import contextlib
import logging
import os
import platform
import sys
from pathlib import Path

# Constants
FILE = Path(__file__).resolve()
ROOT = FILE.parents[2]  # YOLO
RANK = int(os.getenv('RANK', -1))
DATASETS_DIR = ROOT.parent / 'datasets'  # YOLOv5 datasets directory
NUM_THREADS = min(8, max(1, os.cpu_count() - 1))  # number of YOLOv5 multiprocessing threads
AUTOINSTALL = str(os.getenv('YOLOv5_AUTOINSTALL', True)).lower() == 'true'  # global auto-install mode
FONT = 'Arial.ttf'  # https://ultralytics.com/assets/Arial.ttf
VERBOSE = str(os.getenv('YOLOv5_VERBOSE', True)).lower() == 'true'  # global verbose mode


def is_colab():
    # Is environment a Google Colab instance?
    return 'google.colab' in sys.modules


def is_kaggle():
    # Is environment a Kaggle Notebook?
    return os.environ.get('PWD') == '/kaggle/working' and os.environ.get('KAGGLE_URL_BASE') == 'https://www.kaggle.com'


def is_writeable(dir, test=False):
    # Return True if directory has write permissions, test opening a file with write permissions if test=True
    if not test:
        return os.access(dir, os.W_OK)  # possible issues on Windows
    file = Path(dir) / 'tmp.txt'
    try:
        with open(file, 'w'):  # open file with write permissions
            pass
        file.unlink()  # remove file
        return True
    except OSError:
        return False


def user_config_dir(dir='Ultralytics', env_var='YOLOV5_CONFIG_DIR'):
    # Return path of user configuration directory. Prefer environment variable if exists. Make dir if required.
    env = os.getenv(env_var)
    if env:
        path = Path(env)  # use environment variable
    else:
        cfg = {'Windows': 'AppData/Roaming', 'Linux': '.config', 'Darwin': 'Library/Application Support'}  # 3 OS dirs
        path = Path.home() / cfg.get(platform.system(), '')  # OS-specific config dir
        path = (path if is_writeable(path) else Path('/tmp')) / dir  # GCP and AWS lambda fix, only /tmp is writeable
    path.mkdir(exist_ok=True)  # make if required
    return path


USER_CONFIG_DIR = user_config_dir()  # Ultralytics settings dir


def emojis(str=''):
    # Return platform-dependent emoji-safe version of string
    return str.encode().decode('ascii', 'ignore') if platform.system() == 'Windows' else str


def colorstr(*input):
    # Colors a string https://en.wikipedia.org/wiki/ANSI_escape_code, i.e.  colorstr('blue', 'hello world')
    *args, string = input if len(input) > 1 else ("blue", "bold", input[0])  # color arguments, string
    colors = {
        "black": "\033[30m",  # basic colors
        "red": "\033[31m",
        "green": "\033[32m",
        "yellow": "\033[33m",
        "blue": "\033[34m",
        "magenta": "\033[35m",
        "cyan": "\033[36m",
        "white": "\033[37m",
        "bright_black": "\033[90m",  # bright colors
        "bright_red": "\033[91m",
        "bright_green": "\033[92m",
        "bright_yellow": "\033[93m",
        "bright_blue": "\033[94m",
        "bright_magenta": "\033[95m",
        "bright_cyan": "\033[96m",
        "bright_white": "\033[97m",
        "end": "\033[0m",  # misc
        "bold": "\033[1m",
        "underline": "\033[4m",}
    return "".join(colors[x] for x in args) + f"{string}" + colors["end"]


def set_logging(name=None, verbose=VERBOSE):
    # Sets level and returns logger
    if is_colab() or is_kaggle():
        for h in logging.root.handlers:
            logging.root.removeHandler(h)  # remove all handlers associated with the root logger object
    rank = int(os.getenv("RANK", -1))  # rank in world for Multi-GPU trainings
    level = logging.INFO if verbose and rank in {-1, 0} else logging.ERROR
    log = logging.getLogger(name)
    log.setLevel(level)
    handler = logging.StreamHandler()
    handler.setFormatter(logging.Formatter("%(message)s"))
    handler.setLevel(level)
    log.addHandler(handler)


set_logging()  # run before defining LOGGER
LOGGER = logging.getLogger("yolov5")  # define globally
if platform.system() == "Windows":
    for fn in LOGGER.info, LOGGER.warning:
        setattr(LOGGER, fn.__name__, lambda x: fn(emojis(x)))  # emoji safe logging


class TryExcept(contextlib.ContextDecorator):
    # YOLOv5 TryExcept class. Usage: @TryExcept() decorator or 'with TryExcept():' context manager
    def __init__(self, msg=''):
        self.msg = msg

    def __enter__(self):
        pass

    def __exit__(self, exc_type, value, traceback):
        if value:
            print(emojis(f'{self.msg}{value}'))
        return True