/**
 * 스케줄 서비스
 * 스케줄 관련 비즈니스 로직
 */
import config, { CATEGORY_IDS } from '../config/index.js';
import { getOrSet, cacheKeys, TTL } from '../utils/cache.js';

/**
 * 카테고리 목록 조회 (캐시 적용)
 * @param {object} db - 데이터베이스 연결
 * @param {object} redis - Redis 클라이언트 (선택적)
 * @returns {array} 카테고리 목록
 */
export async function getCategories(db, redis = null) {
  const fetchCategories = async () => {
    const [categories] = await db.query(
      'SELECT id, name, color, sort_order FROM schedule_categories ORDER BY sort_order ASC, id ASC'
    );
    return categories;
  };

  if (redis) {
    return getOrSet(redis, cacheKeys.categories, fetchCategories, TTL.VERY_LONG);
  }
  return fetchCategories();
}

/**
 * 일정 상세 조회
 * @param {object} db - 데이터베이스 연결
 * @param {number} id - 일정 ID
 * @param {Function} getXProfile - X 프로필 조회 함수 (선택적)
 * @returns {object|null} 일정 상세 또는 null
 */
export async function getScheduleDetail(db, id, getXProfile = null) {
  const [schedules] = await db.query(`
    SELECT
      s.*,
      c.name as category_name,
      c.color as category_color,
      sy.channel_name as youtube_channel,
      sy.video_id as youtube_video_id,
      sy.video_type as youtube_video_type,
      sx.post_id as x_post_id,
      sx.content as x_content,
      sx.image_urls as x_image_urls
    FROM schedules s
    LEFT JOIN schedule_categories c ON s.category_id = c.id
    LEFT JOIN schedule_youtube sy ON s.id = sy.schedule_id
    LEFT JOIN schedule_x sx ON s.id = sx.schedule_id
    WHERE s.id = ?
  `, [id]);

  if (schedules.length === 0) {
    return null;
  }

  const s = schedules[0];

  // 멤버 정보 조회
  const [members] = await db.query(`
    SELECT m.id, m.name
    FROM schedule_members sm
    JOIN members m ON sm.member_id = m.id
    WHERE sm.schedule_id = ?
    ORDER BY m.id
  `, [id]);

  // datetime 생성 (date + time)
  const dateStr = s.date instanceof Date ? s.date.toISOString().split('T')[0] : s.date?.split('T')[0];
  const timeStr = s.time ? s.time.slice(0, 5) : null;
  const datetime = timeStr ? `${dateStr} ${timeStr}` : dateStr;

  // 공통 필드
  const result = {
    id: s.id,
    title: s.title,
    datetime,
    category: {
      id: s.category_id,
      name: s.category_name,
      color: s.category_color,
    },
    members,
    createdAt: s.created_at,
    updatedAt: s.updated_at,
  };

  // 카테고리별 추가 필드
  if (s.category_id === CATEGORY_IDS.YOUTUBE && s.youtube_video_id) {
    // YouTube
    result.videoId = s.youtube_video_id;
    result.videoType = s.youtube_video_type;
    result.channelName = s.youtube_channel;
    result.videoUrl = s.youtube_video_type === 'shorts'
      ? `https://www.youtube.com/shorts/${s.youtube_video_id}`
      : `https://www.youtube.com/watch?v=${s.youtube_video_id}`;
  } else if (s.category_id === CATEGORY_IDS.X && s.x_post_id) {
    // X (Twitter)
    const username = config.x.defaultUsername;
    result.postId = s.x_post_id;
    result.content = s.x_content || null;
    result.imageUrls = s.x_image_urls ? JSON.parse(s.x_image_urls) : [];
    result.postUrl = `https://x.com/${username}/status/${s.x_post_id}`;

    // 프로필 정보 (선택적)
    if (getXProfile) {
      const profile = await getXProfile(username);
      if (profile) {
        result.profile = {
          username: profile.username,
          displayName: profile.displayName,
          avatarUrl: profile.avatarUrl,
        };
      }
    }
  }

  return result;
}

/**
 * 월별 일정 조회 (생일 포함)
 * @param {object} db - 데이터베이스 연결
 * @param {number} year - 연도
 * @param {number} month - 월
 * @returns {object} 날짜별로 그룹화된 일정
 */
export async function getMonthlySchedules(db, year, month) {
  const startDate = `${year}-${String(month).padStart(2, '0')}-01`;
  const endDate = new Date(year, month, 0).toISOString().split('T')[0];

  // 일정 조회 (YouTube, X 소스 정보 포함)
  const [schedules] = await db.query(`
    SELECT
      s.id,
      s.title,
      s.date,
      s.time,
      s.category_id,
      c.name as category_name,
      c.color as category_color,
      sy.channel_name as youtube_channel,
      sy.video_id as youtube_video_id,
      sy.video_type as youtube_video_type,
      sx.post_id as x_post_id
    FROM schedules s
    LEFT JOIN schedule_categories c ON s.category_id = c.id
    LEFT JOIN schedule_youtube sy ON s.id = sy.schedule_id
    LEFT JOIN schedule_x sx ON s.id = sx.schedule_id
    WHERE s.date BETWEEN ? AND ?
    ORDER BY s.date ASC, s.time ASC
  `, [startDate, endDate]);

  // 일정 멤버 조회
  const scheduleIds = schedules.map(s => s.id);
  let memberMap = {};

  if (scheduleIds.length > 0) {
    const [scheduleMembers] = await db.query(`
      SELECT sm.schedule_id, m.name
      FROM schedule_members sm
      JOIN members m ON sm.member_id = m.id
      WHERE sm.schedule_id IN (?)
      ORDER BY m.id
    `, [scheduleIds]);

    for (const sm of scheduleMembers) {
      if (!memberMap[sm.schedule_id]) {
        memberMap[sm.schedule_id] = [];
      }
      memberMap[sm.schedule_id].push({ name: sm.name });
    }
  }

