satnogs-demo-display/update.py

#!/bin/env python3
import os
import requests
import pytz
from datetime import datetime, timedelta

from PIL import Image
from PIL import ImageFont
from PIL import ImageDraw

from io import BytesIO

from geopy.geocoders import Nominatim

FONT_SIZE = 40
FONT_SIZE_SMALL = 20
TEXT_COLOR = (255, 255, 255, 255)


def invert_back_white(img):
    pixels = img.load()
    for y in range(img.size[1]):
        for x in range(img.size[0]):
            r, g, b, _ = pixels[x, y]
            if abs(r - g) < 5 and abs(r - g) < 5 and abs(b - g) < 5:
                pixels[x, y] = (255 - r, 255 - g, 255 - b, 255)


def scale_to_height(img, new_height):
    width, height = img.size
    new_width = int(new_height * width / height)
    return img.resize((new_width, new_height))


def scale_to_width(img, new_width):
    width, height = img.size
    new_height = int(new_width * height / width)
    return img.resize((new_width, new_height))


def main():
    now = datetime.now(pytz.utc)
    earlier = now - timedelta(hours=1)

    params = {
        'start': earlier.isoformat(),
        'end': now.isoformat(),
        'status': 'good',
    }
    resp = requests.get('https://network.satnogs.org/api/observations',
                        params=params)

    obs = resp.json()
    obs = reversed(sorted(obs, key=lambda x: x['end']))

    for ob in obs:
        if ob['waterfall'] is not None:
            break

    if ob['waterfall'] is None:
        print("No observations with waterfall found")
        return

    resp = requests.get('https://db.satnogs.org/api/satellites/%s/' %
                        ob['norad_cat_id'])

    sat_name = resp.json()['name']

    sat_img_url = None
    if 'image' in resp.json().keys():
        sat_img_url = "https://db-satnogs.freetls.fastly.net/media/%s" % (
            resp.json()['image'])

    geolocator = Nominatim(
        user_agent=
        "satnogs-demo-display - https://forgejo.zenerdio.de/sebastian/satnogs-demo-display"
    )

    mode_desc = ob['transmitter_mode']
    frequency = ob['observation_frequency'] / 1_000_000

    coord = "%f, %f" % (ob['station_lat'], ob['station_lng'])
    address = geolocator.reverse(coord, exactly_one=True,
                                 language="en").raw['address']
    city = address.get('city', '')
    country = address.get('country', '')
    station_location = ""
    if city != "":
        station_location += "near " + city + " "
    if country != "":
        station_location += "in " + country

    resp = requests.get(ob['waterfall'])
    waterfall = Image.open(BytesIO(resp.content)).convert('RGBA')
    invert_back_white(waterfall)

    waterfall = scale_to_height(waterfall, 1024)
    water_width, _ = waterfall.size

    logo = Image.open("satnogs-logo.png").convert('RGBA')
    logo_w, logo_h = logo.size
    invert_back_white(logo)

    sat_img = None
    if sat_img_url is not None:
        resp = requests.get(sat_img_url)
        sat_img_aplha = Image.open(BytesIO(resp.content)).convert('RGBA')

        alpha_chan = sat_img_aplha.convert('RGBA').split()[-1]
        sat_img = Image.new("RGBA", sat_img_aplha.size, (255, 255, 255, 255))
        sat_img.paste(sat_img_aplha, mask=alpha_chan)

        sat_img_width, sat_img_height = sat_img.size
        if sat_img_width > sat_img_height:
            sat_img = scale_to_width(sat_img, 500)
        else:
            sat_img = scale_to_height(sat_img, 500)

    img = Image.new('RGBA', (1280, 1024))
    draw = ImageDraw.Draw(img)
    draw.rectangle((0, 0, 1280, 1024), fill=(0, 0, 0, 255))

    station_name = ob['station_name']
    if len(station_name) > 20:
        station_name = station_name[:20] + "..."
    infos = "Satellite: %s\nStation: %s\n%s\nMode: %s\nFrequency: %f MHz\nStart: %s\nEnd: %s" % (
        sat_name, station_name, station_location, mode_desc, frequency,
        ob['start'], ob['end'])

    font = ImageFont.truetype("Montserrat-Regular.otf", FONT_SIZE)
    draw.text((water_width + 100, logo_h + 50), infos, TEXT_COLOR, font=font)

    img.paste(waterfall, (0, 0))
    img.paste(logo, (water_width + 100, 20))
    if sat_img != None:
        img.paste(sat_img, (water_width + 100, 480))

    font = ImageFont.truetype("Montserrat-Regular.otf", FONT_SIZE_SMALL)
    draw.text((950, 1000), "Geocoding by Nominatim/OSM", TEXT_COLOR, font=font)

    img.save('waterfall_tmp.png')
    os.rename('waterfall_tmp.png', 'waterfall.png')


if __name__ == '__main__':
    main()