#!/usr/bin/python


import socket
##################
#                #
# Default values #
#                #
##################

CONTROLLER  = socket.gethostname()
SERVER      = "localhost"
RFID_PATH   = "/dev/ttyUSB0"
YELLOW_LED  = 7
GREEN_LED   = 11
RED_LED     = 13
DOOR_STRIKE = 15
ZOHO_CLIENT_ID = "Ask George"
ZOHO_CLIENT_SECRET = "Or Check"
ZOHO_REFRESH_TOKEN = "The Wiki"



import os
####################
#                  #
# Read doorrc file #
#                  #
####################

for conf in [ "/etc/doorsrc", "./doorsrc" ]:
    if os.path.exists(conf):
        with open(conf) as f:
            exec(compile(f.read(), "doorsrc", 'exec'))



import atexit
import RPi.GPIO as GPIO
####################
#                  #
# Set up GPIO Pins #
#                  #
####################

GPIO.setmode(GPIO.BOARD)
atexit.register(GPIO.cleanup)

GPIO.setup(DOOR_STRIKE, GPIO.OUT)
GPIO.setup(RED_LED, GPIO.OUT)
GPIO.setup(GREEN_LED, GPIO.OUT)
GPIO.setup(YELLOW_LED, GPIO.OUT)
GPIO.output(YELLOW_LED, GPIO.OUT)


OFF = GPIO.LOW
ON  = GPIO.HIGH


def unlock_door():
    print("Door is unlocked");
    GPIO.output(DOOR_STRIKE, ON)
    GPIO.output(RED_LED, OFF)
    GPIO.output(GREEN_LED, ON)

def lock_door():
    print("Door is locked");
    GPIO.output(DOOR_STRIKE, OFF)
    GPIO.output(RED_LED, ON)
    GPIO.output(GREEN_LED, OFF)
lock_door()

# Turn all LEDs on
def leds_on():
    GPIO.output(RED_LED, ON)
    GPIO.output(GREEN_LED, ON)

# Turn all LEDs off
def leds_off():
    GPIO.output(RED_LED, OFF)
    GPIO.output(GREEN_LED, OFF)

def blink_leds():
    print("Blinking LEDs")
    for i in range(5):
        if (i % 2) == 0:
            leds_on()
        else:
            leds_off()
        time.sleep(1)
    lock_door()




import time
import datetime
from zoho_auth import ZohoToken, authenticate
from slacker import Slacker
#############################################
#                                           #
# Verify a key with openings.workantile.com #
#                                           #
#############################################
CACHED_KEYS = set()
TODAYS_KEYS = set()
NEED_FLUSH  = []
THIS_MONTH  = datetime.date.today().month
THIS_DAY    = datetime.date.today().day

zoho_token = ZohoToken(ZOHO_CLIENT_ID, ZOHO_CLIENT_SECRET, ZOHO_REFRESH_TOKEN)

def ping_server(key):
    GPIO.output(YELLOW_LED, ON)
    authorized = authenticate(zoho_token, key)
    GPIO.output(YELLOW_LED, OFF)

    if authorized:
        CACHED_KEYS.add(key)
    elif key in CACHED_KEYS:
        CACHED_KEYS.remove(key)

    return authorized

def notify_slack(count):
    slack = Slacker(SLACK_TOKEN)
    message = f"{count} people have entered today."
    if count == 1:
        message = f"{count} person has entered today."
    slack.chat.post_message(SLACK_CHANNEL, message)

def clear_cache():
    global THIS_MONTH

    today = datetime.date.today()
    if today.month != THIS_MONTH:
        print("Clearing key cache")
        CACHED_KEYS.clear()
    THIS_MONTH = today.month

def clear_member_count():
    global THIS_DAY

    today = datetime.date.today()
    if today.day != THIS_DAY:
        print("Clearing member count")
        TODAYS_KEYS.clear()
    THIS_DAY = today.day


def verify_key(key):
    print("Verifying key: %s" % key)
    clear_cache()
    if key in CACHED_KEYS:
        print("Using cached key")
        NEED_FLUSH.append(key)
        return True
    return ping_server(key)

def check_today_count(key):
    clear_member_count()
    if key not in TODAYS_KEYS:
        print("New key:", key)
        TODAYS_KEYS.add(key)
        notify_slack(len(TODAYS_KEYS))


def flush_keys():
    if len(NEED_FLUSH) > 0:
        ping_server(NEED_FLUSH[0])
        NEED_FLUSH.pop(0)


#python-pyserial package. Not sure we need this. Grabbed based on
#http://allenmlabs.blogspot.se/2013/01/raspberry-pi-parallax-rfid-reader.html
import serial
###################
#                 #
# Run RFID Reader #
#                 #
###################

RFID_SERIAL = serial.Serial(RFID_PATH, 2400, timeout=1)

def read_key():
    RFID_SERIAL.reset_input_buffer() # Clear input buffer before reading
    string = RFID_SERIAL.read(12)
    if len(string) == 12 and string[0] == 0xA and string[-1] == 0xD:
        key = string[1:11].decode() #exclude start 0xA and stop 0xD bytes
        if key.isalnum():
            return key;
    return None

def read_rfid():
    try:
        key = read_key()
        if key and verify_key(key):
            unlock_door()
            time.sleep(5) # block for 5 seconds before resetting door
            lock_door()
            check_today_count(key)
        flush_keys()
    except Exception as e:
        print(e)
        lock_door()
        blink_leds()



def loop():
    while True:
        read_rfid()

if __name__ == "__main__":
    loop()