from django.db.backends.creation import BaseDatabaseCreation

class DatabaseCreation(BaseDatabaseCreation):
    # This dictionary maps Field objects to their associated MySQL column
    # types, as strings. Column-type strings can contain format strings; they'll
    # be interpolated against the values of Field.__dict__ before being output.
    # If a column type is set to None, it won't be included in the output.
    data_types = {
        'AutoField':         'integer AUTO_INCREMENT',
        'BinaryField':       'longblob',
        'BooleanField':      'bool',
        'CharField':         'varchar(%(max_length)s)',
        'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
        'DateField':         'date',
        'DateTimeField':     'datetime',
        'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
        'FileField':         'varchar(%(max_length)s)',
        'FilePathField':     'varchar(%(max_length)s)',
        'FloatField':        'double precision',
        'IntegerField':      'integer',
        'BigIntegerField':   'bigint',
        'IPAddressField':    'char(15)',
        'GenericIPAddressField': 'char(39)',
        'NullBooleanField':  'bool',
        'OneToOneField':     'integer',
        'PositiveIntegerField': 'integer UNSIGNED',
        'PositiveSmallIntegerField': 'smallint UNSIGNED',
        'SlugField':         'varchar(%(max_length)s)',
        'SmallIntegerField': 'smallint',
        'TextField':         'longtext',
        'TimeField':         'time',
    }

    def sql_table_creation_suffix(self):
        suffix = []
        suffix.append('CHARACTER SET UTF8')
        if self.connection.settings_dict['TEST_COLLATION']:
            suffix.append('COLLATE %s' % self.connection.settings_dict['TEST_COLLATION'])
        return ' '.join(suffix)

    def sql_for_inline_foreign_key_references(self, model, field, known_models, style):
        "All inline references are pending under MySQL"
        return [], True

    def sql_destroy_indexes_for_fields(self, model, fields, style):
        if len(fields) == 1 and fields[0].db_tablespace:
            tablespace_sql = self.connection.ops.tablespace_sql(fields[0].db_tablespace)
        elif model._meta.db_tablespace:
            tablespace_sql = self.connection.ops.tablespace_sql(model._meta.db_tablespace)
        else:
            tablespace_sql = ""
        if tablespace_sql:
            tablespace_sql = " " + tablespace_sql

        field_names = []
        qn = self.connection.ops.quote_name
        for f in fields:
            field_names.append(style.SQL_FIELD(qn(f.column)))

        index_name = "%s_%s" % (model._meta.db_table, self._digest([f.name for f in fields]))

        from django.db.backends.util import truncate_name

        return [
            style.SQL_KEYWORD("DROP INDEX") + " " +
            style.SQL_TABLE(qn(truncate_name(index_name, self.connection.ops.max_name_length()))) + " " +
            style.SQL_KEYWORD("ON") + " " +
            style.SQL_TABLE(qn(model._meta.db_table)) + ";",
        ]
