from gpiozero import Button, LED                                                            # Import libraries
from time import sleep
from signal import pause
from datetime import datetime, timedelta
from pathlib import Path
import pandas as pd
import schedule

best_before_exeeded = timedelta(seconds=18)                                                 # Define thresholds
overdue = timedelta(seconds=30)

consumption_overview = []                                                                   # Key variables
current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")

infrared_sensor = Button(2)                                                                 # GPIO pins of external hardware
orange_led = LED(4)
red_led = LED(17)

def on_a_sensor_signal():                                                                   # On a signal: update  list, save csv and turn off led (if necessary)
    current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    if len(consumption_overview) == 0 or consumption_overview[-1]['Status'] == 'Yogurt eaten up':
        new_status = "Yogurt open"
        passed_time = "pending"
        consumption_overview.append({'Status':new_status, 'Time':current_time, 'Consumed In':passed_time})
    else:
        new_status = "Yogurt eaten up"

        if len(consumption_overview) > 0 and consumption_overview[-1]['Status'] == 'Yogurt open':
            opening_time_str = consumption_overview[-1]['Time']    
        else:
            opening_time_str = current_time

        opening_time = datetime.strptime(opening_time_str, '%Y-%m-%d %H:%M:%S')
        now = datetime.strptime(current_time, '%Y-%m-%d %H:%M:%S')
        time_difference = now - opening_time
        
        consumption_overview.append({'Status':new_status, 'Time':current_time, 'Consumed In':str(time_difference)})
    print(consumption_overview[-1])
    
    if len(consumption_overview) > 0 and consumption_overview[-1]['Status'] == 'Yogurt eaten up':
        orange_led.off()
        print("orange led pin 4 turned off")
        red_led.off()
        print("red led pin 17 turned off")
        df = pd.DataFrame(consumption_overview)
        currentDateTime = datetime.now().strftime("%Y%m%d_%H%M%S")
        df.to_csv(f"Raspberry Yogurt_{currentDateTime}.csv", index=False)
        print("CSV file saved")

def check():                                                                                # Runs periodically the led_check as long as ayogurth is open
    schedule.every(6).seconds.do(led_check)
    
    while not infrared_sensor.is_active and consumption_overview[-1]['Status'] == 'Yogurt open':
        schedule.run_pending()

def led_check():                                                                            # Checks if an led needs to be turend on
    current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    if len(consumption_overview) > 0 and consumption_overview[-1]['Status'] == 'Yogurt open':
        opening_time_str = consumption_overview[-1]['Time']    
    else:
        opening_time_str = current_time
        
    opening_time = datetime.strptime(opening_time_str, '%Y-%m-%d %H:%M:%S')
    now = datetime.strptime(current_time, '%Y-%m-%d %H:%M:%S')
    time_difference = now - opening_time
    print("open since", time_difference)

    if overdue > time_difference >= best_before_exeeded:
        orange_led.on()
        print("ORANGE LED ON", "open since", time_difference)
    elif time_difference >= overdue:
        orange_led.off()
        print("orange led off")
        red_led.on()
        print("RED LED ON", "open since", time_difference)

while True:                                                                                 # Keeps the program running to listen for sensor events
    infrared_sensor.when_pressed = on_a_sensor_signal
    infrared_sensor.when_released = check
    pause()