import logging
import os
import random
import socket
import string
import xml.etree.ElementTree as ET
from logging.handlers import RotatingFileHandler
from pathlib import Path

def configure_logging():
    current_file = Path(__file__).resolve()
    sdsat_root = current_file.parent.parent
    log_dir = sdsat_root / "logs"
    log_dir.mkdir(parents=True, exist_ok=True)
    log_file = log_dir / "change_hostname.log"

    handler = RotatingFileHandler(
        str(log_file),
        maxBytes=2 * 1024 * 1024,
        backupCount=2,
    )
    formatter = logging.Formatter("%(asctime)s %(message)s")
    handler.setFormatter(formatter)

    root = logging.getLogger()
    root.setLevel(logging.INFO)
    root.handlers.clear()
    root.addHandler(handler)

def generate_random_string(length: int) -> str:
    letters = string.ascii_lowercase
    return "".join(random.choice(letters) for _ in range(length))

def update_config_hostname(config_path: str, new_hostname: str) -> tuple[str | None, bool]:
    """
    Met à jour <hostname> dans le XML.
    Retourne (old_hostname, changed)
    """
    tree = ET.parse(config_path)
    root = tree.getroot()

    old_hostname = None
    changed = False

    for elem in root.iter("hostname"):
        old_hostname = elem.text
        elem.text = new_hostname
        changed = True

    if changed:
        tree.write(config_path)

    return old_hostname, changed

def apply_hostname(new_hostname: str) -> int:
    # Retourne le code retour de la commande
    return os.system(f"sudo hostname {new_hostname}")

def main(
    expected_hostname: str = "sd-satxx.dtx.io",
    config_path: str = "/conf/config.xml",
) -> None:
    configure_logging()

    host = socket.gethostname()
    logging.info(f"Hostname recupere : {host}")

    if host != expected_hostname:
        logging.info("No need to change, changed already YBT")
        return

    new_hostname = "DTX-SDSAT-" + generate_random_string(10)
    logging.info(f"New hostname is: {new_hostname}")

    old_hostname, changed = update_config_hostname(config_path, new_hostname)
    if changed:
        logging.info(f"Changed hostname from {old_hostname} to {new_hostname}")
    else:
        logging.info("No <hostname> element found in config.xml")

    rc = apply_hostname(new_hostname)
    logging.info(f"Hostname change completed successfully (rc={rc})")

if __name__ == "__main__":
    main()