# firebird/kinterbasdb.py
# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

"""
.. dialect:: firebird+kinterbasdb
    :name: kinterbasdb
    :dbapi: kinterbasdb
    :connectstring: firebird+kinterbasdb://user:password@host:port/path/to/db[?key=value&key=value...]
    :url: http://firebirdsql.org/index.php?op=devel&sub=python

Arguments
----------

The Kinterbasdb backend accepts the ``enable_rowcount`` and ``retaining``
arguments accepted by the :mod:`sqlalchemy.dialects.firebird.fdb` dialect.
In addition, it also accepts the following:

* ``type_conv`` - select the kind of mapping done on the types: by default
  SQLAlchemy uses 200 with Unicode, datetime and decimal support.  See
  the linked documents below for further information.

* ``concurrency_level`` - set the backend policy with regards to threading
  issues: by default SQLAlchemy uses policy 1.  See the linked documents
  below for further information.

.. seealso::

    http://sourceforge.net/projects/kinterbasdb

    http://kinterbasdb.sourceforge.net/dist_docs/usage.html#adv_param_conv_dynamic_type_translation

    http://kinterbasdb.sourceforge.net/dist_docs/usage.html#special_issue_concurrency

"""  # noqa

import decimal
from re import match

from .base import FBDialect
from .base import FBExecutionContext
from ... import types as sqltypes
from ... import util


class _kinterbasdb_numeric(object):
    def bind_processor(self, dialect):
        def process(value):
            if isinstance(value, decimal.Decimal):
                return str(value)
            else:
                return value

        return process


class _FBNumeric_kinterbasdb(_kinterbasdb_numeric, sqltypes.Numeric):
    pass


class _FBFloat_kinterbasdb(_kinterbasdb_numeric, sqltypes.Float):
    pass


class FBExecutionContext_kinterbasdb(FBExecutionContext):
    @property
    def rowcount(self):
        if self.execution_options.get(
            "enable_rowcount", self.dialect.enable_rowcount
        ):
            return self.cursor.rowcount
        else:
            return -1


class FBDialect_kinterbasdb(FBDialect):
    driver = "kinterbasdb"
    supports_sane_rowcount = False
    supports_sane_multi_rowcount = False
    execution_ctx_cls = FBExecutionContext_kinterbasdb

    supports_native_decimal = True

    colspecs = util.update_copy(
        FBDialect.colspecs,
        {
            sqltypes.Numeric: _FBNumeric_kinterbasdb,
            sqltypes.Float: _FBFloat_kinterbasdb,
        },
    )

    def __init__(
        self,
        type_conv=200,
        concurrency_level=1,
        enable_rowcount=True,
        retaining=False,
        **kwargs
    ):
        super(FBDialect_kinterbasdb, self).__init__(**kwargs)
        self.enable_rowcount = enable_rowcount
        self.type_conv = type_conv
        self.concurrency_level = concurrency_level
        self.retaining = retaining
        if enable_rowcount:
            self.supports_sane_rowcount = True

    @classmethod
    def dbapi(cls):
        return __import__("kinterbasdb")

    def do_execute(self, cursor, statement, parameters, context=None):
        # kinterbase does not accept a None, but wants an empty list
        # when there are no arguments.
        cursor.execute(statement, parameters or [])

    def do_rollback(self, dbapi_connection):
        dbapi_connection.rollback(self.retaining)

    def do_commit(self, dbapi_connection):
        dbapi_connection.commit(self.retaining)

    def create_connect_args(self, url):
        opts = url.translate_connect_args(username="user")
        if opts.get("port"):
            opts["host"] = "%s/%s" % (opts["host"], opts["port"])
            del opts["port"]
        opts.update(url.query)

        util.coerce_kw_type(opts, "type_conv", int)

        type_conv = opts.pop("type_conv", self.type_conv)
        concurrency_level = opts.pop(
            "concurrency_level", self.concurrency_level
        )

        if self.dbapi is not None:
            initialized = getattr(self.dbapi, "initialized", None)
            if initialized is None:
                # CVS rev 1.96 changed the name of the attribute:
                # http://kinterbasdb.cvs.sourceforge.net/viewvc/kinterbasdb/
                # Kinterbasdb-3.0/__init__.py?r1=1.95&r2=1.96
                initialized = getattr(self.dbapi, "_initialized", False)
            if not initialized:
                self.dbapi.init(
                    type_conv=type_conv, concurrency_level=concurrency_level
                )
        return ([], opts)

    def _get_server_version_info(self, connection):
        """Get the version of the Firebird server used by a connection.

        Returns a tuple of (`major`, `minor`, `build`), three integers
        representing the version of the attached server.
        """

        # This is the simpler approach (the other uses the services api),
        # that for backward compatibility reasons returns a string like
        #   LI-V6.3.3.12981 Firebird 2.0
        # where the first version is a fake one resembling the old
        # Interbase signature.

        fbconn = connection.connection
        version = fbconn.server_version

        return self._parse_version_info(version)

    def _parse_version_info(self, version):
        m = match(
            r"\w+-V(\d+)\.(\d+)\.(\d+)\.(\d+)( \w+ (\d+)\.(\d+))?", version
        )
        if not m:
            raise AssertionError(
                "Could not determine version from string '%s'" % version
            )

        if m.group(5) != None:
            return tuple([int(x) for x in m.group(6, 7, 4)] + ["firebird"])
        else:
            return tuple([int(x) for x in m.group(1, 2, 3)] + ["interbase"])

    def is_disconnect(self, e, connection, cursor):
        if isinstance(
            e, (self.dbapi.OperationalError, self.dbapi.ProgrammingError)
        ):
            msg = str(e)
            return (
                "Error writing data to the connection" in msg
                or "Unable to complete network request to host" in msg
                or "Invalid connection state" in msg
                or "Invalid cursor state" in msg
                or "connection shutdown" in msg
            )
        else:
            return False


dialect = FBDialect_kinterbasdb