/*
 *  Copyright 2010 Anyware Services
 *
 *  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.ametys.web.workflow;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.cocoon.components.ContextHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.xml.AttributesImpl;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.commons.lang.StringUtils;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

import org.ametys.cms.repository.Content;
import org.ametys.cms.repository.ContentTypeExpression;
import org.ametys.cms.repository.LanguageExpression;
import org.ametys.core.user.User;
import org.ametys.plugins.repository.AmetysRepositoryException;
import org.ametys.plugins.repository.query.expression.Expression;
import org.ametys.plugins.repository.query.expression.Expression.Operator;
import org.ametys.plugins.repository.query.expression.OrExpression;
import org.ametys.plugins.repository.query.expression.StringExpression;
import org.ametys.web.repository.content.WebContent;
import org.ametys.web.repository.page.ContentTypesAssignmentHandler;
import org.ametys.web.repository.page.Page;
import org.ametys.web.repository.site.Site;
import org.ametys.web.repository.site.SiteManager;

/**
 * Component for saxing tasks specific to an user.<br>
 * The algorithm is the following :
 * <ul>
 *   <li>First, we get all granted sites for the user with the right manager.
 *   <li>If there is at least one site allowed, we get all workflows 
 *       associated with the granted sites.
 *   <li>Then for each step of each task from the configuration, we get
 *       all workflows where this step is in current steps and where
 *       the workflow is contains in the previous list.
 *   <li>For each workflow matching the previous conditions we
 *       test if the user has all the rights associated with the step (from
 *       the configuration) and then we get the content from this workflow.
 *   <li>Finally, for each content, we sax its first page in order to access
 *       it directly from an URL. 
 * </ul>
 */
public class WorkflowTasksComponent extends org.ametys.cms.workflow.WorkflowTasksComponent implements Contextualizable
{
    
    /** The avalon role. */
    @SuppressWarnings("hiding")
    public static final String ROLE = WorkflowTasksComponent.class.getName();

    /** The site manager. */
    protected SiteManager _siteManager;
    
    /** The avalon context. */
    protected Context _context;

    /** The content types assignment handler */
    protected ContentTypesAssignmentHandler _cTypeHandler;
    
    @Override
    public void service(ServiceManager serviceManager) throws ServiceException
    {
        super.service(serviceManager);
        _siteManager = (SiteManager) serviceManager.lookup(SiteManager.ROLE);
        _cTypeHandler = (ContentTypesAssignmentHandler) serviceManager.lookup(ContentTypesAssignmentHandler.ROLE);
    }
    
    @Override
    public void contextualize(Context context) throws ContextException
    {
        _context = context;
    }
    
    @Override
    public void toSAX(ContentHandler ch, User user) throws SAXException
    {
        XMLUtils.startElement(ch, "tasks");
        
        long start = System.currentTimeMillis();
        
        Set<String> grantedSites = _siteManager.getGrantedSites(user.getIdentity());
        long gsEnd = System.currentTimeMillis();
        long wfEnd = 0;
        
        Request request = ContextHelper.getRequest(_context);
        for (String siteName : grantedSites)
        {
            Site site = _siteManager.getSite(siteName);
            
            request.setAttribute("siteName", siteName);
            
            AttributesImpl siteAttr = new AttributesImpl();
            siteAttr.addCDATAAttribute("name", siteName);
            siteAttr.addCDATAAttribute("title", site.getTitle());
            siteAttr.addCDATAAttribute("siteContext", "/" + siteName);
            
            XMLUtils.startElement(ch, "site", siteAttr);
            
            long wfStart = System.currentTimeMillis();
            // Get the workflow corresponding to the configuration.
            Map<Task, Collection<Content>> workflows = _getCorrespondingWorkflows(user);
            wfEnd = System.currentTimeMillis();
            
            getLogger().info("Contents retrieved in " + (wfEnd - wfStart) + "ms for site '" + siteName + "'");
            
            for (Task task : workflows.keySet())
            {
                _saxTask(ch, task, workflows.get(task));
            }
            
