# Copyright (c) 2016-present, Facebook, Inc.
#
# 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.
##############################################################################

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

from hypothesis import given
import hypothesis.strategies as st
import numpy as np
from caffe2.python import brew, core, workspace
import caffe2.python.hypothesis_test_util as hu
from caffe2.python.model_helper import ModelHelper


import unittest

class TestSpatialBN(hu.HypothesisTestCase):

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(min_value=1e-5, max_value=1e-2),
           inplace=st.sampled_from([True, False]),
           **hu.gcs)
    def test_spatialbn_test_mode_3d(
            self, size, input_channels, batch_size, seed, order, epsilon,
            inplace, gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "mean", "var"],
            ["X" if inplace else "Y"],
            order=order,
            is_test=True,
            epsilon=epsilon,
            engine="CUDNN",
        )

        def reference_spatialbn_test(X, scale, bias, mean, var):
            if order == "NCHW":
                scale = scale[np.newaxis, :, np.newaxis, np.newaxis, np.newaxis]
                bias = bias[np.newaxis, :, np.newaxis, np.newaxis, np.newaxis]
                mean = mean[np.newaxis, :, np.newaxis, np.newaxis, np.newaxis]
                var = var[np.newaxis, :, np.newaxis, np.newaxis, np.newaxis]
            return ((X - mean) / np.sqrt(var + epsilon) * scale + bias,)

        np.random.seed(1701)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(batch_size, input_channels, size, size, size)\
                .astype(np.float32) - 0.5

        if order == "NHWC":
            X = X.transpose(0, 2, 3, 4, 1)
        self.assertReferenceChecks(gc, op, [X, scale, bias, mean, var],
                                   reference_spatialbn_test)
        self.assertDeviceChecks(dc, op, [X, scale, bias, mean, var], [0])

    @unittest.skipIf(not workspace.has_gpu_support, "No gpu support")
    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(min_value=1e-5, max_value=1e-2),
           inplace=st.sampled_from([True, False]),
           **hu.gcs)
    def test_spatialbn_test_mode_1d(
            self, size, input_channels, batch_size, seed, order, epsilon,
            inplace, gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "mean", "var"],
            ["X" if inplace else "Y"],
            order=order,
            is_test=True,
            epsilon=epsilon,
            engine="CUDNN",
        )

        def reference_spatialbn_test(X, scale, bias, mean, var):
            if order == "NCHW":
                scale = scale[np.newaxis, :, np.newaxis]
                bias = bias[np.newaxis, :, np.newaxis]
                mean = mean[np.newaxis, :, np.newaxis]
                var = var[np.newaxis, :, np.newaxis]
            return ((X - mean) / np.sqrt(var + epsilon) * scale + bias,)

        np.random.seed(1701)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(
            batch_size, input_channels, size).astype(np.float32) - 0.5

        if order == "NHWC":
            X = X.swapaxes(1, 2)
        self.assertReferenceChecks(gc, op, [X, scale, bias, mean, var],
                                   reference_spatialbn_test)

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(min_value=1e-5, max_value=1e-2),
           engine=st.sampled_from(["", "CUDNN"]),
           inplace=st.sampled_from([True, False]),
           **hu.gcs)
    def test_spatialbn_test_mode(
            self, size, input_channels, batch_size, seed, order, epsilon,
            inplace, engine, gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "mean", "var"],
            ["X" if inplace else "Y"],
            order=order,
            is_test=True,
            epsilon=epsilon,
            engine=engine
        )

        def reference_spatialbn_test(X, scale, bias, mean, var):
            if order == "NCHW":
                scale = scale[np.newaxis, :, np.newaxis, np.newaxis]
                bias = bias[np.newaxis, :, np.newaxis, np.newaxis]
                mean = mean[np.newaxis, :, np.newaxis, np.newaxis]
                var = var[np.newaxis, :, np.newaxis, np.newaxis]
            return ((X - mean) / np.sqrt(var + epsilon) * scale + bias,)

        np.random.seed(1701)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(
            batch_size, input_channels, size, size).astype(np.float32) - 0.5

        if order == "NHWC":
            X = X.swapaxes(1, 2).swapaxes(2, 3)

        self.assertReferenceChecks(gc, op, [X, scale, bias, mean, var],
                                   reference_spatialbn_test)
        self.assertDeviceChecks(dc, op, [X, scale, bias, mean, var], [0])

