/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.juneau.rest.converter;

import org.apache.juneau.*;
import org.apache.juneau.objecttools.*;
import org.apache.juneau.rest.*;
import org.apache.juneau.rest.httppart.*;

/**
 * Converter for enabling of search/view/sort/page support on response objects returned by a <c>@RestOp</c>-annotated method.
 *
 * <p>
 * When enabled, objects in a POJO tree can be filtered using the functionality described in the {@link ObjectSearcher},
 * {@link ObjectViewer}, {@link ObjectSorter}, and {@link ObjectPaginator} classes.
 *
 * <p>
 * The following HTTP request parameters are available for tabular data (e.g. {@code Collections} of {@code Maps},
 * arrays of beans, etc...):
 * <ul class='spaced-list'>
 *    <li>
 *       <c>&amp;s=</c> Search arguments.
 *       <br>Comma-delimited list of key/value pairs representing column names and search tokens.
 *       <br>Example:
 *       <p class='burlenc'>
 *    &amp;s=name=Bill*,birthDate&gt;2000
 *       </p>
 *    <li>
 *       <c>&amp;v=</c> Visible columns.
 *       <br>Comma-delimited list of column names to display.
 *       <br>Example:
 *       <p class='burlenc'>
 *    &amp;v=name,birthDate
 *       </p>
 *    <li>
 *       <c>&amp;o=</c> Sort commands.
 *       <br>Comma-delimited list of columns to sort by.
 *       <br>Column names can be suffixed with <js>'+'</js> or <js>'-'</js> to indicate ascending or descending order.
 *       <br>The default is ascending order.
 *       <br>Example:
 *       <p class='burlenc'>
 *    &amp;o=name,birthDate-
 *       </p>
 *    <li>
 *       <c>&amp;i=</c> Case-insensitive parameter.
 *       <br>Boolean flag for case-insensitive matching on the search parameters.
 *    <li>
 *       <c>&amp;p=</c> - Position parameter.
 *       <br>Only return rows starting at the specified index position (zero-indexed).
 *       <br>Default is {@code 0}.
 *    <li>
 *       <c>&amp;l=</c> Limit parameter.
 *       <br>Only return the specified number of rows.
 *       <br>Default is {@code 0} (meaning return all rows).
 * </ul>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='jc'>{@link ObjectSearcher} - Additional information on searching POJO models.
 *    <li class='jc'>{@link ObjectViewer} - Additional information on filtering POJO models.
 *    <li class='jc'>{@link ObjectSorter} - Additional information on sorting POJO models.
 *    <li class='jc'>{@link ObjectPaginator} - Additional information on paginating POJO models.
 *    <li class='jm'>{@link org.apache.juneau.rest.RestOpContext.Builder#converters()} - Registering converters with REST resources.
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/Converters">Converters</a>
 * </ul>
 */
public class Queryable implements RestConverter {

   /**
    * Swagger parameters for this converter.
    */
   public static final String SWAGGER_PARAMS=""
      + "{"
         + "in:'query',"
         + "name:'s',"
         + "description:'"
            + "Search.\n"
            + "Key/value pairs representing column names and search tokens.\n"
            + "\\'*\\' and \\'?\\' can be used as meta-characters in string fields.\n"
            + "\\'>\\', \\'>=\\', \\'<\\', and \\'<=\\' can be used as limits on numeric and date fields.\n"
            + "Date fields can be matched with partial dates (e.g. \\'2018\\' to match any date in the year 2018)."
         + "',"
         + "type:'array',"
         + "collectionFormat:'csv',"
         + "examples:{example:'?s=Bill*,birthDate>2000'}"
      + "},"
      + "{"
         + "in:'query',"
         + "name:'v',"
         + "description:'"
            + "View.\n"
            + "Column names to display."
         + "',"
         + "type:'array',"
         + "collectionFormat:'csv',"
         + "examples:{example:'?v=name,birthDate'}"
      + "},"
      + "{"
         + "in:'query',"
         + "name:'o',"
         + "description:'"
            + "Order by.\n"
            + "Columns to sort by.\n"
            + "Column names can be suffixed with \\'+\\' or \\'-\\' to indicate ascending or descending order.\n"
            + "The default is ascending order."
         + "',"
         + "type:'array',"
         + "collectionFormat:'csv',"
         + "examples:{example:'?o=name,birthDate-'}"
      + "},"
      + "{"
         + "in:'query',"
         + "name:'p',"
         + "description:'"
            + "Position.\n"
            + "Only return rows starting at the specified index position (zero-indexed).\n"
            + "Default is 0"
         + "',"
         + "type:'integer',"
         + "examples:{example:'?p=100'}"
      + "},"
      + "{"
         + "in:'query',"
         + "name:'l',"
         + "description:'"
            + "Limit.\n"
            + "Only return the specified number of rows.\n"
            + "Default is 0 (meaning return all rows)."
         + "',"
         + "type:'integer',"
         + "examples:{example:'?l=100'}"
      + "}"
   ;

   @Override /* RestConverter */
   public Object convert(RestRequest req, Object o) {
      if (o == null)
         return null;

      Value<Object> v = Value.of(o);
      RequestQueryParams params = req.getQueryParams();
      BeanSession bs = req.getBeanSession();

      params.getSearchArgs().ifPresent(x -> v.set(ObjectSearcher.create().run(bs, v.get(), x)));
      params.getSortArgs().ifPresent(x -> v.set(ObjectSorter.create().run(bs, v.get(), x)));
      params.getViewArgs().ifPresent(x -> v.set(ObjectViewer.create().run(bs, v.get(), x)));
      params.getPageArgs().ifPresent(x -> v.set(ObjectPaginator.create().run(bs, v.get(), x)));
      return v.get();
   }
}