def new_booking():
    global s, p, d
    ch_typ = {'s':s, 'p':p, 'd':d}  # dictionary of choice (got below), and room type
    if all(len(i) != 0 for i in ch_typ.values()):
        print("Enter Info for a New Booking. Press Enter anytime to exit.")
        print("What type of room you want to book?\n\t[magenta]⟪S⟫ Standard Room\n\t⟪D⟫ Deluxe Room\n\t⟪P⟫ Premium Room[/magenta]")
        while True:
            try:
                ch = input("Enter your choice(S, P, D): ").lower()
                if ch not in ch_typ.keys():
                    if ch == '':
                        return
                    else:
                        raise ValueError
                break
            except ValueError:
                print("[red]Pls Enter a Valid Choice.[/red]")
        typ = ch_typ[ch]
        r = list(typ)[0]
        typ.remove(r)
        nam = input("Enter GUEST NAME:")
        if nam == '':
            return
        phone = phone_input()   # a function called
        if phone == '':
            return
        print("[cyan]Room Booked![/cyan]")
        while True:
            print("Your details:")
            print(f"\tRoom no: [magenta]{r}[magenta]")
            print(f"\tName: [magenta]{nam}[/magenta]")
            print(f"\tPhone number: [magenta]{phone}[/magenta]")
            ask = input("Want to change anything? Enter y for yes and n for no\n").lower()
            if ask == 'y':
                try:
                    f = update_guest("ch")
                    if type(f) != tuple:
                        raise MyTypeError
                    else:
                        r, nam, phone = f
                except MyTypeError:
                    pass                    
            else:
                cursor.execute("select room_key from hotel_rooms where roomno={}".format(r))
                k = cursor.fetchone()
                key = k[0]
                cursor.execute(f"update hotel_rooms set guestname='{nam}', phone='{phone}' where roomno={r}")
                print(f"[magenta][cyan]Okay! Here's your key:[/cyan] {key}[/magenta]")
                cnx.commit()
                break
    else:
        print("[cyan]Sorry, Housefull.😥[/cyan]")
    if input("Press Enter to continue.") == '':
        return


def update_guest(a):
    '''
    This function takes 1 argument ("ch" or "up").
    if "ch" is given, a guest recheck is done. Otherwise simple update.
    '''
    if a == "up":
        print("Enter Room No to Update Info. Press Enter anytime to exit.")
        r = get_room_input()
        if r == '':
            return
        if r < 51:
            typ = s
        elif r < 76:
            typ = d
        else:
            typ = p
        if r not in typ:
            cursor.execute("select roomno, guestname, phone, class from hotel_rooms where roomno={}".format(r))
            data = cursor.fetchone()
            room, nam, phone, clss = data
            print(f"Old Info:-\n\t[magenta]Room no: {room}\n\tGuest Name: {nam}\n\tPhone no: {phone}\n\tType of Room: {clss}[/magenta]")
            print("Enter New Info")
            print("Enter New ROOM NO", end='')
            n = get_room_input()
            if n == '':
                return
            elif (n in i for i in (s, p, d)):
                print("Room already occcupied.")
            nam = input("Enter GUEST NAME:")
            if nam == '':
                return
            phone = phone_input()
            if phone == '':
                return
            while True:
                k = input("Enter six-digit-key: ")
                cursor.execute(f"select room_key from hotel_rooms where roomno={r}")
                data = cursor.fetchone()
                if k == data[0]:
                    cursor.execute(f"update hotel_rooms set guestname='{nam}', phone='{phone}' where roomno={r}")
                    cnx.commit()
                    print("Room Updated.")
                    break
                elif k == '':
                    print("Updation cancelled.")
                    time.sleep(1)
                    return
                else:
                    print("[red]Incorrect key.[/red]")
        else:
            print("Room no. {} is unoccupied.".format(r))
        if input("Press Enter to continue.") == '':
            return
    elif a == "ch":
        print("Enter New Values to change. Press Enter anytime to exit.")
        print("Enter New ROOM NO", end='')
        n = get_room_input()
        if n == '':
            return
        r = change_room(r, n)
        nam = input("Enter Name:")
        if nam == '':
            return
        phone = phone_input()
        if phone == '':
            return
        return r, nam, phone


def change_room(old_r, new_r):
    o = old_r
    n = new_r
    cursor.execute("select guestname, phone from hotel_rooms where roomno={}".format(o))
    data = cursor.fetchone()
    nam, phone = data
    cursor.execute("update hotel_rooms set guestname=NULL, phone=NULL where roomno={}".format(o))
    cnx.commit()
    cursor.execute("update hotel_rooms set guestname={}, phone={} where roomno={}".format(nam, phone, n))
    cnx.commit()
    return n