/*
    * 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 com.fatwire.gst.foundation.facade.assetapi;
  
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  
  import COM.FutureTense.Interfaces.ICS;
  import COM.FutureTense.Interfaces.IList;
  
  import com.fatwire.assetapi.common.AssetAccessException;
  import com.fatwire.assetapi.common.SiteAccessException;
  import com.fatwire.assetapi.data.AssetData;
  import com.fatwire.assetapi.data.AssetDataManager;
  import com.fatwire.assetapi.data.AssetId;
  import com.fatwire.assetapi.query.ConditionFactory;
  import com.fatwire.assetapi.query.OpTypeEnum;
  import com.fatwire.assetapi.query.Query;
  import com.fatwire.assetapi.query.SimpleQuery;
  import com.fatwire.assetapi.site.Site;
  import com.fatwire.assetapi.site.SiteInfo;
  import com.fatwire.assetapi.site.SiteManager;
  import com.fatwire.gst.foundation.facade.runtag.asset.AssetList;
  import com.fatwire.system.Session;
  import com.fatwire.system.SessionFactory;
  import com.openmarket.xcelerate.asset.AssetIdImpl;
  
  /**
   * 
   * This class is a one-stop-shop for all read-only access to AssetData. It acts
   * as a helper class to facilitate {@link AssetDataManager} use in a simplified
   * way in delivery ContentServer templates.
   * <p/>
   * This class is inspired by springframework data access template classes like
   * org.springframework.jdbc.core.JdbcTemplate.
   * <p/>
   * This class is not thread safe and should not be shared between threads.
   * 
   * @author Dolf.Dijkstra
   * @since Nov 23, 2009
   * 
   */
  public class AssetAccessTemplate {
  
      private final Session session;
      private AssetDataManager assetDataManager;
  
      /**
       * @param session
       */
      public AssetAccessTemplate(final Session session) {
          super();
          if (session == null) {
              throw new IllegalArgumentException("session cannot be null.");
          }
          this.session = session;
      }
  
      /**
       * Constructor that accepts ICS as an argument.
       * 
       * @param ics
       */
      public AssetAccessTemplate(final ICS ics) {
          if (ics == null) {
              throw new IllegalArgumentException("ics cannot be null.");
          }
          session = SessionFactory.getSession(ics);
      }
  
      /**
       * Helper method to create an AssetId from c and cid as string values.
       * 
       * @param c
       * @param cid
       * @return the assetId for c/cid.
       */
      public AssetId createAssetId(final String c, final String cid) {
          return new AssetIdImpl(c, Long.parseLong(cid));
      }
  
     /**
      * Helper method to create an AssetId from c and cid as string values.
      * 
      * @param c
      * @param cid
      * @return the assetId for c/cid.
      */
     public AssetId createAssetId(final String c, final long cid) {
         return new AssetIdImpl(c, cid);
     }
 
     /**
      * Method to read an asset and use the AssetMapper to transform the
      * AssetData into another object as specified by the AssetMapper.
      * 
      * @param <T>
      * @param id
      * @param mapper
      * @return the Object created by the mapper.
      */
     public <T> T readAsset(final AssetId id, final AssetMapper<T> mapper) {
         final AssetDataManager m = getAssetDataManager();
 
         T t = null;
         try {
             final Iterable<AssetData> assets = m.read(Arrays.asList(id));
             for (final AssetData assetData : assets) {
                 t = mapper.map(assetData);
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
         return t;
     }
 
     /**
      * Method to read an asset and use the AssetMapper to transform the
      * AssetData into another object as specified by the AssetMapper interface..
      * 
      * @param <T>
      * @param c the assetType
      * @param cid the asset id
      * @param mapper
      * @return the object created by the mapper.
      */
     public <T> T readAsset(final String c, final String cid, final AssetMapper<T> mapper) {
         return readAsset(this.createAssetId(c, cid), mapper);
     }
 
     /**
      * Method to read an asset and use the AssetMapper to transform the
      * AssetData into another object as specified by the AssetMapper.
      * 
      * @param <T>
      * @param c the assetType
      * @param cid the asset id
      * @param mapper
      * @return the object created by the mapper.
      */
     public <T> T readAsset(final String c, final long cid, final AssetMapper<T> mapper) {
         return readAsset(new AssetIdImpl(c, cid), mapper);
     }
 
