feat: implement Open-Meteo weather integration with backfill scripts and updated lake data models.

scripts/backfillWeather.ts

@@ -0,0 +1,76 @@
+import fs from 'fs';
+import path from 'path';
+import axios from 'axios';
+import { lakesConfig } from './lakesConfig';
+
+const DATA_DIR = path.resolve(process.cwd(), 'public/data');
+
+async function backfill() {
+  console.log('Starting weather backfill for past 7 days...');
+  
+  for (const lake of lakesConfig) {
+    const internalId = lake.id.split('|')[0];
+    const filePath = path.join(DATA_DIR, `${internalId}.json`);
+    
+    if (!fs.existsSync(filePath)) {
+      console.log(`Skipping ${internalId}, no data file.`);
+      continue;
+    }
+    
+    if (!lake.coords) {
+      console.log(`Skipping ${internalId}, no coordinates.`);
+      continue;
+    }
+    
+    try {
+      const lat = lake.coords[0];
+      const lon = lake.coords[1];
+      const url = `https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&past_days=7&hourly=temperature_2m,precipitation&timezone=GMT`;
+      
+      const res = await axios.get(url, { timeout: 10000 });
+      const hourly = res.data.hourly;
+      
+      // Build lookup map for O(1) matching: '2026-06-02T04:00' -> { temp, precip }
+      const weatherMap = new Map();
+      for (let i = 0; i < hourly.time.length; i++) {
+        weatherMap.set(hourly.time[i], {
+          temperature: hourly.temperature_2m[i],
+          precipitation: hourly.precipitation[i]
+        });
+      }
+      
+      const data = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
+      let updatedCount = 0;
+      
+      for (const record of data) {
+        // record.timestamp is like "2026-06-02T04:00:00.000Z"
+        // Open-Meteo time is like "2026-06-02T04:00"
+        const hourKey = record.timestamp.substring(0, 16); // Extract up to minutes
+        
+        if (weatherMap.has(hourKey)) {
+          const w = weatherMap.get(hourKey);
+          if (w.temperature !== null && w.temperature !== undefined) {
+            record.temperature = w.temperature;
+            updatedCount++;
+          }
+          if (w.precipitation !== null && w.precipitation !== undefined) {
+            record.precipitation = w.precipitation;
+          }
+        }
+      }
+      
+      fs.writeFileSync(filePath, JSON.stringify(data, null, 2));
+      console.log(`[${internalId}] Backfilled ${updatedCount} records with historical Open-Meteo data.`);
+      
+      // small delay to prevent rate limit
+      await new Promise(r => setTimeout(r, 200));
+      
+    } catch (e: any) {
+      console.error(`Error processing ${internalId}:`, e.message);
+    }
+  }
+  
+  console.log('Backfill complete!');
+}
+
+backfill();