import { AppDataSource, UserDayStatistics } from '../models/index.js';
import { logger } from '../utils/logger.js';

export interface UserDayStatisticsItem {
  accountId: number;
  fansCount?: number;
  worksCount?: number;
  playCount?: number;
  commentCount?: number;
  fansIncrease?: number;
  likeCount?: number;
  shareCount?: number;
  collectCount?: number;
  coverClickRate?: string;
  avgWatchDuration?: string;
  totalWatchDuration?: string;
  completionRate?: string;
}

export interface SaveResult {
  inserted: number;
  updated: number;
}

export class UserDayStatisticsService {
  private statisticsRepository = AppDataSource.getRepository(UserDayStatistics);

  /**
   * 获取「中国时区（Asia/Shanghai）当前日历日」的 Date，用于存库保证 record_date 与业务日期一致
   * 避免服务器非中国时区时出现“1月29日却生成 record_date=1月30”等问题
   */
  private getTodayInChina(): Date {
    const formatter = new Intl.DateTimeFormat('en-CA', {
      timeZone: 'Asia/Shanghai',
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
    });
    const parts = formatter.formatToParts(new Date());
    const get = (type: string) => parts.find((p) => p.type === type)?.value ?? '0';
    const y = parseInt(get('year'), 10);
    const m = parseInt(get('month'), 10) - 1;
    const d = parseInt(get('day'), 10);
    return new Date(Date.UTC(y, m, d, 0, 0, 0, 0));
  }

  /**
   * 保存用户每日统计数据
   * 同日更新，隔日新增
   * 「今天」以中国时区（Asia/Shanghai）为准，避免服务器时区导致 record_date 错日
   */
  async saveStatistics(item: UserDayStatisticsItem): Promise<SaveResult> {
    const today = this.getTodayInChina();

    // 检查今天是否已有记录
    const existing = await this.statisticsRepository.findOne({
      where: {
        accountId: item.accountId,
        recordDate: today,
      },
    });

    if (existing) {
      // 更新已有记录
      await this.statisticsRepository.update(existing.id, {
        fansCount: item.fansCount ?? existing.fansCount,
        worksCount: item.worksCount ?? existing.worksCount,
        playCount: item.playCount ?? existing.playCount,
        commentCount: item.commentCount ?? existing.commentCount,
        fansIncrease: item.fansIncrease ?? existing.fansIncrease,
        likeCount: item.likeCount ?? existing.likeCount,
        shareCount: item.shareCount ?? existing.shareCount,
        collectCount: item.collectCount ?? existing.collectCount,
        coverClickRate: item.coverClickRate ?? existing.coverClickRate ?? '0',
        avgWatchDuration: item.avgWatchDuration ?? existing.avgWatchDuration ?? '0',
        totalWatchDuration: item.totalWatchDuration ?? existing.totalWatchDuration ?? '0',
        completionRate: item.completionRate ?? existing.completionRate ?? '0',
      });
      logger.debug(`[UserDayStatistics] Updated record for account ${item.accountId}, date: ${today.toISOString().split('T')[0]}`);
      return { inserted: 0, updated: 1 };
    } else {
      // 插入新记录
      const newStat = this.statisticsRepository.create({
        accountId: item.accountId,
        recordDate: today,
        fansCount: item.fansCount ?? 0,
        worksCount: item.worksCount ?? 0,
        playCount: item.playCount ?? 0,
        commentCount: item.commentCount ?? 0,
        fansIncrease: item.fansIncrease ?? 0,
        likeCount: item.likeCount ?? 0,
        shareCount: item.shareCount ?? 0,
        collectCount: item.collectCount ?? 0,
        coverClickRate: item.coverClickRate ?? '0',
        avgWatchDuration: item.avgWatchDuration ?? '0',
        totalWatchDuration: item.totalWatchDuration ?? '0',
        completionRate: item.completionRate ?? '0',
      });
      await this.statisticsRepository.save(newStat);
      logger.debug(`[UserDayStatistics] Inserted new record for account ${item.accountId}, date: ${today.toISOString().split('T')[0]}`);
      return { inserted: 1, updated: 0 };
    }
  }

