import { useState, useEffect } from 'react';
import { usePipelineHealth } from '../api/hooks';
import { LoadingSpinner, DateRangeSelector, Card } from '../components/ui';

const QUEUE_LABELS: Record<string, string> = {
  ingestion: 'Ingestion',
  parsing: 'Parsing',
  extraction: 'Extraction',
  macro_classification: 'Macro Classify',
  aggregation: 'Aggregation',
  recommendation: 'Recommendation',
  lake_publish: 'Lake Publish',
  trade: 'Trade',
  trading_decisions: 'Trading Decisions',
  broker_orders: 'Broker Orders',
};

interface StreamData {
  queue_depths: Record<string, number>;
  document_stages: Record<string, number>;
}

function usePipelineStream() {
  const [data, setData] = useState<StreamData | null>(null);

  useEffect(() => {
    // EventSource is not available in test environments (jsdom)
    if (typeof EventSource === 'undefined') return;

    const base = import.meta.env.VITE_QUERY_API_BASE || '';
    const url = `${base}/api/ops/pipeline/stream`;
    const es = new EventSource(url);

    es.onmessage = (event) => {
      try {
        setData(JSON.parse(event.data));
      } catch {
        // ignore parse errors
      }
    };

    es.onerror = () => {
      // EventSource auto-reconnects
    };

    return () => es.close();
  }, []);

  return data;
}

export function OpsPipelinePage() {
  const [hours, setHours] = useState(24);
  const { data, isLoading } = usePipelineHealth(hours);
  const stream = usePipelineStream();

  if (isLoading) return <LoadingSpinner />;

  const parsing = (data?.parsing ?? {}) as Record<string, unknown>;
  const extraction = (data?.extraction ?? {}) as Record<string, unknown>;
  const aggregation = (data?.aggregation ?? {}) as Record<string, unknown>;

  // Prefer live stream data for queue depths and doc stages, fall back to initial fetch
  const queueDepths = stream?.queue_depths
    ?? (data?.queue_depths as Record<string, number> | undefined)
    ?? {};
  const docStages = stream?.document_stages
    ?? Object.fromEntries(
      ((data?.document_stages as Array<{ status: string; doc_count: number }>) ?? [])
        .map((s) => [s.status, s.doc_count]),
    );

  // Separate DLQ entries from regular queues
  const dlqEntries = Object.entries(queueDepths).filter(([k]) => k.startsWith('dlq:'));
  const regularQueues = Object.entries(QUEUE_LABELS);

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <h1 className="text-xl font-semibold text-gray-100">Pipeline Health</h1>
        <div className="flex items-center gap-3">
          {stream && (
            <span className="flex items-center gap-1.5 text-xs text-green-400">
              <span className="inline-block h-2 w-2 rounded-full bg-green-400 animate-pulse" aria-hidden="true" />
              Live
            </span>
          )}
          <DateRangeSelector value={hours} onChange={setHours} />
        </div>
      </div>

      {/* Queue Depths */}
      <Card>
        <h2 className="mb-3 text-sm font-medium text-gray-400">Queue Depths</h2>
        <div className="grid grid-cols-2 gap-3 sm:grid-cols-5 lg:grid-cols-5">
          {regularQueues.map(([key, label]) => {
            const depth = queueDepths[key] ?? 0;
            const color = depth > 100 ? 'text-amber-400' : depth > 0 ? 'text-blue-400' : 'text-gray-500';
            return (
              <div key={key} className="rounded-lg border border-surface-700 bg-surface-950 p-3 text-center">
                <div className={`text-2xl font-bold tabular-nums ${color}`}>{depth}</div>
                <div className="text-xs text-gray-500">{label}</div>
              </div>
            );
          })}
        </div>
        {dlqEntries.length > 0 && (
          <div className="mt-3">
            <h3 className="mb-2 text-xs font-medium text-red-400">Dead Letter Queues</h3>
            <div className="flex flex-wrap gap-3">
              {dlqEntries.map(([key, depth]) => (
                <div key={key} className="rounded-lg border border-red-700/50 bg-red-900/20 px-3 py-2 text-center">
                  <div className="text-lg font-bold tabular-nums text-red-400">{depth}</div>
                  <div className="text-xs text-red-400/70">{key.replace('dlq:', '')}</div>
                </div>
              ))}
            </div>
          </div>
        )}
      </Card>

      {/* Document Stage Counts */}
      <Card>
        <h2 className="mb-3 text-sm font-medium text-gray-400">Document Stages</h2>
        <div className="grid grid-cols-2 gap-3 sm:grid-cols-4">
          {Object.entries(docStages).map(([status, count]) => {
            const color = status === 'extracted' ? 'text-green-400'
              : status === 'parsed' ? 'text-yellow-400'
              : status === 'extraction_failed' ? 'text-red-400'
              : status === 'low_quality' ? 'text-orange-400'
              : 'text-gray-100';
            return (
              <div key={status} className="rounded-lg border border-surface-700 bg-surface-950 p-3 text-center">
                <div className={`text-2xl font-bold tabular-nums ${color}`}>{count}</div>
                <div className="text-xs capitalize text-gray-500">{status.replace('_', ' ')}</div>
              </div>
            );
          })}
        </div>
      </Card>

      {/* Parsing Quality */}
      <Card>
        <h2 className="mb-3 text-sm font-medium text-gray-400">Parsing Quality</h2>
        <dl className="grid grid-cols-2 gap-3 text-sm sm:grid-cols-5">
          <Stat label="Total Parsed" value={parsing.total_parsed} />
          <Stat label="High Confidence" value={parsing.high_confidence} color="text-green-400" />
          <Stat label="Medium" value={parsing.medium_confidence} color="text-yellow-400" />
          <Stat label="Low" value={parsing.low_confidence} color="text-red-400" />
          <Stat label="Avg Quality" value={parsing.avg_quality_score} />
        </dl>
      </Card>

      {/* Extraction Stats */}
      <Card>
        <h2 className="mb-3 text-sm font-medium text-gray-400">Extraction Validation</h2>
        <dl className="grid grid-cols-2 gap-3 text-sm sm:grid-cols-5">
          <Stat label="Total" value={extraction.total_extractions} />
          <Stat label="Valid" value={extraction.valid} color="text-green-400" />
          <Stat label="Failed" value={extraction.failed} color="text-red-400" />
          <Stat label="Avg Confidence" value={extraction.avg_confidence} />
          <Stat label="Avg Retries" value={extraction.avg_retries} />
        </dl>
      </Card>

      {/* Aggregation */}
      <Card>
        <h2 className="mb-3 text-sm font-medium text-gray-400">Trend Generation</h2>
        <dl className="grid grid-cols-2 gap-3 text-sm sm:grid-cols-4">
          <Stat label="Trends Generated" value={aggregation.trends_generated} />
          <Stat label="Symbols Covered" value={aggregation.symbols_covered} />
          <Stat label="Avg Confidence" value={aggregation.avg_trend_confidence} />
          <Stat label="Avg Contradiction" value={aggregation.avg_contradiction} />
        </dl>
      </Card>
    </div>
  );
}

function Stat({ label, value, color = 'text-gray-100' }: { label: string; value: unknown; color?: string }) {
  return (
    <div className="rounded-lg border border-surface-700 bg-surface-950 p-3 text-center">
      <div className={`text-xl font-bold ${color}`}>{value != null ? String(value) : '—'}</div>
      <div className="text-xs text-gray-500">{label}</div>
    </div>
  );
}