import logging

import requests

from app import app
from app.terraform.block_mirror import BlockMirrorAutomation


def _trim_prefix(s: str, prefix: str) -> str:
    if s.startswith(prefix):
        return s[len(prefix):]
    return s


def trim_http_https(s: str) -> str:
    """
    Return the string with "http://" or "https://" removed from the start of the string if present.

    :param s: String to modify.
    :return: Modified string.
    """
    return _trim_prefix(
        _trim_prefix(s, "https://"),
        "http://")


class BlockExternalAutomation(BlockMirrorAutomation):
    """
    Automation task to import proxy reachability results from external source.
    """
    short_name = "block_external"
    description = "Import proxy reachability results from external source"

    _content: bytes

    def fetch(self) -> None:
        user_agent = {'User-agent': 'BypassCensorship/1.0'}
        if isinstance(app.config.get('EXTERNAL_CHECK_URL', []), list):
            check_urls = app.config.get('EXTERNAL_CHECK_URL', [])
        elif isinstance(app.config.get('EXTERNAL_CHECK_URL'), str):
            check_urls = [app.config['EXTERNAL_CHECK_URL']]
        else:
            check_urls = []
        for check_url in check_urls:
            if self._data is None:
                self._data = []
            self._data.extend(requests.get(check_url, headers=user_agent, timeout=30).json())

    def parse(self) -> None:
        self.patterns.extend(["https://" + trim_http_https(pattern) for pattern in self._data])
        logging.debug("Found URLs: %s", self.patterns)