/*
    * Copyright 2010 FatWire Corporation. All Rights Reserved.
    *
    * 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 com.fatwire.gst.foundation.wra.navigation;
  
  import java.util.Collection;
  import java.util.Date;
  import java.util.List;
  
  import COM.FutureTense.Interfaces.ICS;
  import COM.FutureTense.Interfaces.Utilities;
  
  import com.fatwire.assetapi.data.AssetData;
  import com.fatwire.assetapi.data.AssetId;
  import com.fatwire.assetapi.site.SiteInfo;
  import com.fatwire.gst.foundation.controller.AssetIdWithSite;
  import com.fatwire.gst.foundation.facade.assetapi.AssetAccessTemplate;
  import com.fatwire.gst.foundation.facade.assetapi.AssetClosure;
  import com.fatwire.gst.foundation.facade.assetapi.AssetDataUtils;
  import com.fatwire.gst.foundation.facade.assetapi.AttributeDataUtils;
  import com.fatwire.gst.foundation.facade.assetapi.asset.DateFilterClosure;
  import com.fatwire.gst.foundation.facade.assetapi.asset.PreviewContext;
  import com.fatwire.gst.foundation.facade.runtag.render.LogDep;
  import com.fatwire.gst.foundation.facade.runtag.siteplan.ListPages;
  import com.fatwire.gst.foundation.wra.Alias;
  import com.fatwire.gst.foundation.wra.AliasCoreFieldDao;
  import com.fatwire.gst.foundation.wra.AssetApiAliasCoreFieldDao;
  import com.fatwire.gst.foundation.wra.AssetApiWraCoreFieldDao;
  import com.fatwire.gst.foundation.wra.VanityAsset;
  import com.fatwire.gst.foundation.wra.WebReferenceableAsset;
  import com.fatwire.gst.foundation.wra.WraCoreFieldDao;
  import com.fatwire.gst.foundation.wra.WraUriBuilder;
  import com.fatwire.mda.DimensionFilterInstance;
  import com.openmarket.xcelerate.asset.AssetIdImpl;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import static com.fatwire.gst.foundation.facade.runtag.asset.FilterAssetsByDate.isValidOnDate;
  
  /**
   * Used to retrieve the Navigation Bar data. See the description of
   * {@link #getSitePlan(String)} for more details.
   * 
   * @author David Chesebro
   * @author Dolf Dijkstra
   * @since Jun 17, 2010
   */
  public class NavigationHelper {
      /**
       * ICS context
       */
      protected final ICS ics;
  
      final AssetAccessTemplate assetTemplate;
      /**
       * Local instance of the WraCoreFieldDao, pre-instantiated and ready to go
       */
      protected final WraCoreFieldDao wraDao;
  
      /**
       * Local instance of the AliasCoreFieldDao.
       */
      protected final AliasCoreFieldDao aliasDao;
      /**
       * Log file
       */
      protected final Log LOG = LogFactory.getLog(NavigationHelper.class);
      /**
       * Effective date for the purposes of startdate/enddate comparisons for an
       * asset.
       */
      protected final Date assetEffectiveDate;
  
      /**
       * Constructor. Initializes assetEffectiveDate to null.
       * 
       * @param ics object
       */
      public NavigationHelper(final ICS ics) {
          this.ics = ics;
          this.wraDao = new AssetApiWraCoreFieldDao(ics);
  
          this.aliasDao = new AssetApiAliasCoreFieldDao(ics, wraDao);
          this.assetEffectiveDate = null;
          assetTemplate = new AssetAccessTemplate(ics);
     }
 
     /**
      * Constructor with all the dependencies listed. Initializes
      * assetEffectiveDate to null.
      * 
      * @param ics
      * @param assetTemplate
      * @param wraDao
      * @param aliasDao
      */
     public NavigationHelper(final ICS ics, AssetAccessTemplate assetTemplate, WraCoreFieldDao wraDao,
             AliasCoreFieldDao aliasDao) {
         this.ics = ics;
         this.wraDao = wraDao;
         this.aliasDao = aliasDao;
         this.assetTemplate = assetTemplate;
         this.assetEffectiveDate = null;
     }
 
     /**
      * Name of the page subtype indicating that this page is NOT rendered on the
      * site but is instead merely used to group navigation components on the
      * site.
      */
     public static final String NAVBAR_NAME = "GSTNavName";
 
     /**
      * Name of the page subtype indicating that this page is a Link, meaning
      * that the content is in the unnamed association
      */
     public static final String NAVBAR_LINK = "GSTNavLink";
 
