import { useState, useEffect, useMemo, useRef, useCallback } from 'react';
import { fetchAircraftFromBackend } from '../services/aircraftApi';
import { fetchSatelliteTLEKorea, propagateAll } from '../services/celestrak';
import { fetchShipsKorea } from '../services/ships';
import { fetchOsintFeed } from '../services/osint';
import type { OsintItem } from '../services/osint';
import { propagateAircraft, propagateShips } from '../services/propagation';
import { getMarineTrafficCategory } from '../utils/marineTraffic';
import type { Aircraft, Ship, Satellite, SatellitePosition } from '../types';

interface UseKoreaDataArgs {
  currentTime: number;
  isLive: boolean;
  hiddenAcCategories: Set<string>;
  hiddenShipCategories: Set<string>;
  hiddenNationalities: Set<string>;
  refreshKey: number;
}

interface UseKoreaDataResult {
  aircraft: Aircraft[];
  ships: Ship[];
  visibleAircraft: Aircraft[];
  visibleShips: Ship[];
  satPositions: SatellitePosition[];
  osintFeed: OsintItem[];
  koreaKoreanShips: Ship[];
  koreaChineseShips: Ship[];
  shipsByCategory: Record<string, number>;
  shipsByNationality: Record<string, number>;
  fishingByNationality: Record<string, number>;
  aircraftByCategory: Record<string, number>;
  militaryCount: number;
}

const SHIP_POLL_INTERVAL = 300_000; // 5 min
const SHIP_STALE_MS = 3_600_000; // 60 min

/** Map flag code to nationality group key */
export function getNationalityGroup(flag?: string): string {
  if (!flag) return 'unclassified';
  if (flag === 'KR') return 'KR';
  if (flag === 'CN') return 'CN';
  if (flag === 'KP') return 'KP';
  if (flag === 'JP') return 'JP';
  return 'unclassified';
}

export function useKoreaData({
  currentTime,
  isLive,
  hiddenAcCategories,
  hiddenShipCategories,
  hiddenNationalities,
  refreshKey,
}: UseKoreaDataArgs): UseKoreaDataResult {
  const [baseAircraftKorea, setBaseAircraftKorea] = useState<Aircraft[]>([]);
  const [baseShipsKorea, setBaseShipsKorea] = useState<Ship[]>([]);
  const [satellitesKorea, setSatellitesKorea] = useState<Satellite[]>([]);
  const [satPositionsKorea, setSatPositionsKorea] = useState<SatellitePosition[]>([]);
  const [osintFeed, setOsintFeed] = useState<OsintItem[]>([]);

  const satTimeKoreaRef = useRef(0);
  const shipMapRef = useRef<Map<string, Ship>>(new Map());

  // Fetch Korea satellite TLE data
  useEffect(() => {
    fetchSatelliteTLEKorea().then(setSatellitesKorea).catch(() => {});
  }, [refreshKey]);

  // Fetch Korea aircraft data
  useEffect(() => {
    const load = async () => {
      const result = await fetchAircraftFromBackend('korea');
      if (result.length > 0) setBaseAircraftKorea(result);
    };
    load();
    const interval = setInterval(load, 60_000);
    return () => clearInterval(interval);
  }, [refreshKey]);

  // Ship merge with stale cleanup
  const mergeShips = useCallback((newShips: Ship[]) => {
    const map = shipMapRef.current;
    for (const s of newShips) {
      map.set(s.mmsi, s);
    }
    const cutoff = Date.now() - SHIP_STALE_MS;
    for (const [mmsi, ship] of map) {
      if (ship.lastSeen < cutoff) map.delete(mmsi);
    }
    setBaseShipsKorea(Array.from(map.values()));
  }, []);

