/*
    * 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 static org.seasar.cubby.action.RequestParameterBindingType.NONE;
  import static org.seasar.cubby.internal.util.LogMessages.format;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.seasar.cubby.action.Action;
  import org.seasar.cubby.action.ActionContext;
  import org.seasar.cubby.action.ActionErrors;
  import org.seasar.cubby.action.ActionException;
  import org.seasar.cubby.action.Form;
  import org.seasar.cubby.action.InitializeMethod;
  import org.seasar.cubby.action.PostRenderMethod;
  import org.seasar.cubby.action.PreRenderMethod;
  import org.seasar.cubby.action.RequestParameterBindingType;
  import org.seasar.cubby.spi.beans.Attribute;
  import org.seasar.cubby.spi.beans.BeanDesc;
  import org.seasar.cubby.spi.beans.BeanDescFactory;
  
  /**
   * アクションのコンテキストの実装です。
   * 
   * @author baba
   */
  class ActionContextImpl implements ActionContext {
  
  	/** アクション。 */
  	private final Object action;
  
  	/** アクションクラス。 */
  	private final Class<?> actionClass;
  
  	/** アクションメソッド。 */
  	private final Method actionMethod;
  
  	/** アクションエラー。 */
  	private final ActionErrors actionErrors;
  
  	/** 揮発性メッセージ。 */
  	private final Map<String, Object> flashMap;
  
  	/**
  	 * インスタンス化します。
  	 * 
  	 * @param request
  	 *            要求
  	 * @param action
  	 *            アクション
  	 * @param actionClass
  	 *            アクションクラス
  	 * @param actionMethod
  	 *            アクションメソッド
  	 * @param actionErrors
  	 *            アクションエラー
  	 * @param flashMap
  	 *            揮発性メッセージ
  	 */
  	public ActionContextImpl(final HttpServletRequest request,
  			final Object action, final Class<?> actionClass,
  			final Method actionMethod, final ActionErrors actionErrors,
  			final Map<String, Object> flashMap) {
  		this.action = action;
  		this.actionClass = actionClass;
  		this.actionMethod = actionMethod;
  
  		this.actionErrors = actionErrors;
  		this.flashMap = flashMap;
  
  		if (action instanceof Action) {
  			initializeAction((Action) action, actionErrors, flashMap);
  		}
  	}
  
  	/**
  	 * アクションを初期化します。
  	 * 
  	 * @param action
  	 *            アクション
 	 * @param actionErrors
 	 *            アクションエラー
 	 * @param flashMap
 	 *            揮発性マップ
 	 */
 	private void initializeAction(final Action action,
 			final ActionErrors actionErrors, final Map<String, Object> flashMap) {
 		action.setErrors(actionErrors);
 		action.setFlash(flashMap);
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public Object getAction() {
 		return action;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public Class<?> getActionClass() {
 		return actionClass;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public Method getActionMethod() {
 		return actionMethod;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public Object getFormBean() {
 		final Form form = getForm();
 		if (form == null) {
 			return action;
 		}
 		if (form.bindingType() == NONE) {
 			return null;
 		}
 		if (Form.THIS.equals(form.value())) {
 			return action;
 		}
 
 		final String attributeName = form.value();
 		final Object formBean;
 		final BeanDesc beanDesc = BeanDescFactory.getBeanDesc(actionClass);
 		if (beanDesc.hasPropertyAttribute(attributeName)) {
 			final Attribute attribute = beanDesc
 					.getPropertyAttribute(attributeName);
 			formBean = attribute.getValue(action);
 			if (formBean == null) {
 				throw new ActionException(format("ECUB0102", actionClass,
 						attributeName));
 			}
 		} else if (beanDesc.hasFieldAttribute(attributeName)) {
 			final Attribute attribute = beanDesc
 					.getFieldAttribute(attributeName);
 			formBean = attribute.getValue(action);
 			if (formBean == null) {
 				throw new ActionException(format("ECUB0111", actionClass,
 						attributeName));
 			}
 		} else {
 			throw new ActionException(format("ECUB0112", actionClass,
 					attributeName));
 		}
 		return formBean;
 	}
 
 	/**
 	 * 指定されたアクションメソッドを修飾する {@link Form} を取得します。
 	 * 
 	 * @return {@link Form}、修飾されていない場合はメソッドが定義されたクラスを修飾する {@link Form}
 	 *         、クラスも修飾されていない場合は <code>null</code>
 	 */
 	private Form getForm() {
 		final Form form;
 		if (actionMethod.isAnnotationPresent(Form.class)) {
 			form = actionMethod.getAnnotation(Form.class);
 		} else {
 			form = actionClass.getAnnotation(Form.class);
 		}
 		return form;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public boolean isBindRequestParameterToAllProperties() {
 		final Form form = this.getForm();
 		if (form == null) {
 			return false;
 		}
 
 		final RequestParameterBindingType type = form.bindingType();
 		switch (type) {
 		case ALL_PROPERTIES:
 			return true;
 		case ONLY_SPECIFIED_PROPERTIES:
 			return false;
 		default:
 			throw new IllegalStateException(type.toString());
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void invokeInitializeMethod() {
 		if (action instanceof Action) {
 			((Action) action).invokeInitializeMethod(actionMethod);
 		} else if (actionMethod.isAnnotationPresent(InitializeMethod.class)) {
 			final InitializeMethod initializeMethod = actionMethod
 					.getAnnotation(InitializeMethod.class);
 			final String methodName = initializeMethod.value();
 			this.invoke(action, methodName);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void invokePreRenderMethod() {
 		if (action instanceof Action) {
 			((Action) action).invokePreRenderMethod(actionMethod);
 		} else if (actionMethod.isAnnotationPresent(PreRenderMethod.class)) {
 			final PreRenderMethod preRenderMethod = actionMethod
 					.getAnnotation(PreRenderMethod.class);
 			final String methodName = preRenderMethod.value();
 			this.invoke(action, methodName);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void invokePostRenderMethod() {
 		if (action instanceof Action) {
 			((Action) action).invokePostRenderMethod(actionMethod);
 		} else if (actionMethod.isAnnotationPresent(PostRenderMethod.class)) {
 			final PostRenderMethod postRenderMethod = actionMethod
 					.getAnnotation(PostRenderMethod.class);
 			final String methodName = postRenderMethod.value();
 			this.invoke(action, methodName);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public ActionErrors getActionErrors() {
 		return actionErrors;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public Map<String, Object> getFlashMap() {
 		return flashMap;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void clearFlash() {
 		if (flashMap != null) {
 			flashMap.clear();
 		}
 	}
 
 	/**
 	 * アクションの指定されたメソッド名のメソッドを実行します。
 	 * 
 	 * @param methodName
 	 *            メソッド名
 	 */
 	private void invoke(final Object action, final String methodName) {
 		try {
 			final Method method = action.getClass().getMethod(methodName);
 			method.invoke(action);
 		} catch (final NoSuchMethodException e) {
 			throw new ActionException(e);
 		} catch (final IllegalAccessException e) {
 			throw new ActionException(e);
 		} catch (final InvocationTargetException e) {
 			throw new ActionException(e);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	@Override
 	public String toString() {
 		final StringBuilder builder = new StringBuilder();
 		builder.append("ActionContext[");
 		builder.append("action=").append(action);
 		builder.append(",actionClass=").append(actionClass);
 		builder.append(",actionMethod=").append(actionMethod);
 		builder.append("]");
 		return builder.toString();
 	}
 
 }