#!/usr/bin/env python3
"""
Babycam Network State Machine
Verwaltet die drei Betriebsmodi:
  A – Heimnetz (wlan0 verbunden, AP aus)
  B – Kein WLAN (AP auf wlan1 automatisch)
  C – Setup-Modus (AP läuft, User konfiguriert WLAN)

Override-Datei: /tmp/babycam-ap-override
  "on"  → AP immer an (manuell)
  "off" → AP immer aus (manuell)
  fehlt → Automatik
"""

import subprocess
import time
import logging
import sys
import os

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    handlers=[logging.StreamHandler(sys.stdout)],
)
log = logging.getLogger(__name__)

AP_INTERFACE = "wlan1"
CLIENT_INTERFACE = "wlan0"
AP_IP = "192.168.50.1"
CHECK_INTERVAL = 30  # Sekunden
OVERRIDE_FILE = "/var/lib/babycam/ap-override"


def run(cmd, check=False):
    result = subprocess.run(cmd, shell=True, capture_output=True, text=True)
    if check and result.returncode != 0:
        log.error(f"Fehler bei: {cmd}\n{result.stderr}")
    return result


def get_override():
    """Liest die manuelle Override-Einstellung. Gibt 'on', 'off' oder None zurück."""
    try:
        with open(OVERRIDE_FILE) as f:
            val = f.read().strip().lower()
            if val in ("on", "off"):
                return val
    except FileNotFoundError:
        pass
    return None


def is_wlan0_connected():
    result = run(f"nmcli -t -f GENERAL.STATE device show {CLIENT_INTERFACE}")
    return "100 (connected)" in result.stdout


def is_ap_running():
    result = run("systemctl is-active hostapd")
    return result.stdout.strip() == "active"


def start_ap():
    log.info("Starte Access Point (BabyCam)...")
    run("ip addr add 192.168.50.1/24 dev wlan1 2>/dev/null || true")
    run("ip link set wlan1 up")
    run("systemctl start hostapd", check=True)
    run("systemctl start dnsmasq", check=True)
    log.info("Access Point gestartet.")


def stop_ap():
    log.info("Stoppe Access Point...")
    run("systemctl stop hostapd")
    run("systemctl stop dnsmasq")
    run("ip addr flush dev wlan1 2>/dev/null || true")
    log.info("Access Point gestoppt.")


def main():
    log.info("Babycam Network State Machine gestartet.")
    current_mode = None

    while True:
        override = get_override()
        connected = is_wlan0_connected()
        ap_running = is_ap_running()

        if override == "on":
            # Manuell: AP immer an
            if current_mode != "MANUAL_ON":
                log.info("Modus: Manuell – Access Point erzwungen AN.")
                if not ap_running:
                    start_ap()
                current_mode = "MANUAL_ON"

        elif override == "off":
            # Manuell: AP immer aus
            if current_mode != "MANUAL_OFF":
                log.info("Modus: Manuell – Access Point erzwungen AUS.")
                if ap_running:
                    stop_ap()
                current_mode = "MANUAL_OFF"

        else:
            # Automatik
            if connected:
                if current_mode != "A":
                    log.info("Modus A: Heimnetz aktiv – AP aus.")
                    if ap_running:
                        stop_ap()
                    current_mode = "A"
            else:
                if current_mode != "B":
                    log.info("Modus B: Kein WLAN – starte Access Point.")
                    if not ap_running:
                        start_ap()
                    current_mode = "B"

        time.sleep(CHECK_INTERVAL)


if __name__ == "__main__":
    main()