import time
import os
import glob
import os.path
import datetime

#################################################################
#Setup local output file to store temp information for use in the event of the pi losing connection to the network
file_name = "brew_data.txt"
if (not(os.path.isfile(file_name))):
        tempfile = open(file_name,"w")
        tempfile.close
with open(file_name) as f:
        try:
                saved_temp = float(f.read())
        except:
                saved_temp = None


#################################################################
#setup GPIO (pin BCM 11 for ssr use)
import RPi.GPIO as GPIO
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(11,GPIO.OUT, initial=GPIO.LOW)

#################################################################
#setup temp probe
os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')
base_dir = '/sys/bus/w1/devices/'
device_folder = glob.glob(base_dir + '28*')[0]
device_file = device_folder + '/w1_slave'
def read_temp_raw():
    f = open(device_file, 'r')
    lines = f.readlines()
    f.close()
    return lines
def read_temp():
    lines = read_temp_raw()
    while lines[0].strip()[-3:] != 'YES':
        time.sleep(0.2)
        lines = read_temp_raw()
    equals_pos = lines[1].find('t=')
    if equals_pos != -1:
        temp_string = lines[1][equals_pos+2:]
        temp_c = float(temp_string) / 1000.0
        return temp_c

#credits Ian Howson @ ianhowson.com for FetchOneAssoc Func
def FetchOneAssoc(cursor):
        data = cursor.fetchone()
        if data == None:
                return None
        desc = cursor.description
        dict = {}
        for (name, value) in zip(desc, data):
                dict[name[0]] = value
        return dict
try:

        ##################################################################
        #setup mysql connection to server
        import mysql.connector
        cnx = mysql.connector.connect(user='fermentation', password='beerbeer',
                                      host='192.168.1.4',
                                      database='fermentation')
        cursor = cnx.cursor()


        ######################################################################
        #program


        chamber_id = 1
        script_iteration_delay = 60 #how often in seconds the script is executed with cron
        query = ("""SELECT * FROM chambers JOIN fermentation on
                (chambers.active_fermentation = fermentation.f_id)
                WHERE chamber_id = """+str(chamber_id)+"""
                """)

        brew_query = cursor.execute(query)
        brew_data = (FetchOneAssoc(cursor))


        if not(brew_data == None):
                #Currently a ongoing fermentation in this chamber, proceed to edit both chamber and fermentation tables
                target_temp = brew_data['temp_c']
                current_temp = read_temp()
                element_status = 0
                element_runtime = brew_data['element_active_seconds']
                active_ferm_id = brew_data['active_fermentation']


                current_element_status = brew_data['element_active']
                if (current_element_status == 1):
                        last_conn = brew_data['last_conn']
                        if (not(last_conn == None)):
                                f = '%Y-%m-%d %H:%M:%S'
                                timestamp = time.mktime(datetime.datetime.strptime(str(last_conn), "%Y-%m-%d %H:%M:%S").timetuple())
                                current_timestamp = time.time()
                                script_iteration_delay = int(round(current_timestamp-timestamp,0))


                f = open(file_name, 'r+')
                f.truncate(0)
                f.write(str(float(target_temp)))
                f.close()
                if (current_temp < target_temp):
                        element_status = 1
                print(str(current_temp))

                if (element_status == 1):
                        GPIO.output(11,1)
                        print("element on")
                        element_runtime = element_runtime + script_iteration_delay
                else:
                        GPIO.output(11,0)
                        print("element off")

                query = ("UPDATE chambers SET last_conn = NOW(), real_time_temp="+str(current_temp)+", element_active="+str(element_status)+" WHERE chamber_id="+str(chamber_id))
                cursor.execute(query)
                cursor.execute("UPDATE fermentation SET element_active_seconds = "+str(element_runtime)+" WHERE f_id="+str(active_ferm_id))
        else:
                #No current active fermentation for this chamber, just update chamber information
                chamber_query = cursor.execute(query)
                chamber_data = FetchOneAssoc(cursor)
                current_temp = read_temp()
                element_active = 0
                GPIO.output(11,0) #failsafe
                query = ("UPDATE chambers SET last_conn=NOW(), real_time_temp = "+str(current_temp)+", element_active=0 WHERE chamber_id="+str(chamber_id))
                cursor.execute(query)
                open(file_name,"w").close() #clear contents of file
        cnx.commit()
        cnx.close()
except Exception as e:
        print("exception: " + str(e))
        #Error in processing query, clean up by checking saved file
        current_temp = read_temp() #get temp in C
        if (saved_temp == None):
                print("No saved temp, turn off element")
                GPIO.output(11,0)
        else:

                if (saved_temp > current_temp):
                        #turn element on
                        print("Saved temp "+str(saved_temp))
                        print("Current temp "+str(current_temp))
                        print("Element on")
                        GPIO.output(11,1)
                else:
                        #turn element off
                        print ("Saved temp "+str(saved_temp))
                        print ("Current temp "+str(current_temp))
                        print ("Element off")
                        GPIO.output(11,0)