weather.py

import logging
from datetime import datetime, timedelta
import time
import math

from canvas import Canvas
from getweatherdata import GetWeatherData 

# #############################################################################
# The Weather class
# Updates the weather conditions from the Weather file, and updates the screen 
# when necessary.
# Only updates every UpdateInterval (seconds), or 10 minutes if there is an 
# error
# #############################################################################
class Weather:
    def __init__(self, matrixobject, positioninmatrix, weatherdefinition, hours_from_now, update_interval, getweatherobject):
        logging.info('Creating new Weather instance')

        self.__Matrix = matrixobject
        self.__MatrixPosition = positioninmatrix
        self.__WeatherDefinition = weatherdefinition
        self.__HoursFromNow = hours_from_now
        self.__UpdateInterval = update_interval

        self.__WeatherCanvas = Canvas(weatherdefinition['Size'])
        self.__ImageChanged = True

        self.__GetWeatherObject = getweatherobject
        self.__WeatherData = []
        self.__WeatherForecast = {}
        self.__CurrentWeatherIcon = ''
        self.__CurrentWeatherWind = -1
        self.__CurrentWeatherRain = -1.0
        self.__CurrentWeatherSnow = -1.0
        self.__CurrentWeatherMaxTemp = 999.0
        self.__CurrentWeatherMinTemp = -999.0
        self.__CurrentWeatherTime = -1
        self.__WeatherReadError = False
        self.__LastUpdateTime = 0
        self.__WindSpeedIcon = -1
        self.__RainSnowIcon = ''

    # -------------------------------------------------------------------------
    # get_canvas_matrix_position
    # Returns the position of the weather canvas on the matrix canvas
    # -------------------------------------------------------------------------
    def get_canvas_matrix_position(self):
        return self.__MatrixPosition

    # -------------------------------------------------------------------------
    # get_weather_canvas
    # Returns the weather canvas
    # -------------------------------------------------------------------------
    def get_weather_canvas(self):
        return self.__WeatherCanvas

    # -------------------------------------------------------------------------
    # update_weather_canvas_thread
    # The weather canvas threads
    # -------------------------------------------------------------------------
    def update_weather_canvas_thread(self):
        while True:
            # Calculate the date of the forecast (only every 3 hours)
            # Adding an offset.
            date = self.get_offset_date(self.__HoursFromNow)

            # Read the weather from TheWeather thread
            thisweather = self.__GetWeatherObject.read_forecast_for_date(date)

            # If there was a read error (happens when the time is too close to the
            # next forecast, read the one 3 hours ahead instead
            if thisweather == {}:
                date = self.get_offset_date(self.__HoursFromNow + 3)
                thisweather = self.__GetWeatherObject.read_forecast_for_date(date)

            self.__WeatherForecast = self.get_readable_forecast(thisweather)

            # Draw the weather forecast canvas
            self.draw_weather_canvas()

            # Don't update unless the time is greater than updateinterval (s) or 10
            # minutes (if there has been an error)
            if self.__WeatherReadError:
                delay = 600
                self.__WeatherReadError = False
            else:
                delay = self.__UpdateInterval

            # Draw the weather canvas on the matrix canvas
            self.draw_on_matrix_canvas()

            time.sleep(delay)

    # -------------------------------------------------------------------------
    # draw_weather_canvas
    # Draw the new Weather canvas according to the definition
    # -------------------------------------------------------------------------
    def draw_weather_canvas(self):
        # Go through each item, updating any images if required
        current_weather = self.__WeatherForecast
        if current_weather == {}:
            logging.warning('The weather was not updated correctly')
            self.__ImageChanged = False
            self.__WeatherReadError += 1
        else:
            self.__ImageChanged = False
            # Weather Icon
            if self.__WeatherDefinition['WeatherIcon'] != ():
                if self.__CurrentWeatherIcon != current_weather['icon']:
                    self.__CurrentWeatherIcon = current_weather['icon']
                    self.draw_weather_icon()
                    self.__ImageChanged = True

            # Max Temperature
            if self.__WeatherDefinition['MaxTemp'] != ():
                if self.__CurrentWeatherMaxTemp != current_weather['MaxTemp']:
                    self.__CurrentWeatherMaxTemp = current_weather['MaxTemp']
                    self.draw_temperature('MaxTemp', self.__CurrentWeatherMaxTemp, 'C')
                    self.__ImageChanged = True

