/*
    * Metis: Java Data Framework
    * Copyright 2012-2026. Tony Washer
    *
    * 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 io.github.tonywasher.joceanus.metis.preference;
  
  import io.github.tonywasher.joceanus.oceanus.base.OceanusException;
  import io.github.tonywasher.joceanus.oceanus.event.OceanusEventManager;
  import io.github.tonywasher.joceanus.oceanus.event.OceanusEventRegistrar;
  import io.github.tonywasher.joceanus.oceanus.event.OceanusEventRegistrar.OceanusEventProvider;
  import io.github.tonywasher.joceanus.oceanus.format.OceanusDataFormatter;
  import io.github.tonywasher.joceanus.oceanus.logger.OceanusLogManager;
  import io.github.tonywasher.joceanus.oceanus.logger.OceanusLogger;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldSet;
  import io.github.tonywasher.joceanus.metis.viewer.MetisViewerManager;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Manager class for preference sets.
   *
   * @author Tony Washer
   */
  public class MetisPreferenceManager
          implements MetisFieldItem, OceanusEventProvider<MetisPreferenceEvent> {
      /**
       * Logger.
       */
      private static final OceanusLogger LOGGER = OceanusLogManager.getLogger(MetisPreferenceManager.class);
  
      /**
       * Report fields.
       */
      private final MetisFieldSet<MetisPreferenceManager> theFields;
  
      /**
       * Load error text.
       */
      private static final String ERROR_LOAD = "Failed to load preference Set";
  
      /**
       * The Event Manager.
       */
      private final OceanusEventManager<MetisPreferenceEvent> theEventManager;
  
      /**
       * Viewer Manager.
       */
      private final MetisViewerManager theViewerManager;
  
      /**
       * Map of preferenceSets.
       */
      private final Map<String, MetisPreferenceSet> theMap = new HashMap<>();
  
      /**
       * Constructor.
       *
       * @param pViewer the viewer manager
       * @throws OceanusException on error
       */
      public MetisPreferenceManager(final MetisViewerManager pViewer) throws OceanusException {
          theViewerManager = pViewer;
          theEventManager = new OceanusEventManager<>();
          theFields = MetisFieldSet.newFieldSet(this);
      }
  
      @Override
      public MetisFieldSet<MetisPreferenceManager> getDataFieldSet() {
          return theFields;
      }
  
      @Override
      public String formatObject(final OceanusDataFormatter pFormatter) {
          return theFields.getName();
      }
  
      @Override
      public OceanusEventRegistrar<MetisPreferenceEvent> getEventRegistrar() {
          return theEventManager.getEventRegistrar();
      }
  
     /**
      * Obtain the viewer manager.
      *
      * @return the viewer manager
      */
     protected MetisViewerManager getViewer() {
         return theViewerManager;
     }
 
     /**
      * Obtain the collection of preference sets.
      *
      * @return the preference sets
      */
     public Collection<MetisPreferenceSet> getPreferenceSets() {
         return theMap.values();
     }
 
     /**
      * Obtain the preference set for the calling class.
      *
      * @param <X>    the preference set type
      * @param pClazz the class of the preference set
      * @return the relevant preferenceSet
      */
     public <X extends MetisPreferenceSet> X getPreferenceSet(final Class<X> pClazz) {
         /* Synchronise */
         synchronized (this) {
             /* Locate a cached PreferenceSet */
             final String myName = pClazz.getSimpleName();
             X mySet = pClazz.cast(theMap.get(myName));
 
             /* If we have not seen this set before */
             if (mySet == null) {
                 /* Create the new preferenceSet */
                 mySet = newPreferenceSet(myName, pClazz);
             }
 
             /* Return the PreferenceSet */
             return mySet;
         }
     }
 
     /**
      * Create a new preferenceSet.
      *
      * @param <X>    the preference set type
      * @param pName  the name of the preference set
      * @param pClazz the class of the preference set
      * @return the new preferenceSet
      */
     private <X extends MetisPreferenceSet> X newPreferenceSet(final String pName,
                                                               final Class<X> pClazz) {
         /* Protect against exceptions */
         try {
             /* Obtain the relevant constructor */
             final Constructor<X> myConstructor = pClazz.getConstructor(MetisPreferenceManager.class);
 
             /* Access the new set */
             final X mySet = myConstructor.newInstance(this);
 
             /* Cache the set */
             theMap.put(pName, mySet);
 
             /* Create the DataField */
             theFields.declareLocalField(pName, m -> mySet);
 
             /* Fire the action performed */
             theEventManager.fireEvent(MetisPreferenceEvent.NEWSET, mySet);
 
             /* Return the PreferenceSet */
             return mySet;
 
         } catch (IllegalAccessException
                  | InstantiationException
                  | NoSuchMethodException
                  | SecurityException
                  | IllegalArgumentException
                  | InvocationTargetException e) {
             LOGGER.error(ERROR_LOAD, e);
             return null;
         }
     }
 }