# -*- coding: utf-8 -*-
# copyright 2016-2021 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr -- mailto:contact@logilab.fr
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.

"""Register the new type."""

from logilab.database import get_db_helper, FunctionDescr
from logilab.database.sqlgen import SQLExpression
from rql.utils import register_function
from yams import register_base_type


#
# EncryptedString type
#

# this key should be stored in the all-in-one.conf (or elsewhere), obviously…
PWD = "toto"


def convert_encryptedstring(x):
    if isinstance(x, SQLExpression):
        return x
    elif isinstance(x, str):
        return SQLExpression("pgp_sym_encrypt(%(x)s, %(key)s)", x=x, key=PWD)
    return SQLExpression("pgp_sym_encrypt(%(x)s, %(key)s)", x=x, key=PWD)


# Register the new type
register_base_type("EncryptedString")

# Map the new type with PostgreSQL
pghelper = get_db_helper("postgres")
pghelper.TYPE_MAPPING["EncryptedString"] = "text"
pghelper.TYPE_CONVERTERS["EncryptedString"] = convert_encryptedstring

# Map the new type with SQLite3
sqlitehelper = get_db_helper("sqlite")
sqlitehelper.TYPE_MAPPING["EncryptedString"] = "text"
sqlitehelper.TYPE_CONVERTERS["EncryptedString"] = lambda x: x


class DECRYPTED(FunctionDescr):
    minargs = 1
    maxargs = 1
    supported_backends = ("postgres", "sqlite")
    rtype = "text"

    def as_sql_postgres(self, args):
        field = args[0]
        return f"pgp_sym_decrypt({field}::bytea, '{PWD}')"

    def as_sql_sqlite(self, args):
        field = args[0]
        return field


register_function(DECRYPTED)