Instruction file imported from anhluu14/chrysos-trading-simulator-app (.cursor/rules/.mdc). Copyright stays with the author.

🚀 PRODUCTION READINESS RULES

• All console.log, console.warn, and console.error calls must be removed.
• Use centralized constants (e.g. TRADING_CONFIG) for default values like 100000.
• Avoid hardcoded color strings; use theme.colors.* instead.
• Input validation is required on all user entry points (text input, trade actions, etc.).
• Ensure that all portfolio operations are transactional and avoid race conditions.
• All critical async operations should have loading indicators and error fallback UIs.
• Add confirmation modals for destructive actions (e.g., portfolio reset, trade sell).
• Trading components must memoize expensive calculations using useMemo and useCallback.
• Components triggering network or state changes must wrap critical flows in try/catch.
• Ensure cleanup in components using useEffect to prevent memory leaks (especially with WebView, Chart, or Socket).

🧱 ARCHITECTURE & STATE

• Balance logic, calculations, and sync functions should be moved to a shared service (e.g. BalanceCalculator).
• No duplication of portfolio sync logic — use a single source of truth (UserSyncService).
• Always use useSelector with memoized selectors when accessing Redux state.
• Redux actions that affect multiple entities (balance, portfolio) should dispatch atomic updates.

🔐 SECURITY & AUTH

• Do not perform any Supabase update without validating uuid/session token first.
• RLS (Row Level Security) must be enforced via Supabase policies.
• Use Expo SecureStore for all token or sensitive value storage.
• No sensitive values (API keys, tokens) should be hardcoded in source files.

📦 CONFIG & METADATA

• app.json must have:
  • "privacy": "public"
  • valid description, keywords, and proper permission usage descriptions.
• Ensure Info.plist and AndroidManifest.xml declare necessary permissions with justifications.
• Remove unused dependencies: react-dom, dotenv, @expo/config-plugins, reflect-metadata, etc.
• Add missing dependencies like redux, lint-staged.

🧪 TESTING & STABILITY

• Trading logic must have unit tests in __tests__/ or tests/ directory.
• All critical screens (trade execution, portfolio view) must have error boundaries.
• Use Sentry/Bugsnag or equivalent for runtime crash reporting in production.
• Offline functionality must be simulated and tested with NetInfo state toggles.

📲 UI/UX STANDARDS

• Use theme.colors.* — never hardcode color strings like "#ffffff".
• Use SafeAreaView and responsive padding/margin logic.
• Show ActivityIndicator or skeletons during all async fetches.
• Error messages should be user-friendly (not technical stack traces).

📋 DEPLOYMENT BLOCKERS (Critical Checkpoints)

• ✅ All console.log statements are removed
• ✅ Privacy policy URL set in app.json
• ✅ Description & Keywords in metadata
• ✅ Camera/notification permission descriptions added
• ✅ Production API domains use HTTPS and certificate pinning
• ✅ No inline API keys or secrets
• ✅ RLS enforced + input validation complete
• ✅ Error boundaries added to all flows
• ✅ App assets (screenshots, icons, descriptions) are ready

📅 FINAL NOTE

These rules ensure production compliance, store readiness, and long-term maintainability. All rules must be followed before deployment to App Store or Google Play.