     /**
      * @param name the name of the Page asset
      * @return NavNode for the Page with the name
      */
     public NavNode getSitePlanByPage(final String name) {
         return getSitePlanByPage(1, name);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided name.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param name the name of the Page asset
      * @return NavNode for the Page with the name
      */
     public NavNode getSitePlanByPage(final int depth, final String name) {
         final String sitename = ics.GetVar("site");
         if (StringUtils.isBlank(sitename)) {
             throw new IllegalStateException(
                     "site is not a ics variable. This function needs this variable to be aviable and contain the name of the site.");
         }
 
         return getSitePlanByPage(depth, name, sitename);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided name.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param name the name of the Page asset
      * @param dimensionFilter in order to translate the output.
      * @return NavNode for the Page with the name
      */
     public NavNode getSitePlanByPage(final int depth, final String name, final DimensionFilterInstance dimensionFilter) {
         final String sitename = ics.GetVar("site");
         if (StringUtils.isBlank(sitename)) {
             throw new IllegalStateException(
                     "site is not a ics variable. This function needs this variable to be aviable and contain the name of the site.");
         }
 
         return getSitePlanByPage(depth, name, sitename, dimensionFilter);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided name.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param name the name of the Page asset
      * @param sitename the name of the site you want the navigation for.
      * @return NavNode for the Page with the name
      */
     public NavNode getSitePlanByPage(final int depth, final String name, final String sitename) {
         return getSitePlanByPage(depth, name, sitename, null);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided name.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param name the name of the Page asset
      * @param sitename the name of the site you want the navigation for.
      * @param dimensionFilter in order to translate the output.
      * @return NavNode for the Page with the name
      */
     public NavNode getSitePlanByPage(final int depth, final String name, final String sitename,
             final DimensionFilterInstance dimensionFilter) {
 
         final SiteInfo site = assetTemplate.readSiteInfo(sitename);
         if (site == null) {
             throw new RuntimeException("Site with name '" + sitename + "' not found.");
         }
         final AssetId pageid = assetTemplate.findByName(ics, "Page", name, site.getId());
         if (pageid == null) {
             return null;
         }
         return getSitePlan(depth, pageid, dimensionFilter);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided id.
      * 
      * The NavNode contains all the attributes necessary to create a nav bar.
      * <p/>
      * Links are not populated for Navigation Placeholders, but it is often very
      * convenient to pass a navigation placeholder into this function in order
      * to return all children under a specific placeholder.
      * <p/>
      * StartDate and EndDate are checked and invalid pages aren't added. If a
      * Page asset is not valid, its children are not even examined.
      * 
      * 
      * @param pageid the assetid of the Page asset.
      * @return the NavNode for this page
      */
     public NavNode getSitePlan(final String pageid) {
         return getSitePlan(new AssetIdImpl("Page", Long.parseLong(pageid)));
     }
 
     /**
      * Get the NavNode for the current page with unlimited depth.
      * 
      * @param pageid
      * @return the NavNode associated with this pageid.
      */
     public NavNode getSitePlan(final AssetId pageid) {
         return getSitePlan(-1, pageid, 0, null);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided id.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param pageid the AssetId for the page
      * @return the NavNode for this page
      */
     public NavNode getSitePlan(final int depth, final AssetId pageid) {
         return getSitePlan(depth, pageid, 0, null);
     }
 
     /**
      * Retrieves the NavNode for the given Page with the provided id.
      * 
      * @param depth the maximum depth to retrieve, -1 for no limit.
      * @param pageid the AssetId for the page
      * @param dimensionFilter in order to translate the output.
      * @return the NavNode for this page
      */
     public NavNode getSitePlan(final int depth, final AssetId pageid, final DimensionFilterInstance dimensionFilter) {
         LOG.debug("Dimension filter " + dimensionFilter + " provided for site plan lookup");
         return getSitePlan(depth, pageid, 0, dimensionFilter);
     }
 
     /**
      * Called from public {@link #getSitePlan(int, AssetId)}. See that
      * function's description for details
      * 
      * @param depth the depth of the tree to retrieve, -1 for unlimited depth.
      * @param pageId id of the page asset
      * @param level starting level number when traversing the site plan tree
      * @return NavNode of the site plan tree
      */
     private NavNode getSitePlan(final int depth, final AssetId pageId, final int level,
             final DimensionFilterInstance dimensionFilter) {
         // check the start/end date of the page asset
         LogDep.logDep(ics, pageId);
         if (!isValidOnDate(ics, pageId, assetEffectiveDate)) {
             // the input object is not valid. Abort
             if (LOG.isDebugEnabled()) {
                 LOG.debug("Input asset " + pageId + " is not effective on " + assetEffectiveDate);
             }
             return null;
         }
 
         // determine if it's a wra, a placeholder or an alias
 
         final AssetData pageData = AssetDataUtils.getAssetData(ics, pageId, "subtype", "name");
         final String subtype = AttributeDataUtils.asString(pageData.getAttributeData("subtype"));
         final String name = AttributeDataUtils.asString(pageData.getAttributeData("name"));
         final boolean isNavigationPlaceholder = NAVBAR_NAME.equals(subtype);
         final NavNode node = new NavNode();
 
         node.setPage(pageId);
         node.setLevel(level);
         node.setPagesubtype(subtype);
         node.setPagename(name);
 
         if (isNavigationPlaceholder) {
             // no link if it's just a placeholder
         } else {
             // not a GSTNavLink, probably 11g page
             final AssetClosure closure = new NodeWraAssetClosure(node);
             final DateFilterClosure dateFilterClosure = new DateFilterClosure(PreviewContext.getPreviewDate(ics,
                     assetEffectiveDate), closure);
 
