import os
import sys
import time
from datetime import datetime
import logging
import numpy as np
import torch
import math

def get_timestamp():
    return datetime.now().strftime('%y%m%d-%H%M%S')

def mkdir_and_rename(path):
    if os.path.exists(path):
        new_name = path + '_archived_' + get_timestamp()
        print('Path already exists. Rename it to [{:s}]'.format(new_name))
        os.rename(path, new_name)
    os.makedirs(path)


def scandir(dir_path, suffix=None, recursive=False, full_path=False):
    """Scan a directory to find the interested files.
    Args:
        dir_path (str): Path of the directory.
        suffix (str | tuple(str), optional): File suffix that we are
            interested in. Default: None.
        recursive (bool, optional): If set to True, recursively scan the
            directory. Default: False.
        full_path (bool, optional): If set to True, include the dir_path.
            Default: False.
    Returns:
        A generator for all the interested files with relative pathes.
    """

    if (suffix is not None) and not isinstance(suffix, (str, tuple)):
        raise TypeError('"suffix" must be a string or tuple of strings')

    root = dir_path

    def _scandir(dir_path, suffix, recursive):
        for entry in os.scandir(dir_path):
            if not entry.name.startswith('.') and entry.is_file():
                if full_path:
                    return_path = entry.path
                else:
                    return_path = os.path.relpath(entry.path, root)

                if suffix is None:
                    yield return_path
                elif return_path.endswith(suffix):
                    yield return_path
            else:
                if recursive:
                    yield from _scandir(
                        entry.path, suffix=suffix, recursive=recursive)
                else:
                    continue

    return _scandir(dir_path, suffix=suffix, recursive=recursive)


def setup_logger(log_file_path):
    log_formatter = logging.Formatter("%(asctime)s    [%(levelname)-5.5s]  %(message)s")
    root_logger = logging.getLogger()
    root_logger.setLevel(logging.INFO)

    log_file_handler = logging.FileHandler(log_file_path, encoding='utf-8')
    log_file_handler.setFormatter(log_formatter)
    root_logger.addHandler(log_file_handler)

    log_stream_handler = logging.StreamHandler(sys.stdout)
    log_stream_handler.setFormatter(log_formatter)
    root_logger.addHandler(log_stream_handler)

    logging.info('Logging file is %s' % log_file_path)


def print_args(args):
    for arg in vars(args):
        logging.info(arg + ':%s'%(getattr(args, arg)))