#   copyright (c) 2019 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 os
import unittest
import random
import numpy as np
import paddle.fluid as fluid
import six
import paddle
from paddle.fluid.framework import IrGraph
from paddle.fluid.contrib.slim.quantization import QuantizationFreezePass
from paddle.fluid.contrib.slim.quantization import QuantizationTransformPass
from paddle.fluid.contrib.slim.quantization import TransformForMkldnnPass
from paddle.fluid import core

os.environ["CPU_NUM"] = "1"


def conv_net(img, label):
    conv_pool_1 = fluid.nets.simple_img_conv_pool(
        input=img,
        filter_size=5,
        num_filters=20,
        pool_size=2,
        pool_stride=2,
        act="relu")
    conv_pool_1 = fluid.layers.batch_norm(conv_pool_1)
    conv_pool_2 = fluid.nets.simple_img_conv_pool(
        input=conv_pool_1,
        filter_size=5,
        num_filters=50,
        pool_size=2,
        pool_stride=2,
        act="relu")
    prediction = fluid.layers.fc(input=conv_pool_2, size=10, act='softmax')
    loss = fluid.layers.cross_entropy(input=prediction, label=label)
    avg_loss = fluid.layers.mean(loss)
    return avg_loss


class TestMKLDNNTransformBasedFreezePass(unittest.TestCase):
    def setUp(self):
        self.quantizable_op_and_inputs = {
            'conv2d': ['Input', 'Filter'],
            'depthwise_conv2d': ['Input', 'Filter'],
            # Mul int8 op is under internal test
            # TODO Update this when mul op is merged
            #'mul': ['X', 'Y']
        }

    def check_program(self, program):
        for block in program.blocks:
            for op in block.ops:
                if op.type in self.quantizable_op_and_inputs:
                    for arg_name in op.output_arg_names:
                        # Check quantizable op's output is linked to
                        # fake_dequantize's output
                        self.assertTrue(arg_name.endswith('.dequantized'))

    def isinteger(self, x):
        return np.equal(np.mod(x, 1), 0)

    def build_program(self, main, startup, is_test, seed):
        main.random_seed = seed
        startup.random_seed = seed
        with fluid.unique_name.guard():
            with fluid.program_guard(main, startup):
                img = fluid.layers.data(
                    name='image', shape=[1, 28, 28], dtype='float32')
                label = fluid.layers.data(
                    name='label', shape=[1], dtype='int64')
                loss = conv_net(img, label)
                if not is_test:
                    opt = fluid.optimizer.Adam(learning_rate=0.001)
                    opt.minimize(loss)
        return [img, label], loss

    def mkldnn_based_freeze_graph(self,
                                  use_cuda,
                                  seed,
                                  activation_quant_type,
                                  weight_quant_type='abs_max',
                                  for_ci=False):
        random.seed(0)
        np.random.seed(0)

        main = fluid.Program()
        startup = fluid.Program()
        test_program = fluid.Program()
        feeds, loss = self.build_program(main, startup, False, seed)
        self.build_program(test_program, startup, True, seed)
        test_program = test_program.clone(for_test=True)
        main_graph = IrGraph(core.Graph(main.desc), for_test=False)
        test_graph = IrGraph(core.Graph(test_program.desc), for_test=True)

        place = fluid.CPUPlace()
        exe = fluid.Executor(place)
        scope = fluid.Scope()
        with fluid.scope_guard(scope):
            exe.run(startup)
        # Apply the QAT QuantizationTransformPass
        transform_pass = QuantizationTransformPass(
            scope=scope,
            place=place,
            activation_quantize_type=activation_quant_type,
            weight_quantize_type=weight_quant_type)
        transform_pass.apply(main_graph)
        transform_pass.apply(test_graph)

        build_strategy = fluid.BuildStrategy()
        build_strategy.memory_optimize = False
        build_strategy.enable_inplace = False
        binary = fluid.CompiledProgram(main_graph.graph).with_data_parallel(
            loss_name=loss.name, build_strategy=build_strategy)
        quantized_test_program = test_graph.to_program()
        iters = 5
        batch_size = 8

        train_reader = paddle.batch(
            paddle.reader.shuffle(
                paddle.dataset.mnist.train(), buf_size=500),
            batch_size=batch_size)
        test_reader = paddle.batch(
            paddle.dataset.mnist.test(), batch_size=batch_size)
        feeder = fluid.DataFeeder(feed_list=feeds, place=place)

        # Training the model to get the weights value
        with fluid.scope_guard(scope):
            for _ in range(iters):
                data = next(train_reader())
                loss_v = exe.run(binary,
                                 feed=feeder.feed(data),
                                 fetch_list=[loss])

        # Freeze graph for inference, but the weight of fc/conv is still float type.
        freeze_pass = QuantizationFreezePass(
            scope=scope, place=place, weight_quantize_type=weight_quant_type)
        freeze_pass.apply(test_graph)

        # Transform quantized graph for MKL-DNN INT8 inference
        mkldnn_int8_pass = TransformForMkldnnPass(scope=scope, place=place)
        mkldnn_int8_pass.apply(test_graph)
        dev_name = '_cpu_'
        if not for_ci:
            marked_nodes = set()
            for op in test_graph.all_op_nodes():
                if op.name().find('quantize') > -1:
                    marked_nodes.add(op)
            test_graph.draw('.', 'test_mkldnn' + dev_name +
                            activation_quant_type + '_' + weight_quant_type,
                            marked_nodes)
        mkldnn_program = test_graph.to_program()
        w_mkldnn = np.array(scope.find_var('conv2d_1.w_0').get_tensor())
        # Check if weights are still integer
        self.assertFalse(self.isinteger(np.sum(w_mkldnn)))

        # Check if the conv2d output is rightly linked to fake_dequantize's 
        # output
        self.check_program(mkldnn_program)
        if not for_ci:
            print('{}: {}'.format('w_mkldnn' + dev_name + activation_quant_type
                                  + '_' + weight_quant_type, np.sum(w_mkldnn)))

    def test_mkldnn_graph_cpu_static(self):
        with fluid.unique_name.guard():
            self.mkldnn_based_freeze_graph(
                False,
                seed=2,
                activation_quant_type='range_abs_max',
                weight_quant_type='abs_max',
                for_ci=True)
            self.mkldnn_based_freeze_graph(
                False,
                seed=2,
                activation_quant_type='moving_average_abs_max',
                weight_quant_type='abs_max',
                for_ci=True)


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