/* Copyright (c) 2008 Google Inc.
 *
 * Licensed 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 sample.contacts;

import java.util.EnumMap;
import java.util.Map;

/**
 * Parser to tokenize element descriptions.
 * The general format of an element specification looks like:
 * [<value>]|[<name_1>:<value_1>][,<name_2>:<value_2>]...[,<name_n>:<value_n>]
 * 
 * For convenience a single unnamed value can be specified. It is treated as 
 * "value:<value>", and the parsed value can be accessed with the VALUE key.
 *
 * 
 */
class ElementParser {

  // Map of parsed property names and values.
  private Map<PropertyName, String> propertyMap;
    
  /**
   * Constructor.
   * Parses the element description, and fills the propertyMap.
   * 
   * @param elementDesc the element description.
   * @throws IllegalArgumentException on badly formated element description.
   */
  ElementParser(String elementDesc) throws IllegalArgumentException {
    propertyMap = new EnumMap<PropertyName, String>(PropertyName.class);
    for (String propertyDesc : elementDesc.split(",")) {
      String nameValuePair[] = propertyDesc.split(":", 2);
      if (nameValuePair.length == 1) {
        propertyMap.put(PropertyName.VALUE, propertyDesc);
      } else if (nameValuePair.length == 2){
        propertyMap.put(
            PropertyName.valueOf(nameValuePair[0].toUpperCase()), 
            nameValuePair[1]);
      } else {
        throw new IllegalArgumentException("Badly formated property:" 
            + propertyDesc);
      }
    }
  }
  
  /**
   * Checks if the given property has a parsed in value.
   * 
   * @param property the property.
   * @return {@code true} if the given property has a parsed in value,
   *         otherwise {@code false} 
   */
  boolean has(PropertyName property) {
    return propertyMap.containsKey(property);
  }
  
  /**
   * Retrieves the parsed in value for the given property.
   * 
   * @param property the property.
   * @return the parsed in value for the given property, or {@code null} if
   *         the given property was not specified in the element description 
   *         string.
   */
  String get(PropertyName property) {
    return propertyMap.get(property);
  }
  
  /**
   * Convenience method to check the value of a boolean property.
   * 
   * @param property the property.
   * @return {@code true} if the parsed in value of the given property is "true"
   *         {@code false} in any other cases.
   */
  boolean is(PropertyName property) {
    String value = propertyMap.get(property);
    return (value != null) && (value.toLowerCase().equals("true"));
  }
}