/*
    * Copyright 2012-2017 CodeLibs Project and the Others.
    *
    * 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 org.codelibs.fess.util;
  
  import java.util.Date;
  import java.util.List;
  import java.util.Map;
  
  import org.codelibs.fess.taglib.FessFunctions;
  
  public final class DocumentUtil {
  
      private DocumentUtil() {
      }
  
      public static <T> T getValue(final Map<String, Object> doc, final String key, final Class<T> clazz, final T defaultValue) {
          T value = getValue(doc, key, clazz);
          if (value == null) {
              return defaultValue;
          }
          return value;
      }
  
      @SuppressWarnings("unchecked")
      public static <T> T getValue(final Map<String, Object> doc, final String key, final Class<T> clazz) {
          if (doc == null || key == null) {
              return null;
          }
  
          final Object value = doc.get(key);
          if (value == null) {
              return null;
          }
  
          if (value instanceof List) {
              if (clazz.isAssignableFrom(List.class)) {
                  return (T) value;
              }
  
              if (((List<?>) value).isEmpty()) {
                  return null;
              }
  
              return convertObj(((List<?>) value).get(0), clazz);
          }
  
          return convertObj(value, clazz);
      }
  
      @SuppressWarnings("unchecked")
      private static <T> T convertObj(final Object value, final Class<T> clazz) {
          if (value == null) {
              return null;
          }
  
          if (clazz.isAssignableFrom(String.class)) {
              return (T) value.toString();
          } else if (clazz.isAssignableFrom(Date.class)) {
              if (value instanceof Date) {
                  return (T) value;
              } else {
                  return (T) FessFunctions.parseDate(value.toString());
              }
          } else if (clazz.isAssignableFrom(Long.class)) {
              if (value instanceof Long) {
                  return (T) value;
              } else {
                  return (T) Long.valueOf(value.toString());
              }
          } else if (clazz.isAssignableFrom(Integer.class)) {
              if (value instanceof Integer) {
                  return (T) value;
              } else {
                  return (T) Integer.valueOf(value.toString());
              }
          } else if (clazz.isAssignableFrom(Double.class)) {
              if (value instanceof Double) {
                  return (T) value;
              } else {
                  return (T) Double.valueOf(value.toString());
              }
          } else if (clazz.isAssignableFrom(Float.class)) {
              if (value instanceof Float) {
                  return (T) value;
              } else {
                  return (T) Float.valueOf(value.toString());
             }
         } else if (clazz.isAssignableFrom(Boolean.class)) {
             if (value instanceof Boolean) {
                 return (T) value;
             } else {
                 return (T) Boolean.valueOf(value.toString());
             }
         }
         return null;
     }
 }