import bcrypt
import datetime

class Users:

    @staticmethod
    def create_user(db, login_info, user_info):

        """
        Creates a new user in the database
        
        Args:
            db (psycopg2.connection): connection to postgres database
            login_info (dict of str:str): username and password info
            user_info (dict of str:value): name (str) and dob (datetime.date) info

        Returns:
            int: 0 if the username is non-unique, user id otherwise
        """

        username, password = login_info["username"], login_info["password"]
        password_hash = bcrypt.hashpw(password.encode(), bcrypt.gensalt()).decode()
        name, dob = user_info["name"], user_info["dob"]
        with db:
            with db.cursor() as curs:
                curs.execute("SELECT * FROM Users WHERE username = %s", (username,))
                conflicts = curs.fetchall()
                if conflicts:
                    return 0
                curs.execute("INSERT INTO Users (username, password_hash, name, dob) VALUES (%s, %s, %s, %s) RETURNING id", (username, password_hash, name, dob))
                user_id = curs.fetchone()[0]
            db.commit()
        return user_id

    @staticmethod
    def get_user_from_username(db, username):

        """
        Get a user id based on their username
        
        Args:
            db (psycopg2.connection): connection to postgres database
            username (str): the username used to query

        Returns:
            int: 0 if the username is not in the system, user id otherwise
        """

        with db:
            with db.cursor() as curs:
                curs.execute("SELECT * FROM Users WHERE username = %s", (username,))
                users = curs.fetchall()
        if not users:
            return 0
        return users[0][0]

    @staticmethod
    def get_user_details(db, user_id):

        """
        Gets the details of a user based on their id
        
        Args:
            db (psycopg2.connection): connection to postgres database
            id (int): user id
        
        Returns:
            bool, dict of str to str, dict of str to value: user existance, login info (username, password), user info (name (str), dob (datetime.date))
        """

        with db:
            with db.cursor() as curs:
                curs.execute("SELECT * FROM Users WHERE id = %s", (user_id,))
                user = curs.fetchall()
        if not user:
            return False, {}, {}
        user = user[0]
        return True, {"username": user[1], "password_hash": user[2]}, {"name": user[3], "dob": user[4]}

class Tournaments:

    @staticmethod
    def create_event(db, name, time, max_age):

        """
        Creates a new event in the database
        
        Args:
            db (psycopg2.connection): connection to postgres database
            name (str): event name
            time (date.datetime): event time
            max_age (int): how old a fencer is allowed to be at the time of the event starting

        Returns:
            int: id of the event created
        """

        with db:
            with db.cursor() as curs:
                curs.execute("INSERT INTO Events (name, datetime, max_age, completed, registration, results) VALUES (%s, %s, %s, False, '', '') RETURNING id", (name, time, max_age))
                event_id = curs.fetchone()[0]
            db.commit()
        return event_id

    @staticmethod
    def create_tournament(db, events):
        pass

    @staticmethod
    def finish_event(db, event):
        pass