            XMLUtils.endElement(ch, "site");
        }
        
        long end = System.currentTimeMillis();
        
        // Display performance indicators.
        AttributesImpl attrs = new AttributesImpl();
        
        attrs.addCDATAAttribute("Total", Long.toString(end - start));
        attrs.addCDATAAttribute("GS", Long.toString(gsEnd - start));
        attrs.addCDATAAttribute("WF", Long.toString(wfEnd - gsEnd));
        attrs.addCDATAAttribute("SAX", Long.toString(end - wfEnd));
        
        XMLUtils.createElement(ch, "render", attrs);
        
        XMLUtils.endElement(ch, "tasks");
    }
    
    @Override
    public void toSAX(ContentHandler ch, User user, String taskId) throws SAXException
    {
        XMLUtils.startElement(ch, "tasks");
        
        long start = System.currentTimeMillis();
        
        Set<String> grantedSites = _siteManager.getGrantedSites(user.getIdentity());
        long gsEnd = System.currentTimeMillis();
        long wfEnd = 0;
        
        Request request = ContextHelper.getRequest(_context);
        for (String siteName : grantedSites)
        {
            Site site = _siteManager.getSite(siteName);
            
            request.setAttribute("siteName", siteName);
            
            AttributesImpl siteAttr = new AttributesImpl();
            siteAttr.addCDATAAttribute("name", siteName);
            siteAttr.addCDATAAttribute("title", site.getTitle());
            siteAttr.addCDATAAttribute("siteContext", "/" + siteName);
            
            XMLUtils.startElement(ch, "site", siteAttr);
            
            long wfStart = System.currentTimeMillis();
            
            Task task = _tasks.get(taskId);
            Collection<Content> contents = _getTaskContents(user, task);
            
            wfEnd = System.currentTimeMillis();
            getLogger().info("Contents retrieved in " + (wfEnd - wfStart) + "ms for site '" + siteName + "'");
            
            _saxTask(ch, task, contents);
            
            XMLUtils.endElement(ch, "site");
        }
        
        long end = System.currentTimeMillis();
        
        // Display performance indicators.
        AttributesImpl attrs = new AttributesImpl();
        
        attrs.addCDATAAttribute("Total", Long.toString(end - start));
        attrs.addCDATAAttribute("GS", Long.toString(gsEnd - start));
        attrs.addCDATAAttribute("WF", Long.toString(wfEnd - gsEnd));
        attrs.addCDATAAttribute("SAX", Long.toString(end - wfEnd));
        
        XMLUtils.createElement(ch, "render", attrs);
        
        XMLUtils.endElement(ch, "tasks");
    }
    
    /**
     * SAX the contents for given user, site and task
     * @param ch the content handler to SAX into
     * @param user the user
     * @param siteName the site name
     * @param language the language.
     * @param taskId the task id
     * @throws SAXException if an error occurred while saxing
     */
    public void toSAX(ContentHandler ch, User user, String siteName, String language, String taskId) throws SAXException
    {
        XMLUtils.startElement(ch, "tasks");
        
        long start = System.currentTimeMillis();
        long wfEnd = 0;
        
        Request request = ContextHelper.getRequest(_context);
        Site site = _siteManager.getSite(siteName);
        
        request.setAttribute("siteName", siteName);
        request.setAttribute("language", language);
        
        AttributesImpl siteAttr = new AttributesImpl();
        siteAttr.addCDATAAttribute("name", siteName);
        siteAttr.addCDATAAttribute("title", site.getTitle());
        siteAttr.addCDATAAttribute("siteContext", "/" + siteName);
        if (language != null)
        {
            siteAttr.addCDATAAttribute("language", language);
        }
        
        XMLUtils.startElement(ch, "site", siteAttr);
        
        long wfStart = System.currentTimeMillis();
        
        if (taskId != null)
        {
            Task task = _tasks.get(taskId);
            Collection<Content> contents = _getTaskContents(user, task);
            
            wfEnd = System.currentTimeMillis();
            
            if (getLogger().isInfoEnabled())
            {
                getLogger().info("Contents retrieved in " + (wfEnd - wfStart) + "ms for site '" + siteName + "'");
            }
            
