/**
 * 축제 서비스
 * TourAPI 축제 데이터 동기화 및 관리
 */

const { tourApiClient, AREA_CODE, AREA_NAME } = require('./tourApiClient');

class FestivalService {
  constructor(db) {
    this.db = db;
  }

  // ============================================
  // 축제 데이터 동기화
  // ============================================

  /**
   * 전체 축제 동기화 (향후 6개월)
   */
  async syncAllFestivals() {
    console.log('=== 축제 데이터 동기화 시작 ===');

    const today = tourApiClient.getTodayString();
    const endDate = tourApiClient.getDateAfterMonths(6);

    let totalSynced = 0;
    let pageNo = 1;

    while (true) {
      try {
        const result = await tourApiClient.searchFestival({
          eventStartDate: today,
          eventEndDate: endDate,
          numOfRows: 100,
          pageNo,
          arrange: 'A',
        });

        if (!result.items || result.items.length === 0) break;

        // 배열로 변환 (단일 아이템일 경우)
        const items = Array.isArray(result.items) ? result.items : [result.items];

        for (const item of items) {
          await this.upsertFestival(item);
          totalSynced++;
        }

        console.log(`  - 페이지 ${pageNo}: ${items.length}건 처리`);

        if (items.length < 100) break;
        pageNo++;

        // API 호출 제한 대응
        await this.sleep(100);
      } catch (error) {
        console.error(`  - 페이지 ${pageNo} 에러:`, error.message);
        break;
      }
    }

    console.log(`=== 축제 동기화 완료: ${totalSynced}건 ===`);
    return totalSynced;
  }

  /**
   * 특정 지역 축제 동기화
   */
  async syncFestivalsByArea(areaCode) {
    console.log(`=== ${AREA_NAME[areaCode] || areaCode} 축제 동기화 ===`);

    const today = tourApiClient.getTodayString();
    const endDate = tourApiClient.getDateAfterMonths(6);

    let totalSynced = 0;
    let pageNo = 1;

    while (true) {
      const result = await tourApiClient.searchFestival({
        eventStartDate: today,
        eventEndDate: endDate,
        areaCode,
        numOfRows: 100,
        pageNo,
      });

      if (!result.items || result.items.length === 0) break;

      const items = Array.isArray(result.items) ? result.items : [result.items];

      for (const item of items) {
        await this.upsertFestival(item);
        totalSynced++;
      }

      if (items.length < 100) break;
      pageNo++;
      await this.sleep(100);
    }

    return totalSynced;
  }

  /**
   * 축제 데이터 저장/업데이트
   */
  async upsertFestival(item) {
    const exists = await this.db.get(
      'SELECT id FROM festivals WHERE content_id = ?',
      [item.contentid]
    );

    const data = {
      content_id: item.contentid,
      content_type_id: item.contenttypeid || '15',
      title: item.title,
      addr1: item.addr1,
      addr2: item.addr2,
      area_code: item.areacode,
      sigungu_code: item.sigungucode,
      sido: AREA_NAME[item.areacode] || null,
      mapx: item.mapx ? parseFloat(item.mapx) : null,
      mapy: item.mapy ? parseFloat(item.mapy) : null,
      event_start_date: item.eventstartdate,
      event_end_date: item.eventenddate,
      first_image: item.firstimage,
      first_image2: item.firstimage2,
      tel: item.tel,
      last_synced_at: new Date().toISOString(),
    };

    if (exists) {
      await this.db.run(`
        UPDATE festivals SET
          title = ?, addr1 = ?, addr2 = ?, area_code = ?, sigungu_code = ?, sido = ?,
          mapx = ?, mapy = ?, event_start_date = ?, event_end_date = ?,
          first_image = ?, first_image2 = ?, tel = ?, last_synced_at = ?,
          updated_at = CURRENT_TIMESTAMP
        WHERE content_id = ?
      `, [
        data.title, data.addr1, data.addr2, data.area_code, data.sigungu_code, data.sido,
        data.mapx, data.mapy, data.event_start_date, data.event_end_date,
        data.first_image, data.first_image2, data.tel, data.last_synced_at,
        data.content_id
      ]);
      return { action: 'updated', id: exists.id };
    } else {
      const result = await this.db.run(`
        INSERT INTO festivals (
          content_id, content_type_id, title, addr1, addr2, area_code, sigungu_code, sido,
          mapx, mapy, event_start_date, event_end_date, first_image, first_image2,
          tel, last_synced_at
        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
      `, [
        data.content_id, data.content_type_id, data.title, data.addr1, data.addr2,
        data.area_code, data.sigungu_code, data.sido, data.mapx, data.mapy,
        data.event_start_date, data.event_end_date, data.first_image, data.first_image2,
        data.tel, data.last_synced_at
      ]);
      return { action: 'inserted', id: result.lastID };
    }
  }