            # Min Temperature
            if self.__WeatherDefinition['MinTemp'] != ():
                if self.__CurrentWeatherMinTemp != current_weather['MinTemp']:
                    self.__CurrentWeatherMinTemp = current_weather['MinTemp']
                    self.draw_temperature('MinTemp', self.__CurrentWeatherMinTemp, 'C')
                    self.__ImageChanged = True

            # Wind speed Icon
            if self.__WeatherDefinition['WindSpeedIcon'] != ():
                if self.__WindSpeedIcon != True:
                    self.draw_windspeed_icon()
                    self.__ImageChanged = True
                    self.__WindSpeedIcon = True

            # Wind Speed
            if self.__WeatherDefinition['WindSpeed'] != ():
                windspeedtobeaufort = current_weather['beaufort']
                if self.__CurrentWeatherWind != windspeedtobeaufort:
                    self.__CurrentWeatherWind = windspeedtobeaufort
                    self.draw_windspeed()
                    self.__ImageChanged = True

            # Rain or snow Icon?
            # If there is snow, replace the rain icon with snow icon
            if self.__WeatherDefinition['RainSnowIcon'] != ():
                # We have snow!
                if current_weather['snow'] > 0:
                    self.__CurrentWeatherRain = -1.0
                    if self.__RainSnowIcon != 'snow':
                        self.draw_rainsnow_icon('SnowIcon')
                        self.__ImageChanged = True
                        self.__RainSnowIcon = 'snow'

                    if self.__CurrentWeatherSnow != current_weather['snow']:
                        self.__CurrentWeatherSnow = current_weather['snow']
                        self.draw_snowfall()
                    self.__ImageChanged = True

                # Booo! Rain
                else:
                    self.__CurrentWeatherSnow = -1.0
                    if self.__RainSnowIcon != 'rain':
                        self.draw_rainsnow_icon('RainIcon')
                        self.__ImageChanged = True
                        self.__RainSnowIcon = 'rain'

                    if self.__CurrentWeatherRain != current_weather['rain']:
                        self.__CurrentWeatherRain = current_weather['rain']
                        self.draw_rainfall()
                        self.__ImageChanged = True

            # Weather Time Indicator (indicator of the 3 hours the forcast covers)
            if self.__WeatherDefinition['WeatherTime'] != ():
                if self.__CurrentWeatherTime != current_weather['WeatherTime']:
                    self.__CurrentWeatherTime = current_weather['WeatherTime']
                    self.draw_weather_time()
                    self.__ImageChanged = True

    # -------------------------------------------------------------------------
    # draw_rainsnow_icon
    # -------------------------------------------------------------------------
    def draw_rainsnow_icon(self, whichicon):
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['RainSnowIcon'], whichicon)

    # -------------------------------------------------------------------------
    # draw_windspeed_icon
    # -------------------------------------------------------------------------
    def draw_windspeed_icon(self):
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['WindSpeedIcon'], 'Icon')

    # -------------------------------------------------------------------------
    # draw_windspeed
    # -------------------------------------------------------------------------
    def draw_windspeed(self):
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['WindSpeed'], 'blank')
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['WindSpeed'], self.__CurrentWeatherWind)

    # -------------------------------------------------------------------------
    # draw_rainfall
    # -------------------------------------------------------------------------
    def draw_rainfall(self):
        whattodraw = 'rain' + str(self.__CurrentWeatherRain)
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['RainSnow'], whattodraw)

    # -------------------------------------------------------------------------
    # draw_snowfall
    # -------------------------------------------------------------------------
    def draw_snowfall(self):
        whattodraw = 'snow' + str(self.__CurrentWeatherSnow)
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['RainSnow'], whattodraw)

    # -------------------------------------------------------------------------
    # draw_weather_icon
    # -------------------------------------------------------------------------
    def draw_weather_icon(self):
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['WeatherIcon'], self.__CurrentWeatherIcon)

