/*
    * Copyright 2008 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 tools.gsf.facade.mda;
  
  import COM.FutureTense.Interfaces.FTValList;
  import COM.FutureTense.Interfaces.ICS;
  import com.fatwire.assetapi.data.AssetId;
  import com.fatwire.cs.core.db.PreparedStmt;
  import com.fatwire.cs.core.db.StatementParam;
  import com.fatwire.mda.Dimension;
  import com.fatwire.mda.DimensionException;
  import com.fatwire.mda.DimensionFilterInstance;
  import com.fatwire.mda.DimensionManager;
  import com.fatwire.mda.DimensionSetInstance;
  import com.fatwire.mda.DimensionableAssetManager;
  import com.fatwire.system.Session;
  import com.fatwire.system.SessionFactory;
  import com.openmarket.xcelerate.asset.AssetIdImpl;
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import tools.gsf.facade.runtag.asset.AssetLoadByName;
  import tools.gsf.facade.runtag.render.LogDep;
  import tools.gsf.facade.sql.IListIterable;
  import tools.gsf.facade.sql.Row;
  import tools.gsf.facade.sql.SqlHelper;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.List;
  import java.util.Locale;
  
  public class DefaultLocaleService implements LocaleService {
      private static final Logger LOG = LoggerFactory.getLogger("tools.gsf.facade.mda.DefaultLocaleService");
  
      /**
       * the variable name for the id of the current Dimension
       */
  
      private final String localeVar;
  
      /**
       * the variable name for the current requested language
       */
  
      private final String langVar;
  
      private final ICS ics;
  
      private Session session;
  
      /**
       * Constructor with "lang" and "locale" as variable names for langVar and
       * localeVar.
       *
       * @param ics Content Server context object
       */
      public DefaultLocaleService(final ICS ics) {
          this(ics, "lang", "locale");
      }
  
      /**
       * Constructor.
       *
       * @param ics       Content Server context object
       * @param langVar   the name of the ics variable for the current 'language',
       *                  as in en_US.
       * @param localeVar the name of the ics variable for the current dimension
       *                  id.
       */
      public DefaultLocaleService(ICS ics, String langVar, String localeVar) {
          if (ics == null) {
              throw new IllegalArgumentException("ICS must not be null.");
          }
  
          this.ics = ics;
          this.langVar = langVar;
          this.localeVar = localeVar;
  
      }
  
      /*
       * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#findTranslation(java
      * .lang.String, java.lang.String, java.lang.String, java.lang.String)
      */
     @Override
     public AssetId findTranslation(final String c, final String cid, final String site,
                                    final String preferredLocaleDimensionId) {
         return findTranslation(new AssetIdImpl(c, Long.parseLong(cid)), site,
                 Long.parseLong(preferredLocaleDimensionId));
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#findTranslation(com
      * .fatwire.assetapi.data.AssetId, java.lang.String, long)
      */
 
     @Override
     public AssetId findTranslation(final AssetId id, final String site, final long preferredDimension) {
 
         final long dimensionSetId = locateDimensionSetForSite(site);
 
         return findTranslation(id, preferredDimension, dimensionSetId);
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#findTranslation(com
      * .fatwire.assetapi.data.AssetId, long, long)
      */
 
     @Override
     public AssetId findTranslation(final AssetId id, final long preferredDimension, final long dimensionSetId) {
         if (id == null) {
             throw new IllegalArgumentException("Required Asset ID missing");
         }
 
         if (_isInputAssetDimensionPreferred(id, preferredDimension)) {
             LOG.debug("Input dimension is already in the preferred dimension.  Not invoking dimension set filter.  Asset: "
                     + id + ", dimension: " + preferredDimension);
             return id;
         } else {
             LOG.debug("About to look for translations.  Input asset id: " + id + ", dimension set: " + dimensionSetId
                     + ", preferred dimension: " + preferredDimension);
         }
 
         // *****************************************************************************
         // The core business logic of this helper class is encapsulated in these
         // 3 lines
         final DimensionSetInstance dimset = _getDimensionSet(dimensionSetId);
         return findTranslation(id, preferredDimension, dimset);
 
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#findTranslation(com
      * .fatwire.assetapi.data.AssetId, long, java.lang.String)
      */
 
