import { create } from 'zustand';
import {
  getEvents,
  getEventStats,
  toLegacyEvent,
  type PredictionEvent,
  type EventStats,
  type LegacyEventRecord,
} from '@/services/event';

/** @deprecated LegacyEventRecord 대신 PredictionEvent 사용 권장 */
export type { LegacyEventRecord as EventRecord } from '@/services/event';

interface EventStore {
  /** 원본 API 이벤트 목록 */
  rawEvents: PredictionEvent[];
  /** 하위 호환용 레거시 형식 이벤트 */
  events: LegacyEventRecord[];
  /** 상태별 통계 */
  stats: EventStats;
  /** 페이지네이션 */
  totalElements: number;
  totalPages: number;
  currentPage: number;
  pageSize: number;
  /** 로딩/에러 */
  loading: boolean;
  error: string | null;
  loaded: boolean;
  /** API 호출 */
  load: (params?: { level?: string; status?: string; category?: string; page?: number; size?: number }) => Promise<void>;
  /** 화면 깜박임 없는 백그라운드 갱신 (loading 상태 변경 없음) */
  silentRefresh: (params?: { level?: string; status?: string; category?: string; page?: number; size?: number }) => Promise<void>;
  loadStats: () => Promise<void>;
  filterByLevel: (level: string | null) => LegacyEventRecord[];
}

export const useEventStore = create<EventStore>((set, get) => ({
  rawEvents: [],
  events: [],
  stats: {},
  totalElements: 0,
  totalPages: 0,
  currentPage: 0,
  pageSize: 20,
  loading: false,
  error: null,
  loaded: false,

  load: async (params) => {
    // 중복 호출 방지 (파라미터 없는 기본 호출은 loaded 체크)
    if (!params && get().loaded && !get().error) return;

    set({ loading: true, error: null });
    try {
      const res = await getEvents(params);
      const legacy = res.content.map(toLegacyEvent);
      set({
        rawEvents: res.content,
        events: legacy,
        totalElements: res.totalElements,
        totalPages: res.totalPages,
        currentPage: res.number,
        pageSize: res.size,
        loaded: true,
        loading: false,
      });
    } catch (err) {
      set({ error: err instanceof Error ? err.message : String(err), loading: false });
    }
  },

  silentRefresh: async (params) => {
    try {
      const res = await getEvents(params);
      const legacy = res.content.map(toLegacyEvent);
      set({
        rawEvents: res.content,
        events: legacy,
        totalElements: res.totalElements,
        totalPages: res.totalPages,
        currentPage: res.number,
        pageSize: res.size,
      });
    } catch {
      // silent: 에러 무시 — 다음 갱신에서 재시도
    }
  },

  loadStats: async () => {
    try {
      const stats = await getEventStats();
      set({ stats });
    } catch {
      // stats 로딩 실패는 무시 (KPI 카드만 빈 값)
    }
  },

  filterByLevel: (level) => {
    const { events } = get();
    if (!level) return events;
    return events.filter((e) => e.level === level);
  },
}));