# 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 tensorflow.ops.stack_ops."""

import numpy as np

from tensorflow.compiler.tests import xla_test
from tensorflow.python.compiler.xla import xla
from tensorflow.python.framework import dtypes
from tensorflow.python.framework import ops
from tensorflow.python.ops import array_ops
from tensorflow.python.ops import gen_data_flow_ops
from tensorflow.python.platform import test


class StackOpTest(xla_test.XLATestCase):

  def testStackPushPop(self):
    with self.session(), self.test_scope():

      v = array_ops.placeholder(dtypes.float32)

      def fn():
        h = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        c = gen_data_flow_ops.stack_push_v2(h, v)
        with ops.control_dependencies([c]):
          c1 = gen_data_flow_ops.stack_pop_v2(h, dtypes.float32)
        return c1

      self.assertAllClose([[4.0, 5.0]],
                          xla.compile(fn)[0].eval({v: [[4.0, 5.0]]}))

  def testStackPushPopSwap(self):
    with self.session(), self.test_scope():
      a = np.arange(2000)
      x = array_ops.placeholder(dtypes.float32)

      def fn():
        h = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        c = gen_data_flow_ops.stack_push_v2(h, x, swap_memory=True)
        with ops.control_dependencies([c]):
          return gen_data_flow_ops.stack_pop_v2(h, dtypes.float32)

      self.assertAllClose(a, xla.compile(fn)[0].eval({x: a}))

  def testMultiStack(self):
    with self.session(), self.test_scope():
      v = array_ops.placeholder(dtypes.float32)

      def fn():
        h1 = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        c1 = gen_data_flow_ops.stack_push_v2(h1, v)
        with ops.control_dependencies([c1]):
          c1 = gen_data_flow_ops.stack_pop_v2(h1, dtypes.float32)
        h2 = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="bar")
        c2 = gen_data_flow_ops.stack_push_v2(h2, 5.0)
        with ops.control_dependencies([c2]):
          c2 = gen_data_flow_ops.stack_pop_v2(h2, dtypes.float32)
        return c1 + c2

      self.assertAllClose(9.0, xla.compile(fn)[0].eval({v: 4.0}))

  def testSameNameStacks(self):
    """Different stacks with the same name do not interfere."""
    with self.session() as sess, self.test_scope():
      v1 = array_ops.placeholder(dtypes.float32)
      v2 = array_ops.placeholder(dtypes.float32)

      def fn():
        h1 = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        h2 = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")

        c1 = gen_data_flow_ops.stack_push_v2(h1, v1)
        with ops.control_dependencies([c1]):
          c2 = gen_data_flow_ops.stack_push_v2(h2, v2)
        with ops.control_dependencies([c2]):
          pop1 = gen_data_flow_ops.stack_pop_v2(h1, dtypes.float32)
          pop2 = gen_data_flow_ops.stack_pop_v2(h2, dtypes.float32)
        return [pop1, pop2]

      [pop1_compiled, pop2_compiled] = xla.compile(fn)
      out1, out2 = sess.run([pop1_compiled, pop2_compiled], {v1: 4.0, v2: 5.0})
      self.assertAllClose(out1, 4.0)
      self.assertAllClose(out2, 5.0)

  def testCloseStack(self):
    with self.session() as sess, self.test_scope():

      def fn():
        h = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        gen_data_flow_ops.stack_close_v2(h)

      sess.run(xla.compile(fn))

  def testPushCloseStack(self):
    with self.session() as sess, self.test_scope():
      v = array_ops.placeholder(dtypes.float32)

      def fn():
        h = gen_data_flow_ops.stack_v2(5, dtypes.float32, stack_name="foo")
        c = gen_data_flow_ops.stack_push_v2(h, v)
        with ops.control_dependencies([c]):
          gen_data_flow_ops.stack_close_v2(h)

      sess.run(xla.compile(fn), {v: [[4.0, 5.0]]})


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