     @Override
     public AssetId findTranslation(final AssetId id, final long preferredDimension, final String dimensionSetName) {
         if (id == null) {
             throw new IllegalArgumentException("Required Asset ID missing");
         }
         final Dimension locale = getLocaleForAsset(id);
 
         if (locale == null) {
             LOG.debug("Asset is not localized.  Not invoking dimension set filter.  Asset: " + id);
             return id;
         }
         if (locale.getId().getId() == preferredDimension) {
             LOG.debug("Input dimension is already in the preferred dimension.  Not invoking dimension set filter.  Asset: "
                     + id + ", dimension: " + preferredDimension);
             return id;
         } else {
             LOG.debug("About to look for translations.  Input asset id: " + id + ", dimension set: " + dimensionSetName
                     + ", preferred dimension: " + preferredDimension);
         }
 
         // *****************************************************************************
         // The core business logic of this helper class is encapsulated in these
         // 3 lines
         final DimensionSetInstance dimset = getDimensionSet(dimensionSetName);
 
         return findTranslation(id, preferredDimension, dimset);
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#findTranslation(com
      * .fatwire.assetapi.data.AssetId, long,
      * com.fatwire.mda.DimensionSetInstance)
      */
 
     @Override
     public AssetId findTranslation(final AssetId id, final long preferredDimension, final DimensionSetInstance dimset) {
 
         final DimensionFilterInstance filter = _getPopulatedDimensionFilter(dimset, preferredDimension);
         AssetId translated = findTranslation(id, filter);
         if (translated == null) {
             LOG.warn("No translation found for asset " + id + " in dimension set " + dimset.getId() + " for dimension "
                     + preferredDimension + ".");
         }
         return translated;
     }
 
     // ///////////////////////////////////////////////////////////////////////////
     // Helper functions
 
     private boolean _isInputAssetDimensionPreferred(final AssetId id, final long preferredDimension) {
         final Dimension dim = getLocaleForAsset(id);
         if (dim == null) {
             return true; // if locale not found, tell that the asset is expected
         }
         // locale
         return dim.getId().getId() == preferredDimension;
     }
 
     private static final PreparedStmt FIND_DIMSET_FOR_SITE_PREPAREDSTMT = new PreparedStmt(
             "select ds.id as id from DimensionSet ds, Publication p, AssetPublication ap where p.name = ? and p.id = ap.pubid and ap.assetid = ds.id and ds.status != 'VO' order by ds.updateddate",
             Arrays.asList("DimensionSet", "AssetPublication", "Publication"));
 
     static {
         FIND_DIMSET_FOR_SITE_PREPAREDSTMT.setElement(0, "Publication", "name");
     }
 
     /**
      * Locates a single dimension set in a site. If no match is found, an
      * exception is thrown. If more than one match is found, an exception is
      * thrown.
      *
      * @param site site containing a dimension set
      * @return DimensionSet ID
      */
     public long locateDimensionSetForSite(final String site) {
         if (StringUtils.isBlank(site)) {
             throw new IllegalArgumentException("Required site name missing");
         }
         final StatementParam params = FIND_DIMSET_FOR_SITE_PREPAREDSTMT.newParam();
         params.setString(0, site);
         final IListIterable list = SqlHelper.select(ics, FIND_DIMSET_FOR_SITE_PREPAREDSTMT, params);
 
         final int numRows = list.size();
         if (numRows == 0) {
             throw new IllegalStateException(
                     "A DimensionSet has not been defined for site '"
                             + site
                             + "'. Cannot determine any translation unless some locales (Dimensions) are enabled for that site. Aborting operation.");
         }
         if (numRows > 1) {
             final StringBuilder msg = new StringBuilder("More than one dimension set found in site " + site
                     + ".  Exactly one is expected.  Dimension set ids: ");
             for (final Row row : list) {
                 final String id = row.getString("id");
                 LogDep.logDep(ics, "DimensionSet", id);
                 msg.append(id).append(" ");
             }
             throw new IllegalStateException(msg.append(".").toString());
         }
 
         final String id = list.iterator().next().getString("id");
         LogDep.logDep(ics, "DimensionSet", id);
         return Long.parseLong(id);
     }
 
     private DimensionFilterInstance _getPopulatedDimensionFilter(final DimensionSetInstance dimset,
                                                                  final long dimensionId) {
 
