#!/usr/bin/python
# -*- coding:utf-8 -*-
import RPi.GPIO as GPIO
import serial
import time
import os
import csv
from datetime import datetime
import paho.mqtt.client as mqtt

myhost = os.uname()[1]

# GPIO setup
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
gpio_initialized = False

ser = serial.Serial('/dev/ttyUSB3', 9600)
ser.flushInput()

rec_buff = ''
time_count = 0

# CSV file setup
csv_filename = 'gps_coordinates.csv'
csv_header = ['Timestamp', 'Latitude', 'Longitude']

# MQTT setup
mqtt_broker = "65.108.199.212"
mqtt_port = 1883  # Default MQTT port
mqtt_topic = "iiot/coordinates"
mqtt_client = mqtt.Client()

def mqtt_connect():
    mqtt_client.connect(mqtt_broker, mqtt_port, 60)
    mqtt_client.loop_start()

def mqtt_publish(message):
    mqtt_client.publish(mqtt_topic, message)

def write_to_csv(lat, lon):
    timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    with open(csv_filename, 'a', newline='') as csvfile:
        csv_writer = csv.writer(csvfile)
        if os.stat(csv_filename).st_size == 0:
            csv_writer.writerow(csv_header)
        csv_writer.writerow([timestamp, lat, lon])

    # Publish to MQTT
    mqtt_message = f"{timestamp},{lat},{lon}"
    mqtt_publish(mqtt_message)

def parse_gps_data(gps_data):
    parts = gps_data.split(',')
    if len(parts) >= 4:
        lat = convert_to_decimal(parts[0], parts[1])
        lon = convert_to_decimal(parts[2], parts[3])
        return lat, lon
    return None, None

def convert_to_decimal(coord, direction):
    degrees = float(coord[:2])
    minutes = float(coord[2:])
    decimal = degrees + (minutes / 60)
    if direction in ['S', 'W']:
        decimal = -decimal
    return round(decimal, 6)

def send_at(command, back, timeout):
    rec_buff = ''
    ser.write((command+'\r\n').encode())
    time.sleep(timeout)
    if ser.inWaiting():
        time.sleep(0.01)
        rec_buff = ser.read(ser.inWaiting())
    if rec_buff != '':
        if back not in rec_buff.decode():
            print(command + ' ERROR')
            print(command + ' back:\t' + rec_buff.decode())
            return 0
        else:
            gps_data = rec_buff.decode()[13:-36]
            print(gps_data)
            lat, lon = parse_gps_data(gps_data)
            if lat is not None and lon is not None:
                write_to_csv(lat, lon)
            return 1
    else:
        print('GPS is not ready')
        return 0

def get_gps_position():
    rec_null = True
    answer = 0
    print('Starting GPS')
    rec_buff = ''
    send_at('AT+CGPS=1','OK',1)
    time.sleep(2)
    while rec_null:
        answer = send_at('AT+CGPSINFO','+CGPSINFO: ',1)
        if 1 == answer:
            answer = 0
            if ',,,,,,' in rec_buff:
                print('GPS is not ready')
                rec_null = False
                time.sleep(1)
        else:
            print('error %d'%answer)
            rec_buff = ''
            send_at('AT+CGPS=0','OK',1)
            return False
        time.sleep(1.5)

def power_on(power_key):
    print('SIM7600X is starting:')
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)
    GPIO.setup(power_key,GPIO.OUT)
    time.sleep(0.1)
    GPIO.output(power_key,GPIO.HIGH)
    time.sleep(2)
    GPIO.output(power_key,GPIO.LOW)
    time.sleep(20)
    ser.flushInput()
    print('SIM7600X is ready')

def power_down(power_key):
    print('SIM7600X is logging off:')
    GPIO.output(power_key,GPIO.HIGH)
    time.sleep(3)
    GPIO.output(power_key,GPIO.LOW)
    time.sleep(18)
    print('Good bye')

try:
    mqtt_connect()
    #power_on(power_key)
    get_gps_position()
    #power_down(power_key)
except:
    if ser != None:
        ser.close()
    #power_down(power_key)
    GPIO.cleanup()
finally:
    if ser != None:
        ser.close()
    GPIO.cleanup()
    mqtt_client.loop_stop()
    mqtt_client.disconnect()