feat: feature flags

apps/web/src/providers/posthog.tsx

@@ -0,0 +1,52 @@
+'use client';
+
+import { useEffect } from 'react';
+
+import { usePathname, useSearchParams } from 'next/navigation';
+
+import { getSession } from 'next-auth/react';
+import posthog from 'posthog-js';
+
+import { extractPostHogConfig } from '@documenso/lib/constants/feature-flags';
+
+export function PostHogPageview(): JSX.Element {
+  const postHogConfig = extractPostHogConfig();
+
+  const pathname = usePathname();
+  const searchParams = useSearchParams();
+
+  if (typeof window !== 'undefined' && postHogConfig) {
+    posthog.init(postHogConfig.key, {
+      api_host: postHogConfig.host,
+      loaded: () => {
+        getSession()
+          .then((session) => {
+            if (session) {
+              posthog.identify(session.user.email ?? session.user.id.toString());
+            } else {
+              posthog.reset();
+            }
+          })
+          .catch(() => {
+            // Do nothing.
+          });
+      },
+    });
+  }
+
+  useEffect(() => {
+    if (!postHogConfig || !pathname) {
+      return;
+    }
+
+    let url = window.origin + pathname;
+    if (searchParams && searchParams.toString()) {
+      url = url + `?${searchParams.toString()}`;
+    }
+    posthog.capture('$pageview', {
+      $current_url: url,
+    });
+  }, [pathname, searchParams, postHogConfig]);
+
+  return <></>;
+}