spothole/server/webserver.py

import json
import logging
from datetime import datetime, timedelta
from threading import Thread

import bottle
import pytz
from bottle import run, response, template

from core.config import MAX_SPOT_AGE
from core.constants import BANDS, ALL_MODES, MODE_TYPES, SIGS, SOURCES, CONTINENTS
from core.utils import serialize_everything


# Provides the public-facing web server.
class WebServer:

    # Constructor
    def __init__(self, spot_list, status_data, port):
        self.last_page_access_time = None
        self.last_api_access_time = None
        self.spot_list = spot_list
        self.status_data = status_data
        self.port = port
        self.thread = Thread(target=self.run)
        self.thread.daemon = True
        self.status = "Starting"

        # Routes for API calls
        bottle.get("/api/spots")(lambda: self.serve_api(self.get_spot_list_with_filters()))
        bottle.get("/api/options")(lambda: self.serve_api(self.get_options()))
        bottle.get("/api/status")(lambda: self.serve_api(self.status_data))
        # Routes for templated pages
        bottle.get("/")(lambda: self.serve_template('webpage_home'))
        bottle.get("/about")(lambda: self.serve_template('webpage_about'))
        bottle.get("/apidocs")(lambda: self.serve_template('webpage_apidocs'))
        # Default route to serve from "webassets"
        bottle.get("/<filepath:path>")(self.serve_static_file)

    # Start the web server
    def start(self):
        self.thread.start()

    # Run the web server itself. This blocks until the server is shut down, so it runs in a separate thread.
    def run(self):
        logging.info("Starting web server on port " + str(self.port) + "...")
        self.status = "Waiting"
        run(host='localhost', port=self.port)

    # Serve a JSON API endpoint
    def serve_api(self, data):
        self.last_api_access_time = datetime.now(pytz.UTC)
        self.status = "OK"
        response.content_type = 'application/json'
        response.set_header('Cache-Control', 'no-store')
        return json.dumps(data, default=serialize_everything)

    # Serve a templated page
    def serve_template(self, template_name):
        self.last_page_access_time = datetime.now(pytz.UTC)
        self.status = "OK"
        return template(template_name)

    # Serve general static files from "webassets" directory.
    def serve_static_file(self, filepath):
        return bottle.static_file(filepath, root="webassets")

    # Utility method to apply filters to the overall spot list and return only a subset. Enables query parameters in
    # the main "spots" GET call.
    def get_spot_list_with_filters(self):
        # Get the query (and the right one, with Bottle magic. This is a MultiDict object
        query = bottle.request.query

        # Create a shallow copy of the spot list, ordered by spot time. We'll then filter it accordingly.
        # We can filter by spot time and received time with "since" and "received_since", which take a UNIX timestamp
        # in seconds UTC.
        # We can also filter by source, sig, band, mode, dx_continent and de_continent. Each of these accepts a single
        # value or a comma-separated list.
        # We can provide a "limit" number as well. Spots are always returned newest-first; "limit" limits to only the
        # most recent X spots.
        spots = sorted(self.spot_list, key=lambda spot: spot.time, reverse=True)
        for k in query.keys():
            match k:
                case "since":
                    since = datetime.fromtimestamp(int(query.get(k)), pytz.UTC)
                    spots = [s for s in spots if s.time > since]
                case "max_age":
                    max_age = int(query.get(k))
                    since = datetime.now(pytz.UTC) - timedelta(seconds=max_age)
                    spots = [s for s in spots if s.time > since]
                case "received_since":
                    since = datetime.fromtimestamp(int(query.get(k)), pytz.UTC)
                    spots = [s for s in spots if s.received_time > since]
                case "source":
                    sources = query.get(k).split(",")
                    spots = [s for s in spots if s.source in sources]
                case "sig":
                    sigs = query.get(k).split(",")
                    spots = [s for s in spots if s.sig in sigs]
                case "band":
                    bands = query.get(k).split(",")
                    spots = [s for s in spots if s.band in bands]
                case "mode":
                    modes = query.get(k).split(",")
                    spots = [s for s in spots if s.mode in modes]
                case "mode_type":
                    mode_families = query.get(k).split(",")
                    spots = [s for s in spots if s.mode_type in mode_families]
                case "dx_continent":
                    dxconts = query.get(k).split(",")
                    spots = [s for s in spots if s.dx_continent in dxconts]
                case "de_continent":
                    deconts = query.get(k).split(",")
                    spots = [s for s in spots if s.de_continent in deconts]
        # If we have a "limit" parameter, we apply that last, regardless of where it appeared in the list of keys.
        if "limit" in query.keys():
            spots = spots[:int(query.get("limit"))]
        return spots

    # Return all the "options" for various things that the server is aware of. This can be fetched with an API call.
    # The idea is that this will include most of the things that can be provided as queries to the main spots call,
    # and thus a client can use this data to configure its filter controls.
    def get_options(self):
        return {"bands": BANDS,
                "modes": ALL_MODES,
                "mode_types": MODE_TYPES,
                "sigs": SIGS,
                "sources": SOURCES,
                "continents": CONTINENTS,
                "max_spot_age": MAX_SPOT_AGE}