  /**
   * 축제 상세 정보 업데이트
   */
  async fetchAndUpdateDetail(contentId) {
    try {
      const detail = await tourApiClient.getFestivalDetail(contentId);

      const { common, intro } = detail;

      await this.db.run(`
        UPDATE festivals SET
          overview = ?,
          homepage = ?,
          place = ?,
          place_info = ?,
          play_time = ?,
          program = ?,
          use_fee = ?,
          age_limit = ?,
          sponsor1 = ?,
          sponsor1_tel = ?,
          sponsor2 = ?,
          sponsor2_tel = ?,
          sub_event = ?,
          booking_place = ?,
          updated_at = CURRENT_TIMESTAMP
        WHERE content_id = ?
      `, [
        common.overview,
        common.homepage,
        intro.eventplace,
        intro.placeinfo,
        intro.playtime,
        intro.program,
        intro.usetimefestival,
        intro.agelimit,
        intro.sponsor1,
        intro.sponsor1tel,
        intro.sponsor2,
        intro.sponsor2tel,
        intro.subevent,
        intro.bookingplace,
        contentId
      ]);

      return detail;
    } catch (error) {
      console.error(`축제 상세 조회 실패 (${contentId}):`, error.message);
      return null;
    }
  }

  // ============================================
  // 축제 조회
  // ============================================

  /**
   * 활성 축제 목록 (종료되지 않은)
   */
  async getActiveFestivals(options = {}) {
    const {
      areaCode = null,
      limit = 20,
      offset = 0,
    } = options;

    const today = tourApiClient.getTodayString();

    let query = `
      SELECT * FROM festivals
      WHERE is_active = 1
        AND event_end_date >= ?
    `;
    const params = [today];

    if (areaCode) {
      query += ' AND area_code = ?';
      params.push(areaCode);
    }

    query += ' ORDER BY event_start_date ASC LIMIT ? OFFSET ?';
    params.push(limit, offset);

    return this.db.all(query, params);
  }

  /**
   * 진행중인 축제
   */
  async getOngoingFestivals(areaCode = null, limit = 20) {
    const today = tourApiClient.getTodayString();

    let query = `
      SELECT * FROM festivals
      WHERE is_active = 1
        AND event_start_date <= ?
        AND event_end_date >= ?
    `;
    const params = [today, today];

    if (areaCode) {
      query += ' AND area_code = ?';
      params.push(areaCode);
    }

    query += ' ORDER BY event_end_date ASC LIMIT ?';
    params.push(limit);

    return this.db.all(query, params);
  }

  /**
   * 예정 축제
   */
  async getUpcomingFestivals(areaCode = null, limit = 20) {
    const today = tourApiClient.getTodayString();

    let query = `
      SELECT * FROM festivals
      WHERE is_active = 1
        AND event_start_date > ?
    `;
    const params = [today];

    if (areaCode) {
      query += ' AND area_code = ?';
      params.push(areaCode);
    }

    query += ' ORDER BY event_start_date ASC LIMIT ?';
    params.push(limit);

    return this.db.all(query, params);
  }

  /**
   * 축제 상세 조회
   */
  async getFestivalById(id) {
    const festival = await this.db.get('SELECT * FROM festivals WHERE id = ?', [id]);

    if (festival && !festival.overview) {
      // 상세 정보가 없으면 API에서 가져오기
      await this.fetchAndUpdateDetail(festival.content_id);
      return this.db.get('SELECT * FROM festivals WHERE id = ?', [id]);
    }

    return festival;
  }

  /**
   * content_id로 축제 조회
   */
  async getFestivalByContentId(contentId) {
    return this.db.get('SELECT * FROM festivals WHERE content_id = ?', [contentId]);
  }

