# Copyright 2019 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 threading
from unittest import SkipTest

from absl.testing import absltest
import jax
from jax import lax, numpy as jnp
from jax._src import core
from jax._src import xla_bridge
from jax._src.lib import xla_client
import jax._src.test_util as jtu
import numpy as np

jax.config.parse_flags_with_absl()


@jtu.thread_unsafe_test_class()  # infeed isn't thread-safe
class InfeedTest(jtu.JaxTestCase):

  def setUp(self):
    if xla_bridge.using_pjrt_c_api():
      raise SkipTest("infeed not implemented in PJRT C API")
    super().setUp()

  @jax.numpy_rank_promotion("allow")  # Test explicitly exercises implicit rank promotion.
  def testInfeed(self):
    raise SkipTest("skipping temporarily for stackless")

    @jax.jit
    def f(x):
      token = lax.create_token(x)
      (y,), token = lax.infeed(
          token, shape=(core.ShapedArray((3, 4), jnp.float32),))
      (z,), _ = lax.infeed(
          token, shape=(core.ShapedArray((3, 1, 1), jnp.float32),))
      return x + y + z

    x = np.float32(1.5)
    y = np.reshape(np.arange(12, dtype=np.float32), (3, 4)) # self.rng().randn(3, 4).astype(np.float32)
    z = self.rng().randn(3, 1, 1).astype(np.float32)
    device = jax.local_devices()[0]
    device.transfer_to_infeed((y,))
    device.transfer_to_infeed((z,))
    self.assertAllClose(f(x), x + y + z)

  def testInfeedPytree(self):
    raise SkipTest("skipping temporarily for stackless")

    x = np.float32(1.5)
    y = np.reshape(np.arange(12, dtype=np.int16), (3, 4))
    to_infeed = dict(a=x, b=y)
    to_infeed_shape = dict(a=core.ShapedArray((), dtype=np.float32),
                           b=core.ShapedArray((3, 4), dtype=np.int16))
    @jax.jit
    def f(x):
      token = lax.create_token(x)
      res, token = lax.infeed(token, shape=to_infeed_shape)
      return res

    device = jax.local_devices()[0]
    # We must transfer the flattened data, as a tuple!!!
    flat_to_infeed, _ = jax.tree.flatten(to_infeed)
    device.transfer_to_infeed(tuple(flat_to_infeed))
    self.assertAllClose(f(x), to_infeed)

  @jax.numpy_rank_promotion("allow")  # Test explicitly exercises implicit rank promotion.
  def testInfeedThenOutfeed(self):

    @jax.jit
    def f(x):
      token = lax.create_token(x)
      y, token = lax.infeed(
          token, shape=core.ShapedArray((3, 4), jnp.float32))
      token = lax.outfeed(token, y + np.float32(1))
      return x - 1

    x = np.float32(7.5)
    y = self.rng().randn(3, 4).astype(np.float32)
    execution = threading.Thread(target=lambda: f(x))
    execution.start()
    device = jax.local_devices()[0]
    device.transfer_to_infeed((y,))
    out, = device.transfer_from_outfeed(
      xla_client.shape_from_pyval((y,)).with_major_to_minor_layout_if_absent())
    execution.join()
    self.assertAllClose(out, y + np.float32(1))

  def testInfeedThenOutfeedInALoop(self):

    def doubler(_, token):
      y, token = lax.infeed(
          token, shape=core.ShapedArray((3, 4), jnp.float32))
      return lax.outfeed(token, y * np.float32(2))

    @jax.jit
    def f(n):
      token = lax.create_token(n)
      token = lax.fori_loop(0, n, doubler, token)
      return n

    device = jax.local_devices()[0]
    n = 10
    execution = threading.Thread(target=lambda: f(n))
    execution.start()
    for _ in range(n):
      x = self.rng().randn(3, 4).astype(np.float32)
      device.transfer_to_infeed((x,))
      y, = device.transfer_from_outfeed(xla_client.shape_from_pyval((x,))
                                        .with_major_to_minor_layout_if_absent())
      self.assertAllClose(y, x * np.float32(2))
    execution.join()


if __name__ == '__main__':
  absltest.main(testLoader=jtu.JaxTestLoader())