import { Link } from '@tanstack/react-router';
import { usePipelineHealth, useIngestionSummary, useRecommendations, useCompanies, useCoverageGaps } from '../api/hooks';
import { LoadingSpinner, Card } from '../components/ui';
import {
  Building2, FileText, TrendingUp, Lightbulb, ShoppingCart,
  Wallet, ShieldCheck, Activity, Download, Cpu, Radar,
  Terminal, LayoutDashboard, AlertTriangle,
} from 'lucide-react';

const quickNav = [
  { to: '/companies', label: 'Companies', icon: <Building2 size={20} />, color: 'text-blue-400' },
  { to: '/documents', label: 'Documents', icon: <FileText size={20} />, color: 'text-green-400' },
  { to: '/trends', label: 'Trends', icon: <TrendingUp size={20} />, color: 'text-purple-400' },
  { to: '/recommendations', label: 'Recommendations', icon: <Lightbulb size={20} />, color: 'text-yellow-400' },
  { to: '/orders', label: 'Orders', icon: <ShoppingCart size={20} />, color: 'text-orange-400' },
  { to: '/positions', label: 'Positions', icon: <Wallet size={20} />, color: 'text-cyan-400' },
  { to: '/trading', label: 'Trading', icon: <ShieldCheck size={20} />, color: 'text-red-400' },
  { to: '/ops/pipeline', label: 'Pipeline', icon: <Activity size={20} />, color: 'text-emerald-400' },
  { to: '/ops/ingestion', label: 'Ingestion', icon: <Download size={20} />, color: 'text-teal-400' },
  { to: '/ops/model', label: 'Model Perf', icon: <Cpu size={20} />, color: 'text-indigo-400' },
  { to: '/ops/coverage', label: 'Coverage', icon: <Radar size={20} />, color: 'text-pink-400' },
  { to: '/analytics/query', label: 'SQL Explorer', icon: <Terminal size={20} />, color: 'text-amber-400' },
  { to: '/analytics/dashboards', label: 'Dashboards', icon: <LayoutDashboard size={20} />, color: 'text-violet-400' },
];

export function HomePage() {
  const { data: pipeline, isLoading: pLoading } = usePipelineHealth(24);
  const { data: ingestion } = useIngestionSummary(24);
  const { data: recs } = useRecommendations({ limit: 5 });
  const { data: companies } = useCompanies();
  const { data: gaps } = useCoverageGaps();

  if (pLoading) return <LoadingSpinner />;

  const ing = (ingestion ?? {}) as Record<string, unknown>;
  const staleCount = (gaps?.stale_sources?.length ?? 0) + (gaps?.missing_source_types?.length ?? 0);

  return (
    <div className="space-y-6">
      <h1 className="text-2xl font-bold text-gray-100">Stonks Oracle</h1>

      {/* Alert banner */}
      {staleCount > 0 && (
        <div className="flex items-center gap-3 rounded-lg border border-yellow-700/50 bg-yellow-900/20 p-3" role="alert">
          <AlertTriangle size={18} className="text-yellow-400" />
          <span className="text-sm text-yellow-300">
            {staleCount} coverage issue{staleCount > 1 ? 's' : ''} detected — check{' '}
            <Link to="/ops/coverage" className="underline hover:text-yellow-200">Source Coverage</Link>
          </span>
        </div>
      )}

      {/* Key metrics */}
      <div className="grid grid-cols-2 gap-3 sm:grid-cols-4">
        <MetricCard label="Active Companies" value={companies?.length ?? 0} />
        <MetricCard label="Ingestion Runs (24h)" value={ing.total_runs} />
        <MetricCard label="Items Fetched (24h)" value={ing.total_items_fetched} />
        <MetricCard label="Recommendations Today" value={recs?.length ?? 0} />
      </div>

      {/* Pipeline status */}
      {pipeline && (
        <Card>
          <h2 className="mb-3 text-sm font-medium text-gray-400">Pipeline Status (24h)</h2>
          <div className="grid grid-cols-2 gap-3 text-sm sm:grid-cols-4">
            {((pipeline.document_stages ?? []) as Array<{ status: string; doc_count: number }>).map((s) => (
              <div key={s.status} className="text-center">
                <div className="text-lg font-bold text-gray-100">{s.doc_count}</div>
                <div className="text-xs capitalize text-gray-500">{s.status}</div>
              </div>
            ))}
          </div>
        </Card>
      )}

      {/* Recent activity */}
      {recs && recs.length > 0 && (
        <Card>
          <h2 className="mb-3 text-sm font-medium text-gray-400">Recent Recommendations</h2>
          <div className="space-y-2">
            {recs.map((r) => (
              <Link key={r.id} to="/recommendations/$id" params={{ id: r.id }} className="flex items-center justify-between rounded border border-surface-700 bg-surface-950 p-2 hover:bg-surface-800/50">
                <div className="flex items-center gap-2">
                  <span className="font-mono text-sm font-semibold text-brand-300">{r.ticker}</span>
                  <span className={`rounded-full px-2 py-0.5 text-xs font-medium ${r.action === 'buy' ? 'bg-green-900/40 text-green-400' : r.action === 'sell' ? 'bg-red-900/40 text-red-400' : 'bg-gray-800/40 text-gray-400'}`}>
                    {r.action}
                  </span>
                  <span className="text-xs text-gray-500 line-clamp-1 max-w-xs">{r.thesis}</span>
                </div>
                <span className="text-xs text-gray-500">{new Date(r.generated_at).toLocaleString()}</span>
              </Link>
            ))}
          </div>
        </Card>
      )}

      {/* Quick nav */}
      <div className="grid grid-cols-3 gap-2 sm:grid-cols-4 lg:grid-cols-5">
        {quickNav.map((item) => (
          <Link
            key={item.to}
            to={item.to}
            className="flex flex-col items-center gap-1.5 rounded-lg border border-surface-700 bg-surface-900 p-3 text-center transition-colors hover:border-brand-500/50 hover:bg-surface-800"
          >
            <span className={item.color}>{item.icon}</span>
            <span className="text-xs text-gray-400">{item.label}</span>
          </Link>
        ))}
      </div>
    </div>
  );
}

function MetricCard({ label, value }: { label: string; value: unknown }) {
  return (
    <Card className="text-center">
      <div className="text-2xl font-bold text-gray-100">{value != null ? String(value) : '—'}</div>
      <div className="text-xs text-gray-500">{label}</div>
    </Card>
  );
}