Initial commit

lib/rateLimiter.js

@@ -0,0 +1,107 @@
+const config = require("../config");
+const logger = require("./logger");
+
+class RateLimiter {
+  constructor() {
+    this.sentCount = 0;
+    this.startTime = Date.now();
+    this.lastSentTime = null;
+  }
+
+  // Record a successful send
+  recordSuccess() {
+    this.sentCount++;
+    this.lastSentTime = Date.now();
+  }
+
+  // Get randomized delay between min and max
+  getRandomDelay() {
+    const baseDelay = config.app.delayMinutes * 60 * 1000; // Convert to ms
+    const minDelay = baseDelay * 0.8; // 20% less than base
+    const maxDelay = baseDelay * 1.2; // 20% more than base
+
+    // Add additional randomization
+    const randomFactor = Math.random() * (maxDelay - minDelay) + minDelay;
+
+    // Add jitter to avoid patterns
+    const jitter = (Math.random() - 0.5) * 30000; // +/- 30 seconds
+
+    return Math.floor(randomFactor + jitter);
+  }
+
+  // Check if we should pause based on sent count
+  shouldPause() {
+    const hoursSinceStart = (Date.now() - this.startTime) / (1000 * 60 * 60);
+    const emailsPerHour = this.sentCount / hoursSinceStart;
+
+    // Gmail limits: ~500/day = ~20/hour
+    // Be conservative: pause if exceeding 15/hour
+    if (emailsPerHour > 15) {
+      return true;
+    }
+
+    // Pause every 50 emails for 30 minutes
+    if (this.sentCount > 0 && this.sentCount % 50 === 0) {
+      return true;
+    }
+
+    return false;
+  }
+
+  // Get pause duration
+  getPauseDuration() {
+    // Standard pause: 30 minutes
+    const basePause = 30 * 60 * 1000;
+
+    // Add randomization to pause duration
+    const randomPause = basePause + Math.random() * 10 * 60 * 1000; // +0-10 minutes
+
+    return randomPause;
+  }
+
+  // Calculate next send time
+  async getNextSendDelay() {
+    if (this.shouldPause()) {
+      const pauseDuration = this.getPauseDuration();
+      const pauseMinutes = Math.round(pauseDuration / 60000);
+
+      logger.rateLimitPause(
+        pauseDuration,
+        `Automatic pause after ${this.sentCount} emails`
+      );
+      console.log(`Rate limit pause: ${pauseMinutes} minutes`);
+      return pauseDuration;
+    }
+
+    return this.getRandomDelay();
+  }
+
+  // Get human-readable time
+  formatDelay(ms) {
+    const minutes = Math.floor(ms / 60000);
+    const seconds = Math.floor((ms % 60000) / 1000);
+    return `${minutes}m ${seconds}s`;
+  }
+
+  // Reset counters (for testing)
+  reset() {
+    this.sentCount = 0;
+    this.startTime = Date.now();
+    this.lastSentTime = null;
+  }
+
+  // Get current stats
+  getStats() {
+    const runtime = (Date.now() - this.startTime) / 1000; // seconds
+    const avgRate = this.sentCount / (runtime / 3600); // emails per hour
+
+    return {
+      sentCount: this.sentCount,
+      runtime: Math.floor(runtime / 60), // minutes
+      averageRate: avgRate.toFixed(1),
+      nextDelay: this.formatDelay(this.getRandomDelay()),
+    };
+  }
+}
+
+module.exports = new RateLimiter();