/**
 * This file Copyright (c) 2012 Magnolia International
 * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
 *
 *
 * This file is dual-licensed under both the Magnolia
 * Network Agreement and the GNU General Public License.
 * You may elect to use one or the other of these licenses.
 *
 * This file is distributed in the hope that it will be
 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
 * Redistribution, except as permitted by whichever of the GPL
 * or MNA you select, is prohibited.
 *
 * 1. For the GPL license (GPL), you can redistribute and/or
 * modify this file under the terms of the GNU General
 * Public License, Version 3, as published by the Free Software
 * Foundation.  You should have received a copy of the GNU
 * General Public License, Version 3 along with this program;
 * if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 2. For the Magnolia Network Agreement (MNA), this file
 * and the accompanying materials are made available under the
 * terms of the MNA which accompanies this distribution, and
 * is available at http://www.magnolia-cms.com/mna.html
 *
 * Any modifications to this file must keep this entire header
 * intact.
 *
 */
package info.magnolia.module.googlesitemap.service;

import info.magnolia.cms.i18n.I18nContentSupport;
import info.magnolia.context.MgnlContext;
import info.magnolia.jcr.predicate.AbstractPredicate;
import info.magnolia.jcr.util.NodeTypes;
import info.magnolia.jcr.util.NodeUtil;
import info.magnolia.jcr.util.SessionUtil;
import info.magnolia.jcr.wrapper.JCRMgnlPropertiesFilteringNodeWrapper;
import info.magnolia.link.LinkUtil;
import info.magnolia.module.googlesitemap.GoogleSiteMapConfiguration;
import info.magnolia.module.googlesitemap.bean.SiteMapEntry;
import info.magnolia.module.googlesitemap.service.query.QueryUtil;
import info.magnolia.module.templatingkit.sites.Site;
import info.magnolia.module.templatingkit.sites.SiteManager;
import info.magnolia.objectfactory.Components;
import info.magnolia.repository.RepositoryConstants;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Set;

import javax.inject.Inject;
import javax.inject.Singleton;
import javax.jcr.Node;
import javax.jcr.NodeIterator;
import javax.jcr.Property;
import javax.jcr.PropertyIterator;
import javax.jcr.RepositoryException;

import org.apache.commons.lang.StringUtils;
import org.apache.jackrabbit.commons.iterator.FilteringNodeIterator;
import org.apache.jackrabbit.commons.predicate.NodeTypePredicate;
import org.apache.jackrabbit.commons.predicate.Predicate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * Main SiteMapService.
 * This service is responsible for:
 *   Searching the appropriate nodes (pages or VirtualUri) that should be displayed (for XML rendering or Editing).
 *   From the search nodes, create SiteMapEntrys (POJO containing preformated infos used for the rendering).
 *
 * @version $Id$
 *
 */
@Singleton
public class SiteMapService {

    private static final Logger log = LoggerFactory.getLogger(SiteMapService.class);

    public static final double DEFAULT_PRIORITY = 0.5;
    public static final String DEFAULT_CHANGE_FREQUENCY = "weekly";

    // Used to filter the current node and just get child nodes starting with SITE_DIALOG_CONFIGURATION_NAME
    private static Predicate All_Site_Nodes = new AbstractPredicate<Node>() {
        @Override
        public boolean evaluateTyped(Node node) {
            try {
                return node.getName().startsWith(GoogleSiteMapConfiguration.SITE_DIALOG_CONFIGURATION_NAME);
            } catch (RepositoryException e) {
                return false;
            }
        }
    };

    /**
     * Injected service.
     */
    private SiteManager siteManager;
    private I18nContentSupport i18nSupport;
    private GoogleSiteMapConfiguration configuration;
    private QueryUtil queryUtil;


    /**
     * Constructor for injection.
     * @param siteManager: Injected.
     */
    @Inject
    public SiteMapService(SiteManager siteManager, GoogleSiteMapConfiguration configuration, QueryUtil queryUtil) {
        this.siteManager = siteManager;
        this.configuration = configuration;
        this.queryUtil = queryUtil;
        i18nSupport = Components.getComponent(I18nContentSupport.class);
    }


