refactor(analytics): abstract analytics into provider pattern

- Add type-safe AnalyticsEvent union types
- Create AnalyticsProvider interface for pluggable analytics backends
- Implement OpenPanelProvider and RybbitProvider adapters
- Create AnalyticsTracker that fans out events to all providers
- Simplifies adding new analytics platforms in the future

src/lib/analytics/core/AnalyticsTracker.ts

@@ -0,0 +1,112 @@
+"use client";
+
+import type { AnalyticsEvent, AnalyticsProvider, UserData } from "./types";
+
+export class AnalyticsTracker {
+  private providers: AnalyticsProvider[] = [];
+
+  addProvider(provider: AnalyticsProvider): void {
+    this.providers.push(provider);
+  }
+
+  track(event: AnalyticsEvent): void {
+    for (const provider of this.providers) {
+      try {
+        provider.track(event);
+      } catch (e) {
+        console.error(`[Analytics] ${provider.name} tracking error:`, e);
+      }
+    }
+  }
+
+  identify(user: UserData): void {
+    for (const provider of this.providers) {
+      if (provider.identify) {
+        try {
+          provider.identify(user);
+        } catch (e) {
+          console.error(`[Analytics] ${provider.name} identify error:`, e);
+        }
+      }
+    }
+  }
+
+  async revenue(amount: number, currency: string, properties?: Record<string, unknown>): Promise<void> {
+    const promises: Promise<void>[] = [];
+    for (const provider of this.providers) {
+      if (provider.revenue) {
+        promises.push(
+          provider.revenue(amount, currency, properties).catch((e) => {
+            console.error(`[Analytics] ${provider.name} revenue error:`, e);
+          })
+        );
+      }
+    }
+    await Promise.all(promises);
+  }
+
+  productViewed(product: { id: string; name: string; price: number; currency: string; category?: string; variant?: string }) {
+    this.track({ type: "product_viewed", product });
+  }
+
+  addToCart(product: { id: string; name: string; price: number; currency: string; quantity: number; variant?: string }) {
+    this.track({ type: "add_to_cart", product });
+  }
+
+  removeFromCart(product: { id: string; name: string; quantity: number }) {
+    this.track({ type: "remove_from_cart", product });
+  }
+
+  cartViewed(cart: { total: number; currency: string; item_count: number }) {
+    this.track({ type: "cart_view", cart });
+  }
+
+  checkoutStarted(cart: { total: number; currency: string; item_count: number; items?: Array<{ id: string; name: string; quantity: number; price: number }> }) {
+    this.track({ type: "checkout_started", cart });
+  }
+
+  checkoutStep(step: string, data?: Record<string, unknown>) {
+    this.track({ type: "checkout_step", step, data });
+  }
+
+  orderCompleted(order: { order_id: string; order_number: string; total: number; currency: string; item_count: number; shipping_cost?: number; coupon_code?: string; customer_email?: string; payment_method?: string }) {
+    this.track({ type: "order_completed", order });
+    this.revenue(order.total, order.currency, {
+      transaction_id: order.order_number,
+      order_id: order.order_id,
+    });
+  }
+
+  searchPerformed(query: string, results_count: number) {
+    this.track({ type: "search", query, results_count });
+  }
+
+  externalLinkClicked(url: string, label?: string) {
+    this.track({ type: "external_link_click", url, label });
+  }
+
+  wishlistAdded(product: { id: string; name: string }) {
+    this.track({ type: "wishlist_add", product });
+  }
+
+  userLoggedIn(method: string) {
+    this.track({ type: "user_login", method });
+  }
+
+  userRegistered(method: string) {
+    this.track({ type: "user_register", method });
+  }
+
+  newsletterSignedUp(email: string, source: string) {
+    this.track({ type: "newsletter_signup", email, source });
+  }
+}
+
+let trackerInstance: AnalyticsTracker | null = null;
+
+export function getTracker(): AnalyticsTracker {
+  if (!trackerInstance) {
+    trackerInstance = new AnalyticsTracker();
+  }
+  return trackerInstance;
+}