/*******************************************************************************
    * jArduino: Arduino C++ Code Generation From Java
    * Copyright 2020 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 net.sourceforge.jarduino.gui;
  
  import java.io.File;
  import java.nio.charset.Charset;
  import java.nio.charset.StandardCharsets;
  import java.util.prefs.BackingStoreException;
  import java.util.prefs.Preferences;
  
  import net.sourceforge.jarduino.ArduinoException;
  
  /**
   * Preferences.
   */
  public final class ArduinoPreferences {
      /**
       * The save error.
       */
      private static final String ERROR_SAVE = "Failed to save preference";
  
      /**
       * The default DBC file variable name.
       */
      private static final String DEFAULT = "DefaultDBC";
  
      /**
       * The default sketchDir variable name.
       */
      private static final String SKETCHDIR = "SketchDir";
  
      /**
       * The default libraryDir variable name.
       */
      private static final String LIBDIR = "LibraryDir";
  
      /**
       * The default charSet variable name.
       */
      private static final String CHARSET = "CharSet";
  
      /**
       * Private constructor.
       */
      private ArduinoPreferences() {
      }
  
      /**
       * Obtain the default location.
       * @return the default location
       */
      static File getDefaultLocation() {
          final Preferences myPreferences = deriveHandle();
          final String myLocation = myPreferences.get(DEFAULT, null);
          return myLocation == null ? null : new File(myLocation);
      }
  
      /**
       * Store the default location.
       * @param pLocation the default location
       * @return the error (or null)
       */
      static ArduinoException storeDefaultLocation(final File pLocation) {
          /* Protect against exceptions */
          try {
              final Preferences myPreferences = deriveHandle();
              myPreferences.put(DEFAULT, pLocation.getAbsolutePath());
              myPreferences.flush();
              return null;
  
          } catch (BackingStoreException e) {
              return new ArduinoException(ERROR_SAVE, e);
          }
      }
  
      /**
       * Obtain the sketch location.
       * @return the sketch location
       */
      static File getSketchLocation() {
          final Preferences myPreferences = deriveHandle();
          final String myLocation = myPreferences.get(SKETCHDIR, null);
          return myLocation == null ? null : new File(myLocation);
      }
  
     /**
      * Store the output location.
      * @param pLocation the output location
      * @return the error (or null)
      */
     static ArduinoException storeSketchLocation(final File pLocation) {
         /* Protect against exceptions */
         try {
             final Preferences myPreferences = deriveHandle();
             myPreferences.put(SKETCHDIR, pLocation.getAbsolutePath());
             myPreferences.flush();
             return null;
 
         } catch (BackingStoreException e) {
             return new ArduinoException(ERROR_SAVE, e);
         }
     }
 
     /**
      * Obtain the library location.
      * @return the library location
      */
     static File getLibraryLocation() {
         final Preferences myPreferences = deriveHandle();
         final String myLocation = myPreferences.get(LIBDIR, null);
         return myLocation == null ? null : new File(myLocation);
     }
 
     /**
      * Store the library location.
      * @param pLocation the library location
      * @return the error (or null)
      */
     static ArduinoException storeLibraryLocation(final File pLocation) {
         /* Protect against exceptions */
         try {
             final Preferences myPreferences = deriveHandle();
             myPreferences.put(LIBDIR, pLocation.getAbsolutePath());
             myPreferences.flush();
             return null;
 
         } catch (BackingStoreException e) {
             return new ArduinoException(ERROR_SAVE, e);
         }
     }
 
     /**
      * Obtain the charSet.
      * @return the charSet
      */
     static Charset getCharSet() {
         final Preferences myPreferences = deriveHandle();
         final String myName = myPreferences.get(CHARSET, StandardCharsets.ISO_8859_1.name());
         return myName.equals(StandardCharsets.UTF_8.name())
                ? StandardCharsets.UTF_8
                : StandardCharsets.ISO_8859_1;
      }
 
     /**
      * Store the charSet.
      * @param pCharSet the charSet
      * @return the error (or null)
      */
     static ArduinoException storeCharSet(final Charset pCharSet) {
         /* Protect against exceptions */
         try {
             final Preferences myPreferences = deriveHandle();
             myPreferences.put(CHARSET, pCharSet.name());
             myPreferences.flush();
             return null;
 
         } catch (BackingStoreException e) {
             return new ArduinoException(ERROR_SAVE, e);
         }
     }
 
     /**
      * Derive handle for node.
      * @return the class name
      */
     private static Preferences deriveHandle() {
         /* Obtain the class name */
         final Class<?> myClass = ArduinoPreferences.class;
         String myName = myClass.getCanonicalName();
 
         /* Obtain the package name */
         final String myPackage = myClass.getPackage().getName();
 
         /* Strip off the package name */
         myName = myName.substring(myPackage.length() + 1);
 
         /* Derive the handle */
         final Preferences myHandle = Preferences.userNodeForPackage(myClass);
         return myHandle.node(myName);
     }
 }