    /**
     * Create the SiteMapEntry List corresponding to the uriMapping.
     */
    public List<SiteMapEntry> getSiteMapBeanForVirtualUri( boolean isForEdit) throws RepositoryException{
        // Init
        List<SiteMapEntry> res = new ArrayList<SiteMapEntry>();
        NodeIterator nodeIterator = null;

        log.info("Requested virtualUri info's for EDIT ");
        // Create a virtualUri info beans
        nodeIterator = searchVirtualUriNodes();
        feedVirtualUriMapBeans(res, nodeIterator, isForEdit);

        return res;
    }

    /**
     * Create the SiteMapEntry for all child's of the rootNode that are of type MgnlNodeType.NT_CONTENT.
     */
    public List<SiteMapEntry> getSiteMapBeanForSite(Node rootNode, boolean isForEdit) throws RepositoryException{
        // Init
        List<SiteMapEntry> res = new ArrayList<SiteMapEntry>();
        NodeIterator nodeIterator = null;

        log.info("Requested siteMap info's for EDIT based on the following root: "+rootNode.getPath());
        // Create a site info beans
        nodeIterator = searchSiteChildNodes(rootNode);
        feedSiteMapBeans(res, nodeIterator, isForEdit, null);

        return res;
    }

    /**
     * Search the nodes related to the UriMappings.
     */
    private NodeIterator searchVirtualUriNodes() {
        NodeIterator nodes = null;

        String xpath = "//virtualURIMapping//element(*," + NodeTypes.ContentNode.NAME + ")";
        nodes = queryUtil.query(RepositoryConstants.CONFIG, xpath, "xpath", NodeTypes.ContentNode.NAME);

        return nodes;
    }


    /**
     * Extract informations form the Node and create a Bean used in the display
     * for Edit and XML rendering.
     */
    private void feedVirtualUriMapBeans(List<SiteMapEntry> siteMapBeans, NodeIterator nodes, boolean isForEdit) throws RepositoryException {
        while(nodes.hasNext()) {
            // Init
            Node child = nodes.nextNode();
            if(hasToBePopulated(child, true, isForEdit, null)) {
                //Populate the Bean used by the display
                SiteMapEntry siteMapBean = populateBean(child, true, isForEdit , null, null);
                //Add the bean to the result
                siteMapBeans.add(siteMapBean);
            }
        }
    }


    /**
     * Search children of the root Node of type MgnlNodeType.NT_CONTENT and all inherited node types.
     * @throws RepositoryException
     */
    private NodeIterator searchSiteChildNodes(Node root) throws RepositoryException {
        NodeIterator nodes = null;

        NodeTypePredicate predicate = new NodeTypePredicate(NodeTypes.Content.NAME, true);
        nodes = new FilteringNodeIterator(root.getNodes(), predicate);

        return nodes;
    }


    /**
     * Create a new SiteMapEntry POJO for all node from the NodeIterator if required.
     */
    private void feedSiteMapBeans(List<SiteMapEntry> siteMapBeans, NodeIterator nodes,  boolean isForEdit, Boolean inheritedParentDisplayColor) throws RepositoryException {

        while(nodes.hasNext()) {
            // Init
            Node child = nodes.nextNode();
            Site site = siteManager.getAssignedSite(child);

            if(hasToBePopulated(child, false, isForEdit, site)) {
                //Populate the Bean used by the display
                SiteMapEntry siteMapBean = populateBean(child, false, isForEdit , site, inheritedParentDisplayColor);
                NodeIterator childNodes = searchSiteChildNodes(child);
                boolean hasChild = (childNodes!=null && childNodes.hasNext()) ? true:false;

                if(isForEdit) {
                    // Handle Edit Mode. Always all the bean.
                    siteMapBeans.add(siteMapBean);

                    if(hasChild) {
                        // Handle the children if any
                        Boolean hideNodeChildInGoogleSitemapTmp = null;
                        // Handle the color of the child to be display.
                        if(inheritedParentDisplayColor != null) {
                            hideNodeChildInGoogleSitemapTmp = inheritedParentDisplayColor;
                        }else if(hideNodeChildInGoogleSitemap(child)) {
                            hideNodeChildInGoogleSitemapTmp = Boolean.TRUE;
                        }

                        feedSiteMapBeans(siteMapBeans, childNodes, isForEdit, hideNodeChildInGoogleSitemapTmp);
                    }

