Weather service backend for 3rd party clients to present bike-nobike weather conditions.

db.ts

const kv = await Deno.openKv();

export interface BikeStatus {
    bike: boolean,
    temp: number,
    uv: number,
    rain: number,
    sunset: string,
    sunrise: string
};

export async function update(day: string, status: BikeStatus) {
    await kv.set(['bikeNobike', day], status);
}

export async function query(day: string) {
    const result = kv.get(["bikeNobike", day]);
    return (await result).value;
}

service.ts

#!/usr/bin/env -S deno run -A --unstable --allow-net
import { format } from "https://deno.land/std@0.193.0/datetime/mod.ts";
import { Cron } from "https://deno.land/x/croner@7.0.3/dist/croner.js";
import { update, query, BikeStatus} from "./db.ts";

const zipcode = "REPLACE ME";
const apikey = "REPLACE ME";
const uri = `https://api.weatherapi.com/v1/forecast.json?key=${apikey}&q=${zipcode}&days=1&aqi=yes&alerts=no`;
const max_temp_f = 103;
const min_temp_f = 50;
const max_uv = 6; // 3-5 Low, 6-7 moderate, 8-10 High

function toBike(fc): boolean {
    return (
        ( fc.day.maxtemp_f <= max_temp_f ) &&
        ( fc.day.mintemp_f >= min_temp_f ) &&
        ( fc.day.uv <= max_uv ) &&
        ( fc.day.daily_will_it_rain == 0 )
    );
}

// update the database every day at 3 AM
const job = new Cron("0 3 * * *", {}, async () => {
    //import weather_data from "./example.json" assert { type: "json"};
    const day = format(new Date, "yyyy-MM-dd");
    const data = await fetch(uri);
    const weather_data = await data.json();
    const forecast = weather_data.forecast.forecastday[0];
    const status: BikeStatus = {
        temp: forecast.day.maxtemp_f,
        uv: forecast.day.uv,
        rain: forecast.day.daily_will_it_rain,
        sunset: forecast.astro.sunset,
        sunrise: forecast.astro.sunrise,
        bike: toBike(forecast)
    };
    update(day, status)
    console.log("Database updated!");
});

// otherwise host an async http server to return current status from query()
async function handler(_req: Request): Response {
    const day = format(new Date, "yyyy-MM-dd");
    const data = await query(day);
    const jdata = JSON.stringify(data);
    const resp = new Response(jdata);
    resp.headers.set("Content-Type", "application/json")
    return resp;
}

// returns json BikeStatus for 3rd party clients, localhost:8000/
Deno.serve(handler);