Check-in script

script.py

#!/usr/bin/python

from time import sleep
from Adafruit_CharLCDPlate import Adafruit_CharLCDPlate
import requests
import os

# Variables
baseURL = 'http://127.0.0.1'

# Initialize the LCD plate.
lcd = Adafruit_CharLCDPlate()
lcd.clear()
lcd.backlight(lcd.OFF)

# Build initial status array with userID's and their status
r = requests.get(baseURL + '/api/users')
users = r.json()
statusArr = {}
for user in users['content']:
    if user['status'] is None:
        statusArr[int(user['ID'])] = 0
    else:
        statusArr[int(user['ID'])] = int(user['status'])


# Check every 3 seconds for new changes
def pollCheckinsAndDisplay():
    checkForChanges()
    sleep(3)


# Check user api for changes in checkin/checkout
def checkForChanges():
    r = requests.get(baseURL + '/api/users')
    users = r.json()

    for user in users['content']:
        if user['status'] is not None:
            # print('Current status: ' + user['status'])
            # print('User ID: ' + user['ID'])
            # previousStatus = statusArr[int(user['ID'])]
            # print('Previous status: ' + str(previousStatus))

            if int(user['status']) != statusArr[int(user['ID'])]:
                print('User with id=' + user['ID'] + ' changed status...')
                showUserCheckinOnDisplay(user)
                sleep(3)
                lcd.clear()
                lcd.backlight(lcd.OFF)


# Show checkin on display when user status changes
def showUserCheckinOnDisplay(user):
    lcd.clear()

    if int(user['status']) == 1:
        lcd.backlight(lcd.GREEN)
        lcd.message(user['username'] + '\nchecked-in')
        statusArr[int(user['ID'])] = 1
    elif int(user['status']) == 0:
        lcd.backlight(lcd.RED)
        lcd.message(user['username'] + '\nchecked-out')
        statusArr[int(user['ID'])] = 0
    else:
        print('error')


# Poll for nfc cards
def pollNFC():
    f = os.popen("/home/pi/libnfc/libnfc-1.6.0-rc1/examples/nfc-poll")
    for i in f.readlines():
        if "UID" in i:
            uidStr = i.strip().replace(" ", "").split(":")
            uid = uidStr[1]
            print('NFC card with UID found: ' + uid)
            doCheckinByUID(uid)


def doCheckinByUID(uid):
    # Do post request
    r = requests.post(baseURL + '/api/users/' + uid + '/checkins')
    if int(r.status_code) == 200:
        print('Succesfully checked user in/out!')

    # Retrieve user info and display it on screen
    r = requests.get(baseURL + '/api/users/' + str(uid))
    userInfo = r.json()
    user = userInfo['content']

    # Display on LCD
    if int(user['status']) == 1:
        lcd.backlight(lcd.GREEN)
        lcd.message(user['username'] + '\nchecked-in')
        statusArr[int(user['ID'])] = 1
    elif int(user['status']) == 0:
        lcd.backlight(lcd.RED)
        lcd.message(user['username'] + '\nchecked-out')
        statusArr[int(user['ID'])] = 0
    else:
        print('Something went wrong...')

    sleep(3)
    lcd.clear()
    lcd.backlight(lcd.OFF)

# Infinite loop
while True:
    #pollCheckinsAndDisplay()  # Poll the api for new checkins and display them on screen (depricated)
    pollNFC()  # Poll for NFC cards and do checkin