#  Copyright (c) 2022 PaddlePaddle 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.

import unittest

import numpy as np
import paddle
import paddle.static
from paddle.fluid.tests.unittests.ipu.op_test_ipu import IPUOpTest


@unittest.skipIf(not paddle.is_compiled_with_ipu(),
                 "core is not compiled with IPU")
@unittest.skipIf(IPUOpTest.use_ipumodel(), "skip for ipumodel")
class TestBase(IPUOpTest):

    def setUp(self):
        self.set_atol()
        self.set_data_feed()
        self.set_feed_attr()
        self.set_attrs()

    def set_atol(self):
        self.atol = 1e-6

    def set_data_feed(self):
        self.feed = {
            "image": np.random.uniform(size=[1, 3, 10, 10]).astype('float32'),
        }

    def set_feed_attr(self):
        self.feed_shape = [x.shape for x in self.feed.values()]
        self.feed_list = list(self.feed.keys())
        self.feed_dtype = [x.dtype for x in self.feed.values()]

    def set_attrs(self):
        self.attrs = {
            "weight_decay": 4.0,
            "loss_scaling": 1.0,
        }

    def _test_optimizer(self, run_ipu=True):

        def exclude_fn(param):
            return param.name.endswith('.w_0')

        scope = paddle.static.Scope()
        main_prog = paddle.static.Program()
        startup_prog = paddle.static.Program()
        main_prog.random_seed = self.SEED
        startup_prog.random_seed = self.SEED
        np.random.seed(self.SEED)

        with paddle.static.scope_guard(scope):
            with paddle.static.program_guard(main_prog, startup_prog):
                image = paddle.static.data(name='image',
                                           shape=[1, 3, 10, 10],
                                           dtype='float32')
                bias = paddle.fluid.layers.create_parameter(
                    shape=[1, 3, 10, 10], is_bias=True, dtype='float32')
                add1 = image + bias
                conv1 = paddle.static.nn.conv2d(add1,
                                                num_filters=3,
                                                filter_size=3,
                                                bias_attr=False)

                loss = paddle.mean(conv1)
                opt = paddle.optimizer.Lamb(
                    learning_rate=1e-1,
                    lamb_weight_decay=self.attrs['weight_decay'],
                    exclude_from_weight_decay_fn=exclude_fn)
                opt.minimize(loss)

            if run_ipu:
                place = paddle.IPUPlace()
            else:
                place = paddle.CPUPlace()
            exe = paddle.static.Executor(place)
            exe.run(startup_prog)
            paddle.static.save(main_prog, "weight_decay")

            if run_ipu:
                feed_list = [image.name]
                fetch_list = [loss.name]
                ipu_strategy = paddle.static.IpuStrategy()
                ipu_strategy.set_graph_config(is_training=True)
                ipu_strategy.set_options(
                    {'loss_scaling': self.attrs["loss_scaling"]})
                program = paddle.static.IpuCompiledProgram(
                    main_prog,
                    ipu_strategy=ipu_strategy).compile(feed_list, fetch_list)
            else:
                program = main_prog

            result = []
            for epoch in range(100):
                loss_res = exe.run(program, feed=self.feed, fetch_list=[loss])
                result.append(loss_res)

            return np.array(result)

    def test(self):
        # cpu and ipu dimenstion mismatch, cpu:(100, 1, 1), ipu:(100, 1)
        ipu_loss = self._test_optimizer(True).flatten()
        cpu_loss = self._test_optimizer(False).flatten()

        self.assertTrue(np.allclose(ipu_loss, cpu_loss, atol=self.atol))


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