from flask import Flask, request, render_template, jsonify, redirect, send_from_directory
from backend.db_config import lade_db_config, speichere_db_config, teste_verbindung, initialisiere_admin_user
from datetime import datetime, timedelta
from jwt import decode, ExpiredSignatureError, InvalidTokenError

import time
import os
import jwt
import logging
from logging.handlers import RotatingFileHandler

app = Flask(__name__)
app.template_folder = "templates"
SECRET_KEY = "bitte_hier_dein_geheimes_passwort_setzen"  # Achtung: später z. B. aus .env

CONFIG_PATH = "config/db_config.json"
MAX_WAIT = 30  # In Sekunden
WAIT_INTERVAL = 10


# Logging-Zielpfade
log_dir = "Tools"
os.makedirs(log_dir, exist_ok=True)

# App-Log (alles ab INFO)
app_log_handler = RotatingFileHandler(
    os.path.join(log_dir, "app.log"), maxBytes=1_000_000, backupCount=3
)
app_log_handler.setLevel(logging.INFO)
app_log_handler.setFormatter(logging.Formatter(
    "%(asctime)s [%(levelname)s] %(message)s"))

# Error-Log (nur ERROR)
error_log_handler = RotatingFileHandler(
    os.path.join(log_dir, "error.log"), maxBytes=1_000_000, backupCount=3
)
error_log_handler.setLevel(logging.ERROR)
error_log_handler.setFormatter(logging.Formatter(
    "%(asctime)s [%(levelname)s] %(message)s"))

# Logging-Grundkonfiguration
logging.basicConfig(
    level=logging.INFO,
    handlers=[
        app_log_handler,
        error_log_handler,
        logging.StreamHandler()
    ]
)

logger = logging.getLogger(__name__)

def ist_konfiguriert():
    return os.path.exists(CONFIG_PATH)

def versuche_verbindung_mit_warten():
    elapsed = 0
    if not ist_konfiguriert():
        logger.warning("⚠️ Noch keine Konfiguration gefunden.")
        return False
    config = lade_db_config()
    while not teste_verbindung(config) and elapsed < MAX_WAIT:
        logger.info(f"🔄 DB nicht erreichbar – warte {WAIT_INTERVAL}s...")
        time.sleep(WAIT_INTERVAL)
        elapsed += WAIT_INTERVAL
    if elapsed >= MAX_WAIT:
        logger.error("❌ Maximale Wartezeit überschritten – DB nicht erreichbar.")
    return elapsed < MAX_WAIT

@app.route('/api/status')
def status():
    if not ist_konfiguriert():
        return jsonify({"status": "init", "db_connected": False})
    elif teste_verbindung(lade_db_config()):
        return jsonify({"status": "ready", "db_connected": True})
    else:
        return jsonify({"status": "error", "db_connected": False})

@app.route('/setup', methods=['GET', 'POST'])
def setup():
    if request.method == 'POST':
        db_config = {
            "host": request.form['host'],
            "port": int(request.form['port']),
            "user": request.form['user'],
            "password": request.form['password'],
            "database": request.form['database']
        }
        speichere_db_config(db_config)
        if teste_verbindung(db_config):
            initialisiere_admin_user(db_config)
            logger.info("✅ Setup erfolgreich, Admin-User erstellt.")
            return redirect('/')
        else:
            logger.error("❌ Setup fehlgeschlagen – DB-Verbindung nicht möglich.")
            return "Verbindung fehlgeschlagen. Bitte zurück und prüfen.", 500
    return render_template('setup.html')

@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def serve_react(path):
    if not ist_konfiguriert() or not teste_verbindung(lade_db_config()):
        return redirect('/setup')

    # setup und API dürfen nicht von React überdeckt werden
    if path.startswith('setup') or path.startswith('api'):
        return redirect(f'/{path}')

    # Pfad zu frontend/dist absolut auflösen
    dist_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'frontend', 'dist'))
    file_path = os.path.join(dist_dir, path)

    if path and os.path.exists(file_path):
        return send_from_directory(dist_dir, path)
    else:
        return send_from_directory(dist_dir, 'index.html')

@app.route('/api/login', methods=['POST'])
def login():
    from mysql.connector import connect
    from werkzeug.security import check_password_hash

    data = request.get_json()
    username = data.get('username')
    password = data.get('password')

    try:
        config = lade_db_config()
        conn = connect(**config)
        cursor = conn.cursor(dictionary=True)
        cursor.execute("SELECT * FROM users WHERE username = %s", (username,))
        user = cursor.fetchone()
        cursor.close()
        conn.close()

        if user and check_password_hash(user['password'], password):
            logger.info(f"✅ Login erfolgreich: {username}")

            payload = {
                "username": user['username'],
                "role": user['role'],
                "exp": datetime.utcnow() + timedelta(minutes=60)
            }
            token = jwt.encode(payload, SECRET_KEY, algorithm="HS256")

            return jsonify({
                "token": token,
                "role": user['role']
            })

        logger.warning(f"⛔ Login fehlgeschlagen: {username}")
        return jsonify({"message": "Login fehlgeschlagen"}), 401

    except Exception as e:
        logger.error(f"[Login-Fehler] {e}")
        return jsonify({"message": "Serverfehler"}), 500

@app.route('/api/logout', methods=['POST'])
def logout():
    return jsonify({"message": "Logout erfolgreich"})

def verify_token():
    auth_header = request.headers.get("Authorization", "")
    if not auth_header.startswith("Bearer "):
        logger.warning("🔐 Kein gültiger Bearer-Header")
        return None

    token = auth_header.replace("Bearer ", "")
    try:
        decoded = decode(token, SECRET_KEY, algorithms=["HS256"])
        return decoded
    except ExpiredSignatureError:
        logger.warning("🔐 Token abgelaufen")
        return None
    except InvalidTokenError:
        logger.warning("🔐 Ungültiger Token")
        return None


@app.route('/api/hash/md5', methods=['POST'])
def hash_md5():
    logger.info("🔁 /api/hash/md5 aufgerufen")

    user = verify_token()
    if not user:
        logger.warning("⛔ Nicht autorisiert")
        return jsonify({"message": "Nicht autorisiert"}), 401

    try:
        data = request.get_json()
        logger.debug(f"📩 Payload: {data}")
        password = data.get("password", "")

        import hashlib
        result = hashlib.md5(password.encode()).hexdigest()

        logger.info(f"✅ Hash erstellt von {user['username']}")
        return jsonify({
            "md5": result,
            "by": user['username']
        })

    except Exception as e:
        logger.error(f"❌ Fehler beim Hashen: {e}")
        return jsonify({"message": "Fehler beim Hashen"}), 500


if __name__ == '__main__':
    os.makedirs("config", exist_ok=True)
    app.run(host='0.0.0.0', port=5000, debug=True)  # debug=True nur für Entwicklung, nicht in Produktion verwenden!