import core.users as users
import core.postgres as postgres
import bcrypt
import jwt
from jwt.exceptions import ExpiredSignatureError, InvalidTokenError
import datetime
import os


def verifyLoginToken(login_token, username=False, userUUID=False):
    if username:
        userUUID = users.getUserUUID(username)

    if userUUID:
        try:
            decoded_token = jwt.decode(
                login_token, os.getenv("JWT_SECRET"), algorithms=["HS256"]
            )
            if decoded_token.get("sub") == str(userUUID):
                return True
            return False
        except (ExpiredSignatureError, InvalidTokenError):
            return False
    return False


def getUserpasswordHash(userUUID):
    user = postgres.select_one("users", {"id": userUUID})
    if user:
        pw_hash = user.get("password_hashed")
        if isinstance(pw_hash, memoryview):
            return bytes(pw_hash)
        return pw_hash
    return None


def getLoginToken(username, password):
    userUUID = users.getUserUUID(username)
    if userUUID:
        formatted_pass = password.encode("utf-8")
        users_hashed_pw = getUserpasswordHash(userUUID)
        if bcrypt.checkpw(formatted_pass, users_hashed_pw):
            payload = {
                "sub": userUUID,
                "name": users.getUserFirstName(userUUID),
                "exp": datetime.datetime.utcnow() + datetime.timedelta(hours=1),
            }
            return jwt.encode(payload, os.getenv("JWT_SECRET"), algorithm="HS256")
    return False


def unregisterUser(userUUID, password):
    pw_hash = getUserpasswordHash(userUUID)
    if not pw_hash:
        return False
    if bcrypt.checkpw(password.encode("utf-8"), pw_hash):
        return users.deleteUser(userUUID)
    return False