"""
This file contains multiple primitive tests for avoiding performance regressions.

- Time bound tests: Benchmarks are done on GHA before adding numbers
- Query count tests: More than expected # of queries for any action is frequent source of
  performance issues. This guards against such problems.


E.g. We know get_controller is supposed to be cached and hence shouldn't make query post first
query. This test can be written like this.

>>> def test_controller_caching(self):
>>>
>>> 	get_controller("User")  # <- "warm up code"
>>> 	with self.assertQueryCount(0):
>>> 		get_controller("User")

"""
import gc
import sys
import time
from unittest.mock import patch

from tenacity import retry, retry_if_exception_type, stop_after_attempt, wait_fixed

import frappe
from frappe.frappeclient import FrappeClient
from frappe.model.base_document import get_controller
from frappe.query_builder.utils import db_type_is
from frappe.tests.test_query_builder import run_only_if
from frappe.tests.utils import FrappeTestCase
from frappe.utils import cint
from frappe.website.path_resolver import PathResolver

TEST_USER = "test@example.com"


@run_only_if(db_type_is.MARIADB)
class TestPerformance(FrappeTestCase):
	def reset_request_specific_caches(self):
		# To simulate close to request level of handling
		frappe.destroy()  # releases everything on frappe.local
		frappe.init(site=self.TEST_SITE)
		frappe.connect()
		frappe.clear_cache()

	def setUp(self) -> None:
		self.HOST = frappe.utils.get_site_url(frappe.local.site)

		self.reset_request_specific_caches()

	def test_meta_caching(self):
		frappe.clear_cache()
		frappe.get_meta("User")
		frappe.clear_cache(doctype="ToDo")

		with self.assertQueryCount(0):
			frappe.get_meta("User")

	def test_permitted_fieldnames(self):
		frappe.clear_cache()

		doc = frappe.new_doc("Prepared Report")
		# load permitted fieldnames once
		doc.permitted_fieldnames

		with patch("frappe.model.base_document.get_permitted_fields") as mocked:
			doc.as_dict()
			# get_permitted_fields should not be called again
			mocked.assert_not_called()

	def test_set_value_query_count(self):
		frappe.db.set_value("User", "Administrator", "interest", "Nothing")

		with self.assertQueryCount(1):
			frappe.db.set_value("User", "Administrator", "interest", "Nothing")

		with self.assertQueryCount(1):
			frappe.db.set_value("User", {"user_type": "System User"}, "interest", "Nothing")

		with self.assertQueryCount(1):
			frappe.db.set_value(
				"User", {"user_type": "System User"}, {"interest": "Nothing", "bio": "boring person"}
			)

	def test_controller_caching(self):
		get_controller("User")
		with self.assertQueryCount(0):
			get_controller("User")

	def test_get_value_limits(self):
		# check both dict and list style filters
		filters = [{"enabled": 1}, [["enabled", "=", 1]]]

		# Warm up code
		frappe.db.get_values("User", filters=filters[0], limit=1)
		for filter in filters:
			with self.assertRowsRead(1):
				self.assertEqual(1, len(frappe.db.get_values("User", filters=filter, limit=1)))
			with self.assertRowsRead(2):
				self.assertEqual(2, len(frappe.db.get_values("User", filters=filter, limit=2)))

			self.assertEqual(
				len(frappe.db.get_values("User", filters=filter)), frappe.db.count("User", filter)
			)

			with self.assertRowsRead(1):
				frappe.db.get_value("User", filters=filter)

			with self.assertRowsRead(1):
				frappe.db.exists("User", filter)

	def test_db_value_cache(self):
		"""Link validation if repeated should just use db.value_cache, hence no extra queries"""
		doc = frappe.get_last_doc("User")
		doc.get_invalid_links()

		with self.assertQueryCount(0):
			doc.get_invalid_links()

	@retry(
		retry=retry_if_exception_type(AssertionError),
		stop=stop_after_attempt(3),
		wait=wait_fixed(0.5),
		reraise=True,
	)
	def test_req_per_seconds_basic(self):
		"""Ideally should be ran against gunicorn worker, though I have not seen any difference
		when using werkzeug's run_simple for synchronous requests."""

		EXPECTED_RPS = 50  # measured on GHA
		FAILURE_THREASHOLD = 0.1

		req_count = 1000
		client = FrappeClient(self.HOST, "Administrator", self.ADMIN_PASSWORD)

		start = time.perf_counter()
		for _ in range(req_count):
			client.get_list("ToDo", limit_page_length=1)
		end = time.perf_counter()

		rps = req_count / (end - start)

		print(f"Completed {req_count} in {end - start} @ {rps} requests per seconds")
		self.assertGreaterEqual(
			rps,
			EXPECTED_RPS * (1 - FAILURE_THREASHOLD),
			"Possible performance regression in basic /api/Resource list  requests",
		)

	def test_homepage_resolver(self):
		paths = ["/", "/app"]
		for path in paths:
			PathResolver(path).resolve()
			with self.assertQueryCount(1):
				PathResolver(path).resolve()

	def test_consistent_build_version(self):
		from frappe.utils import get_build_version

		self.assertEqual(get_build_version(), get_build_version())

	def test_get_list_single_query(self):
		"""get_list should only perform single query."""

		user = frappe.get_doc("User", TEST_USER)

		frappe.set_user(TEST_USER)
		# Give full read access, no share/user perm check should be done.
		user.add_roles("System Manager")

		frappe.get_list("User")
		with self.assertQueryCount(1):
			frappe.get_list("User")

	def test_no_ifnull_checks(self):
		query = frappe.get_all("DocType", {"autoname": ("is", "set")}, run=0).lower()
		self.assertNotIn("coalesce", query)
		self.assertNotIn("ifnull", query)

	def test_no_stale_ref_sql(self):
		"""frappe.db.sql should not hold any internal references to result set.

		pymysql stores results internally. If your code reads a lot and doesn't make another
		query, for that entire duration there's copy of result consuming memory in internal
		attributes of pymysql.
		We clear it manually, this test ensures that it actually works.
		"""

		query = "select * from tabUser"
		for kwargs in ({}, {"as_dict": True}, {"as_list": True}):
			result = frappe.db.sql(query, **kwargs)
			self.assertEqual(sys.getrefcount(result), 2)  # Note: This always returns +1
			self.assertFalse(gc.get_referrers(result))

	def test_no_cyclic_references(self):
		doc = frappe.get_doc("User", "Administrator")
		self.assertEqual(sys.getrefcount(doc), 2)  # Note: This always returns +1