/*
    * Copyright 2003 - 2013 The eFaps Team
    *
    * 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.
   *
   * Revision:        $Rev$
   * Last Changed:    $Date$
   * Last Changed By: $Author$
   */
  
  package org.efaps.db.databases.information;
  
  import java.io.Serializable;
  import java.util.Set;
  
  import org.apache.commons.lang3.builder.ToStringBuilder;
  import org.efaps.db.Context;
  import org.efaps.db.databases.AbstractDatabase.ColumnType;
  
  /**
   * Stores information about one column within a table.
   *
   * @author The eFaps Team
   * @version $Id$
   */
  public class ColumnInformation
      implements Serializable
  {
      /**
       * Needed for serialization.
       */
      private static final long serialVersionUID = 1L;
  
      /**
       * Name of column in upper case.
       *
       * @see #getName()
       */
      private final String name;
  
      /**
       * Set of all possible column types.
       */
      private final Set<ColumnType> types;
  
      /**
       * Size of the column (for string). Precision of the column (for decimal).
       *
       * @see #getSize()
       */
      private final int size;
  
      /**
       * Could the column have a null value?
       *
       * @see #isNullable
       */
      private final boolean isNullable;
  
      /**
       * Scale of the column.
       *
       * @see #getScale()
       */
      private final int scale;
  
      /**
       * Constructor to initialize all instance variables.
       *
       * @param _name       name of column
       * @param _types      set of column types
       * @param _size       size/precision of column
       * @param _scale      sclae of the column
       * @param _isNullable is the column nullable
       */
      protected ColumnInformation(final String _name,
                                  final Set<ColumnType> _types,
                                  final int _size,
                                  final int _scale,
                                  final boolean _isNullable)
      {
          this.name = _name.toUpperCase();
          this.types = _types;
          this.size = _size;
          this.scale = _scale;
          this.isNullable = _isNullable;
      }
  
      /**
      * Returns for the first found column type in {@link #types} the related
      * SQL select statement for null values.
      *
      * @return null value select statement
      * @see #types
      */
     public String getNullValueSelect()
     {
         String ret = null;
         if (!this.types.isEmpty())  {
             ret = Context.getDbType().getNullValueSelect(this.types.iterator().next());
         }
         return ret;
     }
 
     /**
      * This is the getter method for instance variable {@link #name}. The
      * method returns the name of the SQL column always in upper case.
      *
      * @return value of instance variable {@link #name}
      * @see #name
      */
     public String getName()
     {
         return this.name;
     }
 
     /**
      * This is the getter method for instance variable {@link #size}. The
      * method returns the column size for this column (used for string column
      * types defined for eFaps column types {@link ColumnType#STRING_LONG} and
      * {@link ColumnType#STRING_SHORT}). Or the precision/size of this column
      * (used for decimal column types {@link ColumnType#DECIMAL})
      *
      * @return value of instance variable {@link #size}
      * @see #size
      */
     public int getSize()
     {
         return this.size;
     }
 
     /**
      * Getter method for instance variable {@link #scale}. The method
      * returns the scale of this column.
      * The information is used for decimal column types
      * {@link ColumnType#DECIMAL}.
      *
      * @return value of instance variable {@link #scale}
      */
     public int getScale()
     {
         return this.scale;
     }
 
     /**
      * This is the getter method for instance variable {@link #isNullable}. The
      * method returns true, if a null value for this column is allowed.
      *
      * @return value of instance variable {@link #isNullable}
      * @see #isNullable
      */
     public boolean isNullable()
     {
         return this.isNullable;
     }
 
     /**
      * Returns string representation of this class instance. The information
      * includes {@link #name}, {@link #types}, {@link #size} and
      * {@link #isNullable}.
      * @return String representation of this class
      */
     @Override
     public String toString()
     {
         return new ToStringBuilder(this)
                 .append("name", this.name)
                 .append("types", this.types)
                 .append("size", this.size)
                 .append("isNullable", this.isNullable)
                 .toString();
     }
 }