# Copyright 2015 Google Inc. All Rights Reserved.
#
# 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.
# ==============================================================================

# pylint: disable=invalid-name
"""Test utils for tensorflow."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import contextlib
import math
import re
import sys
import threading

import numpy as np
import six

from google.protobuf import text_format

from tensorflow.core.framework import graph_pb2
from tensorflow.core.protobuf import config_pb2
from tensorflow.python import pywrap_tensorflow
from tensorflow.python.client import session
from tensorflow.python.framework import device as pydev
from tensorflow.python.framework import errors
from tensorflow.python.framework import ops
from tensorflow.python.framework import versions
from tensorflow.python.platform import googletest
from tensorflow.python.platform import logging
from tensorflow.python.util import compat
from tensorflow.python.util.protobuf import compare


def assert_ops_in_graph(expected_ops, graph):
  """Assert all expected operations are found.

  Args:
    expected_ops: `dict<string, string>` of op name to op type.
    graph: Graph to check.
  Returns:
    `dict<string, node>` of node name to node.

  Raises:
    ValueError: If the expected ops are not present in the graph.
  """
  actual_ops = {}
  gd = graph.as_graph_def()
  for node in gd.node:
    if node.name in expected_ops:
      if expected_ops[node.name] != node.op:
        raise ValueError(
            "Expected op for node %s is different. %s vs %s" % (
                node.name, expected_ops[node.name], node.op))
      actual_ops[node.name] = node
  if set(expected_ops.keys()) != set(actual_ops.keys()):
    raise ValueError(
        "Not all expected ops are present. Expected %s, found %s" % (
            expected_ops.keys(), actual_ops.keys()))
  return actual_ops


def assert_equal_graph_def(actual, expected):
  """Asserts that two `GraphDef`s are (mostly) the same.

  Compares two `GraphDef` protos for equality, ignoring versions and ordering of
  nodes, attrs, and control inputs.  Node names are used to match up nodes
  between the graphs, so the naming of nodes must be consistent.

  Args:
    actual: The `GraphDef` we have.
    expected: The `GraphDef` we expected.

  Raises:
    AssertionError: If the `GraphDef`s do not match.
    TypeError: If either argument is not a `GraphDef`.
  """
  if not isinstance(actual, graph_pb2.GraphDef):
    raise TypeError("Expected tf.GraphDef for actual, got %s" %
                    type(actual).__name__)
  if not isinstance(expected, graph_pb2.GraphDef):
    raise TypeError("Expected tf.GraphDef for expected, got %s" %
                    type(expected).__name__)
  diff = pywrap_tensorflow.EqualGraphDefWrapper(actual.SerializeToString(),
                                                expected.SerializeToString())
  if diff:
    raise AssertionError(compat.as_str(diff))


def IsGoogleCudaEnabled():
  return pywrap_tensorflow.IsGoogleCudaEnabled()


class TensorFlowTestCase(googletest.TestCase):
  """Base class for tests that need to test TensorFlow.
  """

  def __init__(self, methodName="runTest"):
    super(TensorFlowTestCase, self).__init__(methodName)
    self._threads = []
    self._tempdir = None
    self._cached_session = None

  def setUp(self):
    self._ClearCachedSession()
    ops.reset_default_graph()

  def tearDown(self):
    for thread in self._threads:
      self.assertFalse(thread.is_alive(), "A checkedThread did not terminate")
    self._ClearCachedSession()

  def _ClearCachedSession(self):
    if self._cached_session is not None:
      self._cached_session.close()
      self._cached_session = None

  def get_temp_dir(self):
    if not self._tempdir:
      self._tempdir = googletest.GetTempDir()
    return self._tempdir

  def _AssertProtoEquals(self, a, b):
    """Asserts that a and b are the same proto.

    Uses ProtoEq() first, as it returns correct results
    for floating point attributes, and then use assertProtoEqual()
    in case of failure as it provides good error messages.

    Args:
      a: a proto.
      b: another proto.
    """
    if not compare.ProtoEq(a, b):
      compare.assertProtoEqual(self, a, b, normalize_numbers=True)

  def assertProtoEquals(self, expected_message_maybe_ascii, message):
    """Asserts that message is same as parsed expected_message_ascii.

    Creates another prototype of message, reads the ascii message into it and
    then compares them using self._AssertProtoEqual().

