/*
    * Copyright 2004-2010 the Seasar Foundation 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.seasar.cubby.internal.controller.impl;
  
  import java.lang.reflect.Array;
  import java.util.Collection;
  
  import org.seasar.cubby.action.RequestParameter;
  import org.seasar.cubby.controller.FormWrapper;
  import org.seasar.cubby.controller.FormWrapperFactory;
  import org.seasar.cubby.converter.ConversionHelper;
  import org.seasar.cubby.converter.Converter;
  import org.seasar.cubby.converter.impl.ConversionHelperImpl;
  import org.seasar.cubby.spi.ConverterProvider;
  import org.seasar.cubby.spi.ProviderFactory;
  import org.seasar.cubby.spi.beans.Attribute;
  import org.seasar.cubby.spi.beans.BeanDesc;
  import org.seasar.cubby.spi.beans.BeanDescFactory;
  
  /**
   * フォームオブジェクトのラッパーファクトリの実装です。
   * 
   * @author baba
   */
  public class FormWrapperFactoryImpl implements FormWrapperFactory {
  
  	/** 変換のヘルパクラス。 */
  	private final ConversionHelper conversionHelper = new ConversionHelperImpl();
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public FormWrapper create(final Object form) {
  		final FormWrapper formObject = new FormWrapperImpl(form);
  		return formObject;
  	}
  
  	/**
  	 * フォームオブジェクトのラッパーの実装です。
  	 * 
  	 * @author baba
  	 */
  	private class FormWrapperImpl implements FormWrapper {
  
  		/** フォームオブジェクト */
  		private final Object form;
  
  		/**
  		 * インスタンス化します。
  		 * 
  		 * @param form
  		 *            フォームオブジェクト
  		 * @param context
  		 *            変換中のコンテキスト
  		 */
  		private FormWrapperImpl(final Object form) {
  			this.form = form;
  		}
  
  		/**
  		 * {@inheritDoc}
  		 */
  		public boolean hasValues(final String name) {
  			if (this.form == null) {
  				return false;
  			}
  			final BeanDesc beanDesc = BeanDescFactory.getBeanDesc(this.form
  					.getClass());
  			final Attribute attribute = findAttribute(beanDesc, name);
  			return attribute != null;
  		}
  
  		/**
  		 * {@inheritDoc}
  		 */
  		public String[] getValues(final String name) {
  			if (this.form == null) {
  				return null;
  			}
  
  			final BeanDesc beanDesc = BeanDescFactory.getBeanDesc(this.form
  					.getClass());
  			final Attribute attribute = findAttribute(beanDesc, name);
  			if (attribute == null) {
  				return null;
 			}
 			final Object value = attribute.getValue(this.form);
 
 			if (value == null) {
 				return null;
 			} else if (value instanceof String[]) {
 				return (String[]) value;
 			} else {
 				final Class<? extends Converter> converterType;
 				if (attribute.isAnnotationPresent(RequestParameter.class)) {
 					final RequestParameter requestParameter = attribute
 							.getAnnotation(RequestParameter.class);
 					if (Converter.class.equals(requestParameter.converter())) {
 						converterType = null;
 					} else {
 						converterType = requestParameter.converter();
 					}
 				} else {
 					converterType = null;
 				}
 				if (value.getClass().isArray()) {
 					final int length = Array.getLength(value);
 					final String[] array = (String[]) Array.newInstance(
 							String.class, length);
 					for (int i = 0; i < length; i++) {
 						final Object element = Array.get(value, i);
 						final String converted = convert(element, converterType);
 						Array.set(array, i, converted);
 					}
 					return array;
 				} else if (value instanceof Collection<?>) {
 					final Collection<?> collection = (Collection<?>) value;
 					final String[] array = (String[]) Array.newInstance(
 							String.class, collection.size());
 					int i = 0;
 					for (final Object element : collection) {
 						final String converted = convert(element, converterType);
 						Array.set(array, i++, converted);
 					}
 					return array;
 				} else {
 					final String[] array = (String[]) Array.newInstance(
 							String.class, 1);
 					final String converted = convert(value, converterType);
 					Array.set(array, 0, converted);
 					return array;
 				}
 			}
 		}
 
 		/**
 		 * 指定された名前に対応する属性を検索します。
 		 * 
 		 * @param beanDesc
 		 *            Java Beans の定義
 		 * @param name
 		 *            名前
 		 * @return 属性の定義
 		 */
 		private Attribute findAttribute(final BeanDesc beanDesc,
 				final String name) {
 
 			for (final Attribute attribute : beanDesc.findAllAttributes()) {
 				if (attribute.isAnnotationPresent(RequestParameter.class)) {
 					final RequestParameter requestParameter = attribute
 							.getAnnotation(RequestParameter.class);
 					final String parameterName = requestParameter.name();
 					if (parameterName == null || parameterName.length() == 0) {
 						if (name.equals(attribute.getName())) {
 							return attribute;
 						}
 					} else {
 						if (name.equals(parameterName)) {
 							return attribute;
 						}
 					}
 				} else {
 					if (name.equals(attribute.getName())) {
 						return attribute;
 					}
 				}
 			}
 
 			return null;
 		}
 
 		/**
 		 * 指定されたオブジェクトを文字列に変換します。
 		 * 
 		 * @param value
 		 *            値
 		 * @param converterType
 		 *            コンバータの型
 		 * @return <code>value</code>を変換した文字列
 		 */
 		private String convert(final Object value,
 				final Class<? extends Converter> converterType) {
 			if (value == null) {
 				return null;
 			}
 			final ConverterProvider converterProvider = ProviderFactory
 					.get(ConverterProvider.class);
 			final Converter converter;
 			if (converterType == null) {
 				converter = converterProvider.getConverter(null, value
 						.getClass());
 			} else {
 				converter = converterProvider.getConverter(converterType);
 			}
 			if (converter == null) {
 				return value.toString();
 			} else {
 				return converter.convertToString(value, conversionHelper);
 			}
 		}
 
 	}
 }