import os

import sys

from django.conf import settings

from django.db.backends.creation import BaseDatabaseCreation

class DatabaseCreation(BaseDatabaseCreation):

    # SQLite doesn't actually support most of these types, but it "does the right

    # thing" given more verbose field definitions, so leave them as is so that

    # schema inspection is more useful.

    data_types = {

        'AutoField':                    'integer',

        'BooleanField':                 'bool',

        'CharField':                    'varchar(%(max_length)s)',

        'CommaSeparatedIntegerField':   'varchar(%(max_length)s)',

        'DateField':                    'date',

        'DateTimeField':                'datetime',

        'DecimalField':                 'decimal',

        'FileField':                    'varchar(%(max_length)s)',

        'FilePathField':                'varchar(%(max_length)s)',

        'FloatField':                   'real',

        'IntegerField':                 'integer',

        'IPAddressField':               'char(15)',

        'NullBooleanField':             'bool',

        'OneToOneField':                'integer',

        'PositiveIntegerField':         'integer unsigned',

        'PositiveSmallIntegerField':    'smallint unsigned',

        'SlugField':                    'varchar(%(max_length)s)',

        'SmallIntegerField':            'smallint',

        'TextField':                    'text',

        'TimeField':                    'time',

    }

    def sql_for_pending_references(self, model, style, pending_references):

        "SQLite3 doesn't support constraints"

        return []

    def sql_remove_table_constraints(self, model, references_to_delete, style):

        "SQLite3 doesn't support constraints"

        return []

    def _create_test_db(self, verbosity, autoclobber):

        if settings.TEST_DATABASE_NAME and settings.TEST_DATABASE_NAME != ":memory:":

            test_database_name = settings.TEST_DATABASE_NAME

            # Erase the old test database

            if verbosity >= 1:

                print "Destroying old test database..."

            if os.access(test_database_name, os.F_OK):

                if not autoclobber:

                    confirm = raw_input("Type 'yes' if you would like to try deleting the test database '%s', or 'no' to cancel: " % test_database_name)

                if autoclobber or confirm == 'yes':

                  try:

                      if verbosity >= 1:

                          print "Destroying old test database..."

                      os.remove(test_database_name)

                  except Exception, e:

                      sys.stderr.write("Got an error deleting the old test database: %s\n" % e)

                      sys.exit(2)

                else:

                    print "Tests cancelled."

                    sys.exit(1)

            if verbosity >= 1:

                print "Creating test database..."

        else:

            test_database_name = ":memory:"

        return test_database_name

    def _destroy_test_db(self, test_database_name, verbosity):

        if test_database_name and test_database_name != ":memory:":

            # Remove the SQLite database file

            os.remove(test_database_name)