package com.explosion.expfmodules.rdbmsconn.dbom.sql;
   
   
   /* =============================================================================
    *       
    *     Copyright 2004 Stephen Cowx
    *
    *     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.
   * 
   * =============================================================================
   */
  
  import java.sql.DatabaseMetaData;
  import java.sql.PreparedStatement;
  import java.sql.SQLException;
  import java.text.ParseException;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.log4j.LogManager;
  import org.apache.log4j.Logger;
  
  import com.explosion.expfmodules.rdbmsconn.dbom.DBEntity;
  import com.explosion.expfmodules.rdbmsconn.dbom.DBEntityColumn;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.MetadataException;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.MetadataUtils;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.SQLEngine;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.UnconvertableDataTypeException;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.UnrecognisedTypeException;
  import com.explosion.expfmodules.rdbmsconn.dbom.utils.UnsupportedTypeException;
  
  
  /***
   * This class represents an SQL insert statement
   * @author Stephen
   * Created on Apr 22, 2004
   */
  public class InsertStatement
  {
      private DBEntity entity;
      private static final String BIND_STRING = "?";
      private List columns;
      private static Logger log = LogManager.getLogger(InsertStatement.class);
      private MetadataUtils utils = new MetadataUtils();
      
      /***
       * @param entity The entity into which the data is being inserted
       * @param columns A list of columns which will be inserted into the database row 
       * @param entity
       * @param bindings
       */
      public InsertStatement(DBEntity entity, List columns)
      {
          this.entity = entity;
          this.columns = columns;
      }
      
      /***
       * This method returns the tring that will be used for a prepare statement
       * neccessary variables bound to it.
       * @return
       * @throws Exception
       */
      public String getPreparedStatementString(DatabaseMetaData meta) throws SQLException, InvalidInsertException, MetadataException
      {
          /* First, we need to build an insert statement as a string */
          String statement = "insert into " + utils.getFullEntityName(entity,meta);
          statement += " (";
          String values = "";
  
          for (Iterator i = columns.iterator(); i.hasNext();)
          {
              DBEntityColumn column = entity.getColumn((String) i.next());
  
              if (includeInInsert(column))
              {
                statement += (column.getColumnName() + (i.hasNext() ? ", " : ""));
                values += ("?" + (i.hasNext() ? ", " : ""));
              }
          }
  
          statement += ") values (" + values + ")";
  
          return statement;    
      }
      
      /***
       * This method will bind the variables provided to the statement
      * provided
      * @param bindings A map containing the columnNames (Strings) and the Appropriate values for those columns to be inserted into the database
      *                 e.g. columnName=Value.  Value must be an object of the correct type otherwise an error will be thrown when the 
      *  			   statement gets executed.
      * @param statement Prepared Statement.  Note: this statement needs to have been prepared from the 
      * 					string produced from getPreparedStatementString()  method from this instanceof the 
      *                  class 
      * @throws UnconvertableDataTypeException
      * @throws SQLException
      * @throws ParseException
      * @throws UnsupportedTypeException
      * @throws UnrecognisedTypeException
      */
     public void bindVariables(Map bindVariables, PreparedStatement statement) throws UnconvertableDataTypeException, UnrecognisedTypeException, UnsupportedTypeException, SQLException, ParseException
     {
         SQLEngine engine = new SQLEngine();
         for (int i=0;i<columns.size(); i++)
         {
             String columnName = (String) columns.get(i);
             DBEntityColumn column = entity.getColumn(columnName);
             if (includeInInsert(column))
             {
                 Object object = bindVariables.get(columnName);
                 log.debug("Binding " + object + " to column " + columnName);
                 engine.bind(object,statement, column, i+1);
             }
         }   
     }
     
     /***
      * This method will tell you if the column will be included in an insert statement or not
      * It also outputs a debug level message if not
      * @param column
      */
     public static boolean includeInInsert(DBEntityColumn column)
     {
         boolean include = true;
         
         if (column == null)
             return false;
         
         /* Exclusions and errors */
         if (column.isAutoIncrement())
         {
                log.debug("Not adding column " + column.getColumnName()+ " into insert statement because it is an autoIncrement column.");
                include = false;
         }
         
         return include;
     }    
         
 }