import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository, LessThan } from 'typeorm';
import { BidItem } from '../entities/bid-item.entity';
import { CrawlInfoAdd } from '../../crawler/entities/crawl-info-add.entity';
import {
  getDaysAgo,
  setStartOfDay,
  setEndOfDay,
} from '../../common/utils/timezone.util';

interface FindAllQuery {
  page?: number;
  limit?: number;
  source?: string;
  keyword?: string;
}

interface SourceResult {
  source: string;
}

export interface CrawlInfoAddStats {
  source: string;
  count: number;
  latestUpdate: Date | string;
  latestPublishDate: Date | string | null;
  error: string | null;
}

interface CrawlInfoAddRawResult {
  source: string;
  count: number;
  latestPublishDate: Date | string | null;
  error: string | null;
  latestUpdate: Date | string;
}

@Injectable()
export class BidsService {
  constructor(
    @InjectRepository(BidItem)
    private bidRepository: Repository<BidItem>,
    @InjectRepository(CrawlInfoAdd)
    private crawlInfoRepository: Repository<CrawlInfoAdd>,
  ) {}

  async findAll(query?: FindAllQuery) {
    const { page = 1, limit = 10, source, keyword } = query || {};
    const qb = this.bidRepository.createQueryBuilder('bid');

    if (source) {
      qb.andWhere('bid.source = :source', { source });
    }

    if (keyword) {
      qb.andWhere('bid.title LIKE :keyword', { keyword: `%${keyword}%` });
    }

    qb.orderBy('bid.publishDate', 'DESC')
      .skip((Number(page) - 1) * Number(limit))
      .take(Number(limit));

    const [items, total] = await qb.getManyAndCount();
    return { items, total };
  }

  async createOrUpdate(data: Partial<BidItem>) {
    // Use title or a hash of title to check for duplicates
    const item = await this.bidRepository.findOne({
      where: { title: data.title },
    });
    if (item) {
      Object.assign(item, data);
      return this.bidRepository.save(item);
    }
    return this.bidRepository.save(data);
  }

  async cleanOldData() {
    const thirtyDaysAgo = getDaysAgo(30);
    return this.bidRepository.delete({
      createdAt: LessThan(thirtyDaysAgo),
    });
  }

  async getSources(): Promise<string[]> {
    const result = await this.bidRepository
      .createQueryBuilder('bid')
      .select('DISTINCT bid.source', 'source')
      .where('bid.source IS NOT NULL')
      .orderBy('bid.source', 'ASC')
      .getRawMany<SourceResult>();
    return result.map((item) => item.source);
  }

  async getRecentBids() {
    const thirtyDaysAgo = setStartOfDay(getDaysAgo(30));

    return this.bidRepository
      .createQueryBuilder('bid')
      .where('bid.publishDate >= :thirtyDaysAgo', { thirtyDaysAgo })
      .orderBy('bid.publishDate', 'DESC')
      .getMany();
  }

  async getPinnedBids() {
    return this.bidRepository
      .createQueryBuilder('bid')
      .where('bid.pin = :pin', { pin: true })
      .orderBy('bid.publishDate', 'DESC')
      .getMany();
  }

  async getBidsByDateRange(
    startDate?: string,
    endDate?: string,
    keywords?: string[],
  ) {
    const qb = this.bidRepository.createQueryBuilder('bid');

    if (startDate) {
      const start = setStartOfDay(new Date(startDate));
      qb.andWhere('bid.publishDate >= :startDate', { startDate: start });
    }

    if (endDate) {
      const end = setEndOfDay(new Date(endDate));
      qb.andWhere('bid.publishDate <= :endDate', { endDate: end });
    }

    if (keywords && keywords.length > 0) {
      const keywordConditions = keywords
        .map((keyword, index) => {
          return `bid.title LIKE :keyword${index}`;
        })
        .join(' OR ');
      qb.andWhere(
        `(${keywordConditions})`,
        keywords.reduce((params, keyword, index) => {
          params[`keyword${index}`] = `%${keyword}%`;
          return params;
        }, {}),
      );
    }

    return qb.orderBy('bid.publishDate', 'DESC').getMany();
  }

  async updatePin(title: string, pin: boolean) {
    const item = await this.bidRepository.findOne({ where: { title } });
    if (!item) {
      throw new Error('Bid not found');
    }
    item.pin = pin;
    return this.bidRepository.save(item);
  }

  async getCrawlInfoAddStats(): Promise<CrawlInfoAddStats[]> {
    // 获取每个来源的最新一次爬虫记录（按 createdAt 降序）
    const query = `
      SELECT
        source,
        count,
        latestPublishDate,
        error,
        createdAt as latestUpdate
      FROM crawl_info_add
      WHERE (source, createdAt) IN (
        SELECT source, MAX(createdAt)
        FROM crawl_info_add
        GROUP BY source
      )
      ORDER BY source ASC
    `;

    const results =
      await this.crawlInfoRepository.query<CrawlInfoAddRawResult[]>(query);

    return results.map((item) => ({
      source: String(item.source),
      count: Number(item.count),
      latestUpdate: item.latestUpdate ? item.latestUpdate + 'Z' : null,
      latestPublishDate: item.latestPublishDate,
      // 确保 error 字段正确处理：null 或空字符串都转换为 null，非空字符串保留
      error:
        item.error && String(item.error).trim() !== ''
          ? String(item.error)
          : null,
    }));
  }
}