package liquibase.ext.spatial.sqlgenerator;
   
   import java.util.ArrayList;
   import java.util.Arrays;
   import java.util.List;
   import java.util.Map.Entry;
   import java.util.TreeSet;
   
   import liquibase.database.Database;
  import liquibase.database.core.DerbyDatabase;
  import liquibase.database.core.H2Database;
  import liquibase.datatype.LiquibaseDataType;
  import liquibase.exception.ValidationErrors;
  import liquibase.ext.spatial.datatype.GeometryType;
  import liquibase.sql.Sql;
  import liquibase.sqlgenerator.SqlGenerator;
  import liquibase.sqlgenerator.SqlGeneratorChain;
  import liquibase.sqlgenerator.core.AbstractSqlGenerator;
  import liquibase.sqlgenerator.core.CreateTableGenerator;
  import liquibase.statement.core.AddColumnStatement;
  import liquibase.statement.core.CreateTableStatement;
  
  /**
   * <code>CreateSpatialTableGeneratorGeoDB</code> augments the built-in {@link CreateTableGenerator}
   * by invoking the <code>AddGeometryColumn</code> procedure to add the standard metadata for a
   * geometry column.
   */
  public class CreateSpatialTableGeneratorGeoDB extends AbstractSqlGenerator<CreateTableStatement> {
     /**
      * @see liquibase.sqlgenerator.core.AbstractSqlGenerator#supports(liquibase.statement.SqlStatement,
      *      liquibase.database.Database)
      */
     @Override
     public boolean supports(final CreateTableStatement statement, final Database database) {
        return database instanceof DerbyDatabase || database instanceof H2Database;
     }
  
     /**
      * @see liquibase.sqlgenerator.core.AbstractSqlGenerator#getPriority()
      */
     @Override
     public int getPriority() {
        return super.getPriority() + 1;
     }
  
     @Override
     public ValidationErrors validate(final CreateTableStatement statement, final Database database,
           final SqlGeneratorChain sqlGeneratorChain) {
        final ValidationErrors validationErrors = new ValidationErrors();
        for (final Entry<String, LiquibaseDataType> entry : statement.getColumnTypes().entrySet()) {
           if (entry.getValue() instanceof GeometryType) {
              final GeometryType geometryType = (GeometryType) entry.getValue();
              if (geometryType.getSRID() == null) {
                 validationErrors.addError("The SRID parameter is required on the geometry type");
              }
           }
        }
        validationErrors.addAll(sqlGeneratorChain.validate(statement, database));
        return validationErrors;
     }
  
     @Override
     public Sql[] generateSql(final CreateTableStatement statement, final Database database,
           final SqlGeneratorChain sqlGeneratorChain) {
        final List<Sql> list = new ArrayList<Sql>(Arrays.asList(sqlGeneratorChain.generateSql(
              statement, database)));
        for (final Entry<String, LiquibaseDataType> entry : statement.getColumnTypes().entrySet()) {
           if (entry.getValue() instanceof GeometryType) {
              final String columnName = entry.getKey();
              final GeometryType geometryType = (GeometryType) entry.getValue();
              final AddGeometryColumnGeneratorGeoDB generator = new AddGeometryColumnGeneratorGeoDB();
              final AddColumnStatement addColumnStatement = new AddColumnStatement(
                    statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(),
                    columnName, geometryType.toString(), null);
              @SuppressWarnings("rawtypes")
              final SqlGeneratorChain emptyChain = new SqlGeneratorChain(new TreeSet<SqlGenerator>());
              final Sql[] addGeometryColumnSql = generator.generateSql(addColumnStatement, database,
                    emptyChain);
              list.addAll(Arrays.asList(addGeometryColumnSql));
           }
        }
        return list.toArray(new Sql[list.size()]);
     }
  }