# Copyright 2022 The JAX Authors.
#
# 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
#
#     https://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 contextlib
import datetime
import unittest
from unittest import mock
import re

from absl.testing import absltest

import jax
from jax._src.lib import check_jaxlib_version
from jax._src import test_util as jtu

# This is a subset of the full PEP440 pattern; for example we skip pre & post releases
VERSION_PATTERN = re.compile(r"""
  ^                                   # start of string
  (?P<version>[0-9]+\.[0-9]+\.[0-9]+) # main version; like '0.4.16'
  (?:\.dev(?P<dev>[0-9]+))?           # optional dev version; like '.dev20230908'
  (?:\+(?P<local>[a-zA-Z0-9_]+))?     # optional local version; like '+g6643af3c3'
  $                                   # end of string
""", re.VERBOSE)


@contextlib.contextmanager
def patch_jax_version(version, release_version):
  """
  Patch jax.version._version & jax.version._release_version in order to
  test the version construction logic.
  """
  original_version = jax.version._version
  original_release_version = jax.version._release_version

  jax.version._version = version
  jax.version._release_version = release_version
  try:
    yield
  finally:
    jax.version._version = original_version
    jax.version._release_version = original_release_version


@contextlib.contextmanager
def assert_no_subprocess_call():
  """Run code, asserting that subprocess.Popen *is not* called."""
  with mock.patch("subprocess.Popen") as mock_Popen:
    yield
  mock_Popen.assert_not_called()


@contextlib.contextmanager
def assert_subprocess_call():
  """Run code, asserting that subprocess.Popen *is* called at least once."""
  with mock.patch("subprocess.Popen") as mock_Popen:
    yield
  mock_Popen.assert_called()


class JaxVersionTest(unittest.TestCase):

  def assertValidVersion(self, version):
    self.assertIsNotNone(VERSION_PATTERN.match(version))

  def testVersionValidity(self):
    self.assertValidVersion(jax.__version__)
    self.assertValidVersion(jax._src.lib.version_str)

  @patch_jax_version("1.2.3", "1.2.3.dev4567")
  def testVersionInRelease(self):
    # If the release version is set, subprocess should not be called.
    with assert_no_subprocess_call():
      version = jax.version._get_version_string()
    self.assertEqual(version, "1.2.3.dev4567")
    self.assertValidVersion(version)

  @patch_jax_version("1.2.3", None)
  def testVersionInNonRelease(self):
    # If the release version is not set, we expect subprocess to be called
    # in order to attempt accessing git commit information.
    with assert_subprocess_call():
      version = jax.version._get_version_string()
    self.assertTrue(version.startswith("1.2.3.dev"))
    self.assertValidVersion(version)

  @patch_jax_version("1.2.3", "1.2.3.dev4567")
  def testBuildVersionInRelease(self):
    # If building from a source tree with release version set, subprocess
    # should not be called.
    with assert_no_subprocess_call():
      version = jax.version._get_version_for_build()
    self.assertEqual(version, "1.2.3.dev4567")
    self.assertValidVersion(version)

  @patch_jax_version("1.2.3", None)
  def testBuildVersionFromEnvironment(self):
    # This test covers build-time construction of version strings in the
    # presence of several environment variables.
    base_version = "1.2.3"

    with jtu.set_env(JAX_RELEASE=None, JAXLIB_RELEASE=None,
                     JAX_NIGHTLY=None, JAXLIB_NIGHTLY=None):
      with assert_subprocess_call():
        version = jax.version._get_version_for_build()
      # TODO(jakevdp): confirm that this includes a date string & commit hash?
      self.assertTrue(version.startswith(f"{base_version}.dev"))
      self.assertValidVersion(version)

    with jtu.set_env(JAX_RELEASE=None, JAXLIB_RELEASE=None,
                     JAX_NIGHTLY="1", JAXLIB_NIGHTLY=None):
      with assert_no_subprocess_call():
        version = jax.version._get_version_for_build()
      datestring = datetime.date.today().strftime("%Y%m%d")
      self.assertEqual(version, f"{base_version}.dev{datestring}")
      self.assertValidVersion(version)

    with jtu.set_env(JAX_RELEASE=None, JAXLIB_RELEASE=None,
                      JAX_NIGHTLY=None, JAXLIB_NIGHTLY="1"):
      with assert_no_subprocess_call():
        version = jax.version._get_version_for_build()
      datestring = datetime.date.today().strftime("%Y%m%d")
      self.assertEqual(version, f"{base_version}.dev{datestring}")
      self.assertValidVersion(version)

    with jtu.set_env(JAX_RELEASE="1", JAXLIB_RELEASE=None,
                      JAX_NIGHTLY=None, JAXLIB_NIGHTLY=None):
      with assert_no_subprocess_call():
        version = jax.version._get_version_for_build()
      self.assertEqual(version, base_version)
      self.assertValidVersion(version)

    with jtu.set_env(JAX_RELEASE=None, JAXLIB_RELEASE="1",
                      JAX_NIGHTLY=None, JAXLIB_NIGHTLY=None):
      with assert_no_subprocess_call():
        version = jax.version._get_version_for_build()
      self.assertEqual(version, base_version)
      self.assertValidVersion(version)

  def testVersions(self):
    check_jaxlib_version(jax_version="1.2.3", jaxlib_version="1.2.3",
                         minimum_jaxlib_version="1.2.3")

    check_jaxlib_version(jax_version="1.2.3.4", jaxlib_version="1.2.3",
                         minimum_jaxlib_version="1.2.3")

    check_jaxlib_version(jax_version="2.5.dev234", jaxlib_version="1.2.3",
                         minimum_jaxlib_version="1.2.3")

    with self.assertRaisesRegex(RuntimeError, ".*jax requires version >=.*"):
      check_jaxlib_version(jax_version="1.2.3", jaxlib_version="1.0",
                           minimum_jaxlib_version="1.2.3")

    with self.assertRaisesRegex(RuntimeError, ".*jax requires version >=.*"):
      check_jaxlib_version(jax_version="1.2.3", jaxlib_version="1.0",
                           minimum_jaxlib_version="1.0.1")

    with self.assertRaisesRegex(RuntimeError,
                                ".incompatible with jax version.*"):
      check_jaxlib_version(jax_version="1.2.3", jaxlib_version="1.2.4",
                           minimum_jaxlib_version="1.0.5")


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