  /**
   * 保存指定日期的用户每日统计数据（按 accountId + recordDate 维度 upsert）
   * 说明：recordDate 会被归零到当天 00:00:00（本地时区），避免重复 key 不一致
   */
  async saveStatisticsForDate(
    accountId: number,
    recordDate: Date,
    patch: Omit<UserDayStatisticsItem, 'accountId'>
  ): Promise<SaveResult> {
    const d = new Date(recordDate);
    d.setHours(0, 0, 0, 0);

    const existing = await this.statisticsRepository.findOne({
      where: { accountId, recordDate: d },
    });

    if (existing) {
      await this.statisticsRepository.update(existing.id, {
        fansCount: patch.fansCount ?? existing.fansCount,
        worksCount: patch.worksCount ?? existing.worksCount,
        playCount: patch.playCount ?? existing.playCount,
        commentCount: patch.commentCount ?? existing.commentCount,
        fansIncrease: patch.fansIncrease ?? existing.fansIncrease,
        likeCount: patch.likeCount ?? existing.likeCount,
        shareCount: patch.shareCount ?? existing.shareCount,
        collectCount: patch.collectCount ?? existing.collectCount,
        coverClickRate: patch.coverClickRate ?? existing.coverClickRate ?? '0',
        avgWatchDuration: patch.avgWatchDuration ?? existing.avgWatchDuration ?? '0',
        totalWatchDuration: patch.totalWatchDuration ?? existing.totalWatchDuration ?? '0',
        completionRate: patch.completionRate ?? existing.completionRate ?? '0',
      });
      return { inserted: 0, updated: 1 };
    }

    const newStat = this.statisticsRepository.create({
      accountId,
      recordDate: d,
      fansCount: patch.fansCount ?? 0,
      worksCount: patch.worksCount ?? 0,
      playCount: patch.playCount ?? 0,
      commentCount: patch.commentCount ?? 0,
      fansIncrease: patch.fansIncrease ?? 0,
      likeCount: patch.likeCount ?? 0,
      shareCount: patch.shareCount ?? 0,
      collectCount: patch.collectCount ?? 0,
      coverClickRate: patch.coverClickRate ?? '0',
      avgWatchDuration: patch.avgWatchDuration ?? '0',
      totalWatchDuration: patch.totalWatchDuration ?? '0',
      completionRate: patch.completionRate ?? '0',
    });

    await this.statisticsRepository.save(newStat);
    return { inserted: 1, updated: 0 };
  }

  /**
   * 批量保存用户每日统计数据
   */
  async saveStatisticsBatch(items: UserDayStatisticsItem[]): Promise<SaveResult> {
    let insertedCount = 0;
    let updatedCount = 0;

    for (const item of items) {
      const result = await this.saveStatistics(item);
      insertedCount += result.inserted;
      updatedCount += result.updated;
    }

    logger.info(`[UserDayStatistics] Batch save completed: inserted=${insertedCount}, updated=${updatedCount}`);
    return { inserted: insertedCount, updated: updatedCount };
  }

  /**
   * 批量保存指定日期范围的统计数据（每条记录自带日期）
   */
  async saveStatisticsForDateBatch(
    items: Array<{ accountId: number; recordDate: Date } & Omit<UserDayStatisticsItem, 'accountId'>>
  ): Promise<SaveResult> {
    let insertedCount = 0;
    let updatedCount = 0;

    for (const it of items) {
      const { accountId, recordDate, ...patch } = it;
      const result = await this.saveStatisticsForDate(accountId, recordDate, patch);
      insertedCount += result.inserted;
      updatedCount += result.updated;
    }

    logger.info(`[UserDayStatistics] Date-batch save completed: inserted=${insertedCount}, updated=${updatedCount}`);
    return { inserted: insertedCount, updated: updatedCount };
  }

  /**
   * 获取账号指定日期的统计数据
   */
  async getStatisticsByDate(
    accountId: number,
    date: Date
  ): Promise<UserDayStatistics | null> {
    return await this.statisticsRepository.findOne({
      where: {
        accountId,
        recordDate: date,
      },
    });
  }

  /**
   * 获取账号指定日期范围的统计数据
   */
  async getStatisticsByDateRange(
    accountId: number,
    startDate: Date,
    endDate: Date
  ): Promise<UserDayStatistics[]> {
    return await this.statisticsRepository
      .createQueryBuilder('uds')
      .where('uds.account_id = :accountId', { accountId })
      .andWhere('uds.record_date >= :startDate', { startDate })
      .andWhere('uds.record_date <= :endDate', { endDate })
      .orderBy('uds.record_date', 'ASC')
      .getMany();
  }
}