                } else {
                    // Handle XML Display Mode
                    // If node has to be display.
                    if (!hideNodeInGoogleSitemap(child)){
                        try {
                            // Check Multilang.
                            if(i18nSupport.isEnabled() && site.getI18n().isEnabled()) {
                                Locale currentLocale = i18nSupport.getLocale();
                                for(Locale locale:site.getI18n().getLocales() ){
                                    i18nSupport.setLocale(locale);
                                    SiteMapEntry siteMapBeanLocale = populateBean(child, false, isForEdit, site, null);
                                    if(siteMapBeanLocale != null) {
                                        siteMapBeans.add(siteMapBeanLocale);
                                    }
                                }
                                i18nSupport.setLocale(currentLocale);
                            } else {
                                siteMapBeans.add(siteMapBean);
                            }
                        } catch (Exception e) {
                            siteMapBeans.add(siteMapBean);
                        }
                    }
                    // Check if Child Node has to be included
                    if(hasChild && !hideNodeChildInGoogleSitemap(child)) {
                        // Call recursively
                        feedSiteMapBeans(siteMapBeans, childNodes, isForEdit, null);
                    }

                }

            }

        }
    }

    /**
     * Populate the Bean.
     */
    private SiteMapEntry populateBean( Node child, boolean isForUriMapping, boolean isForEdit, Site site, Boolean inheritedParentDisplayColor ) throws RepositoryException {
        SiteMapEntry res = null;
        // Populate only if true
        if(hasToBePopulated(child, isForUriMapping, isForEdit, site)) {

            String lastmod = "";
            int level = -1;
            String loc = null;
            double priority = DEFAULT_PRIORITY;
            String changefreq = DEFAULT_CHANGE_FREQUENCY;
            // Get Level
            level = child.getDepth();

            // Get priority
            if(child.hasProperty(GoogleSiteMapConfiguration.DEFAULT_PRIORITY_NODEDATA)) {
                priority = child.getProperty(GoogleSiteMapConfiguration.DEFAULT_PRIORITY_NODEDATA).getDouble();
            }

            // Get changefreq
            if(child.hasProperty(GoogleSiteMapConfiguration.DEFAULT_CHANGEFREQ_NODEDATA)) {
                changefreq = child.getProperty(GoogleSiteMapConfiguration.DEFAULT_CHANGEFREQ_NODEDATA).getString();
            }

            // Get lastmod
            Calendar date = null;
            if (NodeTypes.LastModified.getLastModified(child) != null) {
                date = NodeTypes.LastModified.getLastModified(child);
            } else {
                date = NodeTypes.Created.getCreated(child);
            }
            lastmod = configuration.getFastDateFormat().format(date.getTime());

            // Get loc
            if(isForUriMapping) {
                loc = child.hasProperty("fromURI")? MgnlContext.getContextPath()+child.getProperty("fromURI").getString() : "";
            }else {
                loc = LinkUtil.createExternalLink(child);
            }

            //Populate the bean:
            res = new SiteMapEntry(loc, lastmod, changefreq, Double.toString(priority), level);
            log.debug("Populate Basic info for Node: "+child.getPath()+ " with values "+res.toStringDisplay());

            if(isForEdit) {
                res = populateBeanForEdit(child, isForUriMapping, res, inheritedParentDisplayColor);
            }
        }

        return res;
    }


    /**
     * Add additional info's for Edit.
     */
    private SiteMapEntry populateBeanForEdit(Node child, boolean isForUriMapping, SiteMapEntry siteMapBean, Boolean inheritedParentDisplayColor) throws RepositoryException {
        //Common fields
        siteMapBean.setPath(child.getPath());

        if(isForUriMapping) {
            //For VirtualUri
            siteMapBean.setFrom(child.hasProperty("fromURI")?child.getProperty("fromURI").getString():"");
            siteMapBean.setTo(child.hasProperty("toURI")?child.getProperty("toURI").getString():"");
            siteMapBean.setStyleAlert(hideNodeInGoogleSitemap(child));
            log.debug("Populate Edit VirtualUri info for Node: "+child.getPath()+ " with values "+siteMapBean.toStringVirtualUri());
        } else {
            //For Site
            siteMapBean.setPageName(child.hasProperty("title")?child.getProperty("title").getString():"");
            siteMapBean.setStyleAlert(inheritedParentDisplayColor!=null?inheritedParentDisplayColor.booleanValue():hideNodeInGoogleSitemap(child));
            log.debug("Populate Edit Site info for Node: "+child.getPath()+ " with values "+siteMapBean.toStringSite());
        }
        return siteMapBean;
    }


