from django.db.backends.oracle.creation import DatabaseCreation

from django.db.backends.util import truncate_name

class OracleCreation(DatabaseCreation):

    def sql_indexes_for_field(self, model, f, style):

        "Return any spatial index creation SQL for the field."

        from django.contrib.gis.db.models.fields import GeometryField

        output = super(OracleCreation, self).sql_indexes_for_field(model, f, style)

        if isinstance(f, GeometryField):

            gqn = self.connection.ops.geo_quote_name

            qn = self.connection.ops.quote_name

            db_table = model._meta.db_table

            output.append(style.SQL_KEYWORD('INSERT INTO ') +

                          style.SQL_TABLE('USER_SDO_GEOM_METADATA') +

                          ' (%s, %s, %s, %s)\n  ' % tuple(map(qn, ['TABLE_NAME', 'COLUMN_NAME', 'DIMINFO', 'SRID'])) +

                          style.SQL_KEYWORD(' VALUES ') + '(\n    ' +

                          style.SQL_TABLE(gqn(db_table)) + ',\n    ' +

                          style.SQL_FIELD(gqn(f.column)) + ',\n    ' +

                          style.SQL_KEYWORD("MDSYS.SDO_DIM_ARRAY") + '(\n      ' +

                          style.SQL_KEYWORD("MDSYS.SDO_DIM_ELEMENT") +

                          ("('LONG', %s, %s, %s),\n      " % (f._extent[0], f._extent[2], f._tolerance)) +

                          style.SQL_KEYWORD("MDSYS.SDO_DIM_ELEMENT") +

                          ("('LAT', %s, %s, %s)\n    ),\n" % (f._extent[1], f._extent[3], f._tolerance)) +

                          '    %s\n  );' % f.srid)

            if f.spatial_index:

                # Getting the index name, Oracle doesn't allow object

                # names > 30 characters.

                idx_name = truncate_name('%s_%s_id' % (db_table, f.column), 30)

                output.append(style.SQL_KEYWORD('CREATE INDEX ') +

                              style.SQL_TABLE(qn(idx_name)) +

                              style.SQL_KEYWORD(' ON ') +

                              style.SQL_TABLE(qn(db_table)) + '(' +

                              style.SQL_FIELD(qn(f.column)) + ') ' +

                              style.SQL_KEYWORD('INDEXTYPE IS ') +

                              style.SQL_TABLE('MDSYS.SPATIAL_INDEX') + ';')

        return output