app.js

import express from 'express';
import cors from 'cors';
import dotenv from 'dotenv';
import rateLimit from 'express-rate-limit'; // <--- NEW

// Import your modular apps here
// Apps
import trendCatRouter from "./apps/viralcat.js" 
import drCatRouter from './apps/dr_cat.js'; 
import auraMeasure from './apps/aura_measure.js';
// Apps end 

import { generateCompletion, streamCompletion } from './ai_engine.js';

dotenv.config();
const app = express();
const PORT = process.env.PORT || 7860;

// ⚠️ CRITICAL ADVISOR NOTE: 
// If you are hosting on Render, Railway, Heroku, DigitalOcean, etc., 
// you MUST trust the proxy, otherwise the rate limiter will see the hosting 
// platform's IP and block EVERYONE at the same time.
app.set('trust proxy', 1);

app.use(cors());
app.use(express.json({ limit: '50mb' })); 

// --- 🛡️ RATE LIMITERS ---

// 1. Burst Limiter (Per Minute): Stops rapid-fire spam / button mashing
const burstLimiter = rateLimit({
    windowMs: 60 * 1000, // 1 minute window
    max: 8, // Max 5 requests per minute per IP
    message: { 
        success: false, 
        error: "Whoa there, speedy! 🙀 Please wait a minute before scanning again." 
    },
    standardHeaders: true, 
    legacyHeaders: false, 
});

// 2. Daily Limiter (Cost Control): Stops API bankruptcy
const dailyLimiter = rateLimit({
    windowMs: 24 * 60 * 60 * 1000, // 24 hours
    max: 200, // Max 30 requests per DAY per IP (Adjust this number based on your budget)
    message: { 
        success: false, 
        error: "Daily scan limit reached! 🛑 Check back tomorrow or follow us on socials for updates." 
    },
    standardHeaders: true,
    legacyHeaders: false,
});

// Apply the limiters ONLY to your API routes. 
// We don't apply it globally so your health check '/' doesn't get blocked.
app.use('/api/', burstLimiter);
app.use('/api/', dailyLimiter);

// Mount the App-Specific Routes
app.use('/api/viralcat', trendCatRouter);
app.use('/api/drcat', drCatRouter); 
app.use('/api/aurameasure', auraMeasure);


app.get('/', async (req, res) => { res.json({ success: true, ecosystem: "Everyday Cats Backend" }); });

app.listen(PORT, '0.0.0.0', () => console.log(`😻 Everyday Cats Ecosystem live on port ${PORT} with Rate Limits Active!`));