/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.oaipmh.server;
  
  import static org.apache.commons.lang3.StringUtils.trimToNull;
  import static org.opencastproject.util.data.Option.eq;
  import static org.opencastproject.util.data.Option.option;
  
  import org.opencastproject.oaipmh.OaiPmhConstants;
  import org.opencastproject.util.data.Option;
  
  /**
   * Helper to encapsulate HTTP parameter handling.
   */
  public abstract class Params {
    /**
     * Implement this method to supply the needed parameters.
     *
     * @return the parameter or null or a blank string to indicate a missing parameter
     */
    abstract String getParameter(String key);
  
    /**
     * Return the complete repository URL. This is everything before the query parameters.
     * Examples: http://localhost:8080/oaipmh or http://localhost:8080/oaipmh/cq5
     */
    abstract String getRepositoryUrl();
  
    boolean isVerbGetRecord() {
      return getVerb().map(eq(OaiPmhConstants.VERB_GET_RECORD)).getOrElse(false);
    }
  
    boolean isVerbIdentify() {
      return getVerb().map(eq(OaiPmhConstants.VERB_IDENTIFY)).getOrElse(false);
    }
  
    boolean isVerbListMetadataFormats() {
      return getVerb().map(eq(OaiPmhConstants.VERB_LIST_METADATA_FORMATS)).getOrElse(false);
    }
  
    boolean isVerbListSets() {
      return getVerb().map(eq(OaiPmhConstants.VERB_LIST_SETS)).getOrElse(false);
    }
  
    boolean isVerbListIdentifiers() {
      return getVerb().map(eq(OaiPmhConstants.VERB_LIST_IDENTIFIERS)).getOrElse(false);
    }
  
    boolean isVerbListRecords() {
      return getVerb().map(eq(OaiPmhConstants.VERB_LIST_RECORDS)).getOrElse(false);
    }
  
    Option<String> getVerb() {
      return option(trimToNull(getParameter("verb")));
    }
  
    Option<String> getIdentifier() {
      return option(trimToNull(getParameter("identifier")));
    }
  
    Option<String> getMetadataPrefix() {
      return option(trimToNull(getParameter("metadataPrefix")));
    }
  
    Option<String> getFrom() {
      return option(trimToNull(getParameter("from")));
    }
  
    Option<String> getUntil() {
      return option(trimToNull(getParameter("until")));
    }
  
    Option<String> getSet() {
      return option(trimToNull(getParameter("set")));
    }
  
    Option<String> getResumptionToken() {
      return option(trimToNull(getParameter("resumptionToken")));
    }
  
    @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder();
     sb.append("Params");
     sb.append("{verb=");
     sb.append(getVerb());
     sb.append("}");
     return sb.toString();
   }
 }