         // Set the filter's preferred dimension
         // Equivalent to:
         // %><dimensionset:asset assettype="Dimension"
         // assetid="<%=localeDimensionId%>" /><%
         final Dimension preferredDimension = getDM().loadDimension(dimensionId);
         if (preferredDimension == null) {
             throw new RuntimeException("Attempted to load Dimension with id " + dimensionId + " but it came back null");
         }
         return _getPopulatedDimensionFilter(dimset, preferredDimension);
     }
 
     private DimensionFilterInstance _getPopulatedDimensionFilter(final DimensionSetInstance dimset,
                                                                  final Dimension preferredDimension) {
         DimensionFilterInstance filter;
         try {
             filter = dimset.getFilter();
         } catch (final DimensionException e) {
             throw new RuntimeException("Could not get Dimension Filter from DimensionSet", e);
         }
 
         filter.setDimensonPreference(Collections.singletonList(preferredDimension));
         return filter;
     }
 
     private DimensionSetInstance _getDimensionSet(final long dimSetId) {
         final String DIMSET_OBJ_NAME = "LocaleUtils:findTranslation:theDimensionSet:DimensionSet";
         // Load the site-specific DimensionSet asset
         ics.SetObj(DIMSET_OBJ_NAME, null); // clear first
         final FTValList args = new FTValList();
         args.put("NAME", DIMSET_OBJ_NAME);
         args.put("TYPE", "DimensionSet");
         args.put("OBJECTID", Long.toString(dimSetId));
         args.put("EDITABLE", "FALSE");
         ics.runTag("ASSET.LOAD", args);
 
         if (ics.GetErrno() < 0) {
             throw new IllegalStateException("Could not load dimension set.  Errno: " + ics.GetErrno());
         }
 
         final Object o = ics.GetObj(DIMSET_OBJ_NAME);
         ics.SetObj(DIMSET_OBJ_NAME, null);
         if (o == null) {
             throw new IllegalStateException("Could not load dimension set but we got no errno... unexpected...");
         }
 
         DimensionSetInstance dimset;
         if (o instanceof DimensionSetInstance) {
             dimset = (DimensionSetInstance) o;
         } else {
             throw new IllegalStateException("Loaded an asset that is not a DimensionSetInstance.");
         }
         return dimset;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#getDimensionSet(java
      * .lang.String)
      */
 
     @Override
     public DimensionSetInstance getDimensionSet(final String name) {
         final String DIMSET_OBJ_NAME = "LocaleUtils:findTranslation:theDimensionSet:DimensionSet";
         ics.SetObj(DIMSET_OBJ_NAME, null);
         final AssetLoadByName a = new AssetLoadByName();
         a.setAssetType("DimensionSet");
         a.setAssetName(name);
         a.setEditable(false);
         a.setName(DIMSET_OBJ_NAME);
         a.execute(ics);
 
         if (ics.GetErrno() < 0) {
             throw new IllegalStateException("Could not load dimension set.  Errno: " + ics.GetErrno());
         }
 
         final Object o = ics.GetObj(DIMSET_OBJ_NAME);
         ics.SetObj(DIMSET_OBJ_NAME, null);
         if (o == null) {
             throw new IllegalStateException("Could not load dimension set but we got no errno... unexpected...");
         }
 
         DimensionSetInstance dimset;
         if (o instanceof DimensionSetInstance) {
             dimset = (DimensionSetInstance) o;
         } else {
             throw new IllegalStateException("Loaded an asset that is not a DimensionSetInstance");
         }
         return dimset;
     }
 
     private DimensionableAssetManager dam;
 
     /**
      * Shorthand function for returning the DimensionableAssetManager.
      *
      * @return DimensionableAssetManager
      */
     public DimensionableAssetManager getDAM() {
         if (dam == null) {
             dam = getManager(DimensionableAssetManager.class);
         }
         return dam;
     }
 
     private DimensionManager dm;
 
     /**
      * Shorthand function for returning the DimensionManager.
      *
      * @return DimensionManager
      */
     protected DimensionManager getDM() {
         if (dm == null) {
             dm = getManager(DimensionManager.class);
         }
         return dm;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#getLocaleForAsset
      * (com.fatwire.assetapi.data.AssetId)
      */
 
     @Override
     public Dimension getLocaleForAsset(final AssetId id) {
         final Collection<Dimension> dims = getDAM().getDimensionsForAsset(id);
         for (final Dimension dim : dims) {
             if ("locale".equalsIgnoreCase(dim.getGroup())) {
                 return dim;
             }
         }
         return null;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#getDimensionIdForName
      * (java.lang.String)
      */
 
     @Override
     public long getDimensionIdForName(final String name) {
         final AssetId id = getDimensionAssetIdForName(name);
         return id == null ? -1 : id.getId();
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see "tools.gsf.facade.mda.LocaleService#"
      * getDimensionAssetIdForName(java.lang.String)
      */
 
     @Override
     public AssetId getDimensionAssetIdForName(final String name) {
         final Dimension dim = getDimensionForName(name);
         return dim == null ? null : dim.getId();
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#getDimensionForName
      * (java.lang.String)
      */
 