  // Fetch Korea region ship data: initial 60min, then 5min polling with 6min window
  useEffect(() => {
    let initialDone = false;
    const loadInitial = async () => {
      try {
        const data = await fetchShipsKorea(60); // 초기: 60분 데이터
        if (data.length > 0) {
          shipMapRef.current = new Map(data.map(s => [s.mmsi, s]));
          setBaseShipsKorea(data);
          initialDone = true;
        }
      } catch { /* keep previous */ }
    };

    const loadIncremental = async () => {
      if (!initialDone) return;
      try {
        const data = await fetchShipsKorea(6); // polling: 6분 데이터
        if (data.length > 0) mergeShips(data);
      } catch { /* keep previous */ }
    };

    loadInitial();
    const interval = setInterval(loadIncremental, SHIP_POLL_INTERVAL);
    return () => clearInterval(interval);
  }, [refreshKey, mergeShips]);

  // Fetch OSINT feed for Korea tab
  useEffect(() => {
    const load = async () => {
      try {
        const data = await fetchOsintFeed('korea');
        if (data.length > 0) setOsintFeed(data);
      } catch { /* keep previous */ }
    };
    load();
    const interval = setInterval(load, 120_000);
    return () => clearInterval(interval);
  }, [refreshKey]);

  // Propagate Korea satellite positions
  useEffect(() => {
    if (satellitesKorea.length === 0) return;
    const now = Date.now();
    if (now - satTimeKoreaRef.current < 2000) return;
    satTimeKoreaRef.current = now;
    const positions = propagateAll(satellitesKorea, new Date(currentTime));
    setSatPositionsKorea(positions);
  }, [satellitesKorea, currentTime]);

  // Propagate Korea aircraft (live only — no waypoint propagation needed)
  const aircraft = useMemo(() => propagateAircraft(baseAircraftKorea, currentTime), [baseAircraftKorea, currentTime]);

  // Korea region ships
  const ships = useMemo(
    () => propagateShips(baseShipsKorea, currentTime, isLive),
    [baseShipsKorea, currentTime, isLive],
  );

  // Category-filtered data for map rendering
  const visibleAircraft = useMemo(
    () => aircraft.filter(a => !hiddenAcCategories.has(a.category)),
    [aircraft, hiddenAcCategories],
  );

  const visibleShips = useMemo(
    () => ships.filter(s =>
      !hiddenShipCategories.has(getMarineTrafficCategory(s.typecode, s.category))
      && !hiddenNationalities.has(getNationalityGroup(s.flag)),
    ),
    [ships, hiddenShipCategories, hiddenNationalities],
  );

  // Korea region stats
  const koreaKoreanShips = useMemo(() => ships.filter(s => s.flag === 'KR'), [ships]);
  const koreaChineseShips = useMemo(() => ships.filter(s => s.flag === 'CN'), [ships]);

  const shipsByCategory = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const s of ships) {
      const mtCat = getMarineTrafficCategory(s.typecode, s.category);
      counts[mtCat] = (counts[mtCat] || 0) + 1;
    }
    return counts;
  }, [ships]);

  const shipsByNationality = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const s of ships) {
      const nat = getNationalityGroup(s.flag);
      counts[nat] = (counts[nat] || 0) + 1;
    }
    return counts;
  }, [ships]);

  const fishingByNationality = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const s of ships) {
      if (getMarineTrafficCategory(s.typecode, s.category) !== 'fishing') continue;
      const flag = s.flag || 'unknown';
      const group = flag === 'CN' ? 'CN' : flag === 'KR' ? 'KR' : flag === 'JP' ? 'JP' : 'other';
      counts[group] = (counts[group] || 0) + 1;
    }
    return counts;
  }, [ships]);

  // Korea aircraft stats
  const aircraftByCategory = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const ac of aircraft) {
      counts[ac.category] = (counts[ac.category] || 0) + 1;
    }
    return counts;
  }, [aircraft]);

  const militaryCount = useMemo(
    () => aircraft.filter(a => a.category !== 'civilian' && a.category !== 'unknown').length,
    [aircraft],
  );

  return {
    aircraft,
    ships,
    visibleAircraft,
    visibleShips,
    satPositions: satPositionsKorea,
    osintFeed,
    koreaKoreanShips,
    koreaChineseShips,
    shipsByCategory,
    shipsByNationality,
    fishingByNationality,
    aircraftByCategory,
    militaryCount,
  };
}