    # -------------------------------------------------------------------------
    # Draw the Weather Time indicator
    # -------------------------------------------------------------------------
    def draw_weather_time(self):
        self.__WeatherCanvas.draw_on_canvas(self.__WeatherDefinition['WeatherTime'], self.__CurrentWeatherTime)

    # -------------------------------------------------------------------------
    # draw_on_matrix_canvas
    # Draw the Weather canvas onto the LED Matrix canvas if it has changed
    # and only if 'Autodraw' is true
    # -------------------------------------------------------------------------
    def draw_on_matrix_canvas(self):
        if self.__WeatherDefinition['AutoDraw']:
            if self.__ImageChanged:
                self.__Matrix.paste_to_matrix_canvas(self.__MatrixPosition, self.__WeatherCanvas)
                self.__ImageChanged = False

    # -------------------------------------------------------------------------
    #
    # -------------------------------------------------------------------------
    def add_image_width(self, x, imagedef):
        return x + imagedef[2] - imagedef[0] + 1

    # -------------------------------------------------------------------------
    # Draw the Temperature
    # Draws the temperature in the form of
    # Max/Min icon, temperature, Unit
    # -------------------------------------------------------------------------
    def draw_temperature(self, MaxMin, Temperature, TempUnit):
        x = self.__WeatherDefinition[MaxMin][0]
        y = self.__WeatherDefinition[MaxMin][1]
        image = self.__WeatherDefinition[MaxMin][2]
        imagedefinition = self.__WeatherDefinition[MaxMin][3]

        # The Max/Min arrow
        if MaxMin == 'MaxTemp':
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), 'max')
            x = Weather.add_image_width(self, x, imagedefinition['max'])
        else:
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), 'min')
            x = Weather.add_image_width(self, x, imagedefinition['min'])

        # Temperature is below 0
        if Temperature < 0:
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), '-')
            x = Weather.add_image_width(self, x, imagedefinition['-'])
        else:
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), 'ssp')
            x = Weather.add_image_width(self, x, imagedefinition['ssp'])

        # 10's digit
        if Temperature >= 10.0:
            tensdigit = str(abs(int(Temperature)))[0]
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), tensdigit)
            x = Weather.add_image_width(self, x, imagedefinition[tensdigit])
        else:
            tensdigit = 0
            self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), 'sp')
            x = Weather.add_image_width(self, x, imagedefinition['sp'])

        # Units digit
        unitdigit = str(abs(int(Temperature)) - int(tensdigit) * 10)
        self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), unitdigit)
        x = Weather.add_image_width(self, x, imagedefinition[unitdigit])

        # Decimal point
        self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), '.')
        x = Weather.add_image_width(self, x, imagedefinition['.'])

        # Decimal
        Dec = str(int(abs(Temperature) * 10 % 10))
        self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), Dec)
        x = Weather.add_image_width(self, x, imagedefinition[Dec])

        # Temperature unit
        self.__WeatherCanvas.draw_on_canvas((x, y, image, imagedefinition), TempUnit)

    # -------------------------------------------------------------------------
    # get_offset_date
    # Calculate the date for the forecast (offset hours from now)
    # -------------------------------------------------------------------------
    def get_offset_date(self, offset):
        forecastdate = datetime.now() + timedelta(hours=offset)
        forecasthour = int(forecastdate.strftime('%H'))
        forecastseachhour = forecasthour - forecasthour % 3
        return forecastdate.strftime('%Y') + '-' + forecastdate.strftime('%m') + '-' + \
               forecastdate.strftime('%d') + ' ' + '{:02}'.format(forecastseachhour) + ':00:00'


    # -------------------------------------------------------------------------
    # get_readable_forecast
    # Converts the weather for the defined time (weather_forecast_time) into a
    # readable (list) format
    # -------------------------------------------------------------------------
    def get_readable_forecast(self, weatherdict):
        # logging.info('Putting the weather in readable format')

        weatherdata = {}

        if weatherdict == {}:
            logging.warning('The json was blank!')
            return {}
        try:
            # weatherdata['cloudiness'] = weatherdict['clouds']['all']
            # weatherdata['CurrentTemp'] = round(float(weatherdict['main']['temp']) - 273.0, 1)
            weatherdata['MaxTemp'] = self.kelvin_to_celcius(weatherdict['main']['temp_max'])
            weatherdata['MinTemp'] = self.kelvin_to_celcius(weatherdict['main']['temp_min'])
            weatherdata['humidity'] = int(weatherdict['main']['humidity'])