     @Override
     public Dimension getDimensionForName(final String name) {
         return getDM().loadDimension(name);
 
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see
      * tools.gsf.facade.mda.LocaleService#getNameForDimensionId
      * (long)
      */
 
     @Override
     public String getNameForDimensionId(final long dimensionid) {
         final Dimension dim = getDM().loadDimension(dimensionid);
         return dim == null ? null : dim.getName();
     }
 
     protected Session getSession() {
         if (session == null) {
             session = SessionFactory.getSession(ics);
 
         }
         return session;
     }
 
     @SuppressWarnings("unchecked")
     protected <T> T getManager(final Class<T> c) {
         return (T) getSession().getManager(c.getName());
     }
 
     @Override
     public AssetId findTranslation(AssetId id, DimensionFilterInstance filter) {
         // Get the relatives using the appropriate filter
         final Collection<AssetId> relatives = getDAM().getRelatives(id, filter, "Locale");
         // *****************************************************************************
 
         // make the result pretty
         if (relatives == null) {
             LOG.debug("No translation found for asset " + id + ".");
             return null;
         } else {
             switch (relatives.size()) {
                 case 0: {
                     LOG.debug("No translation found for " + id + ".");
                     // Note May 4, 2010 by Tony Field - this had been changed to
                     // return the input ID but that
                     // is incorrect. The contract clearly states that null is to
                     // be returned if no matching
                     // relatives are found. When null is returned and it is not
                     // expected, often the incorrect
                     // dimension filter is configured.
                     return null;
                 }
                 case 1: {
                     final AssetId relative = relatives.iterator().next();
                     LOG.trace("LocaleUtils.findTranslation: RELATIVE FOUND... " + relative.getType() + " '"
                             + relative.getId() + "' // errno = " + ics.GetErrno());
                     return relative;
 
                 }
                 default: {
                     throw new IllegalStateException("found more than one translation for asset " + id
                             + " and that is not supposed to be possible.");
                 }
             }
         }
     }
 
     /**
      * Return a dimension filter instance corresponding to the dimension set
      * specified by the user (or discovered by the tag). The dimension filter is
      * configured with the preferred dimensions of the user (also configured).
      * <p>
      * The preferred locales are identified by checking the following locations,
      * in the order specified:
      * <ol>
      * <li>set by the lang attribute by locale name
      * <li>detected by finding the locale dimension id in the ics variable
      * "locale"
      * <li>detected by finding the locale name in the ics variable "locale"
      * <li>detected by finding the locale dimension id in the ics session
      * variable "locale"
      * <li>detected by finding the locale name in the ics session variable
      * "locale"
      * <li>detected by reading the Accept-Language header
      * </ol>
      * The dimension set is identified by checking in the following places, in
      * order:
      * <ol>
      * <li>set by the dimset attribute by name of dimension set
      * <li>set by dimset attribute by the id of the dimension set
      * <li>looked up by finding the site name in the ics variable "site" and
      * loading the single dimension set associated with that site
      * </ol>
      *
      * @return a dimension filter, configured with the set preferred locales, or
      * null, if either the dimension set or the preferred dimensions
      * could not be found (with extensive errors)
      */
     public DimensionFilterInstance getDimensionFilter(String site) {
 
         DimensionFilterInstance filter;
         try {
             DimensionSetInstance dimSet = locateDimensionSetInstanceForSite(site);
             if (dimSet == null) {
                 if (LOG.isTraceEnabled()) {
                     LOG.trace("no DimensionSet returned from getDimensionSet().");
                 }
                 return null;
             }
             Collection<AssetId> preferredLocales = getPreferredLocales();
 
             filter = DimensionUtils.getDimensionFilter(DimensionUtils.getDM(ics), preferredLocales, dimSet);
             if (LOG.isDebugEnabled()) {
                 LOG.debug("Located dimension filter: " + filter + " in dimensionSet " + dimSet
                         + " with preferred locales: " + preferredLocales + " ");
             }
         } catch (DimensionException e) {
             LOG.error("Could not locate dimension filter", e);
             filter = null;
         } catch (RuntimeException e) {
             LOG.error("Could not locate dimension filter", e);
             filter = null;
         }
         return filter;
     }
 
     /**
      * Get the locale that the user explicitly specified. If not set, null is
      * returned.
      *
      * @return the id of the locale that the user explicitly set. Handles
      * setting by name or assetid.
      */
     protected final AssetId getExplicitlySpecifiedLocale() {
 
