# Copyright (c) OpenMMLab. All rights reserved.
import argparse
import logging
import os
import os.path as osp
from types import FunctionType

from mmengine import print_log
from mmengine.config import Config, DictAction
from mmengine.registry import RUNNERS
from mmengine.runner import Runner

from xtuner.configs import cfgs_name_path
from xtuner.model.utils import guess_load_checkpoint
from xtuner.registry import MAP_FUNC
from mmengine.model import is_model_wrapper


def parse_args():
    parser = argparse.ArgumentParser(description='Test model')
    parser.add_argument('config', help='config file name or path.')
    parser.add_argument('--checkpoint', default=None, help='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(
        '--deepspeed',
        default=None,
        help='Dummy option'
    )
    parser.add_argument(
        '--launcher',
        choices=['none', 'pytorch', 'slurm', 'mpi'],
        default='none',
        help='job launcher')
    parser.add_argument('--local_rank', '--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 register_function(cfg_dict):
    if isinstance(cfg_dict, dict):
        for key, value in dict.items(cfg_dict):
            if isinstance(value, FunctionType):
                value_str = str(value)
                if value_str not in MAP_FUNC:
                    MAP_FUNC.register_module(module=value, name=value_str)
                cfg_dict[key] = value_str
            else:
                register_function(value)
    elif isinstance(cfg_dict, (list, tuple)):
        for value in cfg_dict:
            register_function(value)


def main():
    args = parse_args()

    if args.deepspeed is not None:
        print_log("Deepspeed is not adopted during inference, Skipped.", level=logging.WARN)

    # parse config
    if not osp.isfile(args.config):
        try:
            args.config = cfgs_name_path[args.config]
        except KeyError:
            raise FileNotFoundError(f'Cannot find {args.config}')

    # 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)

    # register FunctionType object in cfg to `MAP_FUNC` Registry and
    # change these FunctionType object to str
    register_function(cfg._cfg_dict)

    # 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])

    # 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 args.checkpoint is not None:
        state_dict = guess_load_checkpoint(args.checkpoint)

        if is_model_wrapper(runner.model):
            runner.model.module.load_state_dict(state_dict, strict=False)
        else:
            runner.model.load_state_dict(state_dict, strict=False)
        runner.logger.info(f'Load checkpoint from {args.checkpoint}')
    else:
        Warning("No checkpoint !!!")

    # start testing
    runner.test()


if __name__ == '__main__':
    main()