     /**
      * Method to read an asset and use the AssetMapper to transform the
      * AssetData into another object as specified by the AssetMapper. Only the
      * list of lister attributes is retrieved from the asset.
      * 
      * @param <T>
      * @param id
      * @param mapper
      * @param attributes
      * @return the object created by the mapper.
      */
     public <T> T readAsset(final AssetId id, final AssetMapper<T> mapper, final String... attributes) {
         final AssetDataManager m = getAssetDataManager();
 
         T t = null;
         try {
             final AssetData asset = m.readAttributes(id, Arrays.asList(attributes));
             t = mapper.map(asset);
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
         return t;
     }
 
     /**
      * Method to read an asset and provide the AssetClosure with the AssetData.
      * Only the list of lister attributes is retrieved from the asset.
      * 
      * @param id
      * @param closure
      * @param attributes
      * 
      */
     public void readAsset(final AssetId id, final AssetClosure closure, final String... attributes) {
         final AssetDataManager m = getAssetDataManager();
 
         try {
             final AssetData asset = m.readAttributes(id, Arrays.asList(attributes));
             if (asset != null) {
                 if (!closure.work(asset)) {
                     return;
                 }
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
     }
 
     /**
      * Method to read an asset and pass the results to the closure for further
      * handling.
      * 
      * @param id the assetid to read
      * @param closure the closure
      */
     public void readAsset(final AssetId id, final AssetClosure closure) {
         final AssetDataManager m = getAssetDataManager();
 
         try {
             final Iterable<AssetData> assets = m.read(Arrays.asList(id));
             for (final AssetData assetData : assets) {
                 if (!closure.work(assetData)) {
                     return;
                 }
 
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
 
     }
 
     /**
      * Method to read an asset and pass the results to the closure for further
      * handling.
      * 
      * @param ids a list of AssetIds
      * @param closure the closure
      */
     public void readAsset(final List<AssetId> ids, final AssetClosure closure) {
         final AssetDataManager m = getAssetDataManager();
 
         try {
             final Iterable<AssetData> assets = m.read(ids);
             for (final AssetData assetData : assets) {
                 if (!closure.work(assetData)) {
                     return;
                 }
 
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
 
     }
 
     /**
      * Method to read an asset and pass the results to the closure for further
      * handling.
      * 
      * @param ids a list of AssetIds
      * @param closure the closure
      */
     public void readAsset(final Iterable<AssetId> ids, final AssetClosure closure, final String... attributes) {
         final AssetDataManager m = getAssetDataManager();
 
         try {
             for (final AssetId id : ids) {
                 final AssetData asset = m.readAttributes(id, Arrays.asList(attributes));
                 if (asset != null) {
                     if (!closure.work(asset)) {
                         return;
                     }
                 }
 
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
 
     }
 
     /**
      * Reads an asset based on the listed attribute names
      * <p/>
      * TODO: do we need to load the attribute values and prevent access to
      * non-listed attributes (prevent lazy loading)
      * 
      * @param id the assetid
      * @param attributes the list of attributes to return
      * @return the asset found
      * 
      * 
      */
     public AssetData readAsset(final AssetId id, final String... attributes) {
         final AssetDataManager m = getAssetDataManager();
 
         Iterable<AssetData> assets;
         try {
             assets = m.read(Arrays.asList(id));
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
         if (assets == null) {
             return null;
         }
         if (assets instanceof List<?>) {
             final List<AssetData> x = (List<AssetData>) assets;
             if (x.isEmpty()) {
                 return null;
             } else {
                 return x.get(0);
             }
         }
         final Iterator<AssetData> i = assets.iterator();
         if (i.hasNext()) {
             return i.next();
         }
         return null;
     }
 
     /**
      * @return the manager
      */
     protected AssetDataManager getAssetDataManager() {
         if (assetDataManager == null) {
             assetDataManager = (AssetDataManager) session.getManager(AssetDataManager.class.getName());
         }
         return assetDataManager;
     }
 
     /**
      * @param id the assetid to read
      * @return the assetdata for this id
      */
     public AssetData readAsset(final AssetId id) {
 
         final AssetDataManager m = getAssetDataManager();
 