         String localeName = ics.GetVar(langVar);
         // check for explicitly specified by name
         if (StringUtils.isNotBlank(localeName)) {
             Dimension d = DimensionUtils.getDimensionForName(ics, localeName);
             if (d != null) {
                 LOG.trace("Preferred locale explicitly set to " + localeName);
                 return d.getId();
             }
         }
         return null;
     }
 
     /**
      * Get the ordered list of preferred locales that the user wants. Multiple
      * attempts are made to figure out the right locale.
      *
      * @return collection of asset identifiers of the preferred locales
      */
     protected final Collection<AssetId> getPreferredLocales() {
         AssetId result = getExplicitlySpecifiedLocale();
         if (result != null) {
             return Collections.singleton(result);
         }
 
         // next, check for implicitly specified by ID using locale variable
         String l = ics.GetVar(localeVar);
         try {
             long localeIdFromVar = Long.parseLong(l);
             DimensionManager dm = DimensionUtils.getDM(ics);
             Dimension d = dm.loadDimension(localeIdFromVar);
             if (d != null) {
                 LOG.trace("Preferred locale detected in ICS context using 'locale' variable: " + localeIdFromVar);
                 return Collections.singletonList(d.getId());
             }
         } catch (NumberFormatException e) {
             // maybe it's a locale name...
             try {
                 Dimension d = DimensionUtils.getDimensionForName(ics, localeVar);
                 if (d != null) {
                     LOG.trace("Preferred locale detected in ICS context using 'locale' variable: " + localeVar);
                     return Collections.singletonList(d.getId());
                 }
             } catch (Exception ex) {
                 // nope... don't worry, we'll find it....
             }
         }
 
         // next, check for implicitly specified by ID using locale session
         // variable
         String localeSSVar = ics.GetSSVar(localeVar);
         try {
             long localeIdFromSSVar = Long.parseLong(localeSSVar);
             DimensionManager dm = DimensionUtils.getDM(ics);
             Dimension d = dm.loadDimension(localeIdFromSSVar);
             if (d != null) {
                 LOG.trace("Preferred locale detected in ICS context using 'locale' session variable: "
                         + localeIdFromSSVar);
                 return Collections.singletonList(d.getId());
             }
         } catch (NumberFormatException e) {
             // maybe it's a locale name...
             try {
                 Dimension d = DimensionUtils.getDimensionForName(ics, localeSSVar);
                 if (d != null) {
                     LOG.trace("Preferred locale detected in ICS context using 'locale' session variable: "
                             + localeSSVar);
                     return Collections.singletonList(d.getId());
                 }
             } catch (Exception ex) {
                 // nope... don't worry, we'll find it....
             }
         }
 
         // finally, get the locale from the servlet request's Accept-Language
         // header..
         List<AssetId> preferredLocales = new ArrayList<AssetId>();
         @SuppressWarnings({"rawtypes", "deprecation"})
         Enumeration locales = ics.getIServlet().getServletRequest().getLocales();
         while (locales.hasMoreElements()) {
             Locale locale = (Locale) locales.nextElement();
             if (locale != null) {
                 String localeName = locale.toString();
                 if (localeName != null && localeName.length() > 0) {
                     try {
                         Dimension dimension = DimensionUtils.getDimensionForName(ics, localeName);
                         if (dimension != null) {
                             preferredLocales.add(dimension.getId());
                             LOG.trace("Found registered locale in user's Accept-Language header (or default): "
                                     + localeName);
                         }
                     } catch (RuntimeException e) {
                         // don't care if the dimension is not in the system -
                         // they probably won't all be there
                         // and we're guessing anyway, so it's okay.
                         LOG.trace(
                                 "Found a locale in the user's Accept-Language header, but it was not registered as a dimension: "
                                         + localeName + " (this is not usually an error)", e);
                     }
                 }
             }
         }
         return preferredLocales;
     }
 
     /**
      * Returns the DimensionSetInstance. This implementation expects one
      * DimensionSet enabled for the current site.
      *
      * @param site current site
      * @return dimension set instance
      */
     public final DimensionSetInstance locateDimensionSetInstanceForSite(String site) {
         try {
             if (StringUtils.isNotBlank(site)) {
                 long discoveredId = locateDimensionSetForSite(site);
                 LOG.trace("Auto-discovered dimension set because there is only one in site " + site + ": DimensionSet:"
                         + discoveredId);
                 return _getDimensionSet(discoveredId);
             }
         } catch (RuntimeException e) {
             if (LOG.isTraceEnabled()) {
                 LOG.trace("Could not auto-discover dimensionset: " + e);
             }
         }
         return null;
     }
 }