    Args:
      expected_message_maybe_ascii: proto message in original or ascii form
      message: the message to validate
    """

    if type(expected_message_maybe_ascii) == type(message):
      expected_message = expected_message_maybe_ascii
      self._AssertProtoEquals(expected_message, message)
    elif isinstance(expected_message_maybe_ascii, str):
      expected_message = type(message)()
      text_format.Merge(expected_message_maybe_ascii, expected_message)
      self._AssertProtoEquals(expected_message, message)
    else:
      assert False, ("Can't compare protos of type %s and %s" %
                     (type(expected_message_maybe_ascii), type(message)))

  def assertProtoEqualsVersion(
      self, expected, actual, producer=versions.GRAPH_DEF_VERSION,
      min_consumer=versions.GRAPH_DEF_VERSION_MIN_CONSUMER):
    expected = "versions { producer: %d min_consumer: %d };\n%s" % (
        producer, min_consumer, expected)
    self.assertProtoEquals(expected, actual)

  def assertStartsWith(self, actual, expected_start, msg=None):
    """Assert that actual.startswith(expected_start) is True.

    Args:
      actual: str
      expected_start: str
      msg: Optional message to report on failure.
    """
    if not actual.startswith(expected_start):
      fail_msg = "%r does not start with %r" % (actual, expected_start)
      fail_msg += " : %r" % (msg) if msg else ""
      self.fail(fail_msg)

  # pylint: disable=g-doc-return-or-yield
  @contextlib.contextmanager
  def test_session(self,
                   graph=None,
                   config=None,
                   use_gpu=False,
                   force_gpu=False):
    """Returns a TensorFlow Session for use in executing tests.

    This method should be used for all functional tests.

    Use the `use_gpu` and `force_gpu` options to control where ops are run. If
    `force_gpu` is True, all ops are pinned to `/gpu:0`. Otherwise, if `use_gpu`
    is True, TensorFlow tries to run as many ops on the GPU as possible. If both
    `force_gpu and `use_gpu` are False, all ops are pinned to the CPU.

    Example:

      class MyOperatorTest(test_util.TensorFlowTestCase):
        def testMyOperator(self):
          with self.test_session(use_gpu=True):
            valid_input = [1.0, 2.0, 3.0, 4.0, 5.0]
            result = MyOperator(valid_input).eval()
            self.assertEqual(result, [1.0, 2.0, 3.0, 5.0, 8.0]
            invalid_input = [-1.0, 2.0, 7.0]
            with self.assertRaisesOpError("negative input not supported"):
              MyOperator(invalid_input).eval()

    Args:
      graph: Optional graph to use during the returned session.
      config: An optional config_pb2.ConfigProto to use to configure the
        session.
      use_gpu: If True, attempt to run as many ops as possible on GPU.
      force_gpu: If True, pin all ops to `/gpu:0`.

    Returns:
      A Session object that should be used as a context manager to surround
      the graph building and execution code in a test case.
    """
    if self.id().endswith(".test_session"):
      self.skipTest("Not a test.")
    def prepare_config(config):
      if config is None:
        config = config_pb2.ConfigProto()
        config.allow_soft_placement = not force_gpu
        config.gpu_options.per_process_gpu_memory_fraction = 0.3
      elif force_gpu and config.allow_soft_placement:
        config = config_pb2.ConfigProto().CopyFrom(config)
        config.allow_soft_placement = False
      # Don't perform optimizations for tests so we don't inadvertently run
      # gpu ops on cpu
      config.graph_options.optimizer_options.opt_level = -1
      return config

    if graph is None:
      if self._cached_session is None:
        self._cached_session = session.Session(graph=None,
                                               config=prepare_config(config))
      sess = self._cached_session
      with sess.graph.as_default(), sess.as_default():
        if force_gpu:
          with sess.graph.device("/gpu:0"):
            yield sess
        elif use_gpu:
          yield sess
        else:
          with sess.graph.device("/cpu:0"):
            yield sess
    else:
      with session.Session(graph=graph, config=prepare_config(config)) as sess:
        if force_gpu:
          with sess.graph.device("/gpu:0"):
            yield sess
        elif use_gpu:
          yield sess
        else:
          with sess.graph.device("/cpu:0"):
            yield sess
  # pylint: enable=g-doc-return-or-yield

  class _CheckedThread(object):
    """A wrapper class for Thread that asserts successful completion.

    This class should be created using the TensorFlowTestCase.checkedThread()
    method.
    """

    def __init__(self, testcase, target, args=None, kwargs=None):
      """Constructs a new instance of _CheckedThread.

