import requests
import json
import re
import os
from datetime import datetime
from typing import Callable, Any


def loadSettings() -> dict:
    path = f"{os.path.expanduser('~')}/.config/dyn-gandi/config.json"

    if not os.path.exists(path):
        path = '/etc/dyn-gandi.json'

    if not os.path.exists(path):
        quit()

    # TODO: check integrity of the config file
    with open(path, 'r') as file:
        # Read if the API keys are path to files
        config = json.load(file)
        keys = config['api'].keys()
        mask = dict()
        for key in keys:
            api_key = key
            if os.path.exists(key):
                with open(key, 'r') as file:
                    api_key = file.readline().strip()
            mask[key] = api_key
        config['api'] = {mask[key]: value for key,
                         value in config['api'].items()}
    return config


def log(logline: str, path: str = './log.txt') -> None:
    # Appends logline at the end of the file file with a timestamp
    with open(path, 'a') as file:
        file.write(
            f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}]{logline}\n")


def getCurrentIP(resolvers: list[str], log: Callable[[str], Any]) -> str | None:
    # Go through resolvers until one retuns an IP
    for resolver in resolvers:
        response = requests.get(resolver)
        if response.status_code == 200:
            current_ip = response.text.strip()
            # it suffices to check whether the search is not None since the regex is matches from beginning to end
            is_ipv4 = re.search(
                '^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\\b){4}$', current_ip) is not None
            if is_ipv4:
                log(f"[OK][{resolver}] Current IP: '{current_ip}'")
                return current_ip  # Break if we have found our IP
            else:
                log(f"[ERROR][{resolver}] '{current_ip}' is not IPv4")
        else:
            log(f"[ERROR][{resolver}][{response.status_code}] {response.text}")
    return None


def checkRecords(api: dict[str, dict[str, list[str]]], current_ip: str, log: Callable[[str], Any]) -> dict[str, dict[str, list[str]]]:
    # Returns the records that need to be renewed
    # TODO: Also detect TTL change
    records_to_renew = api
    for key, domains in api.items():
        headers = {'authorization': f"Apikey {key}"}
        for domain, _ in domains.items():
            response = requests.get(
                f"https://api.gandi.net/v5/livedns/domains/{domain}/records?rrset_type=A", headers=headers)
            if response.status_code == 200:
                records_to_renew[key][domain] = list(
                    set(records_to_renew[key][domain]) - set(record['rrset_name'] for record in (filter(lambda x: current_ip in x['rrset_values'], response.json()))))
            else:
                log(f"[ERROR][{domain}][{response.status_code}] {response.json()}")

    return records_to_renew


def renewRecords(api: dict[str, dict[str, list[str]]], current_ip: str, log: Callable[[str], Any], ttl) -> None:
    # Updates the records and reates them if they don't exist
    payload = json.dumps({
        'rrset_values': [current_ip],
        'rrset_ttl': ttl
    })

    for key, domains in api.items():
        headers = {
            'authorization': f"Apikey {key}",
            'content-type': 'application/json',
        }

        for domain, records in domains.items():
            for record in records:
                response = requests.put(
                    f"https://api.gandi.net/v5/livedns/domains/{domain}/records/{record}/A", data=payload, headers=headers)
                if response.status_code == 201:
                    log(f"[OK][{domain}][{record}] Renewed with IP '{current_ip}'")
                else:
                    log(f"[ERROR][{domain}][{record}][{response.status_code}] {response.json()}")


def main():
    settings = loadSettings()
    log_path, ttl = settings['log_path'], settings['ttl']
    def logger(x: str) -> Any: return log(x, log_path)

    current_ip = getCurrentIP(settings['resolvers'], logger)
    if current_ip is not None:
        records_to_renew = checkRecords(settings['api'], current_ip, logger)
        renewRecords(records_to_renew, current_ip, logger, ttl=ttl)


if __name__ == '__main__':
    main()