from flask import Blueprint, request, jsonify
from mysql.connector import connect
from werkzeug.security import generate_password_hash
from auth.token import verify_token
from util.db_config import load_config
from util.logger import logger

admin_bp = Blueprint("admin", __name__)


def _require_admin():
    user = verify_token()
    if not user:
        return None, (jsonify({"message": "Nicht autorisiert"}), 401)
    if user.get("role") != "admin":
        logger.warning("🚫 Adminbereich verweigert (kein Admin)")
        return None, (jsonify({"message": "Adminrechte erforderlich"}), 403)
    return user, None


@admin_bp.route("/api/admin/users", methods=["GET"])
def list_users():
    _, err = _require_admin()
    if err:
        return err
    try:
        cfg = load_config()
        conn = connect(**cfg)
        cur = conn.cursor(dictionary=True)
        cur.execute("SELECT id, username, role FROM users ORDER BY username ASC")
        users = cur.fetchall()
        cur.close()
        conn.close()
        return jsonify(users)
    except Exception as e:
        logger.error(f"[Admin list_users] {e}")
        return jsonify({"message": "Serverfehler"}), 500


@admin_bp.route("/api/admin/users", methods=["POST"])
def create_user():
    admin, err = _require_admin()
    if err:
        return err
    data = request.get_json() or {}
    username = data.get("username", "").strip()
    password = data.get("password", "")
    role = data.get("role", "user")
    if not username or not password:
        return jsonify({"message": "Username und Passwort erforderlich"}), 400
    try:
        cfg = load_config()
        conn = connect(**cfg)
        cur = conn.cursor(dictionary=True)
        cur.execute("SELECT id FROM users WHERE username=%s", (username,))
        if cur.fetchone():
            cur.close()
            conn.close()
            return jsonify({"message": "Nutzer existiert bereits"}), 409
        cur.execute(
            "INSERT INTO users (username, password, role) VALUES (%s, %s, %s)",
            (username, generate_password_hash(password), role)
        )
        conn.commit()
        new_id = cur.lastrowid
        cur.close()
        conn.close()
        logger.info(f"✅ User erstellt: {username} durch {admin['username']}")
        return jsonify({"id": new_id, "username": username, "role": role}), 201
    except Exception as e:
        logger.error(f"[Admin create_user] {e}")
        return jsonify({"message": "Serverfehler"}), 500


@admin_bp.route("/api/admin/users/<int:user_id>", methods=["PUT"])
def update_user(user_id):
    admin, err = _require_admin()
    if err:
        return err
    data = request.get_json() or {}
    role = data.get("role")
    password = data.get("password")
    if role is None and password is None:
        return jsonify({"message": "Nichts zu aktualisieren"}), 400
    try:
        cfg = load_config()
        conn = connect(**cfg)
        cur = conn.cursor()
        if role:
            cur.execute("UPDATE users SET role=%s WHERE id=%s", (role, user_id))
        if password:
            cur.execute(
                "UPDATE users SET password=%s WHERE id=%s",
                (generate_password_hash(password), user_id)
            )
        conn.commit()
        cur.close()
        conn.close()
        logger.info(f"✏️ User aktualisiert (id={user_id}) durch {admin['username']}")
        return jsonify({"message": "Aktualisiert"}), 200
    except Exception as e:
        logger.error(f"[Admin update_user] {e}")
        return jsonify({"message": "Serverfehler"}), 500


@admin_bp.route("/api/admin/users/<int:user_id>", methods=["DELETE"])
def delete_user(user_id):
    admin, err = _require_admin()
    if err:
        return err
    try:
        cfg = load_config()
        conn = connect(**cfg)
        cur = conn.cursor()
        # Schutz: Admin darf sich nicht selbst löschen
        cur.execute("SELECT username FROM users WHERE id=%s", (user_id,))
        row = cur.fetchone()
        if not row:
            cur.close()
            conn.close()
            return jsonify({"message": "Nicht gefunden"}), 404
        username = row[0]
        if username == admin["username"]:
            cur.close()
            conn.close()
            return jsonify({"message": "Du kannst dich nicht selbst löschen"}), 400
        cur.execute("DELETE FROM users WHERE id=%s", (user_id,))
        conn.commit()
        cur.close()
        conn.close()
        logger.info(f"🗑️ User gelöscht (id={user_id}) durch {admin['username']}")
        return jsonify({"message": "Gelöscht"}), 200
    except Exception as e:
        logger.error(f"[Admin delete_user] {e}")
        return jsonify({"message": "Serverfehler"}), 500