from tkinter import *
from tkinter import ttk
import pandas as pd
from employee_manifest import EmployeeManifest
from home import Home
from sign_in import SignIn
import sched
import time
import os
from datetime import datetime, date , timedelta
from threading import Thread
from queue import Queue
#Special mention to James Haywood for imaging the PI $$ <3 <3!
class Main(Tk):
    def __init__(self):
        Tk.__init__(self)

        if os.name == 'nt':
            self.geometry('520x450')  
        else:
            self.geometry('720x450')
        
        self.winfo_toplevel().title("Sign in App")
        self.main_frame = Frame(self)
        self.main_frame.pack(side='top', fill=BOTH, expand=1, pady=10)

        #Thread safe queue and event to check queue for scheduled sign out at midnight
        #Required because scheduler is run in seperate thread which causes tkinter to break without
        self.sched_queue = Queue()
        self.bind('<<CheckQueue>>', self.run_signout)

        #List of GUI's used for mounting on button click    
        class FramesList():
            home = Home
            employee_manifest = EmployeeManifest
            sign_in = SignIn

        self.frames =  FramesList()

        #Mount home frame when class envoked (program started)
        self.current_frame = self.frames.home(self.main_frame, self)
        self.current_frame.place(anchor="c", relx=.5, rely=.5)

        self.home_btn = Button(text = 'Home', command=lambda: Main.frame_update(self, 'home'))
        self.home_btn.place(anchor='w', x=5, y=20)
            
        self.sched_thread = Thread(target=self.run_sched, daemon=True)
        self.sched_thread.start()
        
    #Destroy the current GUI frame and mount a requested GUI
    def frame_update(self, requested_frame):
        self.current_frame.destroy()
        next_frame = getattr(self.frames, requested_frame)
        self.current_frame = next_frame(self.main_frame, self)
        self.current_frame.place(anchor="c", relx=.5, rely=.5)
    
    #Add function to the thread safe queue and then generate an event that causes the queue to be checked
    def update_queue(event, self):
        self.sched_queue.put(self.clear_all_signin)
        self.event_generate('<<CheckQueue>>')
    
    #When CheckQueue event is fired this function is run
    #Gets function from queue and then runs it
    def run_signout(self, event):
        msg = self.sched_queue.get()
        msg()

    #Clears sign ins (scheduled to run at the start of next day) by just destroying and re-mounting the sign in frame
    def clear_all_signin(self):
        print('clear sign in executed')
        if type(app.current_frame).__name__ == 'SignIn':
            print('p0ng')
            self.frame_update('sign_in')
        self.run_sched()

    #Rune scheduled task at 12am each day
    def run_sched(self):
            scheduler = sched.scheduler(time.time, time.sleep)
            tomorrows_date = date.today() + timedelta(1)
            #todays_date = date.today()
            scheduled_time = datetime(tomorrows_date.year, tomorrows_date.month, tomorrows_date.day, 00, 00, 00)
            scheduler.enterabs(scheduled_time.timestamp(), 1, self.clear_all_signin)
            scheduler.run()
    
app = Main()
app.mainloop()