    /**
     * Check if the node has to be populated.
     * True for UriMapping if:
     *  !hideInGoogleSitemap && node has a modification date
     * True for Site if:
     *  !hideInGoogleSitemap && !hideInGoogleSitemapChildren &&  node has a creation date && site.isEnabled()
     *
     */
    private boolean hasToBePopulated( Node child, boolean isForUriMapping, boolean isForEdit, Site site ) throws RepositoryException {
        boolean hasCreationDate = NodeTypes.Created.getCreated(child) != null;
        boolean hasModificationDate = NodeTypes.LastModified.getLastModified(child) != null;
        boolean hasTemplate = StringUtils.isNotBlank(NodeTypes.Renderable.getTemplate(child));

        // Exclude SiteMap pages
        if (hasTemplate && NodeTypes.Renderable.getTemplate(child).endsWith(GoogleSiteMapConfiguration.SITE_MAP_TEMPLATE_NAME)) {
            return false;
        }

        // For edit and if has creation date --> true.
        if(isForEdit) {
            return hasCreationDate;
        }

        // Node has a property set to hide node to be display --> false.
        if(hideNodeInGoogleSitemap(child) && (isForUriMapping || hideNodeChildInGoogleSitemap(child))) {
            return false;
        }
        // For uriMapping.
        if(isForUriMapping  && hasModificationDate) {
            return true;
        }
        // For site.
        if(!isForUriMapping && site.isEnabled() && hasCreationDate ) {
            return true;
        }

        return false;
    }

    /**
     * Check if we have to display in SiteMap.
     */
    private boolean hideNodeInGoogleSitemap(Node child) throws RepositoryException {
        boolean res = false;

        if(child.hasProperty(GoogleSiteMapConfiguration.DEFAULT_HIDEINGOOGLESITEMAP_NODEDATA)) {
            res = child.getProperty(GoogleSiteMapConfiguration.DEFAULT_HIDEINGOOGLESITEMAP_NODEDATA).getBoolean();
        }

        return res;
    }

    /**
     * Check if we have to display in SiteMap.
     */
    private boolean hideNodeChildInGoogleSitemap(Node child) throws RepositoryException {
        boolean res = false;

        if(child.hasProperty(GoogleSiteMapConfiguration.DEFAULT_HIDEINGOOGLESITEMAPCHILDREN_NODEDATA)) {
            res = child.getProperty(GoogleSiteMapConfiguration.DEFAULT_HIDEINGOOGLESITEMAPCHILDREN_NODEDATA).getBoolean();
        }

        return res;
    }


    /**
     * Get Site and virtualUri informations if they are defined as components.
     * Notice that by using a HashSet, a single object will be keeped in case of equality of the location.
     */
    public Iterator<SiteMapEntry> getSiteMapBeans(Node content) throws RepositoryException {
        Set<SiteMapEntry> res = new HashSet<SiteMapEntry>();
        // Return if no content set.
        if (!NodeUtil.isNodeType(content, GoogleSiteMapConfiguration.NODE_TYPE)) {
            return res.iterator();
        }

        // Display Site informations part... if defined
        Node node = null;
        Iterator<Node> iterator = NodeUtil.collectAllChildren(content, All_Site_Nodes).iterator();
        while (iterator.hasNext()) {
            // Get node
            node = iterator.next();

            Node childNode = new JCRMgnlPropertiesFilteringNodeWrapper(node);
            PropertyIterator properties = childNode.getProperties();

            while (properties.hasNext()) {
                Property property = properties.nextProperty();
                Node root = SessionUtil.getNode(RepositoryConstants.WEBSITE, property.getString());
                // Call service and Remove Duplicate
                res.addAll(getSiteMapBeanForSite(root, false));

            }
        }

        boolean includeVirtualUris =
            content.hasProperty(GoogleSiteMapConfiguration.INCLUDE_VIRTUAL_URI_MAPPINGS_PROPERTIES) &&
            content.getProperty(GoogleSiteMapConfiguration.INCLUDE_VIRTUAL_URI_MAPPINGS_PROPERTIES).getBoolean();
        if (includeVirtualUris) {
            res.addAll(getSiteMapBeanForVirtualUri(false));
        }
        return res.iterator();
    }

}