#!/usr/bin/env python3
"""
WinDHCPD - Windows-native DHCP server
======================================
Python 3 + Scapy based lightweight DHCP server for Windows.

Usage:
    python run.py                 # uses dhcpd.yaml in cwd
    python run.py config.yaml     # specify config file
    python run.py config.yaml -i  # specify interface
    python run.py --help

Web panel: http://localhost:8080
"""

from __future__ import annotations

import argparse
import logging
import os
import signal
import sys
import threading

from dhcpd.config import Config
from dhcpd.lease import LeaseDB
from dhcpd.server import DHCPd
from dhcpd.web import app as web_app

# ── logging setup ────────────────────────────────────────────────────────

def setup_logging(level: str = "INFO", log_file: str = "dhcpd.log") -> None:
    """Configure logging to both console and file."""
    numeric = getattr(logging, level.upper(), logging.INFO)
    fmt = logging.Formatter(
        "%(asctime)s [%(levelname)s] %(name)s: %(message)s",
        datefmt="%Y-%m-%d %H:%M:%S",
    )

    # Console handler
    ch = logging.StreamHandler(sys.stdout)
    ch.setFormatter(fmt)
    ch.setLevel(numeric)

    # File handler
    try:
        fh = logging.FileHandler(log_file, encoding="utf-8")
        fh.setFormatter(fmt)
        fh.setLevel(numeric)
    except OSError:
        fh = None

    root = logging.getLogger()
    root.setLevel(numeric)
    root.addHandler(ch)
    if fh:
        root.addHandler(fh)

    # Scapy is chatty
    logging.getLogger("scapy").setLevel(logging.WARNING)


# ── main ─────────────────────────────────────────────────────────────────

def main():
    parser = argparse.ArgumentParser(description="WinDHCPD - DHCP server for Windows")
    parser.add_argument("config", nargs="?", default="dhcpd.yaml",
                        help="Path to YAML config file (default: dhcpd.yaml)")
    parser.add_argument("-i", "--interface", default=None,
                        help="Network interface name to listen on")
    parser.add_argument("--no-web", action="store_true",
                        help="Disable web management panel")
    parser.add_argument("--web-port", type=int, default=0,
                        help="Web panel port (overrides config)")
    args = parser.parse_args()

    # Load config
    config_path = args.config
    if not os.path.exists(config_path):
        print(f"[ERROR] Config not found: {config_path}")
        print(f"        Create one from dhcpd.yaml.example")
        sys.exit(1)

    cfg = Config(config_path)
    setup_logging(cfg.log_level, cfg.log_file)
    logging.getLogger("dhcpd").info("=" * 60)
    logging.getLogger("dhcpd").info("WinDHCPD starting")
    logging.getLogger("dhcpd").info("Config: %s", config_path)
    logging.getLogger("dhcpd").info("Scopes: %s", ", ".join(s.name for s in cfg.scopes))
    logging.getLogger("dhcpd").info("Bindings: %d", len(cfg.bindings))

    # Lease database
    db_path = os.path.join(os.path.dirname(os.path.abspath(config_path)), "leases.db")
    db = LeaseDB(db_path)
    logging.getLogger("dhcpd").info("Lease DB: %s (%d leases loaded)",
                                    db_path, db.count())

    # Server
    srv = DHCPd(cfg, db, iface=args.interface)
    srv.start()

    # Web panel
    if not args.no_web:
        web_port = args.web_port or cfg.web_port
        web_host = cfg.web_host
        web_app.init(srv, cfg, db)
        t = threading.Thread(
            target=web_app.run,
            args=(web_host, web_port),
            daemon=True,
            name="web-panel",
        )
        t.start()
        logging.getLogger("dhcpd").info("Web panel: http://%s:%d", web_host, web_port)

    # Graceful shutdown
    def shutdown(sig, frame):
        logging.getLogger("dhcpd").info("Received signal %s, shutting down...", sig)
        srv.stop()
        sys.exit(0)

    signal.signal(signal.SIGINT, shutdown)
    signal.signal(signal.SIGTERM, shutdown)

    logging.getLogger("dhcpd").info("Server running. Press Ctrl+C to stop.")
    # Keep main thread alive
    try:
        while True:
            import time as _t
            _t.sleep(1)
    except KeyboardInterrupt:
        shutdown(signal.SIGINT, None)


if __name__ == "__main__":
    main()