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(1e-5, 1e-2),
           engine=st.sampled_from(["", "CUDNN"]),
           inplace=st.sampled_from([True, False]),
           **hu.gcs)
    def test_spatialbn_train_mode(
            self, size, input_channels, batch_size, seed, order, epsilon,
            inplace, engine, gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "running_mean", "running_var"],
            ["X" if inplace else "Y",
             "running_mean", "running_var", "saved_mean", "saved_var"],
            order=order,
            is_test=False,
            epsilon=epsilon,
            engine=engine,
        )
        np.random.seed(1701)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(
            batch_size, input_channels, size, size).astype(np.float32) - 0.5

        if order == "NHWC":
            X = X.swapaxes(1, 2).swapaxes(2, 3)

        self.assertDeviceChecks(dc, op, [X, scale, bias, mean, var],
                                [0, 1, 2, 3, 4])

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(min_value=1e-5, max_value=1e-2),
           engine=st.sampled_from(["", "CUDNN"]),
           **hu.gcs)
    def test_spatialbn_train_mode_gradient_check(
            self, size, input_channels, batch_size, seed, order, epsilon,
            engine, gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "mean", "var"],
            ["Y", "mean", "var", "saved_mean", "saved_var"],
            order=order,
            is_test=False,
            epsilon=epsilon,
            engine=engine
        )
        np.random.seed(seed)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(
            batch_size, input_channels, size, size).astype(np.float32) - 0.5
        if order == "NHWC":
            X = X.swapaxes(1, 2).swapaxes(2, 3)

        for input_to_check in [0, 1, 2]:  # dX, dScale, dBias
            self.assertGradientChecks(gc, op, [X, scale, bias, mean, var],
                                      input_to_check, [0])

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           order=st.sampled_from(["NCHW", "NHWC"]),
           epsilon=st.floats(min_value=1e-5, max_value=1e-2),
           **hu.gcs)
    def test_spatialbn_train_mode_gradient_check_1d(
            self, size, input_channels, batch_size, seed, order, epsilon,
            gc, dc):
        op = core.CreateOperator(
            "SpatialBN",
            ["X", "scale", "bias", "mean", "var"],
            ["Y", "mean", "var", "saved_mean", "saved_var"],
            order=order,
            is_test=False,
            epsilon=epsilon,
            engine="CUDNN",
        )
        np.random.seed(seed)
        scale = np.random.rand(input_channels).astype(np.float32) + 0.5
        bias = np.random.rand(input_channels).astype(np.float32) - 0.5
        mean = np.random.randn(input_channels).astype(np.float32)
        var = np.random.rand(input_channels).astype(np.float32) + 0.5
        X = np.random.rand(
            batch_size, input_channels, size).astype(np.float32) - 0.5
        if order == "NHWC":
            X = X.swapaxes(1, 2)

        for input_to_check in [0, 1, 2]:  # dX, dScale, dBias
            self.assertGradientChecks(gc, op, [X, scale, bias, mean, var],
                                      input_to_check, [0], stepsize=0.01)

    @given(size=st.integers(7, 10),
           input_channels=st.integers(1, 10),
           batch_size=st.integers(1, 3),
           seed=st.integers(0, 65535),
           epsilon=st.floats(1e-5, 1e-2),
           engine=st.sampled_from(["", "CUDNN"]),
           **hu.gcs)
    def test_spatialbn_brew_wrapper(
            self, size, input_channels, batch_size, seed, epsilon,
            engine, gc, dc):
        np.random.seed(seed)
        X = np.random.rand(
            batch_size, input_channels, size, size).astype(np.float32)

        workspace.FeedBlob('X', X)

        model = ModelHelper(name='test_spatialbn_brew_wrapper')

        brew.spatial_bn(
            model,
            'X',
            'Y',
            input_channels,
            epsilon=epsilon,
            is_test=False,
        )

        workspace.RunNetOnce(model.param_init_net)
        workspace.RunNetOnce(model.net)


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