import { useState, useMemo, useCallback, useRef } from 'react';
import { useNavigate } from 'react-router';
import { useGlobalFilters } from '@cameleer/design-system';
import { useExecutionDetail } from '../../api/queries/executions';
import { useDiagramByRoute } from '../../api/queries/diagrams';
import { useRouteCatalog } from '../../api/queries/catalog';
import type { NodeAction } from '../../components/ProcessDiagram/types';
import { ExchangeHeader } from './ExchangeHeader';
import { ExecutionDiagram } from '../../components/ExecutionDiagram/ExecutionDiagram';
import { ProcessDiagram } from '../../components/ProcessDiagram';
import styles from './ExchangesPage.module.css';

import Dashboard from '../Dashboard/Dashboard';
import type { SelectedExchange } from '../Dashboard/Dashboard';

export default function ExchangesPage() {
  const [selected, setSelected] = useState<SelectedExchange | null>(null);
  const [splitPercent, setSplitPercent] = useState(50);
  const containerRef = useRef<HTMLDivElement>(null);

  const handleExchangeSelect = useCallback((exchange: SelectedExchange) => {
    setSelected(exchange);
  }, []);

  const handleCorrelatedSelect = useCallback((executionId: string, applicationName: string, routeId: string) => {
    setSelected({ executionId, applicationName, routeId });
  }, []);

  const handleClearSelection = useCallback(() => {
    setSelected(null);
  }, []);

  const handleSplitterDown = useCallback((e: React.PointerEvent) => {
    e.currentTarget.setPointerCapture(e.pointerId);
    const container = containerRef.current;
    if (!container) return;
    const onMove = (me: PointerEvent) => {
      const rect = container.getBoundingClientRect();
      const x = me.clientX - rect.left;
      const pct = Math.min(80, Math.max(20, (x / rect.width) * 100));
      setSplitPercent(pct);
    };
    const onUp = () => {
      document.removeEventListener('pointermove', onMove);
      document.removeEventListener('pointerup', onUp);
    };
    document.addEventListener('pointermove', onMove);
    document.addEventListener('pointerup', onUp);
  }, []);

  // No exchange selected: full-width Dashboard
  if (!selected) {
    return <Dashboard onExchangeSelect={handleExchangeSelect} />;
  }

  // Exchange selected: resizable split — Dashboard on left, diagram on right
  return (
    <div ref={containerRef} className={styles.splitView}>
      <div className={styles.leftPanel} style={{ width: `${splitPercent}%` }}>
        <Dashboard onExchangeSelect={handleExchangeSelect} />
      </div>
      <div className={styles.splitter} onPointerDown={handleSplitterDown} />
      <div className={styles.rightPanel} style={{ width: `${100 - splitPercent}%` }}>
        <DiagramPanel
          appId={selected.applicationName}
          routeId={selected.routeId}
          exchangeId={selected.executionId}
          onCorrelatedSelect={handleCorrelatedSelect}
          onClearSelection={handleClearSelection}
        />
      </div>
    </div>
  );
}

// ─── Right panel: diagram + execution overlay ───────────────────────────────

interface DiagramPanelProps {
  appId: string;
  routeId: string;
  exchangeId: string;
  onCorrelatedSelect: (executionId: string, applicationName: string, routeId: string) => void;
  onClearSelection: () => void;
}

function DiagramPanel({ appId, routeId, exchangeId, onCorrelatedSelect, onClearSelection }: DiagramPanelProps) {
  const navigate = useNavigate();
  const { timeRange } = useGlobalFilters();
  const timeFrom = timeRange.start.toISOString();
  const timeTo = timeRange.end.toISOString();

  const { data: detail } = useExecutionDetail(exchangeId);

  const { data: catalog } = useRouteCatalog(timeFrom, timeTo);
  const knownRouteIds = useMemo(() => {
    const ids = new Set<string>();
    if (catalog) {
      for (const app of catalog as any[]) {
        for (const r of app.routes || []) {
          ids.add(r.routeId);
        }
      }
    }
    return ids;
  }, [catalog]);

  const handleNodeAction = useCallback((nodeId: string, action: NodeAction) => {
    if (action === 'configure-tap') {
      navigate(`/admin/appconfig?app=${encodeURIComponent(appId)}&processor=${encodeURIComponent(nodeId)}`);
    }
  }, [appId, navigate]);

  if (detail) {
    return (
      <>
        <ExchangeHeader detail={detail} onCorrelatedSelect={onCorrelatedSelect} onClearSelection={onClearSelection} />
        <ExecutionDiagram
          executionId={exchangeId}
          executionDetail={detail}
          knownRouteIds={knownRouteIds}
          onNodeAction={handleNodeAction}
        />
      </>
    );
  }

  return (
    <div className={styles.emptyRight}>
      Loading execution...
    </div>
  );
}