/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.spi.config.ds;
  
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  
  import de.smartics.properties.api.config.domain.Property;
  import de.smartics.properties.api.config.domain.PropertyCollection;
  import de.smartics.properties.api.config.domain.PropertyLocation;
  import de.smartics.util.lang.Arguments;
  
  /**
   * Provides access to properties in a data source.
   */
  public final class PropertiesStore extends DefaultDataSourceManager implements
      PropertiesDataSourceAccessor
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param builder the builder of manager instance.
     */
    protected PropertiesStore(final Builder builder)
    {
      super(builder);
    }
  
    // ****************************** Inner Classes *****************************
  
    /**
     * The builder of manager instances.
     */
    public static class Builder extends DefaultDataSourceManager.Builder
    {
      // ******************************** Fields ********************************
  
      // --- constants ----------------------------------------------------------
  
      // --- members ------------------------------------------------------------
  
      // ***************************** Initializer ******************************
  
      // ***************************** Constructors *****************************
  
      // ***************************** Inner Classes ****************************
  
      // ******************************** Methods *******************************
  
      // --- init ---------------------------------------------------------------
  
      // --- get&set ------------------------------------------------------------
  
      // --- business -----------------------------------------------------------
  
      /**
       * Creates the instance.
       *
       * @return the created instance.
       * @throws NullPointerException if no data source proxy has been provided.
       */
      @Override
      public final PropertiesStore build() throws NullPointerException
      {
        Arguments.checkNotNull("dataSourceProxy", dataSourceProxy);
  
        return new PropertiesStore(this);
      }
  
     // --- object basics ------------------------------------------------------
   }
 
   // ********************************* Methods ********************************
 
   // --- init -----------------------------------------------------------------
 
   // --- get&set --------------------------------------------------------------
 
   // --- business -------------------------------------------------------------
 
   @Override
   public Property getProperty(final String name)
     throws IllegalArgumentException, DataSourceException
   {
     Arguments.checkNotBlank("name", name); // NOPMD
 
     try
     {
       final Connection connection =
           getDataSourceProxy().getDataSource().getConnection();
 
       try
       {
         final PreparedStatement statement =
             createGetPropertyStatement(connection);
         statement.setString(1, name);
         final ResultSet resultSet = statement.executeQuery();
         final String value;
         if (resultSet.next())
         {
           value = resultSet.getString(1);
         }
         else
         {
           value = null;
         }
         return new Property(new PropertyLocation(getDataSourceId()), name,
             value);
       }
       finally
       {
         connection.close();
       }
     }
     catch (final SQLException e)
     {
       final String dataSourceId = getDataSourceId();
       final String message =
           String.format("Cannot access property '%s' on data source '%s'.",
               name, dataSourceId);
       throw new DataSourceException(message, e, dataSourceId);
     }
   }
 
   @Override
   public void setProperty(final String name, final String value)
     throws IllegalArgumentException, DataSourceException
   {
     Arguments.checkNotBlank("name", name);
 
     try
     {
       final Connection connection =
           getDataSourceProxy().getDataSource().getConnection();
 
       try
       {
         final PreparedStatement statement =
             createSetPropertyStatement(connection);
         statement.setString(2, name);
         statement.setString(1, value);
         statement.executeUpdate();
       }
       finally
       {
         connection.close();
       }
     }
     catch (final SQLException e)
     {
       final String dataSourceId = getDataSourceId();
       final String message =
           String.format(
               "Cannot set property '%s' to value '%s' on data source '%s'.",
               name, value, dataSourceId);
       throw new DataSourceException(message, e, dataSourceId);
     }
   }
 
   @Override
   public void deleteProperty(final String name)
     throws IllegalArgumentException, DataSourceException
   {
     Arguments.checkNotBlank("name", name);
 
     try
     {
       final Connection connection =
           getDataSourceProxy().getDataSource().getConnection();
 
       try
       {
         final PreparedStatement statement =
             createDeletePropertyStatement(connection);
         statement.setString(1, name);
         statement.executeUpdate();
       }
       finally
       {
         connection.close();
       }
     }
     catch (final SQLException e)
     {
       final String dataSourceId = getDataSourceId();
       final String message =
           String.format("Cannot delete property '%s' from data source '%s'.",
               name, dataSourceId);
       throw new DataSourceException(message, e, dataSourceId);
     }
   }
 
   /**
    * The collection of all properties stored.
    *
    * @return the collection of all properties stored.
    */
   public PropertyCollection getCollection()
   {
     try
     {
       final Connection connection =
           getDataSourceProxy().getDataSource().getConnection();
 
       final PreparedStatement statement =
           createGetPropertiesStatement(connection);
       final ResultSet resultSet = statement.executeQuery(); // NOPMD
       final DsPropertyCollection collection =
           new DsPropertyCollection(getDataSourceId(), connection, resultSet);
       return collection;
     }
     catch (final SQLException e)
     {
       final String dataSourceId = getDataSourceId();
       final String message =
           String.format("Cannot access properties on data source '%s'.",
               dataSourceId);
       throw new DataSourceException(message, e, dataSourceId);
     }
   }
 
   /**
    * Checks if a property with the given {@code name} is stored.
    *
    * @param name the name of the property to check if it is stored.
    * @return <code>true</code> if there is a property with that name and a non-
    *         <code>null</code> value, <code>false</code> otherwise.
    * @throws IllegalArgumentException if {@code name} is blank.
    */
   public boolean containsKey(final String name) throws IllegalArgumentException
   {
     final Property property = getProperty(name);
     return property.getValue() != null;
   }
 
   private PreparedStatement createGetPropertyStatement(
       final Connection connection) throws SQLException
   {
     final String sql =
         "SELECT " + getValueColumn() + " FROM " + getTable() + " WHERE "
             + getNameColumn() + " = ?";
     return connection.prepareStatement(sql);
   }
 
   private PreparedStatement createGetPropertiesStatement(
       final Connection connection) throws SQLException
   {
     final String sql =
         "SELECT " + getNameColumn() + ", " + getValueColumn() + " FROM "
             + getTable();
     return connection.prepareStatement(sql);
   }
 
   private PreparedStatement createSetPropertyStatement(
       final Connection connection) throws SQLException
   {
     final String sql =
         "UPDATE " + getTable() + " SET " + getValueColumn() + " = ? WHERE "
             + getNameColumn() + " = ?";
     return connection.prepareStatement(sql);
   }
 
   private PreparedStatement createDeletePropertyStatement(
       final Connection connection) throws SQLException
   {
     final String sql =
         "DELETE FROM " + getTable() + " WHERE" + getNameColumn() + " = ? ";
     return connection.prepareStatement(sql);
   }
 
   // --- object basics --------------------------------------------------------
 
 }