  // 생일 조회
  const [birthdays] = await db.query(`
    SELECT m.id, m.name, m.name_en, m.birth_date,
           i.thumb_url as image_url
    FROM members m
    LEFT JOIN images i ON m.image_id = i.id
    WHERE m.is_former = 0 AND MONTH(m.birth_date) = ?
  `, [month]);

  // 날짜별로 그룹화
  const grouped = {};

  // 일정 추가
  for (const s of schedules) {
    const dateKey = s.date instanceof Date
      ? s.date.toISOString().split('T')[0]
      : s.date;

    if (!grouped[dateKey]) {
      grouped[dateKey] = {
        categories: [],
        schedules: [],
      };
    }

    // 멤버 정보 (5명 이상이면 프로미스나인)
    const scheduleMembers = memberMap[s.id] || [];
    const members = scheduleMembers.length >= 5
      ? [{ name: '프로미스나인' }]
      : scheduleMembers;

    const schedule = {
      id: s.id,
      title: s.title,
      time: s.time,
      category: {
        id: s.category_id,
        name: s.category_name,
        color: s.category_color,
      },
      members,
    };

    // source 정보 추가
    if (s.category_id === CATEGORY_IDS.YOUTUBE && s.youtube_video_id) {
      const videoUrl = s.youtube_video_type === 'shorts'
        ? `https://www.youtube.com/shorts/${s.youtube_video_id}`
        : `https://www.youtube.com/watch?v=${s.youtube_video_id}`;
      schedule.source = {
        name: s.youtube_channel || 'YouTube',
        url: videoUrl,
      };
    } else if (s.category_id === CATEGORY_IDS.X && s.x_post_id) {
      schedule.source = {
        name: '',
        url: `https://x.com/${config.x.defaultUsername}/status/${s.x_post_id}`,
      };
    }

    grouped[dateKey].schedules.push(schedule);

    // 카테고리 카운트
    const existingCategory = grouped[dateKey].categories.find(c => c.id === s.category_id);
    if (existingCategory) {
      existingCategory.count++;
    } else {
      grouped[dateKey].categories.push({
        id: s.category_id,
        name: s.category_name,
        color: s.category_color,
        count: 1,
      });
    }
  }

  // 생일 일정 추가
  for (const member of birthdays) {
    const birthDate = new Date(member.birth_date);
    const birthYear = birthDate.getFullYear();

    // 조회 연도가 생년보다 이전이면 스킵
    if (year < birthYear) continue;

    const birthdayThisYear = new Date(year, birthDate.getMonth(), birthDate.getDate());
    const dateKey = birthdayThisYear.toISOString().split('T')[0];

    if (!grouped[dateKey]) {
      grouped[dateKey] = {
        categories: [],
        schedules: [],
      };
    }

    // 생일 카테고리
    const BIRTHDAY_CATEGORY = {
      id: CATEGORY_IDS.BIRTHDAY,
      name: '생일',
      color: '#f472b6',
    };

    const birthdaySchedule = {
      id: `birthday-${member.id}`,
      title: `HAPPY ${member.name_en} DAY`,
      time: null,
      category: BIRTHDAY_CATEGORY,
      is_birthday: true,
      member_name: member.name,
      member_image: member.image_url,
    };

    grouped[dateKey].schedules.push(birthdaySchedule);

    // 생일 카테고리 카운트
    const existingBirthdayCategory = grouped[dateKey].categories.find(c => c.id === CATEGORY_IDS.BIRTHDAY);
    if (existingBirthdayCategory) {
      existingBirthdayCategory.count++;
    } else {
      grouped[dateKey].categories.push({
        ...BIRTHDAY_CATEGORY,
        count: 1,
      });
    }
  }

  return grouped;
}

/**
 * 다가오는 일정 조회 (startDate부터 limit개)
 * @param {object} db - 데이터베이스 연결
 * @param {string} startDate - 시작 날짜
 * @param {number} limit - 조회 개수
 * @returns {array} 일정 목록
 */
export async function getUpcomingSchedules(db, startDate, limit) {
  const [schedules] = await db.query(`
    SELECT
      s.id,
      s.title,
      s.date,
      s.time,
      s.category_id,
      c.name as category_name,
      c.color as category_color
    FROM schedules s
    LEFT JOIN schedule_categories c ON s.category_id = c.id
    WHERE s.date >= ?
    ORDER BY s.date ASC, s.time ASC
    LIMIT ?
  `, [startDate, limit]);

  // 멤버 정보 조회
  const scheduleIds = schedules.map(s => s.id);
  let memberMap = {};

  if (scheduleIds.length > 0) {
    const [scheduleMembers] = await db.query(`
      SELECT sm.schedule_id, m.name
      FROM schedule_members sm
      JOIN members m ON sm.member_id = m.id
      WHERE sm.schedule_id IN (?)
      ORDER BY m.id
    `, [scheduleIds]);

    for (const sm of scheduleMembers) {
      if (!memberMap[sm.schedule_id]) {
        memberMap[sm.schedule_id] = [];
      }
      memberMap[sm.schedule_id].push({ name: sm.name });
    }
  }

  // 결과 포맷팅
  return schedules.map(s => {
    const scheduleMembers = memberMap[s.id] || [];
    const members = scheduleMembers.length >= 5
      ? [{ name: '프로미스나인' }]
      : scheduleMembers;

    return {
      id: s.id,
      title: s.title,
      date: s.date,
      time: s.time,
      category_id: s.category_id,
      category_name: s.category_name,
      category_color: s.category_color,
      members,
    };
  });
}