import hashlib, time, json
from cryptography.fernet import Fernet
from connect import connection, engine, metadata
import sqlalchemy as db

def hash_pass(password):
    return hashlib.sha256(password.encode()).hexdigest()

class Auth:
    def __init__(self, session, expire=0):
        self.session = session
        self.id = None
        self.email = None
        self.session["fc"] = 0
        self.fernet = Fernet(b'3UH3USxvBcFITpnVa2gvTUIMO5jbc8jqU_Q1O6SNBLs=')

        if session.get("id"):
            value = json.loads(self.fernet.decrypt(session["id"]))
            self.id = value["id"]
            self.email = value["email"]
        # Remember to always change
        self.expire=expire

    def checkAuth(self):
        if self.expire and time.time() - self.session["tiempo"] > self.expire:
            self.delAuth()
        else:
            self.session["tiempo"] = time.time()

        return self.session.get("gallitosccom")

    def setAuth(self, id, email):
        self.session["gallitosccom"] = True
        self.id = id
        self.email = email
        self.session["id"] = self.fernet.encrypt(json.dumps({"id": id, "email": email}).encode())
        if self.expire:
            self.session["tiempo"] = time.time()

    def delAuth(self):
        if self.session.get("gallitosccom"):
            self.session.pop("gallitosccom", None)
            self.session.pop("id", None)
            # self.session.pop("email", None)

    def do_login(self, username, password):
        password = hash_pass(password)
        usuarios = db.Table('usuarios', metadata, autoload=True, autoload_with=engine)
        query = db.select([usuarios])
        if username.find("@") > 1:
            print("email")
            query = query.select_from(usuarios).where(usuarios.columns.email == username)
        else:
            print("username")
            query = query.select_from(usuarios).where(usuarios.columns.username == username)

        result = connection.execute(query).fetchone()
        if result and password == result["password"]:
            print(result)
            self.setAuth(result["id"], result["email"])
            # Añadir feature de last login.
            self.session["fc"] = 0
            return True

        #introduce an authentication fail delay
        time.sleep(self.session["fc"] * 2)
        self.session["fc"] += 1
        return False

    def checkRole(self, tipo):
        tables = {"admin": "administracion", "madre": "madres", "enfermera":"enfermeras", "facultad": "facultad", "estudiante": "estudiantes"}
        if tipo in tables:
            table = tables[tipo]
        else:
            return False

        usuarios = db.Table('usuarios', metadata, autoload=True, autoload_with=engine)
        role = db.Table(table, metadata, autoload=True, autoload_with=engine)
        query = db.select([usuarios, role])
        query = query.select_from(usuarios.join(role, usuarios.columns.id == role.columns.user_id)).where(role.columns.user_id == self.id)
        result = connection.execute(query).fetchone()

        if result:
            return True

        return False

    def do_logout(self):
        self.delAuth()