# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.

import argparse
import os
import os.path as osp

from mmengine.config import Config, DictAction
from mmengine.model import is_model_wrapper
from mmengine.registry import RUNNERS
from mmengine.runner import Runner
from mmengine.runner.checkpoint import load_checkpoint

from mmdet.utils import register_all_modules


# TODO: support fuse_conv_bn, visualization, and format_only
def parse_args():
    parser = argparse.ArgumentParser(
        description='MMTrack test (and eval) a model')
    parser.add_argument('config', help='test config file path')
    parser.add_argument('--checkpoint', help='checkpoint file')
    parser.add_argument('--detector', help='detection checkpoint file')
    parser.add_argument('--reid', help='reid checkpoint file')
    parser.add_argument(
        '--work-dir',
        help='the directory to save the file containing evaluation metrics')
    parser.add_argument(
        '--cfg-options',
        nargs='+',
        action=DictAction,
        help='override some settings in the used config, the key-value pair '
        'in xxx=yyy format will be merged into config file. If the value to '
        'be overwritten is a list, it should be like key="[a,b]" or key=a,b '
        'It also allows nested list/tuple values, e.g. key="[(a,b),(c,d)]" '
        'Note that the quotation marks are necessary and that no white space '
        'is allowed.')
    parser.add_argument(
        '--launcher',
        choices=['none', 'pytorch', 'slurm', 'mpi'],
        default='none',
        help='job launcher')
    parser.add_argument('--local-rank', type=int, default=0)
    args = parser.parse_args()
    if 'LOCAL_RANK' not in os.environ:
        os.environ['LOCAL_RANK'] = str(args.local_rank)
    return args


def main():
    args = parse_args()

    # register all modules in mmtrack into the registries
    # do not init the default scope here because it will be init in the runner
    register_all_modules(init_default_scope=False)

    # load config
    cfg = Config.fromfile(args.config)
    cfg.launcher = args.launcher
    if args.cfg_options is not None:
        cfg.merge_from_dict(args.cfg_options)

    # work_dir is determined in this priority: CLI > segment in file > filename
    if args.work_dir is not None:
        # update configs according to CLI args if args.work_dir is not None
        cfg.work_dir = args.work_dir
    elif cfg.get('work_dir', None) is None:
        # use config filename as default work_dir if cfg.work_dir is None
        cfg.work_dir = osp.join('./work_dirs',
                                osp.splitext(osp.basename(args.config))[0])

    cfg.load_from = args.checkpoint

    # build the runner from config
    if 'runner_type' not in cfg:
        # build the default runner
        runner = Runner.from_cfg(cfg)
    else:
        # build customized runner from the registry
        # if 'runner_type' is set in the cfg
        runner = RUNNERS.build(cfg)

    if is_model_wrapper(runner.model):
        model = runner.model.module
    else:
        model = runner.model

    if args.detector:
        assert not (args.checkpoint and args.detector), \
            'Error: checkpoint and detector checkpoint cannot both exist'
        load_checkpoint(model.detector, args.detector)

    if args.reid:
        assert not (args.checkpoint and args.reid), \
             'Error: checkpoint and reid checkpoint cannot both exist'
        load_checkpoint(model.reid, args.reid)

    # start testing
    runner.test()


if __name__ == '__main__':
    main()