import { useState, useEffect, useCallback } from 'react';
import { BrowserRouter } from 'react-router-dom';
import { useWebSocket } from './hooks/useWebSocket';
import { useAuth } from './components/AuthContext';
import { Login } from './components/Login';
import { ResetPassword } from './components/ResetPassword';
import { ChatControl } from './components/ChatControl';
import { AppContext } from './context/AppContext';
import { AppShell } from './components/layout/AppShell';
import { useBacktestFeatureGate } from './backtest/useBacktestFeatureGate';
import { useTabFeatureFlags } from './hooks/useTabFeatureFlags';
import { tradingRuntime, tradingTelemetry } from './lib/runtime';
import { createTradeProfile, fetchTradeProfiles, updateTradeProfile } from './lib/profileApi';

// ─── Helpers (preserved from original App.tsx) ───────────────────────────────

export const resolveProfileNameForAction = (
  action: string,
  requestedName: string | undefined,
  chatProfiles: Array<{ name?: string }>,
  suffixProvider: () => string = () =>
    new Date().toLocaleTimeString([], { hour: '2-digit', minute: '2-digit', second: '2-digit' }).replace(/:/g, '')
) => {
  let profileName = requestedName || 'AI Profile';
  if (action === 'create_profile') {
    const existing = chatProfiles.find(p => p.name === profileName);
    if (existing) profileName = `${profileName} (${suffixProvider()})`;
  }
  return profileName;
};

export const buildChatApplyPayload = (
  profileData: any,
  currentUserId: string,
  profileName: string
) => ({
  name: profileName,
  user_id: currentUserId,
  allocated_capital: Number(profileData.allocated_capital || 1000),
  risk_per_trade_percent: Number(profileData.risk_per_trade_percent || 1),
  symbols: profileData.symbols || 'BTC/USDT',
  is_active: profileData.is_active ?? true,
  strategy_config: profileData.strategy_config,
});

// ─── App ─────────────────────────────────────────────────────────────────────

function App() {
  const { user, profile, loading, signOut } = useAuth();
  const { socket, botState, connected } = useWebSocket(tradingRuntime.tradingApiUrl);
  const [activeSymbol, setActiveSymbol] = useState('');
  const [chatProfiles, setChatProfiles]  = useState<any[]>([]);
  const [previewAsCustomer] = useState(false);

  const { enabled: backtestEnabledForView, loading: backtestGateLoading } =
    useBacktestFeatureGate({ previewAsCustomer });
  const { flags: tabFlags } = useTabFeatureFlags();

  // Feature gates
  const isAdminAccount   = profile?.role === 'admin';
  const isAdmin          = isAdminAccount && !previewAsCustomer;
  const showBacktestTab  = isAdmin || (!backtestGateLoading && backtestEnabledForView);
  const showMarketplaceTab = isAdmin || tabFlags.marketplace;

  // Critical system events (for the alert banner)
  const recentCriticalEvents = (botState.operationalEvents ?? []).filter(e =>
    (e.severity === 'ERROR' || e.severity === 'WARN') &&
    Date.now() - e.timestamp < 600_000
  );
  const hasCriticalEvents = recentCriticalEvents.length > 0;

  // Chat profile management
  const fetchChatProfiles = useCallback(async () => {
    const data = await fetchTradeProfiles();
    setChatProfiles(data ?? []);
  }, []);

  useEffect(() => {
    if (user) {
      fetchChatProfiles();
      const id = setInterval(fetchChatProfiles, 30_000);
      return () => clearInterval(id);
    }
  }, [user, fetchChatProfiles]);

  const handleChatApply = async (
    action: string,
    profileData: any
  ): Promise<{ success: boolean; error?: string }> => {
    const currentUserId = user?.id;
    if (!currentUserId) return { success: false, error: 'Not authenticated' };

    const profileName = resolveProfileNameForAction(action, profileData.name, chatProfiles);
    const payload = buildChatApplyPayload(profileData, currentUserId, profileName);

    if (action === 'create_profile') {
      try {
        await createTradeProfile(payload);
        fetchChatProfiles();
        window.dispatchEvent(new Event('profiles-updated'));
        return { success: true };
      } catch (err: any) {
        return { success: false, error: err.message };
      }
    }
    if (action === 'update_profile' && profileData.id) {
      try {
        await updateTradeProfile(profileData.id, payload);
        fetchChatProfiles();
        window.dispatchEvent(new Event('profiles-updated'));
        return { success: true };
      } catch (err: any) {
        return { success: false, error: err.message };
      }
    }
    return { success: false, error: 'Unknown action' };
  };

  const handleSignOut = async () => {
    tradingTelemetry.client.trackEvent('info', 'auth', 'trading_web_sign_out', {
      userId: user?.id ?? 'anonymous',
      feature: 'sign_out',
      tags: { surface: 'web' },
    });
    await signOut();
  };

  // ── Auth gates ──────────────────────────────────────────────────────────────
  if (window.location.pathname === '/reset-callback') return <ResetPassword />;

  if (loading) {
    return (
      <div style={{
        display: 'flex', justifyContent: 'center', alignItems: 'center',
        height: '100vh', background: '#F3F4F6', color: '#374151',
        fontSize: 15, fontFamily: 'Inter, system-ui, sans-serif',
      }}>
        Loading…
      </div>
    );
  }

  if (!user) return <Login />;

  // ── Render ──────────────────────────────────────────────────────────────────
  return (
    <BrowserRouter>
      <AppContext.Provider value={{
        botState,
        socket,
        connected,
        activeSymbol,
        setActiveSymbol,
        isAdmin,
        user,
        profile,
        showBacktestTab,
        showMarketplaceTab,
        handleSignOut,
      }}>
        {/* Critical system alert banner */}
        {hasCriticalEvents && (
          <div style={{
            position: 'fixed', top: 0, left: 0, right: 0, zIndex: 9999,
            background: 'linear-gradient(90deg, #991b1b 0%, #dc2626 50%, #991b1b 100%)',
            color: '#fff',
            padding: '6px 20px',
            textAlign: 'center',
            fontSize: 11,
            fontWeight: 900,
            textTransform: 'uppercase',
            letterSpacing: '0.1em',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            gap: 10,
          }}>
            <span>⚠️</span>
            <span>
              SYSTEM ALERT: {recentCriticalEvents.length} CRITICAL ISSUES DETECTED — GO TO SETTINGS › ADMIN PANEL
            </span>
            <span>⚠️</span>
          </div>
        )}

        <div style={{ paddingTop: hasCriticalEvents ? 32 : 0 }}>
          <AppShell />
        </div>

        {/* Floating AI strategy assistant */}
        <ChatControl profiles={chatProfiles} onApplyProfile={handleChatApply} />
      </AppContext.Provider>
    </BrowserRouter>
  );
}

export default App;