import { useCallback, useEffect, useMemo, useState } from 'react';
import {
  loadVirtualTargets,
  VIRTUAL_SESSION_CHANGED_EVENT,
} from '../utils/virtualTradingStorage';
import {
  addVirtualTarget,
  removeVirtualTarget,
  type VirtualTargetMeta,
} from '../utils/virtualTargetMutations';
import { getVirtualTargetMaxCount } from './useAppSettings';
import { virtualTargetLimitMessage } from '../utils/virtualTargetLimits';

/** 가상투자 투자대상 마켓 집합 (추세검색 카드 등) */
export function useVirtualTargetRegistry() {
  const [targets, setTargets] = useState(() => loadVirtualTargets());
  const [busyMarket, setBusyMarket] = useState<string | null>(null);

  const refresh = useCallback(() => {
    setTargets(loadVirtualTargets());
  }, []);

  useEffect(() => {
    refresh();
    const onChange = () => refresh();
    window.addEventListener(VIRTUAL_SESSION_CHANGED_EVENT, onChange);
    return () => window.removeEventListener(VIRTUAL_SESSION_CHANGED_EVENT, onChange);
  }, [refresh]);

  const addedSet = useMemo(
    () => new Set(targets.map(t => t.market)),
    [targets],
  );

  const isInTargets = useCallback(
    (market: string) => addedSet.has(market),
    [addedSet],
  );

  const isPinned = useCallback(
    (market: string) => targets.find(t => t.market === market)?.pinned === true,
    [targets],
  );

  const add = useCallback(async (market: string, meta?: VirtualTargetMeta) => {
    if (addedSet.has(market) || busyMarket === market) return;
    const maxCount = getVirtualTargetMaxCount();
    if (targets.length >= maxCount) {
      window.alert(virtualTargetLimitMessage(maxCount));
      return;
    }
    setBusyMarket(market);
    try {
      const next = await addVirtualTarget(market, meta);
      setTargets(next);
    } catch (e) {
      console.warn('[VirtualTarget] add failed', market, e);
      window.alert('투자대상 추가에 실패했습니다.');
    } finally {
      setBusyMarket(null);
    }
  }, [addedSet, busyMarket, targets]);

  const remove = useCallback(async (market: string) => {
    if (!addedSet.has(market) || busyMarket === market) return;
    setBusyMarket(market);
    try {
      const next = await removeVirtualTarget(market);
      setTargets(next);
    } catch (e) {
      console.warn('[VirtualTarget] remove failed', market, e);
      window.alert('투자대상 제거에 실패했습니다.');
    } finally {
      setBusyMarket(null);
    }
  }, [addedSet, busyMarket, targets]);

  return {
    addedSet,
    isInTargets,
    isPinned,
    add,
    remove,
    busyMarket,
  };
}