from ..helpers.classes import ConnectionConfigurationMixin
from .base import SQLAdapter
from . import adapters, with_connection_or_raise


@adapters.register_for('informix')
class Informix(ConnectionConfigurationMixin, SQLAdapter):
    dbengine = 'informix'
    drivers = ('informixdb',)

    def _initialize_(self, do_connect):
        super(Informix, self)._initialize_(do_connect)
        ruri = self.uri.split('://', 1)[1]
        m = self.REGEX_URI.match(ruri)
        if not m:
            raise SyntaxError("Invalid URI string in DAL")
        user = self.credential_decoder(m.group('user'))
        if not user:
            raise SyntaxError('User required')
        password = self.credential_decoder(m.group('password'))
        if not password:
            password = ''
        host = m.group('host')
        if not host:
            raise SyntaxError('Host name required')
        db = m.group('db')
        if not db:
            raise SyntaxError('Database name required')
        self.dsn = '%s@%s' % (db, host)
        self.driver_args.update(user=user, password=password)
        self._mock_reconnect()

    def connector(self):
        return self.driver.connect(self.dsn, **self.driver_args)

    def _configure_on_first_reconnect(self):
        self.dbms_version = int(self.connection.dbms_version.split('.')[0])

    @with_connection_or_raise
    def execute(self, *args, **kwargs):
        command = self.filter_sql_command(args[0])
        if command[-1:] == ';':
            command = command[:-1]
        handlers = self._build_handlers_for_execution()
        for handler in handlers:
            handler.before_execute(command)
        rv = self.cursor.execute(command, *args[1:], **kwargs)
        for handler in handlers:
            handler.after_execute(command)
        return rv

    def test_connection(self):
        self.execute('SELECT COUNT(*) FROM systables;')

    def lastrowid(self, table):
        return self.cursor.sqlerrd[1]


@adapters.register_for('informix-se')
class InformixSE(Informix):
    def rowslice(self, rows, minimum=0, maximum=None):
        if maximum is None:
            return rows[minimum:]
        return rows[minimum:maximum]