            _saxTask(ch, task, contents);
        }
        else
        {
            Map<Task, Collection<Content>> workflows = _getCorrespondingWorkflows(user);
            wfEnd = System.currentTimeMillis();
            
            if (getLogger().isInfoEnabled())
            {
                getLogger().info("Contents retrieved in " + (wfEnd - wfStart) + "ms for site '" + siteName + "'");
            }
            
            for (Task task : workflows.keySet())
            {
                _saxTask(ch, task, workflows.get(task));
            }
        }
        
        XMLUtils.endElement(ch, "site");
    
        long end = System.currentTimeMillis();
        
        // Display performance indicators.
        AttributesImpl attrs = new AttributesImpl();
        
        attrs.addCDATAAttribute("Total", Long.toString(end - start));
        attrs.addCDATAAttribute("WF", Long.toString(wfEnd - start));
        attrs.addCDATAAttribute("SAX", Long.toString(end - wfEnd));
        
        XMLUtils.createElement(ch, "render", attrs);
        
        XMLUtils.endElement(ch, "tasks");
    }
    
    /**
     * Get the list of contents for a given user, task and site.
     * @param user the user.
     * @param taskId the task ID.
     * @param siteName the site name.
     * @param language the language.
     * @param limit the maximum number of results, 0 for all.
     * @return the contents as an iterable collection of contents.
     * @throws AmetysRepositoryException if an error occurred
     */
    public Collection<Content> getContents(User user, String taskId, String siteName, String language, int limit) throws AmetysRepositoryException
    {
        Request request = ContextHelper.getRequest(_context);
        request.setAttribute("siteName", siteName);
        request.setAttribute("language", siteName);
        
        return super.getContents(user, taskId, limit);
    }
    
    @Override
    protected List<Expression> _getContentsAndExpressions(TaskStep step, User user)
    {
        List<Expression> exprs = super._getContentsAndExpressions(step, user);
        
        Request request = ContextHelper.getRequest(_context);
        String siteName = (String) request.getAttribute("siteName");
        if (StringUtils.isNotEmpty(siteName))
        {
            exprs.add(new StringExpression("site", Operator.EQ, siteName));
        }
        
        Expression cTypeExpr = _getContentTypeExpression (siteName);
        if (cTypeExpr != null)
        {
            exprs.add(cTypeExpr);
        }
        
        String language = (String) request.getAttribute("language");
        if (StringUtils.isNotEmpty(language))
        {
            exprs.add(new LanguageExpression(Operator.EQ, language));
        }
        
        return exprs;
    }
    
    /**
     * The content type expression 
     * @param siteName the site name
     * @return The content type expression 
     */
    protected Expression _getContentTypeExpression (String siteName)
    {
        Site site = _siteManager.getSite(siteName);
        
        List<Expression> cTypeExprs = new ArrayList<>();
        
        Set<String> cTypeIds = _cTypeHandler.getAvailableContentTypes(site, false);
        for (String cTypeId : cTypeIds)
        {
            cTypeExprs.add(new ContentTypeExpression(Operator.EQ, cTypeId));
        }
        
        if (cTypeIds.size() == 0)
        {
            return null;
        }
        
        return new OrExpression(cTypeExprs.toArray(new Expression[cTypeExprs.size()]));
    }
    
    @Override
    protected void _saxAdditionalAttributes(Content content, Task task, AttributesImpl attrs) throws SAXException
    {
        if (content instanceof WebContent)
        {
            WebContent webContent = (WebContent) content;
            Iterator<Page> pages = webContent.getReferencingPages().iterator();
            if (pages.hasNext())
            {
                Page page = pages.next();
                attrs.addCDATAAttribute("pageTitle", page.getTitle());
                attrs.addCDATAAttribute("pageUri", page.getSitemapName() + "/" + page.getPathInSitemap());
                attrs.addCDATAAttribute("pageId", page.getId());
            }
        }
    }
}