import re
from typing import Optional

import ruamel.yaml
import ruamel.yaml.compat

from ._constants import HEADER_KIWI_CONF_NAME


class YAML(ruamel.yaml.YAML):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.indent(offset=2)

    def dump(self, data, stream=None, **kwargs) -> Optional[str]:
        into_str: bool = False
        if stream is None:
            into_str = True
            stream = ruamel.yaml.compat.StringIO()

        super().dump(data, stream=stream, **kwargs)
        if into_str:
            return stream.getvalue()

    @staticmethod
    def _format_kiwi_yml(yml_string: str):
        # insert newline before every main key
        yml_string = re.sub(r'^(\S)', r'\n\1', yml_string, flags=re.MULTILINE)

        # load header comment from file
        with open(HEADER_KIWI_CONF_NAME, 'r') as stream:
            yml_string = stream.read() + yml_string

        return yml_string

    def dump_kiwi_yml(self, data, **kwargs) -> Optional[str]:
        return self.dump(data, transform=YAML._format_kiwi_yml, **kwargs)


def _surround(string, bang):
    midlane = f"{bang * 3} {string} {bang * 3}"
    sidelane = bang * len(midlane)

    return f"{sidelane}\n{midlane}\n{sidelane}"


def _emphasize(lines):
    if isinstance(lines, list):
        return '\n'.join([_emphasize(line) for line in lines])
    elif lines:
        return f">>> {lines} <<<"
    else:
        return lines


def are_you_sure(prompt, default="no"):
    if default.lower() == 'yes':
        suffix = "[YES|no]"
    else:
        suffix = "[yes|NO]"

    answer = input(
        f"{_surround('MUST HAVE CAREFULING IN PROCESS', '!')}\n"
        f"\n"
        f"{_emphasize(prompt)}\n"
        f"\n"
        f"Are you sure you want to proceed? {suffix} "
    ).strip().lower()

    if answer == '':
        answer = default

    while answer not in ['yes', 'no']:
        answer = input("Please type 'yes' or 'no' explicitly: ").strip().lower()

    return answer == 'yes'