import argparse
import json
import os
from datetime import datetime

from cryptography.fernet import Fernet


LEGACY_LICENSE_KEY = b"vS-C5Z_R1ST-Gf_K8_L9_Xo2-M1A3B5C7D9E1F2G3H4="


def load_master_key() -> bytes:
    env_key = os.getenv("VFM_LICENSE_MASTER_KEY")
    if env_key:
        return env_key.encode("utf-8")
    return LEGACY_LICENSE_KEY


def parse_args():
    parser = argparse.ArgumentParser(description="Gerador de licenca do V-Fire Monitor")
    parser.add_argument("--hwid", help="Hardware ID do cliente")
    parser.add_argument("--cliente", help="Nome do cliente")
    parser.add_argument("--expira", help="Data de expiracao no formato AAAA-MM-DD")
    return parser.parse_args()


def ask_if_missing(value: str, prompt: str) -> str:
    return value if value else input(prompt).strip()


def validate_expiration(date_text: str) -> str:
    datetime.strptime(date_text, "%Y-%m-%d")
    return date_text


def gerar_serial(hardware_id: str, cliente: str, data_expiracao: str) -> str:
    fernet = Fernet(load_master_key())
    payload = {"h": hardware_id.strip(), "c": cliente.strip(), "e": validate_expiration(data_expiracao)}
    return fernet.encrypt(json.dumps(payload, ensure_ascii=False).encode("utf-8")).decode("utf-8")


def main():
    args = parse_args()

    hardware_id = ask_if_missing(args.hwid, "Hardware ID do cliente: ")
    cliente = ask_if_missing(args.cliente, "Nome do cliente: ")
    expiracao = ask_if_missing(args.expira, "Validade (AAAA-MM-DD): ")

    if not hardware_id:
        raise SystemExit("Hardware ID obrigatorio.")
    if not cliente:
        raise SystemExit("Nome do cliente obrigatorio.")

    print(gerar_serial(hardware_id, cliente, expiracao))


if __name__ == "__main__":
    main()