updated image downloader to accept 3XX codes

generate.mjs

@@ -28,24 +28,28 @@ function downloadImage(time_string, filepath) {
         }
         client.get(options, (res) => {
             console.log(`Downloading ${time_string}`);
-            if (res.statusCode === 200) {
+            if (res.statusCode >= 200 && res.statusCode < 400) {
                 res.pipe(fs.createWriteStream(filepath))
                     .on('error', reject)
                     .once('close', () => resolve(filepath));
             } else {
                 // Consume response data to free up memory
+                console.log(`Failed to download ${time_string} with status code ${res.statusCode}`);
                 res.resume();
                 reject(new Error(res.statusCode));
-
             }
         });
     });
 }
 
 export async function initImages(count) {
+    let files = fs.readdirSync('images/');
     for (let i = count; i >= 0; i--) {
         let time_string = getTimeString(i);
         let filename = `images/${time_string}.png`;
+        if (files.includes(`${time_string}.png`)) {
+            continue;
+        }
         try {
             await downloadImage(time_string, filename)
         } catch (error) {