# Copyright 2012-2014 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.

"""Test Motor by testing that Synchro, a fake PyMongo implementation built on
top of Motor, passes the same unittests as PyMongo.

This program monkey-patches sys.modules, so run it alone, rather than as part
of a larger test suite.
"""

import fnmatch
import importlib
import importlib.abc
import importlib.machinery
import os
import re
import shutil
import sys
from pathlib import Path

import pytest

import synchro

excluded_modules = [
    # Exclude some PyMongo tests that can't be applied to Synchro.
    "test.test_examples",
    "test.test_threads",
    "test.test_pooling",
    "test.test_saslprep",
    # Complex PyMongo-specific mocking.
    "test.test_replica_set_reconfig",
    # Accesses PyMongo internals.
    "test.test_retryable_writes",
    # Accesses PyMongo internals. Tested directly in Motor.
    "test.test_session",
    # Deprecated in PyMongo, removed in Motor 2.0.
    "test.test_gridfs",
    # Skip mypy/typing tests.
    "test.test_typing",
    # Relies of specifics of __all__
    "test.test_default_exports",
    # Motor does not support CSOT.
    "test.test_csot",
]


# Patterns consist of the TestClass.test_method
# You can use * for any portion of the class or method pattern
excluded_tests = [
    # Motor's reprs aren't the same as PyMongo's.
    "*.test_repr",
    "TestClient.test_unix_socket",
    # Motor extends the handshake metadata.
    "ClientUnitTest.test_metadata",
    # Lazy-connection tests require multithreading; we test concurrent
    # lazy connection directly.
    "TestClientLazyConnect.*",
    # Motor doesn't support forking or threading.
    "*.test_interrupt_signal",
    "TestSCRAM.test_scram_threaded",
    "TestGSSAPI.test_gssapi_threaded",
    "*.test_concurrent_close",
    "TestUnifiedInterruptInUsePoolClear.*",
    # These are in test_gridfs_bucket.
    "TestGridfs.test_threaded_reads",
    "TestGridfs.test_threaded_writes",
    # Can't do MotorCollection(name, create=True), Motor constructors do no I/O.
    "TestCollection.test_create",
    # Requires indexing / slicing cursors, which Motor doesn't do, see MOTOR-84.
    "TestCollection.test_min_query",
    "TestCursor.test_clone",
    "TestCursor.test_clone_empty",
    "TestCursor.test_getitem_numeric_index",
    "TestCursor.test_getitem_slice_index",
    "TestCursor.test_tailable",
    "TestRawBatchCursor.test_get_item",
    "TestRawBatchCommandCursor.test_get_item",
    # No context-manager protocol for MotorCursor.
    "TestCursor.test_with_statement",
    # Motor's cursors initialize lazily.
    "TestRawBatchCommandCursor.test_monitoring",
    # Can't iterate a GridOut in Motor.
    "TestGridFile.test_iterator",
    "TestGridfs.test_missing_length_iter",
    # No context-manager protocol for MotorGridIn, and can't set attrs.
    "TestGridFile.test_context_manager",
    "TestGridFile.test_grid_in_default_opts",
    "TestGridFile.test_set_after_close",
    # GridOut always connects lazily in Motor.
    "TestGridFile.test_grid_out_lazy_connect",
    "TestGridfs.test_gridfs_lazy_connect",  # In test_gridfs_bucket.
    # Complex PyMongo-specific mocking.
    "*.test_wire_version",
    "TestClient.test_heartbeat_frequency_ms",
    "TestExhaustCursor.*",
    "TestHeartbeatMonitoring.*",
    "TestMongoClientFailover.*",
    "TestMongosLoadBalancing.*",
    "TestSSL.test_system_certs_config_error",
    "TestCMAP.test_cmap_wait_queue_timeout_must_aggressively_timeout_threads_enqueued_longer_than_waitQueueTimeoutMS",
    # Accesses PyMongo internals.
    "TestClient.test_close_kills_cursors",
    "TestClient.test_stale_getmore",
    "TestClient.test_direct_connection",
    "TestCollection.test_aggregation_cursor",
    "TestCommandAndReadPreference.*",
    "TestCommandMonitoring.test_get_more_failure",
    "TestCommandMonitoring.test_sensitive_commands",
    "TestCursor.test_allow_disk_use",
    "TestCursor.test_close_kills_cursor_synchronously",
    "TestCursor.test_delete_not_initialized",
    "TestGridFile.test_grid_out_cursor_options",
    "TestGridFile.test_survive_cursor_not_found",
    "TestMaxStaleness.test_last_write_date",
    "TestSelections.test_bool",
    "TestCollation.*",
