import jwt
import re
from db.db import users_db
from tinydb import Query
from flask import request, current_app, jsonify

from events.sse import send_event_to_user


def normalize_email(email: str) -> str:
    """Normalize email for uniqueness checks (Gmail: remove dots and +aliases)."""
    email = email.strip().lower()
    if '@' not in email:
        return email
    local, domain = email.split('@', 1)
    if domain in ('gmail.com', 'googlemail.com'):
        local = local.split('+', 1)[0].replace('.', '')
    return f"{local}@{domain}"

def sanitize_email(email):
    return email.replace('@', '_at_').replace('.', '_dot_')

def get_current_user_id():
    token = request.cookies.get('token')
    if not token:
        return None
    try:
        payload = jwt.decode(token, current_app.config['SECRET_KEY'], algorithms=['HS256'])
        user_id = payload.get('user_id')
        if not user_id:
            return None
        return user_id
    except jwt.InvalidTokenError:
        return None
    
def get_validated_user_id():
    user_id = get_current_user_id()
    if not user_id or not users_db.get(Query().id == user_id):
        return None
    return user_id    

def send_event_for_current_user(event):
    user_id = get_current_user_id()
    if not user_id:
        return jsonify({'error': 'Unauthorized'}), 401
    send_event_to_user(user_id, event)
    return None