import os
from pymongo import MongoClient
import hashlib
from bson.objectid import ObjectId


MONGO_URI = os.environ.get("MONGO_URI", "mongodb://localhost:27017")
MONGO_DB_NAME = os.environ.get("MONGO_DB_NAME", "Invario_Website")


def _get_users_collection():
    client = MongoClient(MONGO_URI, serverSelectionTimeoutMS=1500)
    db = client[MONGO_DB_NAME]
    return client, db["users"]


def check_password_strength(password):
    if len(password) < 6:
        return False
    return True


def hashing(password):
    return hashlib.scrypt(
        password.encode(),
        salt=b'salt_1234567890',
        n=16384,
        r=8,
        p=1,
        dklen=64,
    ).hex()


def check_nm_pwd(username, password):
    client = None
    try:
        client, users = _get_users_collection()
        hashed_password = hashing(password)
        return users.find_one({'Username': username, 'Password': hashed_password})
    finally:
        if client:
            client.close()


def add_user(username, password, school_name="", contact_person="", email="", marketing_opt_in=False, verified=False, verification_token=None):
    """
    Legt einen neuen Benutzer mit allen Verifizierungsdaten in MongoDB an.
    """
    if not check_password_strength(password):
        return False

    client = None
    try:
        client, users = _get_users_collection()
        users.insert_one(
            {
                'Username': username,
                'Password': hashing(password),
                'Admin': False,
                'active_ausleihung': None,
                'school_name': school_name,
                'contact_person': contact_person,
                'email': (email or '').strip().lower(),
                'marketing_opt_in': marketing_opt_in,
                'verified': verified,
                'verification_token': hashing(verification_token) if verification_token else None,
            }
        )
        return True
    finally:
        if client:
            client.close()


def verify_user_token(username, token):
    """
    Prüft den Token und markiert das Konto als verifiziert.
    """
    client = None
    try:
        client, users = _get_users_collection()
        user = users.find_one({'Username': username})
        if user and user.get('verification_token') == hashing(token):
            users.update_one(
                {'Username': username},
                {'$set': {'verified': True, 'verification_token': None}}
            )
            return True
        return False
    finally:
        if client:
            client.close()


def make_admin(username):
    client = None
    try:
        client, users = _get_users_collection()
        users.update_one({'Username': username}, {'$set': {'Admin': True}})
        return True
    finally:
        if client:
            client.close()


def remove_admin(username):
    client = None
    try:
        client, users = _get_users_collection()
        users.update_one({'Username': username}, {'$set': {'Admin': False}})
        return True
    finally:
        if client:
            client.close()


def get_user(username):
    client = None
    try:
        client, users = _get_users_collection()
        return users.find_one({'Username': username})
    finally:
        if client:
            client.close()


def check_admin(username):
    client = None
    try:
        client, users = _get_users_collection()
        user = users.find_one({'Username': username})
        return user and user.get('Admin', False)
    finally:
        if client:
            client.close()


def delete_user(username):
    client = None
    try:
        client, users = _get_users_collection()
        result = users.delete_one({'username': username})
        if result.deleted_count == 0:
            result = users.delete_one({'Username': username})
        return result.deleted_count > 0
    finally:
        if client:
            client.close()


def get_all_users():
    try:
        client, users = _get_users_collection()
        all_users = list(users.find())
        client.close()
        return all_users
    except Exception:
        return []


def update_password(username, new_password):
    try:
        if not check_password_strength(new_password):
            return False

        client, users = _get_users_collection()
        hashed_password = hashing(new_password)
        
        result = users.update_one(
            {'Username': username}, 
            {'$set': {'Password': hashed_password}}
        )
        client.close()
        return result.modified_count > 0
    except Exception as e:
        print(f"Error updating password: {e}")
        return False