             // retrieve the unnamed association(s) based on date filter
             if (dimensionFilter == null) {
                 assetTemplate.readAssociatedAssets(pageId, "-", dateFilterClosure);
             } else {
 
                 final Collection<AssetId> associatedWraList = assetTemplate.readAssociatedAssetIds(pageId, "-");
                 for (final AssetId child : dimensionFilter.filterAssets(associatedWraList)) {
                     assetTemplate.readAsset(child, dateFilterClosure);
                 }
             }
 
         }
 
         if (depth < 0 || depth > level) {
             // get the children in the Site Plan
             final List<AssetId> childrenIDs = ListPages.getChildPages(ics, pageId.getId());
             for (final AssetId aid : childrenIDs) {
                 // note recursing here
                 final NavNode kidInfo = getSitePlan(depth, aid, level + 1, dimensionFilter);
                 if (kidInfo != null && kidInfo.getPage() != null) {
                     node.addChild(kidInfo);
                 }
             }
         }
         return node;
     }
 
     /**
      * Constant containing the asset type of the GST Alias asset.
      */
     public final String GST_ALIAS_TYPE = Alias.ALIAS_ASSET_TYPE_NAME;
 
     /**
      * Return true if the asset type is a GSTAlias asset type. May be overridden
      * if customers are attempting to retrofit this class for alias-like
      * functionality that is not implemented by the GSTAlias asset type.
      * 
      * @param id asset for which a link is required
      * @return true if the asset is an alias, false if it is a web-referenceable
      *         asset
      */
     protected boolean isGstAlias(final AssetId id) {
         return GST_ALIAS_TYPE.equals(id.getType());
     }
 
     /**
      * Get the URL for the alias.
      * 
      * For external links, the targeturl attribute is rendered.
      * 
      * For Aliases that refer to another WRA, the alias is allowed to override
      * any WRA fields. For instance, the path, and the template can be
      * overridden by an alias for a WRA (though the template in the Alias had
      * better be typeless, or a template of the same name must exist in the
      * WRA's asset type or there will be a problem).
      * 
      * @param alias Alias bean, which of course is also a WRA.
      * @return url
      */
     protected String getUrlForAlias(final Alias alias) {
         if (alias.getTargetUrl() != null) {
             return alias.getTargetUrl();
         } else {
             return getUrlForWra(alias);
         }
     }
 
     /**
      * Get the URL to use for the web-referenceable asset.
      * 
      * @param wra WebReferenceableAsset bean
      * @return url
      */
     protected String getUrlForWra(final VanityAsset wra) {
         if (wra.getTemplate() == null || wra.getTemplate().length() == 0) {
             LOG.warn("Asset " + wra + " does not have a valid template set.");
             return null;
         }
         String wrapper = ics.GetProperty("com.fatwire.gst.foundation.url.wrapathassembler.dispatcher",
                 "ServletRequest.properties", true);
         if (!Utilities.goodString(wrapper)) {
             wrapper = "GST/Dispatcher";
         }
         return new WraUriBuilder(wra, wrapper).toURI(ics);
 
     }
 
     protected void decorateAsWra(final AssetId id, final NavNode node) {
 
         final WebReferenceableAsset wra = wraDao.getWra(id);
         final String url = getUrlForWra(wra);
         final String linktext = wra.getLinkText();
         node.setWra(wra);
         if (url != null) {
             node.setUrl(url);
         }
         if (linktext != null) {
             node.setLinktext(linktext);
         }
     }
 
     protected void decorateAsAlias(final AssetId id, final NavNode node) {
         final Alias alias = aliasDao.getAlias(id);
         final String url = getUrlForAlias(alias);
         final String linktext = alias.getLinkText();
         node.setWra(alias);
         if (url != null) {
             node.setUrl(url);
         }
         if (linktext != null) {
             node.setLinktext(linktext);
         }
 
     }
 
     /**
      * Locate the page that contains the specified Web-Referenceable Asset.
      * <p/>
      * A WRA is supposed to just be placed on one page (in the unnamed
      * association block), and this method locates it. If it is not found, 0L is
      * returned.
      * <p/>
      * If multiple matches are found, a warning is logged and the first one is
      * returned.
      * 
      * @param site_name name of the site to search within
      * @param wraAssetId the asset id of the web-referenceable asset
      * @return page asset ID or 0L.
      */
     public long findP(final String site_name, final AssetId wraAssetId) {
         return wraDao.findP(new AssetIdWithSite(wraAssetId.getType(), wraAssetId.getId(), site_name));
     }
 
     class NodeWraAssetClosure implements AssetClosure {
 
         private final NavNode node;
 
         public NodeWraAssetClosure(final NavNode node) {
             this.node = node;
         }
 
         @Override
         public boolean work(final AssetData asset) {
             final AssetId id = asset.getAssetId();
             node.setId(id);
             if (isGstAlias(id)) {
                 decorateAsAlias(id, node);
             } else {
                 decorateAsWra(id, node);
             }
             return false; // needs to return only one node
         }
 
     }
 
 }