# 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.


import mango
import os
import unittest


class ExecutionStatsTests(mango.UserDocsTests):
    def test_simple_json_index(self):
        resp = self.db.find({"age": {"$lt": 35}}, return_raw=True, executionStats=True)
        self.assertEqual(len(resp["docs"]), 3)
        self.assertEqual(resp["execution_stats"]["total_keys_examined"], 3)
        self.assertEqual(resp["execution_stats"]["total_docs_examined"], 3)
        self.assertEqual(resp["execution_stats"]["total_quorum_docs_examined"], 0)
        self.assertEqual(resp["execution_stats"]["results_returned"], 3)
        # See https://github.com/apache/couchdb/issues/1732
        # Erlang os:timestamp() only has ms accuracy on Windows!
        if os.name != "nt":
            self.assertGreater(resp["execution_stats"]["execution_time_ms"], 0)

    def test_no_execution_stats(self):
        resp = self.db.find({"age": {"$lt": 35}}, return_raw=True, executionStats=False)
        assert "execution_stats" not in resp

    def test_quorum_json_index(self):
        resp = self.db.find(
            {"age": {"$lt": 35}}, return_raw=True, r=3, executionStats=True
        )
        self.assertEqual(len(resp["docs"]), 3)
        self.assertEqual(resp["execution_stats"]["total_keys_examined"], 3)
        self.assertEqual(resp["execution_stats"]["total_docs_examined"], 0)
        self.assertEqual(resp["execution_stats"]["total_quorum_docs_examined"], 3)
        self.assertEqual(resp["execution_stats"]["results_returned"], 3)
        # See https://github.com/apache/couchdb/issues/1732
        # Erlang os:timestamp() only has ms accuracy on Windows!
        if os.name != "nt":
            self.assertGreater(resp["execution_stats"]["execution_time_ms"], 0)

    def test_results_returned_limit(self):
        resp = self.db.find(
            {"age": {"$lt": 35}}, limit=2, return_raw=True, executionStats=True
        )
        self.assertEqual(resp["execution_stats"]["results_returned"], len(resp["docs"]))

    def test_no_matches_index_scan(self):
        resp = self.db.find(
            {"age": {"$lt": 35}, "nomatch": "me"}, return_raw=True, executionStats=True
        )
        self.assertEqual(resp["execution_stats"]["total_docs_examined"], 3)
        self.assertEqual(resp["execution_stats"]["results_returned"], 0)

    def test_covering_json_index(self):
        resp = self.db.find(
            {"age": {"$lt": 35}},
            fields=["_id", "age"],
            return_raw=True,
            executionStats=True,
        )
        self.assertEqual(len(resp["docs"]), 3)
        self.assertEqual(resp["execution_stats"]["total_keys_examined"], 3)
        self.assertEqual(resp["execution_stats"]["total_docs_examined"], 0)
        self.assertEqual(resp["execution_stats"]["total_quorum_docs_examined"], 0)
        self.assertEqual(resp["execution_stats"]["results_returned"], 3)

    def test_reporting_consistency(self):
        cases = [
            {
                "title": "with limit",
                "selector": {"age": {"$lte": 42}},
                "fields": ["name", "email", "age"],
                "limit": 3,
                "total_keys_examined": 4,
                "total_docs_examined": 4,
                "results_returned": 3,
            },
            {
                "title": "partial matches",
                "selector": {"favorites": {"$elemMatch": {"$eq": "Erlang"}}},
                "fields": ["name", "email", "twitter"],
                "limit": 200,
                "total_keys_examined": 15,
                "total_docs_examined": 15,
                "results_returned": 6,
            },
            {
                "title": "no matches, using _all_docs",
                "selector": {"foo": "bar"},
                "fields": [],
                "limit": 200,
                "total_keys_examined": 25,
                "total_docs_examined": 25,
                "results_returned": 0,
            },
            {
                "title": "no matches, indexed column (no keys examined)",
                "selector": {"name.first": "Lee", "name.last": "Jackson"},
                "fields": ["email", "twitter"],
                "limit": 200,
                "total_keys_examined": 0,
                "total_docs_examined": 0,
                "results_returned": 0,
            },
            {
                "title": "no matches, indexed column",
                "selector": {"favorites": {"$elemMatch": {"$eq": "Haskell"}}},
                "fields": ["name", "email", "twitter"],
                "limit": 200,
                "total_keys_examined": 15,
                "total_docs_examined": 15,
                "results_returned": 0,
            },
        ]

        for case in cases:
            with self.subTest(scenario=case["title"]):
                resp = self.db.find(
                    case["selector"],
                    fields=case["fields"],
                    limit=case["limit"],
                    return_raw=True,
                    executionStats=True,
                )
                executionStats = resp["execution_stats"]
                self.assertEqual(
                    executionStats["total_keys_examined"], case["total_keys_examined"]
                )
                self.assertEqual(
                    executionStats["total_docs_examined"], case["total_docs_examined"]
                )
                self.assertEqual(
                    executionStats["results_returned"], case["results_returned"]
                )


@unittest.skipUnless(mango.has_text_service(), "requires text service")
class ExecutionStatsTests_Text(mango.UserDocsTextTests):
    def test_simple_text_index(self):
        resp = self.db.find(
            {"$text": "Stephanie"}, return_raw=True, executionStats=True
        )
        self.assertEqual(len(resp["docs"]), 1)
        self.assertEqual(resp["execution_stats"]["total_keys_examined"], 1)
        self.assertEqual(resp["execution_stats"]["total_docs_examined"], 1)
        self.assertEqual(resp["execution_stats"]["total_quorum_docs_examined"], 0)
        self.assertEqual(resp["execution_stats"]["results_returned"], 1)
        self.assertGreater(resp["execution_stats"]["execution_time_ms"], 0)

    def test_no_execution_stats(self):
        resp = self.db.find({"$text": "Stephanie"}, return_raw=True)
        self.assertNotIn("execution_stats", resp)
