import datetime
import json
import os
from typing import Any, Union

import bcrypt
import jwt
from fastapi import Cookie, Depends, HTTPException, status
from fastapi.security import HTTPBearer, OAuth2PasswordRequestForm
from jwt.exceptions import InvalidTokenError

ACCESS_TOKEN_EXPIRE_MINUTES = 30  # 30 minutes
ALGORITHM = "HS256"
JWT_SECRET_KEY = 'abcdefghijklmnopqrstuvwxyz'

security = HTTPBearer()


def create_access_token(subject: str|int, encryption_key: str, expires_delta: int = None) -> str:
    """Creates a jwt token for the logged in user"""

    if expires_delta is not None:
        expires_delta = datetime.datetime.now(datetime.timezone.utc) + expires_delta
    else:
        expires_delta = datetime.datetime.now(datetime.timezone.utc) + datetime.timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)

    to_encode = {"exp": expires_delta, "sub": subject, "key": encryption_key}
    encoded_jwt = jwt.encode(to_encode, JWT_SECRET_KEY, ALGORITHM)
    return encoded_jwt


def get_current_user(token: str = Depends(security)) -> dict:
    """Parses a jwt token and if it's valid, returns the user ID from it"""

    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={'WWW-Authenticate': 'Bearer'}
    )
    credential = token.credentials

    try:
        payload = jwt.decode(credential, JWT_SECRET_KEY, algorithms=[ALGORITHM])
        user_id: str = payload.get("sub")
        if user_id is None:
            raise credentials_exception

    except InvalidTokenError:
        raise credentials_exception

    with open('database/users.json', 'r') as f:
        text = f.read()
        if text:
            data = json.loads(text)
        else:
            raise credentials_exception

    user = [i for i in data if i['id']==user_id]
    if not user:
        raise credentials_exception

    cur_user = {'id': user_id}
    cur_user['username'] = user[0]['username']
    cur_user['encryption_key'] = payload['key']

    return cur_user


def get_current_user2(token: str = Cookie(default=None)):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={'WWW-Authenticate': 'Bearer'}
    )
    print('TOKEN: ', token)

    try:
        payload = jwt.decode(token, JWT_SECRET_KEY, algorithms=[ALGORITHM])
        user_id: str = payload.get("sub")
        if user_id is None:
            raise credentials_exception

    except InvalidTokenError:
        raise credentials_exception

    with open('database/users.json', 'r') as f:
        text = f.read()
        if text:
            data = json.loads(text)
        else:
            raise credentials_exception

    user = [i for i in data if i['id']==user_id]
    if not user:
        raise credentials_exception

    cur_user = {'id': user_id}
    cur_user['username'] = user[0]['username']
    cur_user['encryption_key'] = payload['key']

    return cur_user

class Hasher:
    """Class for hashing and verifying passwords"""

    @staticmethod
    def verify_password(plain_password: str, hashed_password: str) -> bool:
        encoded_password = plain_password.encode('utf-8')
        encoded_hash = hashed_password.encode('utf-8')
        return bcrypt.checkpw(encoded_password, encoded_hash)

    @staticmethod
    def get_password_hash(password: str) -> str:
        salt = bcrypt.gensalt()
        encoded_password = password.encode('utf-8')
        hash = bcrypt.hashpw(encoded_password, salt)
        return hash.decode('utf-8')