    "TestCollection.test_find_one_and_write_concern",
    "TestCollection.test_write_error_text_handling",
    "TestBinary.test_uuid_queries",
    "TestCursor.test_comment",
    "TestCursor.test_where",
    "TestGridfs.test_gridfs_find",
    # Uses patching on grid_file._UPLOAD_BUFFER_SIZE which fails in synchro.
    "TestGridfs.test_abort",
    "TestGridfs.test_upload_batching",
    "TestGridfs.test_upload_bulk_write_error",
    "TestKmsTLSOptions.test_05_tlsDisableOCSPEndpointCheck_is_permitted",
    # Tests that use "authenticate" or "logoout", removed in Motor 2.0.
    "TestSASLPlain.test_sasl_plain_bad_credentials",
    "TestSCRAM.test_scram",
    "TestSCRAMSHA1.test_scram_sha1",
    # Uses "collection_names", deprecated in PyMongo, removed in Motor 2.0.
    "TestSingleSecondaryOk.test_reads_from_secondary",
    # Slow.
    "TestDatabase.test_list_collection_names",
    # MOTOR-425 these tests fail with duplicate key errors.
    "TestClusterChangeStreamsWCustomTypes.*",
    "TestCollectionChangeStreamsWCustomTypes.*",
    "TestDatabaseChangeStreamsWCustomTypes.*",
    # Tests that use warnings.catch_warnings which don't show up in Motor.
    "TestCursor.test_min_max_without_hint",
    # TODO: MOTOR-606
    "TestTransactionsConvenientAPI.*",
    "TestTransactions.test_create_collection",
    # Motor's change streams need Python 3.5 to support async iteration but
    # these change streams tests spawn threads which don't work without an
    # IO loop.
    "*.test_next_blocks",
    "*.test_aggregate_cursor_blocks",
    # Can't run these tests because they use threads.
    "*.test_ignore_stale_connection_errors",
    "*.test_pool_paused_error_is_retryable",
    # Needs synchro.GridFS class, see MOTOR-609.
    "TestTransactions.test_gridfs_does_not_support_transactions",
    # PYTHON-3228 _tmp_session should validate session input
    "*.test_helpers_with_let",
    # Relies on comment being in the method signatures, which would force use
    # to rewrite much of AgnosticCollection.
    "*.test_collection_helpers",
    "*.test_database_helpers",
    "*.test_client_helpers",
    # This test is too slow given all of the wrapping logic.
    "*.test_transaction_starts_with_batched_write",
    # This test is too flaky given all the wrapping logic.
    "TestProse.test_load_balancing",
    # This feature is going away in PyMongo 5
    "*.test_iteration",
    # MD5 is deprecated
    "*.test_md5",
    # Causes a deadlock.
    "TestFork.*",
    # Also causes a deadlock.
    "TestClientSimple.test_fork",
    # This method requires credentials.
    "TestOnDemandAWSCredentials.test_02_success",
    # These methods are picked up by nose despite not being a unittest.
    "TestRewrapWithSeparateClientEncryption.run_test",
    "TestCustomEndpoint.run_test_expected_success",
    "TestDataKeyDoubleEncryption.run_test",
    # These tests are failing right now.
    "TestUnifiedFindShutdownError.test_Concurrent_shutdown_error_on_find",
    "TestUnifiedInsertShutdownError.test_Concurrent_shutdown_error_on_insert",
    "TestUnifiedPoolClearedError.test_PoolClearedError_does_not_mark_server_unknown",
    # These tests have hard-coded values that differ from motor.
    "TestClient.test_handshake*",
    # This test is not a valid unittest target.
    "TestRangeQueryProse.run_test_cases",
]


excluded_modules_matched = set()
excluded_tests_matched = set()

# Validate the exclude lists.
for item in excluded_modules:
    if not re.match(r"^test\.[a-zA-Z_]+$", item):
        raise ValueError(f"Improper excluded module {item}")
for item in excluded_tests:
    cls_pattern, _, mod_pattern = item.partition(".")
    if cls_pattern != "*" and not re.match(r"^[a-zA-Z\d]+$", cls_pattern):
        raise ValueError(f"Ill-formatted excluded test: {item}")
    if mod_pattern != "*" and not re.match(r"^[a-zA-Z\d_\*]+$", mod_pattern):
        raise ValueError(f"Ill-formatted excluded test: {item}")


class SynchroModuleFinder(importlib.abc.MetaPathFinder):
    def __init__(self):
        self._loader = SynchroModuleLoader()

    def find_spec(self, fullname, path, target=None):
        if self._loader.patch_spec(fullname):
            return importlib.machinery.ModuleSpec(fullname, self._loader)

