/*
    * 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.chemistry.opencmis.client.mapper;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Properties;
  
  import org.apache.chemistry.opencmis.client.parser.MetadataParser;
  import org.apache.chemistry.opencmis.client.parser.MetadataParserTika;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  public class Configurator {
  
      private static final Log LOG = LogFactory.getLog(Configurator.class.getName());
      
      private static Configurator INSTANCE;
      static final String PREFIX = "mapping.contentType";
      
      public static Configurator getInstance() {
          if (null == INSTANCE)
              INSTANCE = new Configurator();
          return INSTANCE;
      }
      
      private Properties properties;
      private Map<String, PropertyMapper> contentTypeMapperMap  = new HashMap<String, PropertyMapper>();
      private Map<String, MetadataParser> parserMap = new HashMap<String, MetadataParser>();
      private String defaultDocumentType;
      private String defaultFolderType;
      
      private Configurator() {     
          loadProperties();
          loadDefaults();
          buildMapperMap();
          createParsers();
      }
      
      // just for unit tests
      Configurator(Properties props) {
  //        contentTypeMapperMap = new HashMap<String, PropertyMapper>();
          this.properties = props;
      }
      
      
      public PropertyMapper getPropertyMapper(String contentType) {
          MetadataParser parser = getParser(contentType);
          return parser.getMapper();
      }
      
      public MetadataParser getParser(String contentType) {
          MetadataParser parser = parserMap.get(contentType);
          if (null == parser) {
              // if not found try a more generic one
              String genericContentType = contentType.substring(0, contentType.indexOf('/')) + "/*";
              for (String key: parserMap.keySet()) {
                  if (key.equals(genericContentType))
                      return parserMap.get(key);
              }
          }
          return parser;
          
  //        for (String contentType : contentTypes) {
  //            if (contentType.equals(mimeType))
  //                return cmisTypeId;
  //            boolean isStar = contentType.endsWith("/*");
  //            if (isStar) {
  //                String generalPartParam = mimeType.substring(0, mimeType.indexOf('/'));
  //                String generalPartCfg = contentType.substring(0, mimeType.indexOf('/'));
  //                if (generalPartParam.equals(generalPartCfg))
  //                    return cmisTypeId;
  //            }
  //        }
  //        return null;        
      }
  
      private void loadProperties() {
          // Returns null on lookup failures:
          InputStream in = Configurator.class.getResourceAsStream ("/mapping.properties");
          if (in != null)
         {
             properties = new Properties();
             try {
                 properties.load (in);
             } catch (IOException e) {
                 LOG.error(e);
                 e.printStackTrace();
                 throw new MapperException("Could not load file mapping.properties as resource", e);
             } 
         }
     }
     
     private void loadDefaults() {
         defaultDocumentType = properties.getProperty(PREFIX + ".default.document");
         if (null == defaultDocumentType)
             defaultDocumentType = "cmis:document";
         
         defaultFolderType = properties.getProperty(PREFIX + ".default.folder");
         if (null == defaultFolderType)
             defaultFolderType = "cmis:folder";                
     }
     
     public String getDefaultDocumentType() {
         return defaultDocumentType;
     }
     
     public String getDefaultFolderType() {
         return defaultFolderType;
     }
 
     public final Properties getProperties() {
         return properties;
     }
     
     /**
      * return an overridden MIME type from a file extension
      * 
      * @param fileExtension
      *      enforced or content-type or null if none is set
      */
     public String getContentType(String fileExtension) {
         return properties.getProperty(PREFIX+ ".forceContentType." + fileExtension, null);
     }
     
     String[] getTypeKeys() {
         String s = properties.getProperty(PREFIX + "s");
         
         if (null == s)
             return null;
         
         String[] keys = s.split(",");
         
         for (int i=0; i<keys.length; i++)
             keys[i] = keys[i].trim();
         
         return keys;
     }
     
     void  buildMapperMap() {
         
         String[] typeKeys = getTypeKeys();
         for (String typeKey : typeKeys) {
             PropertyMapper mapper = loadMapperClass(typeKey);
             String contentType = properties.getProperty(PREFIX + "." + typeKey);
             if (null == contentType) 
                 throw new MapperException("Missingt content type in properties: " + PREFIX + "." + contentType);
             boolean ok = mapper.initialize(PREFIX, typeKey, properties);
 
             if (ok)
                 contentTypeMapperMap.put(typeKey, mapper);
         }        
     }
     
     void createParsers() {
         String[] typeKeys = getTypeKeys();
         for (String typeKey : typeKeys) {
             MetadataParser parser = loadParserClass(typeKey);
             String contentType = properties.getProperty(PREFIX + "." + typeKey);
             if (null == contentType) 
                 throw new MapperException("Missing content type in properties: " + PREFIX + "." + contentType);
             
             PropertyMapper mapper = contentTypeMapperMap.get(typeKey);
 
             parser.initialize(mapper, contentType);
             String[] contentTypes = parser.getContentTypes();
             for (String ct : contentTypes)
                 parserMap.put(ct, parser);
         }                
     }
     
     MetadataParser loadParserClass(String typeKey) {
         String className = properties.getProperty(PREFIX + "." + typeKey + ".parserClass");
         if (null == className) // use Tika as default parser if none is configured
             className = MetadataParserTika.class.getName();
 //            throw new MapperException("Missing parser class in properties: " + PREFIX + "." + typeKey + ".parserClass");
 
         Object obj = null;
 
         try {
             obj = Class.forName(className).newInstance();
         } catch (InstantiationException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load metadata parser, cannot instantiate " + className, e);
         } catch (IllegalAccessException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load metadata parser, cannot access " + className, e);
         } catch (ClassNotFoundException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load metadata parser, class not found: " + className, e);
         }
 
         if (obj instanceof MetadataParser) {
             return (MetadataParser) obj;
         } else {
             throw new MapperException("Illegal class to create metadata parser: " + className + ", must implement MetadataParser interface.");
         }
     }
 
     PropertyMapper loadMapperClass(String typeKey) {
         String className = properties.getProperty(PREFIX + "." + typeKey + ".mapperClass");
         if (null == className) 
             className = PropertyMapperTika.class.getName();
 //            throw new MapperException("Missing property mapper in properties: " + PREFIX + "." + typeKey + ".mapperClass");
 
         Object obj = null;
 
         try {
             obj = Class.forName(className).newInstance();
         } catch (InstantiationException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load mapping configuration, cannot instantiate " + className, e);
         } catch (IllegalAccessException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load mapping configuration, cannot access " + className, e);
         } catch (ClassNotFoundException e) {
             LOG.error(e);
             throw new MapperException(
                     "Illegal class to load mapping configuration, class not found: " + className, e);
         }
 
         if (obj instanceof PropertyMapper) {
             return (PropertyMapper) obj;
         } else {
             throw new MapperException("Illegal class to create property mapper: " + className + ", must implement PropertyMapper interface.");
         }
     }
 }