#   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 unittest
import os
import sys
import argparse
import paddle
import paddle.fluid as fluid
from paddle.fluid.framework import IrGraph
from paddle.fluid.contrib.slim.quantization import Quant2Int8MkldnnPass
from paddle.fluid import core

paddle.enable_static()


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        '--quant_model_path',
        type=str,
        default='',
        help='A path to a Quant model.')
    parser.add_argument(
        '--int8_model_save_path',
        type=str,
        default='',
        help='Saved optimized and quantized INT8 model')
    parser.add_argument(
        '--ops_to_quantize',
        type=str,
        default='',
        help='A comma separated list of operators to quantize. Only quantizable operators are taken into account. If the option is not used, an attempt to quantize all quantizable operators will be made.'
    )
    parser.add_argument(
        '--op_ids_to_skip',
        type=str,
        default='',
        help='A comma separated list of operator ids to skip in quantization.')
    parser.add_argument(
        '--debug',
        action='store_true',
        help='If used, the graph of Quant model is drawn.')
    parser.add_argument(
        '--quant_model_filename',
        type=str,
        default="",
        help='The input model`s file name. If empty, search default `__model__` and separate parameter files and use them or in case if not found, attempt loading `model` and `params` files.'
    )
    parser.add_argument(
        '--quant_params_filename',
        type=str,
        default="",
        help='If quant_model_filename is empty, this field is ignored. The input model`s all parameters file name. If empty load parameters from separate files.'
    )
    parser.add_argument(
        '--save_model_filename',
        type=str,
        default="__model__",
        help='The name of file to save the inference program itself. If is set None, a default filename __model__ will be used.'
    )
    parser.add_argument(
        '--save_params_filename',
        type=str,
        default=None,
        help='The name of file to save all related parameters. If it is set None, parameters will be saved in separate files'
    )

    test_args, args = parser.parse_known_args(namespace=unittest)
    return test_args, sys.argv[:1] + args


def transform_and_save_int8_model(original_path,
                                  save_path,
                                  ops_to_quantize='',
                                  op_ids_to_skip='',
                                  debug=False,
                                  quant_model_filename='',
                                  quant_params_filename='',
                                  save_model_filename="__model__",
                                  save_params_filename=None):
    place = fluid.CPUPlace()
    exe = fluid.Executor(place)
    inference_scope = fluid.executor.global_scope()
    with fluid.scope_guard(inference_scope):
        if not quant_model_filename:
            if os.path.exists(os.path.join(original_path, '__model__')):
                [inference_program, feed_target_names,
                 fetch_targets] = fluid.io.load_inference_model(original_path,
                                                                exe)
            else:
                [inference_program, feed_target_names,
                 fetch_targets] = fluid.io.load_inference_model(
                     original_path, exe, 'model', 'params')
        else:
            [inference_program, feed_target_names,
             fetch_targets] = fluid.io.load_inference_model(
                 original_path, exe, quant_model_filename,
                 quant_params_filename)

        ops_to_quantize_set = set()
        print(ops_to_quantize)
        if len(ops_to_quantize) > 0:
            ops_to_quantize_set = set(ops_to_quantize.split(','))

        op_ids_to_skip_set = set([-1])
        print(op_ids_to_skip)
        if len(op_ids_to_skip) > 0:
            op_ids_to_skip_set = set(map(int, op_ids_to_skip.split(',')))

        graph = IrGraph(core.Graph(inference_program.desc), for_test=True)
        if (debug):
            graph.draw('.', 'quant_orig', graph.all_op_nodes())
        transform_to_mkldnn_int8_pass = Quant2Int8MkldnnPass(
            ops_to_quantize_set,
            _op_ids_to_skip=op_ids_to_skip_set,
            _scope=inference_scope,
            _place=place,
            _core=core,
            _debug=debug)
        graph = transform_to_mkldnn_int8_pass.apply(graph)
        inference_program = graph.to_program()
        with fluid.scope_guard(inference_scope):
            fluid.io.save_inference_model(
                save_path,
                feed_target_names,
                fetch_targets,
                exe,
                inference_program,
                model_filename=save_model_filename,
                params_filename=save_params_filename)
        print(
            "Success! INT8 model obtained from the Quant model can be found at {}\n"
            .format(save_path))


if __name__ == '__main__':
    global test_args
    test_args, remaining_args = parse_args()
    transform_and_save_int8_model(
        test_args.quant_model_path, test_args.int8_model_save_path,
        test_args.ops_to_quantize, test_args.op_ids_to_skip, test_args.debug,
        test_args.quant_model_filename, test_args.quant_params_filename,
        test_args.save_model_filename, test_args.save_params_filename)