Grab screenshot of PurpleAir's US EPA PM2.5 AQI map

purpleair.py

#!/usr/bin/env python3
# headless playwright script that screenshots the map canvas from PurpleAir's US EPA PM2.5 AQI map
# ex: add cronjob and use with KDE media frame widget https://userbase.kde.org/Plasma/PictureFrame
# */30 * * * * /usr/local/bin/purpleair.py -q --latest --dir=~/purpleair
import argparse
import shutil
import subprocess
from datetime import datetime
from pathlib import Path
from playwright.sync_api import sync_playwright

# map baselayer options: /l opt: '/ls' s=sat, d=dark, t=topo p=detailed (default)
# CONUS
#URL_TEMPLATE = "https://map.purpleair.com/air-quality-standards-us-epa-aqi?opt=/1/l{layer}/a10/p604800/cC0#3.74/39.61/-95.87"
# PNW
URL_TEMPLATE = "https://map.purpleair.com/air-quality-standards-us-epa-aqi?opt=/1/l{layer}/a10/p604800/cC0#5.54/46.311/-118.371"

BASELAYERS = {"s": "satellite", "d": "dark", "t": "topo", "p": "detailed"}

parser = argparse.ArgumentParser()
parser.add_argument("--headed", action="store_true", help="Open a browser window instead of headless")
parser.add_argument("--view", action="store_true", help="Open the screenshot after saving (uses xdg-open unless --viewer is set)")
parser.add_argument("--viewer", help="Command to open the screenshot with instead of xdg-open (implies --view)")
parser.add_argument(
    "--baselayer",
    choices=BASELAYERS.keys(),
    default="s",
    help="Map baselayer: s=satellite (default), d=dark, t=topo, p=detailed",
)
parser.add_argument(
    "--latest",
    action="store_true",
    help="Save a copy to purpleair-latest.png (single updated file for KDE media frame widget)",
)
parser.add_argument("-q", "--quiet", action="store_true", help="Suppress print output")
parser.add_argument(
    "--dir", "--savedir",
    dest="savedir",
    default=".",
    help="Directory to save screenshots to (default: current directory)",
)
args = parser.parse_args()

URL = URL_TEMPLATE.format(layer=args.baselayer)

savedir = Path(args.savedir).expanduser()
savedir.mkdir(parents=True, exist_ok=True)

with sync_playwright() as p:
    browser = p.chromium.launch(headless=not args.headed)
    page = browser.new_page(viewport={"width": 1600, "height": 900})
    page.goto(URL)

    canvas = page.locator(".mapboxgl-canvas")
    canvas.wait_for(state="visible")

    # long wait here, but needed for icons/markers to populate
    page.wait_for_timeout(7000)

    page.evaluate("""
        document.querySelectorAll('.paControlContainer').forEach(el => el.remove());
        const gdpr = document.getElementById('gdpr-cookie-message');
        if (gdpr) gdpr.remove();
        document.querySelectorAll('header').forEach(el => el.remove());
    """)

    page.evaluate("window.dispatchEvent(new Event('resize'))")
    page.wait_for_timeout(1000)

    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    filename = savedir / f"purpleair_map_{timestamp}.png"
    canvas.screenshot(path=str(filename))
    if not args.quiet:
        print(f"Screenshot saved {filename}")

    if args.latest:
        latest_filename = savedir / "purpleair-latest.png"
        shutil.copyfile(filename, latest_filename)
        if not args.quiet:
            print(f"Screenshot saved {latest_filename}")

    if args.headed:
        input("Screenshot saved. Browser is open for inspection - press Enter to close...")

    browser.close()

if args.view or args.viewer:
    opener = args.viewer.split() if args.viewer else ["xdg-open"]
    subprocess.Popen(opener + [str(filename)])