         Iterable<AssetData> assets;
         try {
             assets = m.read(Collections.singletonList(id));
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
         if (assets == null) {
             return null;
         }
         if (assets instanceof List<?>) {
             final List<AssetData> x = (List<AssetData>) assets;
             if (x.isEmpty()) {
                 return null;
             } else {
                 return x.get(0);
             }
         }
         final Iterator<AssetData> i = assets.iterator();
         if (i.hasNext()) {
             return i.next();
         }
         return null;
     }
 
     /**
      * @param query
      * @return iterable with AssetData from the query result.
      */
     public Iterable<AssetData> readAssets(final Query query) {
         final AssetDataManager m = getAssetDataManager();
 
         Iterable<AssetData> assets;
         try {
             assets = m.read(query);
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
 
         return assets;
     }
 
     /**
      * Invokes the work(asset) method on the provided Closure for assets
      * returned by the Query.
      * 
      * @param query the query
      * @param closure the closure
      */
     public void readAssets(final Query query, final AssetClosure closure) {
         final AssetDataManager m = getAssetDataManager();
 
         try {
             for (final AssetData asset : m.read(query)) {
                 if (!closure.work(asset)) {
                     return;
                 }
 
             }
         } catch (final AssetAccessException e) {
             throw new RuntimeAssetAccessException(e);
         }
     }
 
     /**
      * Reading assets with the Query and using the mapper to transform the
      * AssetData into another object, as specified by T.
      * 
      * @param <T>
      * @param query
      * @param mapper
      * @return the objects created by the mapper.
      */
     public <T> Iterable<T> readAssets(final Query query, final AssetMapper<T> mapper) {
 
         final List<T> r = new LinkedList<T>();
 
         for (final AssetData data : readAssets(query)) {
             r.add(mapper.map(data));
         }
 
         return r;
     }
 
     /**
      * Finds the assetid by the name of the asset in a particular site. The
      * asset can not be voided.
      * 
      * @param ics
      * @param assetType the type of the asset.
      * @param name the name of the asset.
      * @param siteid the Site id.
      * @return the assetid, null if asset is not found.
      */
     public AssetId findByName(final ICS ics, final String assetType, final String name, final long siteid) {
         // TODO: name does not need to be unique, how do we handle this?
         final AssetList tag = new AssetList();
         tag.setType(assetType);
         tag.setField("name", name);
         tag.setExcludeVoided(true);
         tag.setPubid(Long.toString(siteid));
         tag.setList("name__");
         tag.execute(ics);
 
         final IList list = ics.GetList("name__");
         ics.RegisterList("name__", null);
         if (list != null && list.hasData()) {
             list.moveTo(1);
             try {
                 return new AssetIdImpl(assetType, Long.parseLong(list.getValue("id")));
             } catch (final NoSuchFieldException e) {
                 throw new RuntimeException(e);
             }
         } else {
             return null;
         }
 
     }
 
     /**
      * Finds the assetid by the name of the asset. The asset can not be voided.
      * 
      * @param ics
      * @param assetType the type of the asset.
      * @param name the name of the asset.
      * @return the assetid, null if asset is not found.
      */
 
     public AssetId findByName(final ICS ics, final String assetType, final String name) {
         // TODO: name does not need to be unique, how do we handle this?
         final AssetList x = new AssetList();
         x.setType(assetType);
         x.setField("name", name);
         x.setExcludeVoided(true);
         x.setList("name__");
         x.execute(ics);
 
         final IList list = ics.GetList("name__");
         ics.RegisterList("name__", null);
         if (list != null && list.hasData()) {
             list.moveTo(1);
             try {
                 return new AssetIdImpl(assetType, Long.parseLong(list.getValue("id")));
             } catch (final NoSuchFieldException e) {
                 throw new RuntimeException(e);
             }
         } else {
             return null;
         }
 
     }
 
     /**
      * Creates a Query to retrieve the asset by it's name.
      * 
      * @param assetType
      * @param assetName
      * @return the simple query
      */
     public SimpleQuery createNameQuery(final String assetType, final String assetName) {
         final SimpleQuery q = new SimpleQuery(assetType, null, ConditionFactory.createCondition("name",
                 OpTypeEnum.EQUALS, assetName), Arrays.asList("id"));
         q.getProperties().setIsBasicSearch(true);
         return q;
     }
 
