instagram-scraper/utils.js

function randomSleep(minMs = 2000, maxMs = 5000) {
  const delay = Math.floor(Math.random() * (maxMs - minMs + 1)) + minMs;
  return new Promise((res) => setTimeout(res, delay));
}

async function humanLikeMouseMovement(page, steps = 10) {
  // Simulate human-like mouse movements across the page
  const viewport = await page.viewport();
  const width = viewport.width;
  const height = viewport.height;

  for (let i = 0; i < steps; i++) {
    const x = Math.floor(Math.random() * width);
    const y = Math.floor(Math.random() * height);

    await page.mouse.move(x, y, { steps: Math.floor(Math.random() * 10) + 5 });
    await randomSleep(100, 500);
  }
}

async function randomScroll(page, scrollCount = 3) {
  // Perform random scrolling to simulate human behavior
  for (let i = 0; i < scrollCount; i++) {
    const scrollAmount = Math.floor(Math.random() * 300) + 100;
    await page.evaluate((amount) => {
      window.scrollBy(0, amount);
    }, scrollAmount);
    await randomSleep(800, 1500);
  }
}

async function simulateHumanBehavior(page, options = {}) {
  // Combined function to simulate various human-like behaviors
  const { mouseMovements = 5, scrolls = 2, randomClicks = false } = options;

  // Random mouse movements
  if (mouseMovements > 0) {
    await humanLikeMouseMovement(page, mouseMovements);
  }

  // Random scrolling
  if (scrolls > 0) {
    await randomScroll(page, scrolls);
  }

  // Optional: Random clicks on non-interactive elements
  if (randomClicks) {
    try {
      await page.evaluate(() => {
        const elements = document.querySelectorAll("div, span, p");
        if (elements.length > 0) {
          const randomElement =
            elements[Math.floor(Math.random() * elements.length)];
          const rect = randomElement.getBoundingClientRect();
          // Just move to it, don't actually click to avoid triggering actions
        }
      });
    } catch (err) {
      // Ignore errors from random element selection
    }
  }

  await randomSleep(500, 1000);
}

async function withRetry(fn, options = {}) {
  const {
    maxRetries = 3,
    initialDelay = 2000,
    maxDelay = 30000,
    shouldRetry = (error) => true,
  } = options;

  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await fn();
    } catch (error) {
      const isLastAttempt = attempt === maxRetries - 1;

      // Check if we should retry this error
      if (!shouldRetry(error) || isLastAttempt) {
        throw error;
      }

      // Calculate exponential backoff delay: 2s, 4s, 8s, 16s, 30s (capped)
      const exponentialDelay = Math.min(
        initialDelay * Math.pow(2, attempt),
        maxDelay
      );

      // Add jitter (randomize ±20%) to avoid thundering herd
      const jitter = exponentialDelay * (0.8 + Math.random() * 0.4);
      const delay = Math.floor(jitter);

      console.log(
        `Retry attempt ${attempt + 1}/${maxRetries} after ${delay}ms delay...`
      );
      console.log(`Error: ${error.message || error}`);

      await randomSleep(delay, delay);
    }
  }
}

async function handleRateLimitedRequest(page, requestFn, context = "") {
  return withRetry(requestFn, {
    maxRetries: 5,
    initialDelay: 2000,
    maxDelay: 60000,
    shouldRetry: (error) => {
      // Retry on rate limit (429) or temporary errors
      if (error.status === 429 || error.statusCode === 429) {
        console.log(`Rate limited (429) ${context}. Backing off...`);
        return true;
      }

      // Retry on 5xx server errors
      if (error.status >= 500 || error.statusCode >= 500) {
        console.log(
          `Server error (${
            error.status || error.statusCode
          }) ${context}. Retrying...`
        );
        return true;
      }

      // Retry on network errors
      if (error.code === "ECONNRESET" || error.code === "ETIMEDOUT") {
        console.log(`Network error (${error.code}) ${context}. Retrying...`);
        return true;
      }

      // Don't retry on client errors (4xx except 429)
      return false;
    },
  });
}

module.exports = {
  randomSleep,
  humanLikeMouseMovement,
  randomScroll,
  simulateHumanBehavior,
  withRetry,
  handleRateLimitedRequest,
};