/*
 * Copyright (c) 2007 Pentaho Corporation.  All rights reserved. 
 * This software was developed by Pentaho Corporation and is provided under the terms 
 * of the GNU Lesser General Public License, Version 2.1. You may not use 
 * this file except in compliance with the license. If you need a copy of the license, 
 * please go to http://www.gnu.org/licenses/lgpl-2.1.txt. The Original Code is Pentaho 
 * Data Integration.  The Initial Developer is Pentaho Corporation.
 *
 * Software distributed under the GNU Lesser Public License is distributed on an "AS IS" 
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or  implied. Please refer to 
 * the license for the specific language governing your rights and limitations.
*/

package org.pentaho.di.core.database;

import org.pentaho.di.core.Const;
import org.pentaho.di.core.row.ValueMetaInterface;

/**
 * Contains Hypersonic specific information through static final members 
 * 
 * @author Matt
 * @since  11-mrt-2005
 */

public class H2DatabaseMeta extends BaseDatabaseMeta implements DatabaseInterface
{
	public int[] getAccessTypeList()
	{
		return new int[] { DatabaseMeta.TYPE_ACCESS_NATIVE, DatabaseMeta.TYPE_ACCESS_ODBC, DatabaseMeta.TYPE_ACCESS_JNDI };
	}
	
	/**
	 * @see DatabaseInterface#getNotFoundTK(boolean)
	 */
	public int getNotFoundTK(boolean use_autoinc)
	{
		return super.getNotFoundTK(use_autoinc);
	}
	
	public String getDriverClass()
	{
        if (getAccessType()==DatabaseMeta.TYPE_ACCESS_NATIVE)
        {
            return "org.h2.Driver";
        }
        else
        {
            return "sun.jdbc.odbc.JdbcOdbcDriver"; // always ODBC!
        }

	}
    
	public int getDefaultDatabasePort() {
    if (getAccessType()==DatabaseMeta.TYPE_ACCESS_NATIVE) return 8082;
    return -1;
	}
	
    public String getURL(String hostname, String port, String databaseName)
    {
        if (getAccessType()==DatabaseMeta.TYPE_ACCESS_NATIVE)
        {
          // If the database is an in-memory DB or if there is no valid port and hostname, go embedded
          //
          if ( (databaseName!=null && databaseName.startsWith("mem:")) || 
              ((Const.isEmpty(port)||"-1".equals(port)) && Const.isEmpty(hostname)) ) 
          {
            return "jdbc:h2:"+databaseName;
          }
          else
          {
            // Connect over TCP/IP
            //
            return "jdbc:h2:tcp://"+hostname+ ":" + port +"/"+databaseName;
          }
        }
        else
        {
            return "jdbc:odbc:"+databaseName;
        }
	}

	/**
	 * Checks whether or not the command setFetchSize() is supported by the JDBC driver...
	 * @return true is setFetchSize() is supported!
	 */
	public boolean isFetchSizeSupported()
	{
		return true;
	}

	/**
	 * @see DatabaseInterface#getSchemaTableCombination(String, String)
	 */
	public String getSchemaTableCombination(String schema_name, String table_part)
	{
		return getBackwardsCompatibleSchemaTableCombination(schema_name, table_part);
	}	
	/**
	 * @return true if the database supports bitmap indexes
	 */
	public boolean supportsBitmapIndex()
	{
		return false;
	}
	
	/**
	 * @return true if Kettle can create a repository on this type of database.
	 */
	public boolean supportsRepository()
	{
		return true;
	}
    
    public boolean supportsAutoInc()
    {
        return true;
    }
    
    public boolean supportsGetBlob()
    {
        return true;
    }
    
    public boolean supportsSetCharacterStream()
    {
        return false;
    }

	/**
	 * Generates the SQL statement to add a column to the specified table
	 * For this generic type, i set it to the most common possibility.
	 * 
	 * @param tablename The table to add
	 * @param v The column defined as a value
	 * @param tk the name of the technical key field
	 * @param use_autoinc whether or not this field uses auto increment
	 * @param pk the name of the primary key field
	 * @param semicolon whether or not to add a semi-colon behind the statement.
	 * @return the SQL statement to add a column to the specified table
	 */
	public String getAddColumnStatement(String tablename, ValueMetaInterface v, String tk, boolean use_autoinc, String pk, boolean semicolon)
	{
		return "ALTER TABLE "+tablename+" ADD "+getFieldDefinition(v, tk, pk, use_autoinc, true, false);
	}

