request req, final Repo repo,

         final String base, final String head) {

         this.owner = repo;

         this.request = req.uri()

             .path("/repos")

             .path(repo.coordinates().toString())

             .path("/compare")

             .path(String.format("%s...%s", base, head))

             .back();

     }

     @Override

     public Repo repo() {

         return this.owner;

     }

     @Override

     public Iterable<FileChange> files() throws IOException {

         return new FileChanges(this.json().getJsonArray("files"));

     }

     @Override

     public String toString() {

         return this.request.uri().get().toString();

     }

     @Override

     public JsonObject json() throws IOException {

         return new RtJson(this.request).fetch();

     }

     /**

      * Iterator that yields FileChange objects converted

      * from JSON objects in a JSON list.

      */

     @EqualsAndHashCode(of = { "iterator" })

     @ToString

     private static final class FileChangesIterator

         implements Iterator<FileChange> {

         /**

          * Encapsulated iterator of file change JSON objects.

          */

         private final transient Iterator<JsonObject> iterator;

         /**

          * Ctor.

          * @param iter Iterator of file change JSON objects

          */

         FileChangesIterator(

             final Iterator<JsonObject> iter

         ) {

             this.iterator = iter;

         }

         @Override

         public FileChange next() {

             return new RtFileChange(this.iterator.next());

         }

         @Override

         public boolean hasNext() {

             return this.iterator.hasNext();

         }

         @Override

         public void remove() {

             throw new UnsupportedOperationException("#remove()");

         }

     }

     /**

      * Trivial iterable that returns FileChangesIterators using

      * the given JSON list.

      */

     @EqualsAndHashCode(of = { "list" })

     @Loggable(Loggable.DEBUG)

     @ToString

     private static final class FileChanges

         implements Iterable<FileChange> {

         /**

          * List of file change JSON objects.

          */

         private final transient List<JsonObject> list;

         /**

          * Ctor.

          * @param files JsonArray of file change objects

          */

         FileChanges(

             final JsonArray files

         ) {

             this.list = files.getValuesAs(JsonObject.class);

         }

         @Override

         public Iterator<FileChange> iterator() {

             return new FileChangesIterator(this.list.iterator());

         }

     }

 }