import { useState, useCallback, useEffect } from 'react';
import type { ScatSegment, ScatDetail } from './scatTypes';
import { fetchSections, fetchSectionDetail, fetchZones } from '../services/scatApi';
import type { ApiZoneItem } from '../services/scatApi';
import ScatLeftPanel from './ScatLeftPanel';
import ScatMap from './ScatMap';
import ScatTimeline from './ScatTimeline';
import ScatPopup from './ScatPopup';
import ScatRightPanel from './ScatRightPanel';

// ═══ Main PreScatView ═══

export function PreScatView() {
  const [segments, setSegments] = useState<ScatSegment[]>([]);
  const [zones, setZones] = useState<ApiZoneItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [selectedSeg, setSelectedSeg] = useState<ScatSegment | null>(null);
  const [jurisdictionFilter, setJurisdictionFilter] = useState('전체 (제주도)');
  const [areaFilter, setAreaFilter] = useState('전체');
  const [phaseFilter, setPhaseFilter] = useState('Pre-SCAT (사전조사)');
  const [statusFilter, setStatusFilter] = useState('전체');
  const [searchTerm, setSearchTerm] = useState('');
  const [popupData, setPopupData] = useState<ScatDetail | null>(null);
  const [panelDetail, setPanelDetail] = useState<ScatDetail | null>(null);
  const [panelLoading, setPanelLoading] = useState(false);
  const [timelineIdx, setTimelineIdx] = useState(6);

  // API에서 구역 및 구간 데이터 로딩
  useEffect(() => {
    let cancelled = false;

    async function loadData() {
      try {
        setLoading(true);
        const [zonesData, sectionsData] = await Promise.all([fetchZones(), fetchSections()]);
        if (cancelled) return;
        setZones(zonesData);
        setSegments(sectionsData);
        if (sectionsData.length > 0) {
          setSelectedSeg(sectionsData[0]);
        }
      } catch (err) {
        console.error('[SCAT] 데이터 로딩 오류:', err);
        if (!cancelled) setError('데이터를 불러오지 못했습니다.');
      } finally {
        if (!cancelled) setLoading(false);
      }
    }

    loadData();
    return () => {
      cancelled = true;
    };
  }, []);

  // 선택 구간 변경 시 우측 패널 상세 로딩
  useEffect(() => {
    if (!selectedSeg) {
      setPanelDetail(null);
      return;
    }
    let cancelled = false;
    setPanelLoading(true);
    fetchSectionDetail(selectedSeg.id)
      .then(detail => { if (!cancelled) setPanelDetail(detail); })
      .catch(err => console.error('[SCAT] 패널 상세 로딩 오류:', err))
      .finally(() => { if (!cancelled) setPanelLoading(false); });
    return () => { cancelled = true; };
  }, [selectedSeg]);

  // 관할 기반 세그먼트 필터링
  const filteredSegments = segments.filter((s) => {
    if (jurisdictionFilter === '서귀포해양경비안전서') return s.jurisdiction === '서귀포';
    if (jurisdictionFilter === '제주해양경비안전서') return s.jurisdiction === '제주';
    return true; // 전체
  });

  const handleOpenPopup = useCallback(async (sn: number) => {
    try {
      const detail = await fetchSectionDetail(sn);
      setPopupData(detail);
    } catch (err) {
      console.error('[SCAT] 상세 데이터 로딩 오류:', err);
    }
  }, []);

  const handleClosePopup = useCallback(() => {
    setPopupData(null);
  }, []);

  const handleTimelineSeek = useCallback(
    (idx: number) => {
      if (idx === -1) {
        // advance signal from play
        setTimelineIdx((prev) => {
          const next = (prev + 1) % Math.min(filteredSegments.length, 12);
          if (filteredSegments[next]) setSelectedSeg(filteredSegments[next]);
          return next;
        });
      } else {
        setTimelineIdx(idx);
        if (filteredSegments[idx]) setSelectedSeg(filteredSegments[idx]);
      }
    },
    [filteredSegments],
  );

  if (error) {
    return (
      <div className="flex w-full h-full bg-bg-0 items-center justify-center flex-col gap-3">
        <div className="text-status-red text-sm font-korean">{error}</div>
        <button
          onClick={() => { setError(null); setLoading(true); }}
          className="px-4 py-1.5 bg-primary-cyan text-white text-xs rounded font-korean"
        >
          다시 시도
        </button>
      </div>
    );
  }

  if (loading || !selectedSeg) {
    return (
      <div className="flex w-full h-full bg-bg-0 items-center justify-center">
        <div className="text-text-2 text-sm font-korean">SCAT 데이터 로딩 중...</div>
      </div>
    );
  }

  return (
    <div className="flex w-full h-full bg-bg-0 overflow-hidden">
      <ScatLeftPanel
        segments={filteredSegments}
        zones={zones}
        selectedSeg={selectedSeg}
        onSelectSeg={setSelectedSeg}
        onOpenPopup={handleOpenPopup}
        jurisdictionFilter={jurisdictionFilter}
        onJurisdictionChange={setJurisdictionFilter}
        areaFilter={areaFilter}
        onAreaChange={setAreaFilter}
        phaseFilter={phaseFilter}
        onPhaseChange={setPhaseFilter}
        statusFilter={statusFilter}
        onStatusChange={setStatusFilter}
        searchTerm={searchTerm}
        onSearchChange={setSearchTerm}
      />

      <div className="flex-1 relative">
        <ScatMap
          segments={filteredSegments}
          selectedSeg={selectedSeg}
          onSelectSeg={setSelectedSeg}
          onOpenPopup={handleOpenPopup}
        />
        <ScatTimeline
          segments={filteredSegments}
          currentIdx={timelineIdx}
          onSeek={handleTimelineSeek}
        />
      </div>

      <ScatRightPanel
        detail={panelDetail}
        loading={panelLoading}
      />

      {popupData && (
        <ScatPopup data={popupData} segCode={selectedSeg.code} onClose={handleClosePopup} />
      )}
    </div>
  );
}