  /**
   * 축제 검색
   */
  async searchFestivals(keyword, limit = 20) {
    return this.db.all(`
      SELECT * FROM festivals
      WHERE is_active = 1
        AND (title LIKE ? OR addr1 LIKE ?)
        AND event_end_date >= ?
      ORDER BY event_start_date ASC
      LIMIT ?
    `, [`%${keyword}%`, `%${keyword}%`, tourApiClient.getTodayString(), limit]);
  }

  /**
   * 월별 축제 조회
   */
  async getFestivalsByMonth(year, month) {
    const startDate = `${year}${String(month).padStart(2, '0')}01`;
    const endDate = `${year}${String(month).padStart(2, '0')}31`;

    return this.db.all(`
      SELECT * FROM festivals
      WHERE is_active = 1
        AND event_start_date <= ?
        AND event_end_date >= ?
      ORDER BY event_start_date ASC
    `, [endDate, startDate]);
  }

  /**
   * 지역별 축제 통계
   */
  async getFestivalStatsByRegion() {
    const today = tourApiClient.getTodayString();

    return this.db.all(`
      SELECT
        area_code,
        sido,
        COUNT(*) as total,
        SUM(CASE WHEN event_start_date <= ? AND event_end_date >= ? THEN 1 ELSE 0 END) as ongoing,
        SUM(CASE WHEN event_start_date > ? THEN 1 ELSE 0 END) as upcoming
      FROM festivals
      WHERE is_active = 1 AND event_end_date >= ?
      GROUP BY area_code
      ORDER BY total DESC
    `, [today, today, today, today]);
  }

  // ============================================
  // 좌표 기반 조회
  // ============================================

  /**
   * 좌표 근처 축제 조회 (DB에서)
   */
  async getNearbyFestivals(mapX, mapY, radiusKm = 50) {
    const today = tourApiClient.getTodayString();

    // 대략적인 위경도 범위 계산 (1도 ≈ 111km)
    const latRange = radiusKm / 111;
    const lngRange = radiusKm / 88; // 한국 위도 기준

    const festivals = await this.db.all(`
      SELECT * FROM festivals
      WHERE is_active = 1
        AND event_end_date >= ?
        AND mapx IS NOT NULL AND mapy IS NOT NULL
        AND mapy BETWEEN ? AND ?
        AND mapx BETWEEN ? AND ?
    `, [
      today,
      mapY - latRange, mapY + latRange,
      mapX - lngRange, mapX + lngRange,
    ]);

    // 정확한 거리 계산 및 필터링
    return festivals
      .map(f => ({
        ...f,
        distance_km: this.calculateDistance(mapY, mapX, f.mapy, f.mapx),
      }))
      .filter(f => f.distance_km <= radiusKm)
      .sort((a, b) => a.distance_km - b.distance_km);
  }

  /**
   * 좌표 근처 축제 조회 (API 직접)
   */
  async getNearbyFestivalsFromApi(mapX, mapY, radius = 20000) {
    return tourApiClient.getNearbyFestivals(mapX, mapY, radius);
  }

  // ============================================
  // 유틸리티
  // ============================================

  /**
   * Haversine 공식으로 거리 계산 (km)
   */
  calculateDistance(lat1, lon1, lat2, lon2) {
    const R = 6371; // 지구 반경 (km)
    const dLat = this.toRad(lat2 - lat1);
    const dLon = this.toRad(lon2 - lon1);

    const a =
      Math.sin(dLat / 2) * Math.sin(dLat / 2) +
      Math.cos(this.toRad(lat1)) * Math.cos(this.toRad(lat2)) *
      Math.sin(dLon / 2) * Math.sin(dLon / 2);

    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    return Math.round(R * c * 100) / 100; // 소수점 2자리
  }

  toRad(deg) {
    return deg * (Math.PI / 180);
  }

  sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
  }
}

module.exports = FestivalService;