#!/usr/bin/env python
import cayenne.client
from gpiozero import Button
import time
import math
import logging

# Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
MQTT_USERNAME  = "xxxx"
MQTT_PASSWORD  = "xxxx"
MQTT_CLIENT_ID = "xxxx"


client = cayenne.client.CayenneMQTTClient()
client.begin(MQTT_USERNAME, MQTT_PASSWORD, MQTT_CLIENT_ID, port=8883)
# For a secure connection use port 8883 when calling client.begin:
# client.begin(MQTT_USERNAME, MQTT_PASSWORD, MQTT_CLIENT_ID, port=8883, loglevel=logging.INFO)

wind_count = 0 # counts how many half-rotations
radius_cm = 9.0 # radius in cm of the anemometer
wind_interval = 10 # how often (secs) to report speed
ADJUSTMENT = 1.18 # adjustment of the anemometer given by the manufacturer
timestamp = 0

# every half-rotation, add 1 count
def spin():
    global wind_count
    wind_count = wind_count + 1
    print("spin" + str(wind_count))   
    
# calculate the wind speed
def calculate_speed(time_sec):
        global wind_count
        circumference_cm = (2 * math.pi) * radius_cm
        rotations = wind_count / 2.0
        dist_km = (circumference_cm * rotations) / 100000.0 # divided by cm in a km
        km_per_sec = dist_km / time_sec
        km_per_hour = km_per_sec * 3600 # multiplied by secs in an hour
        return km_per_hour * ADJUSTMENT
        
wind_speed_sensor = Button(5)   
wind_speed_sensor.when_pressed = spin
        

while True:
    client.loop()
    
    if (time.time() > timestamp + 10):
            print(calculate_speed(wind_interval), "km/h")
            x = calculate_speed(wind_interval)
            client.windspeedWrite(1,x)
            timestamp = time.time()