# Copyright 2015 The TensorFlow Authors. 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.
# ==============================================================================
"""Tests for the binary ops priority mechanism."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import numpy as np

from tensorflow.python.framework import ops
from tensorflow.python.platform import test as test_lib


class TensorPriorityTest(test_lib.TestCase):

  def testSupportedRhsWithoutDelegation(self):

    class NumpyArraySubclass(np.ndarray):
      pass

    supported_rhs_without_delegation = (3, 3.0, [1.0, 2.0], np.array(
        [1.0, 2.0]), NumpyArraySubclass(
            shape=(1, 2), buffer=np.array([1.0, 2.0])),
                                        ops.convert_to_tensor([[1.0, 2.0]]))
    for rhs in supported_rhs_without_delegation:
      tensor = ops.convert_to_tensor([[10.0, 20.0]])
      res = tensor + rhs
      self.assertIsInstance(res, ops.Tensor)

  def testUnsupportedRhsWithoutDelegation(self):

    class WithoutReverseAdd(object):
      pass

    tensor = ops.convert_to_tensor([[10.0, 20.0]])
    rhs = WithoutReverseAdd()
    with self.assertRaisesWithPredicateMatch(
        TypeError, lambda e: "Expected float" in str(e)):
      # pylint: disable=pointless-statement
      tensor + rhs

  def testUnsupportedRhsWithDelegation(self):

    class WithReverseAdd(object):

      def __radd__(self, lhs):
        return "Works!"

    tensor = ops.convert_to_tensor([[10.0, 20.0]])
    rhs = WithReverseAdd()
    res = tensor + rhs
    self.assertEqual(res, "Works!")

  def testFullDelegationControlUsingRegistry(self):

    class NumpyArraySubclass(np.ndarray):

      def __radd__(self, lhs):
        return "Works!"

    def raise_to_delegate(value, dtype=None, name=None, as_ref=False):
      del value, dtype, name, as_ref  # Unused.
      raise TypeError

    ops.register_tensor_conversion_function(
        NumpyArraySubclass, raise_to_delegate, priority=0)
    tensor = ops.convert_to_tensor([[10.0, 20.0]])
    rhs = NumpyArraySubclass(shape=(1, 2), buffer=np.array([1.0, 2.0]))
    res = tensor + rhs
    self.assertEqual(res, "Works!")


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