	/**
	 * Generates the SQL statement to modify a column in the specified table
	 * @param tablename The table to add
	 * @param v The column defined as a value
	 * @param tk the name of the technical key field
	 * @param use_autoinc whether or not this field uses auto increment
	 * @param pk the name of the primary key field
	 * @param semicolon whether or not to add a semi-colon behind the statement.
	 * @return the SQL statement to modify a column in the specified table
	 */
	public String getModifyColumnStatement(String tablename, ValueMetaInterface v, String tk, boolean use_autoinc, String pk, boolean semicolon)
	{
		return "ALTER TABLE "+tablename+" ALTER "+getFieldDefinition(v, tk, pk, use_autoinc, true, false);
	}

	public String getFieldDefinition(ValueMetaInterface v, String tk, String pk, boolean use_autoinc, boolean add_fieldname, boolean add_cr)
	{
		String retval="";
		
		String fieldname = v.getName();
		int    length    = v.getLength();
		int    precision = v.getPrecision();
		
		if (add_fieldname) retval+=fieldname+" ";
		
		int type         = v.getType();
		switch(type)
		{
		case ValueMetaInterface.TYPE_DATE   : retval+="TIMESTAMP"; break;
		case ValueMetaInterface.TYPE_BOOLEAN:
			if (supportsBooleanDataType()) {
				retval+="BOOLEAN"; 
			} else {
				retval+="CHAR(1)";
			}
			break;
		case ValueMetaInterface.TYPE_NUMBER : 
		case ValueMetaInterface.TYPE_INTEGER: 
        case ValueMetaInterface.TYPE_BIGNUMBER: 
			if (fieldname.equalsIgnoreCase(tk) || // Technical key
			    fieldname.equalsIgnoreCase(pk)    // Primary key
			    ) 
			{
				retval+="IDENTITY";
			} 
			else
			{
				if (length>0)
				{
					if (precision>0 || length>18)
					{
						retval+="DECIMAL("+length+", "+precision+")";
					}
					else
					{
                        if (length>9)
                        {
                            retval+="BIGINT";
                        }
                        else
                        {
                            if (length<5)
                            {
                                if (length<3)
                                {
                                    retval+="TINYINT";
                                }
                                else
                                {
                                    retval+="SMALLINT";
                                }
                            }
                            else
                            {
                                retval+="INTEGER";
                            }
                        }
					}
					
				}
				else
				{
					retval+="DOUBLE";
				}
			}
			break;
		case ValueMetaInterface.TYPE_STRING:
			if (length>=DatabaseMeta.CLOB_LENGTH)
			{
				retval+="TEXT";
			}
			else
			{
				retval+="VARCHAR"; 
				if (length>0)
				{
					retval+="("+length;
				}
				else
				{
				  // http://www.h2database.com/html/datatypes.html#varchar_type
					retval+="("+Integer.MAX_VALUE; 
				}
				retval+=")";
			}
			break;
        case ValueMetaInterface.TYPE_BINARY:
            retval+="BLOB"; 
            break;
		default:
			retval+="UNKNOWN";
			break;
		}
		
		if (add_cr) retval+=Const.CR;
		
		return retval;
	}
    
    public String[] getReservedWords()
    {
        return new String[]
          {
             "CURRENT_TIMESTAMP", "CURRENT_TIME", "CURRENT_DATE", "CROSS", "DISTINCT", "EXCEPT", "EXISTS", "FROM", "FOR", "FALSE", 
             "FULL", "GROUP", "HAVING", "INNER", "INTERSECT", "IS", "JOIN", "LIKE", "MINUS", "NATURAL", "NOT", "NULL", "ON", 
             "ORDER", "PRIMARY", "ROWNUM", "SELECT", "SYSDATE", "SYSTIME", "SYSTIMESTAMP", "TODAY", "TRUE", "UNION", "WHERE",    
          };
    }

    public String[] getUsedLibraries()
    {
        return new String[] { "h2.jar" };
    }
    
	/**
	 * Most databases allow you to retrieve result metadata by preparing a SELECT statement.
	 * 
	 * @return true if the database supports retrieval of query metadata from a prepared statement.  False if the query needs to be executed first.
	 */
	public boolean supportsPreparedStatementMetadataRetrieval() {
		return false;
	}

}
