# Copyright 2017 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 continue_statements module."""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

from tensorflow.python.autograph.converters import continue_statements
from tensorflow.python.autograph.core import converter_testing
from tensorflow.python.framework import ops
from tensorflow.python.platform import test


class ContinueCanonicalizationTest(converter_testing.TestCase):

  def assertTransformedEquivalent(self, f, *inputs):
    tr = self.transform(f, continue_statements)
    self.assertEqual(f(*inputs), tr(*inputs))

  def test_basic(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        if x % 2 == 0:
          continue
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_multiple_continues(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        if x > 1:
          continue
        if x > 2:
          continue
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_multiple_continues_in_nested_scope(self):

    def f(a):
      v = []
      for x in a:
        x -= 1
        if x > 100:
          continue
        try:
          raise ValueError('intentional')
        except ValueError:
          continue
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, [])
    self.assertTransformedEquivalent(f, [1])
    self.assertTransformedEquivalent(f, [2])
    self.assertTransformedEquivalent(f, [1, 2, 3])

  def test_for_loop(self):

    def f(a):
      v = []
      for x in a:
        x -= 1
        if x % 2 == 0:
          continue
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, [])
    self.assertTransformedEquivalent(f, [1])
    self.assertTransformedEquivalent(f, [2])
    self.assertTransformedEquivalent(f, [1, 2, 3])

  def test_nested_with(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        with ops.name_scope(''):
          if x % 2 == 0:
            continue
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_nested_multiple_withs(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        with ops.name_scope(''):
          if x % 2 == 0:
            continue
        with ops.name_scope(''):
          v.append(x)
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_nested_multiple_withs_and_statements(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        with ops.name_scope(''):
          if x % 2 == 0:
            continue
          v.append(x)
        v.append(x)
        with ops.name_scope(''):
          v.append(x)
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_nested_multiple_withs_and_nested_withs(self):

    def f(x):
      v = []
      while x > 0:
        x -= 1
        with ops.name_scope(''):
          if x % 2 == 0:
            continue
          with ops.name_scope(''):
            v.append(x)
        v.append(x)
        with ops.name_scope(''):
          v.append(x)
        v.append(x)
      return v

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_nested(self):

    def f(x):
      v = []
      u = []
      w = []
      while x > 0:
        x -= 1
        if x % 2 == 0:
          if x % 3 != 0:
            u.append(x)
          else:
            w.append(x)
            continue
        v.append(x)
      return v, u, w

    self.assertTransformedEquivalent(f, 0)
    self.assertTransformedEquivalent(f, 1)
    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 4)

  def test_multiple_guarded_continues_with_side_effects(self):

    def f(x):
      def track(u, x):
        u.append(x)
        return x

      u = []
      v = []
      while x > 0:
        x -= 1
        if track(u, x) > 1:
          continue
        if track(u, x) > 2:
          continue
        v.append(x)
      return u, v

    self.assertTransformedEquivalent(f, 3)
    self.assertTransformedEquivalent(f, 2)


if __name__ == '__main__':
  test.main()
