From 9a8387157139893ef547eed46017d057941130b0 Mon Sep 17 00:00:00 2001
From: synzr <mikhail@synzr.space>
Date: Tue, 2 Dec 2025 09:19:14 +0500
Subject: [PATCH] feat(clients/weather): yandex weather integration

---
 src/lib/clients/weather.ts | 175 +++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 src/lib/clients/weather.ts

diff --git a/src/lib/clients/weather.ts b/src/lib/clients/weather.ts
new file mode 100644
index 0000000..7a97052
--- /dev/null
+++ b/src/lib/clients/weather.ts
@@ -0,0 +1,175 @@
+import crypto from "node:crypto";
+
+/**
+ * User agent header.
+ */
+const USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36';
+
+/**
+ * Token secret. Used to hash the token.
+ */
+const WEATHER_TOKEN_SECRET = "gravisfrontem";
+
+interface YandexWeatherData {
+    /**
+     * Message from the server.
+     */
+    message?: string | null;
+
+    info: {
+        /**
+         * URL of the location page on Yandex Weather
+         **/
+        url: string;
+    };
+
+    fact: {
+        /**
+         * Current air temperature in °C
+         **/
+        temp: number;
+
+        /**
+         * Water temperature in °C (may be missing)
+         **/
+        temp_water?: number;
+
+        /**
+         * Perceived (“feels like”) temperature in °C
+         **/
+        feels_like: number;
+
+        /**
+         * Weather condition code (e.g., "clear", "rain")
+         **/
+        condition: string;
+
+        /**
+         * Wind speed in m/s
+         **/
+        wind_speed: number;
+
+        /**
+         * Wind gust speed in m/s (may be missing)
+         **/
+        wind_gust?: number;
+
+        /**
+         * Wind direction code (e.g., "nw", "s")
+         **/
+        wind_dir: string;
+
+        /**
+         * Atmospheric pressure in mmHg
+         **/
+        pressure_mm: number;
+
+        /**
+         * Air humidity percentage
+         **/
+        humidity: number;
+    };
+}
+
+export interface FetchWeatherResult {
+    /**
+     * Link to the weather in location.
+     **/
+    url: string;
+
+    temperature: {
+        /**
+         * Current temperature in °C.
+         **/
+        current: number;
+
+        /**
+         * Water temperature in °C.
+         **/
+        water?: number;
+
+        /**
+         * Perceived ("feels like") temperature in °C.
+         **/
+        feelsLike: number;
+    };
+
+    /**
+     * Weather condition.
+     **/
+    condition: string;
+
+    wind: {
+        /**
+         * Wind speed in m/s.
+         **/
+        speed: number;
+
+        /**
+         * Wind gust speed in m/s.
+         **/
+        gust?: number;
+
+        /**
+         * Wind direction code.
+         **/
+        direction: string;
+    };
+
+    /**
+     * Atmospheric pressure in mmHg.
+     **/
+    pressure: number;
+
+    /**
+     * Air humidity percentage.
+     **/
+    humidity: number;
+}
+
+function getWeatherHeaders() {
+    const timestamp = Date.now();
+
+    return {
+        // NOTE: no one would pay ~$7k to have a weather on their personal website
+        'x-yandex-weather-timestamp': timestamp.toString(),
+        'x-yandex-weather-token':
+            crypto.createHash('md5').update(`${WEATHER_TOKEN_SECRET}${timestamp}`).digest('hex'),
+        'x-yandex-weather-client': 'YandexWeatherFront2',
+    };
+}
+
+export default async function fetchWeather(lat: number, lon: number): Promise<FetchWeatherResult> {
+    const response = await fetch(
+        `https://api.weather.yandex.ru/v2/informers?lat=${lat}&lon=${lon}&lang=en_US`,
+        {
+            headers: {
+                'user-agent': USER_AGENT,
+                ...getWeatherHeaders(),
+            },
+        }
+    );
+
+    const result: YandexWeatherData = await response.json();
+
+    if (!response.ok) {
+        throw new Error(`Yandex Weather API error: ${result.message}`)
+    }
+
+    return {
+        url: result.info.url,
+        temperature: {
+            current: result.fact.temp,
+            water: result.fact.temp_water,
+            feelsLike: result.fact.feels_like,
+        },
+        condition: result.fact.condition,
+        wind: {
+            speed: result.fact.wind_speed,
+            gust: result.fact.wind_gust,
+            direction: result.fact.wind_dir,
+        },
+        pressure: result.fact.pressure_mm,
+        humidity: result.fact.humidity,
+    };
+}