/**
 * useConnectionResolver - 런타임 컴포넌트 연결 해석기
 *
 * PopViewerWithModals에서 사용.
 * layout.dataFlow.connections를 읽고, 소스 컴포넌트의 __comp_output__ 이벤트를
 * 타겟 컴포넌트의 __comp_input__ 이벤트로 자동 변환/중계한다.
 *
 * 이벤트 규칙:
 *   소스:  __comp_output__${sourceComponentId}__${outputKey}
 *   타겟:  __comp_input__${targetComponentId}__${inputKey}
 */

import { useEffect, useRef } from "react";
import { usePopEvent } from "./usePopEvent";
import type { PopDataConnection } from "@/components/pop/designer/types/pop-layout";

interface UseConnectionResolverOptions {
  screenId: string;
  connections: PopDataConnection[];
}

export function useConnectionResolver({
  screenId,
  connections,
}: UseConnectionResolverOptions): void {
  const { publish, subscribe } = usePopEvent(screenId);

  // 연결 목록을 ref로 저장하여 콜백 안정성 확보
  const connectionsRef = useRef(connections);
  connectionsRef.current = connections;

  useEffect(() => {
    if (!connections || connections.length === 0) return;

    const unsubscribers: (() => void)[] = [];

    // 소스별로 그룹핑하여 구독 생성
    const sourceGroups = new Map<string, PopDataConnection[]>();
    for (const conn of connections) {
      const sourceEvent = `__comp_output__${conn.sourceComponent}__${conn.sourceOutput || conn.sourceField}`;
      const existing = sourceGroups.get(sourceEvent) || [];
      existing.push(conn);
      sourceGroups.set(sourceEvent, existing);
    }

    for (const [sourceEvent, conns] of sourceGroups) {
      const unsub = subscribe(sourceEvent, (payload: unknown) => {
        for (const conn of conns) {
          const targetEvent = `__comp_input__${conn.targetComponent}__${conn.targetInput || conn.targetField}`;

          // 항상 통일된 구조로 감싸서 전달: { value, filterConfig?, _connectionId }
          const enrichedPayload = {
            value: payload,
            filterConfig: conn.filterConfig,
            _connectionId: conn.id,
          };

          publish(targetEvent, enrichedPayload);
        }
      });
      unsubscribers.push(unsub);
    }

    return () => {
      for (const unsub of unsubscribers) {
        unsub();
      }
    };
  }, [screenId, connections, subscribe, publish]);
}