added genai rate limiting

src/services/aiService.server.ts

@@ -8,6 +8,7 @@
 import { GoogleGenAI } from '@google/genai';
 import fsPromises from 'node:fs/promises';
 import { logger } from './logger.server';
+import pRateLimit from 'p-ratelimit';
 import type { FlyerItem, MasterGroceryItem, ExtractedFlyerItem } from '../types';
 
 /**
@@ -43,6 +44,7 @@ type RawFlyerItem = {
 export class AIService {
   private aiClient: IAiClient;
   private fs: IFileSystem;
+  private rateLimiter: <T>(fn: () => Promise<T>) => Promise<T>;
 
   constructor(aiClient?: IAiClient, fs?: IFileSystem) {
     if (aiClient) {
@@ -65,6 +67,16 @@ export class AIService {
     }
 
     this.fs = fs || fsPromises;
+
+    // Initialize the rate limiter based on an environment variable.
+    // Defaults to 5 requests per minute (60,000 ms) if not specified.
+    const requestsPerMinute = parseInt(process.env.GEMINI_RPM || '5', 10);
+    this.rateLimiter = pRateLimit({
+      interval: 60 * 1000, // 1 minute
+      rate: requestsPerMinute,
+      concurrency: requestsPerMinute, // Allow up to `rate` requests to be running in parallel.
+    });
+    logger.info(`[AIService] Rate limiter initialized to ${requestsPerMinute} requests per minute.`);
   }
 
   private async serverFileToGenerativePart(path: string, mimeType: string) {
@@ -174,10 +186,12 @@ export class AIService {
     const imagePart = await this.serverFileToGenerativePart(imagePath, imageMimeType);
 
     try {
-      const response = await this.aiClient.generateContent({
-        model: 'gemini-2.5-flash',
-        contents: [{ parts: [{text: prompt}, imagePart] }]
-      });
+      // Wrap the AI call with the rate limiter.
+      const response = await this.rateLimiter(() => 
+        this.aiClient.generateContent({
+          model: 'gemini-2.5-flash',
+          contents: [{ parts: [{text: prompt}, imagePart] }]
+        }));
       const text = response.text;
       const parsedJson = this._parseJsonFromAiResponse<any[]>(text);
 
@@ -215,11 +229,13 @@ export class AIService {
       try {
          logger.debug(`[aiService.server] Calling Gemini API for flyer processing with ${imageParts.length} image(s).`);
           const geminiCallStartTime = process.hrtime.bigint();
-
-        const response = await this.aiClient.generateContent({
-          model: 'gemini-2.5-flash',
-          contents: [{ parts: [{ text: prompt }, ...imageParts] }]
-        });
+        
+        // Wrap the AI call with the rate limiter.
+        const response = await this.rateLimiter(() => 
+          this.aiClient.generateContent({
+            model: 'gemini-2.5-flash',
+            contents: [{ parts: [{ text: prompt }, ...imageParts] }]
+          }));
 
         const geminiCallEndTime = process.hrtime.bigint();
         const durationMs = Number(geminiCallEndTime - geminiCallStartTime) / 1_000_000;
@@ -307,10 +323,12 @@ export class AIService {
     // 4. Call the AI model
     try {
       logger.info(`[aiService.server] Calling Gemini for targeted rescan of type: ${extractionType}`);
-      const response = await this.aiClient.generateContent({
-        model: 'gemini-2.5-flash',
-        contents: [{ parts: [{ text: prompt }, imagePart] }]
-      });
+      // Wrap the AI call with the rate limiter.
+      const response = await this.rateLimiter(() => 
+        this.aiClient.generateContent({
+          model: 'gemini-2.5-flash',
+          contents: [{ parts: [{ text: prompt }, imagePart] }]
+        }));
 
       const text = response.text?.trim() ?? '';
       logger.info(`[aiService.server] Gemini rescan completed. Extracted text: "${text}"`);
@@ -334,13 +352,14 @@ export class AIService {
       const storeName = store?.name || 'the grocery store';
       
       try {
-          const response = await this.aiClient.generateContent({
+          // Wrap the AI call with the rate limiter.
+          const response = await this.rateLimiter(() => this.aiClient.generateContent({
               model: "gemini-2.5-flash",
               contents: [{ parts: [{ text: `My current location is latitude ${userLocation.latitude}, longitude ${userLocation.longitude}.
               I have a shopping list with items like ${topItems}. Find the nearest ${storeName} to me and suggest the best route.
               Also, are there any other specialty stores nearby (like a bakery or butcher) that might have good deals on related items?`}]}],
               tools: [{ "googleSearch": {} }],
-          });
+          }));
   
           // In a real implementation, you would render the map URLs from the sources.
           const sources = (response.candidates?.[0]?.groundingMetadata?.groundingAttributions || []).map((att: any) => ({