#copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
#
#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

import argparse
import os
import sys

import paddle
import paddle.fluid as fluid

import program

from ppcls.data import Reader
import ppcls.utils.environment as env
from ppcls.utils.config import get_config
from ppcls.utils.save_load import init_model, save_model
from ppcls.utils import logger

from paddle.fluid.incubate.fleet.collective import fleet
from paddle.fluid.incubate.fleet.base import role_maker


def parse_args():
    parser = argparse.ArgumentParser("PaddleClas train script")
    parser.add_argument(
        '-c',
        '--config',
        type=str,
        default='configs/ResNet/ResNet18_vd.yaml',
        help='config file path')
    parser.add_argument(
        '-o',
        '--override',
        action='append',
        default=[],
        help='config options to be overridden')
    args = parser.parse_args()
    return args


def main(args):
    role = role_maker.PaddleCloudRoleMaker(is_collective=True)
    fleet.init(role)

    config = get_config(args.config, overrides=args.override, show=True)
    place = env.place()

    startup_prog = fluid.Program()
    train_prog = fluid.Program()

    train_dataloader, train_fetchs = program.build(
        config, train_prog, startup_prog, is_train=True)

    if config.validate:
        valid_prog = fluid.Program()
        valid_dataloader, valid_fetchs = program.build(
            config, valid_prog, startup_prog, is_train=False)
        valid_prog = valid_prog.clone(for_test=True)

    exe = fluid.Executor(place)
    exe.run(startup_prog)

    init_model(config, train_prog, exe)

    train_reader = Reader(config, 'train')()
    train_dataloader.set_sample_list_generator(train_reader, place)

    if config.validate:
        valid_reader = Reader(config, 'valid')()
        valid_dataloader.set_sample_list_generator(valid_reader, place)
        compiled_valid_prog = program.compile(config, valid_prog)

    compiled_train_prog = fleet.main_program
    for epoch_id in range(config.epochs):
        program.run(train_dataloader, exe, compiled_train_prog, train_fetchs,
                    epoch_id, 'train')

        if config.validate and epoch_id % config.valid_interval == 0:
            program.run(valid_dataloader, exe, compiled_valid_prog,
                        valid_fetchs, epoch_id, 'valid')

        if epoch_id % config.save_interval == 0:
            model_path = os.path.join(config.model_save_dir,
                                      config.architecture)
            save_model(train_prog, model_path, epoch_id)


if __name__ == '__main__':
    args = parse_args()
    main(args)