/*
    * 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.tika.metadata;
  
  // JDK imports
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Properties;
  
  /**
   * A multi-valued metadata container.
   * 
   * 
   * 
   */
  public class Metadata implements CreativeCommons, DublinCore, HttpHeaders,
      MSOffice, TikaMetadataKeys, TikaMimeKeys {
  
  
    /**
     * A map of all metadata attributes.
     */
    private Map<String, String[]> metadata = null;
  
    /**
     * Constructs a new, empty metadata.
     */
    public Metadata() {
      metadata = new HashMap<String, String[]>();
    }
  
    /**
     * Returns true if named value is multivalued.
     * 
     * @param name
     *          name of metadata
     * @return true is named value is multivalued, false if single value or null
     */
    public boolean isMultiValued(final String name) {
      return metadata.get(name) != null && metadata.get(name).length > 1;
    }
  
    /**
     * Returns an array of the names contained in the metadata.
     * 
     * @return Metadata names
     */
    public String[] names() {
      return metadata.keySet().toArray(new String[metadata.keySet().size()]);
    }
  
    /**
     * Get the value associated to a metadata name. If many values are assiociated
     * to the specified name, then the first one is returned.
     * 
     * @param name
     *          of the metadata.
     * @return the value associated to the specified metadata name.
     */
    public String get(final String name) {
      String[] values = metadata.get(name);
      if (values == null) {
        return null;
      } else {
        return values[0];
      }
    }
  
    /**
     * Get the values associated to a metadata name.
     * 
     * @param name
     *          of the metadata.
     * @return the values associated to a metadata name.
     */
    public String[] getValues(final String name) {
      return _getValues(name);
    }
  
    private String[] _getValues(final String name) {
      String[] values = metadata.get(name);
      if (values == null) {
        values = new String[0];
      }
     return values;
   }
 
   /**
    * Add a metadata name/value mapping. Add the specified value to the list of
    * values associated to the specified metadata name.
    * 
    * @param name
    *          the metadata name.
    * @param value
    *          the metadata value.
    */
   public void add(final String name, final String value) {
     String[] values = metadata.get(name);
     if (values == null) {
       set(name, value);
     } else {
       String[] newValues = new String[values.length + 1];
       System.arraycopy(values, 0, newValues, 0, values.length);
       newValues[newValues.length - 1] = value;
       metadata.put(name, newValues);
     }
   }
 
   /**
    * Copy All key-value pairs from properties.
    * 
    * @param properties
    *          properties to copy from
    */
   public void setAll(Properties properties) {
     Enumeration names = properties.propertyNames();
     while (names.hasMoreElements()) {
       String name = (String) names.nextElement();
       metadata.put(name, new String[] { properties.getProperty(name) });
     }
   }
 
   /**
    * Set metadata name/value. Associate the specified value to the specified
    * metadata name. If some previous values were associated to this name, they
    * are removed.
    * 
    * @param name
    *          the metadata name.
    * @param value
    *          the metadata value.
    */
   public void set(String name, String value) {
     metadata.put(name, new String[] { value });
   }
 
   /**
    * Remove a metadata and all its associated values.
    * 
    * @param name
    *          metadata name to remove
    */
   public void remove(String name) {
     metadata.remove(name);
   }
 
   /**
    * Returns the number of metadata names in this metadata.
    * 
    * @return number of metadata names
    */
   public int size() {
     return metadata.size();
   }
 
   public boolean equals(Object o) {
 
     if (o == null) {
       return false;
     }
 
     Metadata other = null;
     try {
       other = (Metadata) o;
     } catch (ClassCastException cce) {
       return false;
     }
 
     if (other.size() != size()) {
       return false;
     }
 
     String[] names = names();
     for (int i = 0; i < names.length; i++) {
       String[] otherValues = other._getValues(names[i]);
       String[] thisValues = _getValues(names[i]);
       if (otherValues.length != thisValues.length) {
         return false;
       }
       for (int j = 0; j < otherValues.length; j++) {
         if (!otherValues[j].equals(thisValues[j])) {
           return false;
         }
       }
     }
     return true;
   }
 
   public String toString() {
     StringBuffer buf = new StringBuffer();
     String[] names = names();
     for (int i = 0; i < names.length; i++) {
       String[] values = _getValues(names[i]);
       for (int j = 0; j < values.length; j++) {
         buf.append(names[i]).append("=").append(values[j]).append(" ");
       }
     }
     return buf.toString();
   }
 
 }