from functools import wraps
from tempfile import mkdtemp
from shutil import rmtree
from subprocess import check_output, CalledProcessError
from sys import exit


VERBOSE = True

def call_verbose(before_message='', after_message='Done!'):
    def tag(f):
        @wraps(f)
        def wrapper(*args, **kwargs):
            print_opt(before_message, end='', flush=True)
            f(*args, **kwargs)
            print_opt(after_message)
        return wrapper
    return tag

def print_opt(*args, **kwargs):
    if VERBOSE:
        print(*args, **kwargs)


def yes_no_question(question, default):
    valid = {"yes": True, "y": True, "ye": True,
             "no": False, "n": False}
    if default is None:
        prompt = " [y/n] "
    elif default == "yes":
        prompt = " [Y/n] "
    elif default == "no":
        prompt = " [y/N] "
    else:
        raise ValueError("Invalid default answer: {}!".format(default))

    while True:
        print(question + prompt)
        choice = input().lower()
        if default is not None and choice == '':
            return valid[default]
        elif choice in valid:
            return valid[choice]
        else:
            print("Please respond with 'yes'(y) or 'no'(n)!")


# tempfile.TemporaryDirectory replacement to provide backwards compatibility
class temporary_directory:
    def __enter__(self):
        self.name = mkdtemp()
        return self.name

    def __exit__(self, exc_type, exc_val, exc_tb):
        rmtree(self.name)


def get_output(*args, **kwargs):
    return check_output(*args, **kwargs).decode().rstrip('\n')


@call_verbose(before_message='Checking your system for dependencies... ', after_message='Found all!')
def check_dependencies(check_for):
    error_str = '\nMissing dependencies: {}'
    missing = []

    for command in check_for:
        try: check_output(command)
        except (CalledProcessError, FileNotFoundError): missing.append(command[0])

    if missing: exit(error_str.format(', '.join(missing)))