#!/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


FONT_SIZE = 40
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), Image.ANTIALIAS)


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), Image.ANTIALIAS)


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

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

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

    for ob in obs:
        if ob['waterfall'] != None:
            break

    if ob['waterfall'] == None:
        print("No 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 = resp.json()['image']

    mode_desc = ob['transmitter_mode']

    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 != None:
        resp = requests.get(sat_img_url)
        sat_img = Image.open(BytesIO(resp.content)).convert('RGBA')
        sat_img = scale_to_width(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\nMode: %s\nStart: %s\nEnd: %s" % (sat_name, station_name, mode_desc, 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, 400))

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


if __name__ == '__main__':
    main()