Hourly cron weather report for Lublin (Open-Meteo) broadcast on mesh (#24)

src/weather/weather.service.ts

@@ -0,0 +1,81 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { Cron } from '@nestjs/schedule';
+import { BROADCAST_ADDR } from '../mesh/codec.js';
+import type { MeshService } from '../mesh/mesh.service.js';
+
+/** Open-Meteo `current` block fields we use (free API, no key). */
+export interface CurrentWeather {
+  temperature_2m: number;
+  apparent_temperature: number;
+  relative_humidity_2m: number;
+  wind_speed_10m: number;
+  weather_code: number;
+}
+
+// WMO weather interpretation codes (the common ones); unknown → `code <n>`
+const WMO_CODES: Record<number, string> = {
+  0: 'clear',
+  1: 'mainly clear',
+  2: 'partly cloudy',
+  3: 'overcast',
+  45: 'fog',
+  48: 'freezing fog',
+  51: 'light drizzle',
+  53: 'drizzle',
+  55: 'heavy drizzle',
+  61: 'light rain',
+  63: 'rain',
+  65: 'heavy rain',
+  71: 'light snow',
+  73: 'snow',
+  75: 'heavy snow',
+  80: 'light rain showers',
+  81: 'rain showers',
+  82: 'violent rain showers',
+  95: 'thunderstorm',
+};
+
+@Injectable()
+export class WeatherService {
+  private readonly logger = new Logger(WeatherService.name);
+  // read at construction, like MeshService's env config
+  private readonly lat = parseFloat(process.env.WEATHER_LAT ?? '51.2465');
+  private readonly lon = parseFloat(process.env.WEATHER_LON ?? '22.5684');
+  private readonly city = process.env.WEATHER_CITY ?? 'Lublin';
+
+  constructor(private readonly mesh: MeshService) {}
+
+  /** Fetch current conditions from Open-Meteo; throws on HTTP/parse failure. */
+  async fetchWeather(): Promise<CurrentWeather> {
+    const url =
+      `https://api.open-meteo.com/v1/forecast?latitude=${this.lat}` +
+      `&longitude=${this.lon}` +
+      `&current=temperature_2m,apparent_temperature,relative_humidity_2m,wind_speed_10m,weather_code`;
+    const res = await fetch(url);
+    if (!res.ok) throw new Error(`open-meteo HTTP ${res.status}`);
+    const json = (await res.json()) as { current: CurrentWeather };
+    return json.current;
+  }
+
+  /** One short line, e.g. `Lublin weather: 18°C (feels 17), partly cloudy, humidity 65%, wind 12 km/h`. */
+  formatReport(current: CurrentWeather): string {
+    const desc =
+      WMO_CODES[current.weather_code] ?? `code ${current.weather_code}`;
+    return `${this.city} weather: ${Math.round(current.temperature_2m)}°C (feels ${Math.round(
+      current.apparent_temperature,
+    )}), ${desc}, humidity ${Math.round(current.relative_humidity_2m)}%, wind ${Math.round(
+      current.wind_speed_10m,
+    )} km/h`;
+  }
+
+  /** Hourly cron: fetch → format → broadcast on the pinned send channel. Never throws — a failed report must not crash the app. */
+  @Cron(process.env.WEATHER_CRON || '0 * * * *')
+  async report(): Promise<void> {
+    try {
+      const current = await this.fetchWeather();
+      await this.mesh.sendText(BROADCAST_ADDR, this.formatReport(current));
+    } catch (err) {
+      this.logger.warn(`[weather] report failed: ${(err as Error).message}`);
+    }
+  }
+}