/*
 * 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.myfaces.view.facelets.util;

import java.util.ArrayList;
import java.util.List;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import org.apache.myfaces.renderkit.html.util.JSFAttr;
import org.apache.myfaces.renderkit.html.util.ResourceUtils;
import org.apache.myfaces.util.lang.ClassUtils;
import org.apache.myfaces.util.lang.StringUtils;

/**
 * Utility methods used in FaceletsViewDeclarationLanguage
 *
 * @author Leonardo Uribe
 */
public class FaceletsViewDeclarationLanguageUtils
{
    public static Class getReturnType(String signature)
    {
        int endName = signature.indexOf('(');
        if (endName < 0)
        {
            throw new FacesException("Invalid method signature:" + signature);
        }

        int end = signature.lastIndexOf(' ', endName);
        if (end < 0)
        {
            throw new FacesException("Invalid method signature:" + signature);
        }

        try
        {
            return ClassUtils.javaDefaultTypeToClass(signature.substring(0, end));
        }
        catch (ClassNotFoundException e)
        {
            throw new FacesException("Invalid method signature:" + signature);
        }
    }

    /**
     * Get the parameters types from the function signature.
     *
     * @return An array of parameter class names
     */
    public static Class[] getParameters(String signature) throws FacesException
    {
        ArrayList<Class> params = new ArrayList<>();

        // Signature is of the form
        // <return-type> S <method-name S? '('
        // < <arg-type> ( ',' <arg-type> )* )? ')'
        int start = signature.indexOf('(') + 1;
        boolean lastArg = false;
        while (true)
        {
            int p = signature.indexOf(',', start);
            if (p < 0)
            {
                p = signature.indexOf(')', start);
                if (p < 0)
                {
                    throw new FacesException("Invalid method signature:" + signature);
                }
                lastArg = true;
            }

            String arg = signature.substring(start, p);
            if (StringUtils.isNotBlank(arg))
            {
                try
                {
                    params.add(ClassUtils.javaDefaultTypeToClass(arg.trim()));
                }
                catch (ClassNotFoundException e)
                {
                    throw new FacesException("Invalid method signature:" + signature);
                }
            }
            
            if (lastArg)
            {
                break;
            }

            start = p + 1;
        }

        return params.toArray(new Class[params.size()]);
    }

    /**
     * Called on restoreView(...) to mark resources as rendered.
     * 
     * @since 2.3
     * @param facesContext
     * @param view 
     */
    public static void markRenderedResources(FacesContext facesContext, UIViewRoot view)
    {
        if (view != null && facesContext.getPartialViewContext().isAjaxRequest())
        {
            markRenderedResources(facesContext, view, view.getComponentResources(facesContext, "head"));
            markRenderedResources(facesContext, view, view.getComponentResources(facesContext, "body"));
        }
    }

    private static void markRenderedResources(FacesContext facesContext, UIViewRoot view, 
            List<UIComponent> componentResources)
    {
        if (componentResources != null)
        {
            for (UIComponent component : componentResources)
            {
                if (ResourceUtils.DEFAULT_SCRIPT_RENDERER_TYPE.equals(component.getRendererType()) ||
                    ResourceUtils.DEFAULT_STYLESHEET_RENDERER_TYPE.equals(component.getRendererType()))
                {
                    String resourceName = (String) component.getAttributes().get(JSFAttr.NAME_ATTR);
                    String libraryName = (String) component.getAttributes().get(JSFAttr.LIBRARY_ATTR);
                    
                    if (resourceName == null || resourceName.isEmpty())
                    {
                        continue;
                    }

                    int index = resourceName.indexOf('?');
                    if (index >= 0)
                    {
                        resourceName = resourceName.substring(0, index);
                    }
                    
                    facesContext.getApplication().getResourceHandler().markResourceRendered(
                            facesContext, resourceName, libraryName);
                }
            }
        }
    }
}