      Args:
        testcase: The TensorFlowTestCase for which this thread is being created.
        target: A callable object representing the code to be executed in the
          thread.
        args: A tuple of positional arguments that will be passed to target.
        kwargs: A dictionary of keyword arguments that will be passed to target.
      """
      self._testcase = testcase
      self._target = target
      self._args = () if args is None else args
      self._kwargs = {} if kwargs is None else kwargs
      self._thread = threading.Thread(target=self._protected_run)
      self._exception = None

    def _protected_run(self):
      """Target for the wrapper thread. Sets self._exception on failure."""
      try:
        self._target(*self._args, **self._kwargs)
      except Exception as e:  # pylint: disable=broad-except
        self._exception = e

    def start(self):
      """Starts the thread's activity.

      This must be called at most once per _CheckedThread object. It arranges
      for the object's target to be invoked in a separate thread of control.
      """
      self._thread.start()

    def join(self):
      """Blocks until the thread terminates.

      Raises:
        self._testcase.failureException: If the thread terminates with due to
          an exception.
      """
      self._thread.join()
      if self._exception is not None:
        self._testcase.fail(
            "Error in checkedThread: %s" % str(self._exception))

    def is_alive(self):
      """Returns whether the thread is alive.

      This method returns True just before the run() method starts
      until just after the run() method terminates.

      Returns:
        True if the thread is alive, otherwise False.
      """
      return self._thread.is_alive()

  def checkedThread(self, target, args=None, kwargs=None):
    """Returns a Thread wrapper that asserts 'target' completes successfully.

    This method should be used to create all threads in test cases, as
    otherwise there is a risk that a thread will silently fail, and/or
    assertions made in the thread will not be respected.

    Args:
      target: A callable object to be executed in the thread.
      args: The argument tuple for the target invocation. Defaults to ().
      kwargs: A dictionary of keyword arguments for the target invocation.
        Defaults to {}.

    Returns:
      A wrapper for threading.Thread that supports start() and join() methods.
    """
    ret = TensorFlowTestCase._CheckedThread(self, target, args, kwargs)
    self._threads.append(ret)
    return ret
# pylint: enable=invalid-name

  def assertNear(self, f1, f2, err, msg=None):
    """Asserts that two floats are near each other.

    Checks that |f1 - f2| < err and asserts a test failure
    if not.

    Args:
      f1: A float value.
      f2: A float value.
      err: A float value.
      msg: An optional string message to append to the failure message.
    """
    self.assertTrue(math.fabs(f1 - f2) <= err,
                    "%f != %f +/- %f%s" % (
                        f1, f2, err, " (%s)" % msg if msg is not None else ""))

  def assertArrayNear(self, farray1, farray2, err):
    """Asserts that two float arrays are near each other.

    Checks that for all elements of farray1 and farray2
    |f1 - f2| < err.  Asserts a test failure if not.

    Args:
      farray1: a list of float values.
      farray2: a list of float values.
      err: a float value.
    """
    self.assertEqual(len(farray1), len(farray2))
    for f1, f2 in zip(farray1, farray2):
      self.assertNear(float(f1), float(f2), err)

  def _NDArrayNear(self, ndarray1, ndarray2, err):
    return np.linalg.norm(ndarray1 - ndarray2) < err

  def assertNDArrayNear(self, ndarray1, ndarray2, err):
    """Asserts that two numpy arrays have near values.

    Args:
      ndarray1: a numpy ndarray.
      ndarray2: a numpy ndarray.
      err: a float. The maximum absolute difference allowed.
    """
    self.assertTrue(self._NDArrayNear(ndarray1, ndarray2, err))

  def _GetNdArray(self, a):
    if not isinstance(a, np.ndarray):
      a = np.array(a)
    return a

  def assertAllClose(self, a, b, rtol=1e-6, atol=1e-6):
    """Asserts that two numpy arrays have near values.

    Args:
      a: a numpy ndarray or anything can be converted to one.
      b: a numpy ndarray or anything can be converted to one.
      rtol: relative tolerance
      atol: absolute tolerance
    """
    a = self._GetNdArray(a)
    b = self._GetNdArray(b)
    self.assertEqual(
        a.shape, b.shape,
        "Shape mismatch: expected %s, got %s." % (a.shape, b.shape))
    if not np.allclose(a, b, rtol=rtol, atol=atol):
      # Prints more details than np.testing.assert_allclose.
      #
      # NOTE: numpy.allclose (and numpy.testing.assert_allclose)
      # checks whether two arrays are element-wise equal within a
      # tolerance. The relative difference (rtol * abs(b)) and the
      # absolute difference atol are added together to compare against
      # the absolute difference between a and b.  Here, we want to
      # print out which elements violate such conditions.
      cond = np.abs(a - b) > atol + rtol * np.abs(b)
      if a.ndim:
        x = a[np.where(cond)]
        y = b[np.where(cond)]
        print("not close where = ", np.where(cond))
      else:
        # np.where is broken for scalars
        x, y = a, b
      print("not close lhs = ", x)
      print("not close rhs = ", y)
      print("not close dif = ", np.abs(x - y))
      print("not close tol = ", atol + rtol * np.abs(y))
      np.testing.assert_allclose(a, b, rtol=rtol, atol=atol)

  def assertAllEqual(self, a, b):
    """Asserts that two numpy arrays have the same values.

