Churn Reduction for Desktop Apps

import { app } from "electron";
import fs from "fs";
import path from "path";

interface LicenseCache {
  valid: boolean;
  expiresAt: string; // ISO date
  plan: "pro" | "team" | "expired";
}

const CACHE_PATH = path.join(app.getPath("userData"), "license.json");
const GRACE_DAYS = 14;

async function validateLicense(
  licenseKey: string
): Promise<LicenseCache> {
  try {
    // Try online validation
    const res = await fetch("https://api.yourapp.com/license/validate", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ key: licenseKey }),
    });

    if (res.ok) {
      const data = await res.json();
      const cache: LicenseCache = {
        valid: data.active,
        expiresAt: new Date(
          Date.now() + GRACE_DAYS * 86400000
        ).toISOString(),
        plan: data.plan,
      };
      // Cache for offline use
      fs.writeFileSync(CACHE_PATH, JSON.stringify(cache));
      return cache;
    }
  } catch {
    // Offline. fall through to cached license
  }

  // Check cached license
  if (fs.existsSync(CACHE_PATH)) {
    const cached: LicenseCache = JSON.parse(
      fs.readFileSync(CACHE_PATH, "utf-8")
    );
    if (new Date(cached.expiresAt) > new Date()) {
      return cached; // Still within grace period
    }
    // Grace period expired. degraded mode
    return { valid: false, expiresAt: cached.expiresAt, plan: "expired" };
  }

  return { valid: false, expiresAt: "", plan: "expired" };
}

import { Notification, BrowserWindow, shell } from "electron";

interface PaymentFailure {
  customerEmail: string;
  cardLast4: string;
  amount: string;
  updateUrl: string;
}

function showPaymentFailureNotification(failure: PaymentFailure) {
  // System notification (works even when app is backgrounded)
  const notification = new Notification({
    title: "Payment Update Needed",
    body: `Your card ending in ${failure.cardLast4} was declined. Click to update your payment method.`,
    urgency: "critical",
  });

  notification.on("click", () => {
    shell.openExternal(failure.updateUrl);
  });

  notification.show();

  // Also show in-app banner on all windows
  const windows = BrowserWindow.getAllWindows();
  for (const win of windows) {
    win.webContents.send("payment-failure-banner", {
      message: `Your ${failure.amount} payment failed. Update your card to keep Pro features.`,
      updateUrl: failure.updateUrl,
    });
  }
}

// Called when your backend notifies the app of a payment failure
// (via WebSocket, polling, or on-launch API check)
export function handlePaymentWebhook(data: PaymentFailure) {
  showPaymentFailureNotification(data);
}