#--------------------------------------------------

#!/usr/bin/env python3

#--------------------------------------------------


import time
import os
import serial
import struct
import csv
from lcd import *
from var_save import *
from threading import Timer


#--------------------------------------------------
#global vars
h_store = 0
prev_fsize = 0
ser = 0


#--------------------------------------------------

def init_vars():
    global h_store
    global prev_fsize
    global ser

    h_store = 0
    prev_fsize = 0
    der = 0

#--------------------------------------------------

def init_ser():

    global ser
    try:
        ser = serial.Serial(

            port        = '/dev/ttyUSB0',
            baudrate    = 460800,
            parity      = serial.PARITY_NONE,
            stopbits    = serial.STOPBITS_TWO,
            bytesize    = serial.EIGHTBITS,
            timeout     = 1

        )

    except:
        raise ValueError('SERIAL INIT')

#--------------------------------------------------

def millis():
    millis = int(round(time.time() * 1000))
    return millis

#--------------------------------------------------


def btus(b_in, index):

    temp = int(b_in[index])
    temp = temp << 8
    temp += b_in[index+1]
    return temp;

#--------------------------------------------------


def btfp(b_in, index):

    byte_list=[b_in[index+3], b_in[index+2], b_in[index+1], b_in[index]]
    aa= bytearray(byte_list)
    return struct.unpack('<f', aa)[0];


#--------------------------------------------------

def write_csv_headings(log_file):
    f = open("/home/pi/Desktop/Scripts/DMU30_LOGGER/dmu30_logs/dmu30_log"+str(log_file)+".csv", 'w')
    c = csv.writer(f)
    c.writerow(["t-(mS)","MC","x_r","x_a","y_r","y_a","z_r","z_a", "aux_v", "temp", "x_dt", "x_dv", "y_dt", "y_dv", "z_dt", "z_dv"])
    f.close()

#--------------------------------------------------

def write_to_csv(read_in, t_stamp, log_file):

    f = open("/home/pi/Desktop/Scripts/DMU30_LOGGER/dmu30_logs/dmu30_log"+str(log_file)+".csv", 'a')
    c = csv.writer(f)

    #mc     0
    #axr    2
    #axa    6
    #ayr    10
    #aya    14
    #azr    18
    #aza    22
    #aux    26
    #tmp    30
    #axdt   34
    #axdv   38
    #aydt   42
    #aydv   46
    #azdt   50
    #azdv   54
    #ss     58
    #so     60
    #eo     62
    #cs     64


    items = [t_stamp, btus(read_in,0), btfp(read_in,2), btfp(read_in,6), btfp(read_in,10), btfp(read_in,14), btfp(read_in,18), btfp(read_in,22), btfp(read_in,26), btfp(read_in,30),
                btfp(read_in,34), btfp(read_in,38), btfp(read_in,42), btfp(read_in,46), btfp(read_in,50), btfp(read_in,54)]

    c.writerow(items)

    f.close()


#--------------------------------------------------


def test_header():

    global h_store
    h_new = 0
    try:
        h_new = ser.read(1)[0]
    except:
        raise ValueError('SERIAL READ1')


    if (h_new == 0xaa) and (h_store == 0x55):
        h_store = 0
        return 1
    else:
        h_store = h_new
        return 0


#--------------------------------------------------


def us_wrap_add(us1, us2):
    output = us1 + us2
    if output > 0xffff:
        output = (output % 0xffff) - 1

    return output


#--------------------------------------------------


def calc_chksum(read_in):

    chksum = 0x55aa #Header
    x = 0

    while x< 64:

        us_bytes = bytes([read_in[x], read_in[x+1]])
        chksum = us_wrap_add(chksum, btus(us_bytes, 0))
        x += 2


    chksum ^= 0xffff
    chksum += 1

    return chksum;

#--------------------------------------------------


def init_logfile(log_file):
    try:
        log_file = read_var_from_file("/home/pi/Desktop/Scripts/DMU30_LOGGER/log_count")
    except:
        try:
            write_var_to_file("/home/pi/Desktop/Scripts/DMU30_LOGGER/log_count", 1)
            log_file = read_var_from_file("/home/pi/Desktop/Scripts/DMU30_LOGGER/log_count")
        except:
            raise ValueError('JSON1')
        else:
            if log_file != 1:
                raise ValueError('JSON2')
            else:
                log_file = 0
                pass
    else:
        try:
            write_var_to_file("/home/pi/Desktop/Scripts/DMU30_LOGGER/log_count", log_file+1)
        except:
            raise ValueError('JSON3')
        else:
            pass
    return log_file

#--------------------------------------------------

def main():


    s_time = 100
    log_file = -1
    count = 0


    init_vars()
    lcd_init()
    init_ser()
    lcd_clear()
    lcd_print("DMU30 - Data Logger", 0,0)
    time.sleep(1)

    log_file = init_logfile(log_file)



    try:
        write_csv_headings(log_file)
    except:
        raise ValueError('CSV_WRITE1')
    else:
        pass

    drop_count = 0

    stx = millis()


    lcd_clear()
    lcd_print_pad("STATUS:  RUNNING", 0)
    lcd_print_pad("FILE: dmu30_log"+str(log_file),1)
    lcd_print_pad("SIZE (kb): 0", 2)
    lcd_print_pad("DROPPED:  0",  3)



    while 1:

        bytes_waiting = 0

        try:
            bytes_waiting = ser.in_waiting
        except:
            raise ValueError('SERIAL WAIT')
        else:
            pass

        if bytes_waiting>65:

            if test_header():

                read_in = bytearray()
                try:
                    read_in = ser.read(66)
                except:
                    raise ValueError('SERIAL READ2')
                else:
                    pass

                chksum = calc_chksum(read_in)
                chksum_in = bytes([read_in[64], read_in[65]])


                if(btus(chksum_in, 0) == chksum):

                    if((millis() - stx) >= s_time):
                        try:
                            count+=1
                            write_to_csv(read_in, s_time*(count-1), log_file)
                            fsize = os.path.getsize("/home/pi/Desktop/Scripts/DMU30_LOGGER/dmu30_logs/dmu30_log"+str(log_file)+".csv")
                            fsize /= 1000#mb
                            fsize = int(fsize)
                            global prev_fsize
                            if fsize > prev_fsize:
                                lcd_print_pad("SIZE (kb): "+str(fsize), 2)
                                prev_fsize = fsize


                        except:
                            raise ValueError('CSV WRITE2')
                        else:
                            pass
                        stx = millis()
                else:
                    drop_count+=1
                    lcd_print_pad("DROPPED: "+str(drop_count),  3)



if __name__ == '__main__':
    while 1:
        try:
            main()
        except ValueError as e:
            print("YO BITCH - DAS ERROR")
            lcd_error(str(e))
            timeout = 10
            t = Timer(timeout, print, ['Sorry, times up'])
            t.start()
            prompt = "You have %d seconds to choose the correct answer...\n" % timeout
            answer = input(prompt)
            t.cancel()
            if answer == "y":
                quit()
            pass
        else:
            pass

#--------------------------------------------------

###EOF###

#--------------------------------------------------