    Args:
      a: a numpy ndarray or anything can be converted to one.
      b: a numpy ndarray or anything can be converted to one.
    """
    a = self._GetNdArray(a)
    b = self._GetNdArray(b)
    self.assertEqual(
        a.shape, b.shape,
        "Shape mismatch: expected %s, got %s." % (a.shape, b.shape))
    same = (a == b)

    if a.dtype == np.float32 or a.dtype == np.float64:
      same = np.logical_or(same, np.logical_and(np.isnan(a), np.isnan(b)))
    if not np.all(same):
      # Prints more details than np.testing.assert_array_equal.
      diff = np.logical_not(same)
      if a.ndim:
        x = a[np.where(diff)]
        y = b[np.where(diff)]
        print("not equal where = ", np.where(diff))
      else:
        # np.where is broken for scalars
        x, y = a, b
      print("not equal lhs = ", x)
      print("not equal rhs = ", y)
      np.testing.assert_array_equal(a, b)

  # pylint: disable=g-doc-return-or-yield
  @contextlib.contextmanager
  def assertRaisesWithPredicateMatch(self, exception_type,
                                     expected_err_re_or_predicate):
    """Returns a context manager to enclose code expected to raise an exception.

    Args:
      exception_type: The expected type of exception that should be raised.
      expected_err_re_or_predicate: If this is callable, it should be a function
        of one argument that inspects the passed-in OpError exception and
        returns True (success) or False (please fail the test). Otherwise, the
        error message is expected to match this regular expression partially.

    Returns:
      A context manager to surround code that is expected to raise an
      errors.OpError exception.
    """
    if callable(expected_err_re_or_predicate):
      predicate = expected_err_re_or_predicate
    else:
      def predicate(e):
        err_str = e.message
        op = e.op
        while op is not None:
          err_str += "\nCaused by: " + op.name
          op = op._original_op
        logging.info("Searching within error strings: '%s' within '%s'",
                     expected_err_re_or_predicate, err_str)
        return re.search(expected_err_re_or_predicate, err_str)
    try:
      yield
      self.fail(exception_type.__name__ + " not raised")
    except Exception as e:  # pylint: disable=broad-except
      if not isinstance(e, exception_type) or not predicate(e):
        raise AssertionError(e)
  # pylint: enable=g-doc-return-or-yield

  def assertRaisesOpError(self, expected_err_re_or_predicate):
    return self.assertRaisesWithPredicateMatch(errors.OpError,
                                               expected_err_re_or_predicate)

  def assertShapeEqual(self, np_array, tf_tensor):
    """Asserts that a Numpy ndarray and a TensorFlow tensor have the same shape.

    Args:
      np_array: A Numpy ndarray or Numpy scalar.
      tf_tensor: A Tensor.

    Raises:
      TypeError: If the arguments have the wrong type.
    """
    if not isinstance(np_array, (np.ndarray, np.generic)):
      raise TypeError("np_array must be a Numpy ndarray or Numpy scalar")
    if not isinstance(tf_tensor, ops.Tensor):
      raise TypeError("tf_tensor must be a Tensor")
    self.assertAllEqual(np_array.shape, tf_tensor.get_shape().as_list())

  def assertDeviceEqual(self, device1, device2):
    """Asserts that the two given devices are the same.

    Args:
      device1: A string device name or TensorFlow `Device` object.
      device2: A string device name or TensorFlow `Device` object.
    """
    device1 = pydev.canonical_name(device1)
    device2 = pydev.canonical_name(device2)
    self.assertEqual(device1, device2,
                     "Devices %s and %s are not equal" % (device1, device2))

  # Fix Python 3 compatibility issues
  if six.PY3:
    # Silence a deprecation warning
    assertRaisesRegexp = googletest.TestCase.assertRaisesRegex

    # assertItemsEqual is assertCountEqual as of 3.2.
    assertItemsEqual = googletest.TestCase.assertCountEqual
