/**
    * Copyright (c) 2012-2017, s3auth.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 s3auth.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.s3auth.hosts;
  
  import com.jcabi.aspects.Immutable;
  import com.jcabi.aspects.Loggable;
  import com.jcabi.immutable.Array;
  import java.io.Closeable;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.net.HttpURLConnection;
  import java.util.Collection;
  import java.util.Date;
  import javax.validation.constraints.NotNull;
  import lombok.EqualsAndHashCode;
  import lombok.ToString;
  import org.apache.commons.codec.digest.DigestUtils;
  import org.apache.commons.io.Charsets;
  import org.apache.commons.io.IOUtils;
  import org.apache.http.HttpHeaders;
  
  /**
   * Found resource.
   *
   * @author Yegor Bugayenko (yegor@tpc2.com)
   * @version $Id: c31d6b662e1c3a6afeb91768a36717e936101741 $
   * @since 0.0.1
   */
  @Immutable
  @SuppressWarnings("PMD.TooManyMethods")
  public interface Resource extends Closeable {
  
      /**
       * Get HTTP status.
       * @return The status
       */
      int status();
  
      /**
       * Write its content to the writer.
       * @param stream The stream to write to
       * @return How many bytes were written
       * @throws IOException If some error with I/O inside
       */
      long writeTo(OutputStream stream) throws IOException;
  
      /**
       * Get a collection of all necessary HTTP headers for this resource.
       * @return Collection of HTTP headers
       * @throws IOException If some error with I/O inside
       */
      Collection<String> headers() throws IOException;
  
      /**
       * Get its ETag.
       * @return The etag
       * @link <a href="http://en.wikipedia.org/wiki/HTTP_ETag">ETag</a>
       */
      String etag();
  
      /**
       * Get its last modified date.
       * @return The last modified date.
       */
      Date lastModified();
  
      /**
       * Get the resource's HTTP Content-Type.
       * @return The HTTP Content-Type of the resource.
       */
      String contentType();
  
     /**
      * Simple resource made out of plain text.
      */
     @Immutable
     @ToString
     @EqualsAndHashCode(of = "text")
     @Loggable(Loggable.DEBUG)
     final class PlainText implements Resource {
         /**
          * Plain text to show.
          */
         @Immutable.Array
         private final transient byte[] text;
         /**
          * Last modified date to return. Equal to the time of object creation.
          */
         private final transient long modified = System.currentTimeMillis();
         /**
          * Headers associated with this resource.
          */
         private final Array<String> hdrs;
         /**
          * Public ctor.
          * @param txt The text to show
          */
         public PlainText(@NotNull final String txt) {
             this.text = txt.getBytes(Charsets.UTF_8);
             this.hdrs = new Array<String>(
                 String.format(
                     "%s: %s",
                     HttpHeaders.CONTENT_TYPE,
                     this.contentType()
                 ),
                 String.format(
                     "%s: %d",
                     HttpHeaders.CONTENT_LENGTH,
                     this.text.length
                 )
             );
         }
         @Override
         public int status() {
             return HttpURLConnection.HTTP_OK;
         }
         @Override
         public long writeTo(@NotNull final OutputStream stream)
             throws IOException {
             IOUtils.write(this.text, stream);
             return this.text.length;
         }
         @Override
         public String etag() {
             return DigestUtils.md5Hex(this.text);
         }
         @Override
         public Date lastModified() {
             return new Date(this.modified);
         }
         @Override
         public String contentType() {
             return "text/plain";
         }
         @Override
         @NotNull
         public Collection<String> headers() {
             return this.hdrs;
         }
         @Override
         public void close() {
             // nothing to do
         }
     }
 
 }