from datetime import datetime
from flask import current_app as app


def file_date_human(num):
    return datetime.fromtimestamp(num).strftime("%y-%m-%d")


def file_time_human(num):
    return datetime.fromtimestamp(num).strftime("%y-%m-%d %H:%M")


def file_size_human(num, HTML=True):
    space = " " if HTML else " "
    for x in [space + "B", "KB", "MB", "GB", "TB"]:
        if num < 1024.0:
            if x == space + "B":
                return "%d%s%s" % (num, space, x)
            return "%3.1f%s%s" % (num, space, x)
        num /= 1024.0


def file_size_MB(num):
    return "{:,.2f}".format(num / (1024 * 1024))


def get_or_none(key, d, none=None):
    if key in d:
        return d[key]
    else:
        return none


def is_path_safe(path):
    if path.startswith("."):
        return False
    if "/." in path:
        return False
    return True


def is_valid_url(url, qualifying=None):
    min_attributes = ("scheme", "netloc")
    qualifying = min_attributes if qualifying is None else qualifying
    token = urlparse(url)
    return all([getattr(token, qualifying_attr) for qualifying_attr in qualifying])


def path2url(path):
    return pathname2url(path)


def safe_name(s):
    return safe_string(s, "-_")


def safe_path(s):
    return safe_string(s, "-_/")


def safe_string(s, valid, no_repeat=False):
    """return a safe string, replace non alnum characters with _ . all characters in valid are considered valid."""
    safe = "".join([c if c.isalnum() or c in valid else "_" for c in s])
    if no_repeat:
        safe = re.sub(r"_+", "_", safe)
    return safe