# Copyright 2018-present MongoDB, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations

import copy
import itertools
import unittest
from typing import Any

from mockupdb import CommandBase, MockupDB, going
from operations import operations  # type: ignore[import]

from pymongo import MongoClient, ReadPreference
from pymongo.read_preferences import (
    _MONGOS_MODES,
    make_read_preference,
    read_pref_mode_from_name,
)


class OpMsgReadPrefBase(unittest.TestCase):
    single_mongod = False
    primary: MockupDB
    secondary: MockupDB

    @classmethod
    def setUpClass(cls):
        super().setUpClass()

    @classmethod
    def add_test(cls, mode, test_name, test):
        setattr(cls, test_name, test)

    def setup_client(self, read_preference):
        client = MongoClient(self.primary.uri, read_preference=read_preference)
        self.addCleanup(client.close)
        return client


class TestOpMsgMongos(OpMsgReadPrefBase):
    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        auto_ismaster = {
            "ismaster": True,
            "msg": "isdbgrid",  # Mongos.
            "minWireVersion": 2,
            "maxWireVersion": 6,
        }
        cls.primary = MockupDB(auto_ismaster=auto_ismaster)
        cls.primary.run()
        cls.secondary = cls.primary

    @classmethod
    def tearDownClass(cls):
        cls.primary.stop()
        super().tearDownClass()


class TestOpMsgReplicaSet(OpMsgReadPrefBase):
    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        cls.primary, cls.secondary = MockupDB(), MockupDB()
        for server in cls.primary, cls.secondary:
            server.run()

        hosts = [server.address_string for server in (cls.primary, cls.secondary)]

        primary_ismaster = {
            "ismaster": True,
            "setName": "rs",
            "hosts": hosts,
            "minWireVersion": 2,
            "maxWireVersion": 6,
        }
        cls.primary.autoresponds(CommandBase("ismaster"), primary_ismaster)
        secondary_ismaster = copy.copy(primary_ismaster)
        secondary_ismaster["ismaster"] = False
        secondary_ismaster["secondary"] = True
        cls.secondary.autoresponds(CommandBase("ismaster"), secondary_ismaster)

    @classmethod
    def tearDownClass(cls):
        for server in cls.primary, cls.secondary:
            server.stop()
        super().tearDownClass()

    @classmethod
    def add_test(cls, mode, test_name, test):
        # Skip nearest tests since we don't know if we will select the primary
        # or secondary.
        if mode != "nearest":
            setattr(cls, test_name, test)

    def setup_client(self, read_preference):
        client = MongoClient(self.primary.uri, replicaSet="rs", read_preference=read_preference)

        # Run a command on a secondary to discover the topology. This ensures
        # that secondaryPreferred commands will select the secondary.
        client.admin.command("ismaster", read_preference=ReadPreference.SECONDARY)
        self.addCleanup(client.close)
        return client


class TestOpMsgSingle(OpMsgReadPrefBase):
    single_mongod = True

    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        auto_ismaster = {
            "ismaster": True,
            "minWireVersion": 2,
            "maxWireVersion": 6,
        }
        cls.primary = MockupDB(auto_ismaster=auto_ismaster)
        cls.primary.run()
        cls.secondary = cls.primary

    @classmethod
    def tearDownClass(cls):
        cls.primary.stop()
        super().tearDownClass()


def create_op_msg_read_mode_test(mode, operation):
    def test(self):
        pref = make_read_preference(read_pref_mode_from_name(mode), tag_sets=None)

        client = self.setup_client(read_preference=pref)
        expected_pref: Any
        if operation.op_type == "always-use-secondary":
            expected_server = self.secondary
            expected_pref = ReadPreference.SECONDARY
        elif operation.op_type == "must-use-primary":
            expected_server = self.primary
            expected_pref = None
        elif operation.op_type == "may-use-secondary":
            if mode == "primary":
                expected_server = self.primary
                expected_pref = None
            elif mode == "primaryPreferred":
                expected_server = self.primary
                expected_pref = pref
            else:
                expected_server = self.secondary
                expected_pref = pref
        else:
            self.fail("unrecognized op_type %r" % operation.op_type)
        # For single mongod we omit the read preference.
        if self.single_mongod:
            expected_pref = None
        with going(operation.function, client):
            request = expected_server.receive()
            request.reply(operation.reply)

        actual_pref = request.doc.get("$readPreference")
        if expected_pref:
            self.assertEqual(expected_pref.document, actual_pref)
        else:
            self.assertIsNone(actual_pref)
        self.assertNotIn("$query", request.doc)

    return test


def generate_op_msg_read_mode_tests():
    matrix = itertools.product(_MONGOS_MODES, operations)

    for entry in matrix:
        mode, operation = entry
        test = create_op_msg_read_mode_test(mode, operation)
        test_name = "test_{}_with_mode_{}".format(operation.name.replace(" ", "_"), mode)
        test.__name__ = test_name
        for cls in TestOpMsgMongos, TestOpMsgReplicaSet, TestOpMsgSingle:
            cls.add_test(mode, test_name, test)


generate_op_msg_read_mode_tests()


if __name__ == "__main__":
    unittest.main()