     /**
      * Finds the Site object by the given name.
      * 
      * @param name the name of the site.
      * @return the Site object.
      */
     public Site readSite(final String name) {
         final SiteManager sm = (SiteManager) session.getManager(SiteManager.class.getName());
         try {
 
             final List<Site> list = sm.read(Arrays.asList(name));
             if (list == null || list.isEmpty()) {
                 return null;
             }
             return list.get(0);
         } catch (final SiteAccessException e) {
             throw new SiteAccessRuntimeException(e);
         }
     }
 
     /**
      * @param name
      * @return the site info object
      */
     public SiteInfo readSiteInfo(final String name) {
         final SiteManager sm = (SiteManager) session.getManager(SiteManager.class.getName());
         try {
 
             for (SiteInfo si : sm.list()) {
                 if (name.equals(si.getName())) {
                     return si;
                 }
             }
         } catch (final SiteAccessException e) {
             throw new SiteAccessRuntimeException(e);
         }
         throw new SiteAccessRuntimeException("Site " + name + " does not exist in Content Server.");
     }
 
     /**
      * Reads the associated assets of the asset and returns the AssetIds.
      * 
      * @param id
      * @param associationType
      * @return the assets from the associations.
      */
     public Collection<AssetId> readAssociatedAssetIds(final AssetId id, final String associationType) {
         final List<AssetId> list = readAsset(id).getAssociatedAssets(associationType);
         if (list == null) {
             return Collections.emptyList();
         }
         return list;
 
     }
 
     /**
      * Reads the associated assets of an asset and returns them as a
      * ScatteredAsset. This takes care of the asset read operation of the
      * associated assets. The returned ScatteredAssets are only loaded with the
      * mentioned attributes.
      * 
      * @param id the parent asset
      * @param associationType the name of the association or '-' for an unnamed
      *            association
      * @param closure the AssetClosure to work on.
      * @param attributes the list of attributes to load
      * 
      */
     public void readAssociatedAssets(final AssetId id, final String associationType, final AssetClosure closure,
             final String... attributes) {
         final List<AssetId> list = this.readAsset(id).getAssociatedAssets(associationType);
         if (list == null || list.isEmpty()) {
             return;
         }
 
         for (final AssetId child : list) {
             readAsset(child, closure, attributes);
         }
 
     }
 
     /**
      * Queries for a list of objects as mapped by the AssetMapper.
      * <p/>
      * Sample queries are:
      * <ul>
      * <li>name='foo'</li>
      * <li>name = 'foo'</li>
      * <li>name = foo</li>
      * <li>name= 'foo bar'</li>
      * <li>size=[1,2]</li>
      * <li>size{10,250}</li>
      * <li>name!='foo'</li>
      * 
      * 
      * @param <T>
      * @param assetType
      * @param subType
      * @param query
      * @param mapper
      * @param attributes
      * @return a iterable of assets.
      * @see AssetAccessTemplate#query(String, String, String, AssetMapper,
      *      String...)
      */
     public <T> Iterable<T> query(final String assetType, final String subType, final String query,
             AssetMapper<T> mapper, final String... attributes) {
         final Query q = new QueryBuilder(assetType, subType).condition(query).attributes(attributes).toQuery();
         return this.readAssets(q, mapper);
     }
 
     /**
      * Queries for a list of objects as mapped by the AssetMapper.
      * <p/>
      * Sample queries are:
      * <ul>
      * <li>name='foo'</li>
      * <li>name = 'foo'</li>
      * <li>name = foo</li>
      * <li>name= 'foo bar'</li>
      * <li>size=[1,2]</li>
      * <li>size{10,250}</li>
      * <li>name!='foo'</li>
      * 
      * @param <T>
      * @param assetType
      * @param subType
      * @param query
      * @param mapper
      * 
      * @return a iterable of assets.
      */
     public <T> Iterable<T> query(final String assetType, final String subType, final String query, AssetMapper<T> mapper) {
         final Query q = new QueryBuilder(assetType, subType).condition(query).setReadAll(true).toQuery();
         return this.readAssets(q, mapper);
     }
 
 }