        # Let regular module search continue.
        return None


class SynchroModuleLoader(importlib.abc.Loader):
    def patch_spec(self, fullname):
        parts = fullname.split(".")
        if parts[-1] in ("gridfs", "pymongo"):
            # E.g. "import pymongo"
            return True
        elif len(parts) >= 2 and parts[-2] in ("gridfs", "pymongo"):
            # E.g. "import pymongo.mongo_client"
            return True

        return False

    def exec_module(self, module):
        pass

    def create_module(self, spec):
        if self.patch_spec(spec.name):
            return synchro

        # Let regular module search continue.
        return None


class SynchroPytestPlugin:
    def pytest_collection_modifyitems(self, session, config, items):
        for item in items[:]:
            if not want_module(item.module):
                item.addSkip("", reason="Synchro excluded module")
                continue
            fn = item.function
            if item.parent == item.module:
                if not want_function(fn):
                    item.addSkip("", reason="Synchro excluded function")
            elif not want_method(fn, item.parent.name):
                item.addSkip("", reason="Synchro excluded method")


def want_module(module):
    # Depending on PYTHONPATH, Motor's direct tests may be imported - don't
    # run them now.
    if module.__name__.startswith("test.test_motor_"):
        return False

    for module_name in excluded_modules:
        if module_name.endswith("*"):
            if module.__name__.startswith(module_name.rstrip("*")):
                # E.g., test_motor_cursor matches "test_motor_*".
                excluded_modules_matched.add(module_name)
                return False

        elif module.__name__ == module_name:
            excluded_modules_matched.add(module_name)
            return False

    return True


def want_function(fn):
    # PyMongo's test generators run at import time; tell pytest not to run
    # them as unittests.
    if fn.__name__ in ("test_cases",):
        return False
    return True


def want_method(method, classname):
    for excluded_name in excluded_tests:
        # Should we exclude this method's whole TestCase?
        cls_pattern, _, method_pattern = excluded_name.partition(".")
        suite_matches = fnmatch.fnmatch(classname, cls_pattern)

        # Should we exclude this particular method?
        method_matches = method.__name__ == method_pattern or fnmatch.fnmatch(
            method.__name__, method_pattern
        )
        if suite_matches and method_matches:
            excluded_tests_matched.add(excluded_name)
            return False

    return True


if __name__ == "__main__":
    # Monkey-patch all pymongo's unittests so they think Synchro is the
    # real PyMongo.
    sys.meta_path[0:0] = [SynchroModuleFinder()]
    # Delete the cached pymongo/gridfs modules so that SynchroModuleFinder will
    # be invoked in Python 3, see
    # https://docs.python.org/3/reference/import.html#import-hooks
    for n in [
        "pymongo",
        "pymongo.collection",
        "pymongo.client_session",
        "pymongo.command_cursor",
        "pymongo.change_stream",
        "pymongo.cursor",
        "pymongo.encryption",
        "pymongo.encryption_options",
        "pymongo.mongo_client",
        "pymongo.database",
        "pymongo.srv_resolver",
        "gridfs",
        "gridfs.grid_file",
    ]:
        sys.modules.pop(n)

    # Prep the xUnit report dir.
    root = Path(__file__).absolute().parent.parent
    xunit_dir = root / "xunit-results"
    if xunit_dir.exists():
        shutil.rmtree(xunit_dir)

    # Run the tests from the pymongo target dir with our custom plugin.
    os.chdir(sys.argv[1])
    code = pytest.main(sys.argv[2:] + ["-p", "no:warnings"], plugins=[SynchroPytestPlugin()])

    if code != 0:
        sys.exit(code)

    # Copy over the xUnit report.
    xunit_dir.mkdir()
    target = Path(sys.argv[1]) / "xunit-results"
    shutil.copy(target / "TEST-results.xml", xunit_dir / "TEST-results.xml")

    if os.environ.get("CHECK_EXCLUDE_PATTERNS"):
        unused_module_pats = set(excluded_modules) - excluded_modules_matched
        assert not unused_module_pats, "Unused module patterns: {unused_module_pats}"

        unused_test_pats = set(excluded_tests) - excluded_tests_matched
        assert not unused_test_pats, f"Unused test patterns: {unused_test_pats}"
