# Copyright (c) 2021 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 paddle
import paddle.fluid as fluid
import six

from paddle.fluid.framework import IrGraph
from paddle.fluid.framework import IrNode
from paddle.fluid.tests.unittests.op_test import OpTestTool
from paddle.fluid import core
import paddle.fluid.layers as layers
from paddle.fluid.framework import Program, program_guard, default_startup_program
from paddle.fluid.contrib.slim.quantization import QuantizationTransformPass

paddle.enable_static()


class TestQuantizationSubGraph(unittest.TestCase):
    def build_graph_with_sub_graph(self):
        def linear_fc(num):
            data = fluid.layers.data(
                name='image', shape=[1, 32, 32], dtype='float32')
            label = fluid.layers.data(name='label', shape=[1], dtype='int64')
            hidden = data
            for _ in six.moves.xrange(num):
                hidden = fluid.layers.fc(hidden, size=128, act='relu')
            loss = fluid.layers.cross_entropy(input=hidden, label=label)
            loss = fluid.layers.mean(loss)
            return loss

        main_program = Program()
        startup_program = Program()

        def true_func():
            return linear_fc(3)

        def false_func():
            return linear_fc(5)

        with program_guard(main_program, startup_program):
            x = layers.fill_constant(shape=[1], dtype='float32', value=0.1)
            y = layers.fill_constant(shape=[1], dtype='float32', value=0.23)
            pred = layers.less_than(y, x)
            out = layers.cond(pred, true_func, false_func)

        core_graph = core.Graph(main_program.desc)
        # We should create graph for test, otherwise it will throw a 
        # error that it cannot find the node of "STEP_COUNTER"
        graph = IrGraph(core_graph, for_test=True)
        sub_graph = graph.get_sub_graph(0)
        all_sub_graphs = graph.all_sub_graphs(
            for_test=True)  # same reason for subgraph
        # Should return graph and sub_graphs at the same time. If only return sub_graph, the graph will
        # be destructed and the sub_graphs will be empty.
        return graph, all_sub_graphs

    def test_quant_sub_graphs(self, use_cuda=False):
        graph, sub_graphs = self.build_graph_with_sub_graph()
        place = fluid.CUDAPlace(0) if use_cuda else fluid.CPUPlace()
        transform_pass = QuantizationTransformPass(
            scope=fluid.global_scope(),
            place=place,
            activation_quantize_type='abs_max',
            weight_quantize_type='range_abs_max')
        Find_inserted_quant_op = False
        for sub_graph in sub_graphs:
            transform_pass.apply(sub_graph)
            for op in sub_graph.all_op_nodes():
                if 'quantize' in op.name():
                    Find_inserted_quant_op = True
        self.assertTrue(Find_inserted_quant_op)

    def test_quant_sub_graphs_cpu(self):
        self.test_quant_sub_graphs(use_cuda=False)

    @OpTestTool.skip_if(not paddle.is_compiled_with_cuda(),
                        "Not GPU version paddle")
    def test_quant_sub_graphs_gpu(self):
        self.test_quant_sub_graphs(use_cuda=True)


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