            # If [rain][3h] is in the forecast, set it, or set rainfall to 0mm
            if 'rain' in weatherdict:
                if '3h' in weatherdict['rain']:
                    weatherdata['rain'] = min(8.0, math.ceil(float(weatherdict['rain']['3h'] * 2)) / 2.0)
                else:
                    weatherdata['rain'] = 0.0
            else:
                weatherdata['rain'] = 0.0

            if 'snow' in weatherdict:
                if '3h' in weatherdict['snow']:
                    weatherdata['snow'] = min(16, int(math.ceil(float(weatherdict['snow']['3h']))))
                else:
                    weatherdata['snow'] = 0
            else:
                weatherdata['snow'] = -1

            weatherdata['description'] = weatherdict['weather'][0]['description']
            weatherdata['wind'] = float(weatherdict['wind']['speed'])
            weatherdata['beaufort'] = self.windspeed_to_beaufort(float(weatherdict['wind']['speed']))
            weatherdata['winddir'] = self.degrees_to_direction(float(weatherdict['wind']['deg']))
            weatherdata['icon'] = weatherdict['weather'][0]['icon']
            weatherdata['WeatherTime'] = time.strptime(weatherdict['dt_txt'], '%Y-%m-%d %H:%M:%S').tm_hour
            weatherdata['dt_txt'] = weatherdict['dt_txt']

            return weatherdata
        except:
            logging.warning('Error get_readable_forecast')
            return {}

    # -------------------------------------------------------------------------
    # kelvin_to_celcius
    # Converts the temperature from Kelvins to celcius
    # -------------------------------------------------------------------------
    def kelvin_to_celcius(self, kelvin):
        return round(float(kelvin) - 273.15, 1)

    # -------------------------------------------------------------------------
    # windspeed_to_beaufort
    # Converts the wind speed from m/s to Beaufort scale
    # -------------------------------------------------------------------------
    def windspeed_to_beaufort(self, windspeedmps):
        beaufort = 0

        if windspeedmps <= 2.0:
            beaufort = 1
        elif windspeedmps <= 3.0:
            beaufort = 2
        elif windspeedmps <= 5.0:
            beaufort = 3
        elif windspeedmps <= 8.0:
            beaufort = 4
        elif windspeedmps <= 11.0:
            beaufort = 5
        elif windspeedmps <= 14.0:
            beaufort = 6
        elif windspeedmps <= 17.0:
            beaufort = 7
        elif windspeedmps <= 21.0:
            beaufort = 8
        elif windspeedmps <= 24.0:
            beaufort = 9
        elif windspeedmps <= 28.0:
            beaufort = 10
        elif windspeedmps <= 32.0:
            beaufort = 11
        elif windspeedmps > 32.0:
            beaufort = 12

        return beaufort

    # -------------------------------------------------------------------------
    # degrees_to_direction
    # Convert the wind direction from degrees to compass direction
    # -------------------------------------------------------------------------
    def degrees_to_direction(self, degrees):
        try:
            degrees = float(degrees)
        except ValueError:
            return None

        if degrees < 0 or degrees > 360:
            return None

        if degrees <= 11.25 or degrees >= 348.76:
            return "N"
        elif degrees <= 33.75:
            return "NNE"
        elif degrees <= 56.25:
            return "NE"
        elif degrees <= 78.75:
            return "ENE"
        elif degrees <= 101.25:
            return "E"
        elif degrees <= 123.75:
            return "ESE"
        elif degrees <= 146.25:
            return "SE"
        elif degrees <= 168.75:
            return "SSE"
        elif degrees <= 191.25:
            return "S"
        elif degrees <= 213.75:
            return "SSW"
        elif degrees <= 236.25:
            return "SW"
        elif degrees <= 258.75:
            return "WSW"
        elif degrees <= 281.25:
            return "W"
        elif degrees <= 303.75:
            return "WNW"
        elif degrees <= 326.25:
            return "NW"
        elif degrees <= 348.75:
            return "NNW"
        else:
            return None