from servo import Servo
from hcsr04 import HCSR04
from time import sleep
from machine import Pin, SoftI2C
from lcd_api import LcdApi
from i2c_lcd import I2cLcd

#Ultra Sonic Sensor setup
sensor = HCSR04(trigger_pin = 5, echo_pin = 18, echo_timeout_us = 100000)

#Servo setup
motor = Servo(pin=19)

#I2C LCD Setup
I2C_ADDR = 0x27  
totalRows = 2  
totalColumns = 16

i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=10000)				#initializing the I2C method for ESP32  
lcd = I2cLcd(i2c, I2C_ADDR, totalRows, totalColumns)

#Global Variables
freeSlots = 5
entryFlag = 0
exitFlag = 0

#PIR pin declaration
entry_PIR = Pin(13, Pin.IN)
exit_PIR = Pin(25, Pin.IN)

#Functions Definition
def displayWelcome():
    lcd.move_to(0,0)
    lcd.putstr("Welcome, DriveIn")


def displaySlots():
    lcd.move_to(2,0)
    lcd.putstr("Free Slots: " + str(freeSlots))



while True:
    distance = sensor.distance_cm()
    if(freeSlots > 0):
        if(distance < 50):
            #Open Servo
            motor.move(0)

            #Welcome
            displayWelcome()
            sleep(2)
            lcd.clear()

        

        elif(distance > 50):
            motor.move(90)

        if(entry_PIR.value() == 1 and entryFlag == 0):
            #Decrease free slots
            freeSlots = freeSlots - 1
            if(freeSlots < 0):
                freeSlots = 0
            
            entryFlag = 1

        elif(entry_PIR.value() == 0):
            entryFlag = 0

    if(freeSlots < 5):
        if(exit_PIR.value() == 1 and exitFlag == 0):
            #Increase free slots
            freeSlots = freeSlots + 1
            if(freeSlots < 0):
                freeSlots = 0
            
            exitFlag = 1

        elif(exit_PIR.value() == 0):
            exitFlag = 0

    print('Distance: ', distance)
    
    displaySlots()