import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { ShareParticipant } from '../entities/share-participant.entity';

type ShareParticipantCountRow = {
  shareConfigId: string;
  participantCount: string;
};

export type ShareParticipantRankingRow = {
  shareConfigId: string;
  participantId: string;
  correctCount: number;
  totalTimeSpent: number;
  submittedAt: Date;
};

@Injectable()
export class ShareParticipantRepository {
  constructor(
    @InjectRepository(ShareParticipant)
    private readonly repository: Repository<ShareParticipant>,
  ) {}

  /** 添加参与者（已存在则忽略） */
  async addParticipant(
    shareConfigId: string,
    participantId: string,
  ): Promise<void> {
    await this.repository
      .createQueryBuilder()
      .insert()
      .into(ShareParticipant)
      .values({ shareConfigId, participantId })
      .orIgnore()
      .execute();
  }

  async countByShareConfigId(shareConfigId: string): Promise<number> {
    return this.repository.count({ where: { shareConfigId } });
  }

  async countByShareConfigIds(
    shareConfigIds: string[],
  ): Promise<Map<string, number>> {
    if (shareConfigIds.length === 0) {
      return new Map();
    }

    const rows = await this.repository
      .createQueryBuilder('participant')
      .select('participant.shareConfigId', 'shareConfigId')
      .addSelect('COUNT(*)', 'participantCount')
      .where('participant.shareConfigId IN (:...shareConfigIds)', {
        shareConfigIds,
      })
      .groupBy('participant.shareConfigId')
      .getRawMany<ShareParticipantCountRow>();

    return new Map(
      rows.map((row) => [row.shareConfigId, Number(row.participantCount)]),
    );
  }

  async upsertSubmissionSummary(data: {
    shareConfigId: string;
    participantId: string;
    correctCount: number;
    totalTimeSpent: number;
    submittedAt: Date;
  }): Promise<void> {
    await this.repository
      .createQueryBuilder()
      .insert()
      .into(ShareParticipant)
      .values(data)
      .orUpdate(
        ['correctCount', 'totalTimeSpent', 'submittedAt'],
        ['shareConfigId', 'participantId'],
      )
      .execute();
  }

  async countSubmittedByShareConfigId(shareConfigId: string): Promise<number> {
    return this.repository
      .createQueryBuilder('participant')
      .where('participant.shareConfigId = :shareConfigId', { shareConfigId })
      .andWhere('participant.submittedAt IS NOT NULL')
      .getCount();
  }

  async countSubmittedByShareConfigIds(
    shareConfigIds: string[],
  ): Promise<Map<string, number>> {
    if (shareConfigIds.length === 0) {
      return new Map();
    }

    const rows = await this.repository
      .createQueryBuilder('participant')
      .select('participant.shareConfigId', 'shareConfigId')
      .addSelect('COUNT(*)', 'participantCount')
      .where('participant.shareConfigId IN (:...shareConfigIds)', {
        shareConfigIds,
      })
      .andWhere('participant.submittedAt IS NOT NULL')
      .groupBy('participant.shareConfigId')
      .getRawMany<ShareParticipantCountRow>();

    return new Map(
      rows.map((row) => [row.shareConfigId, Number(row.participantCount)]),
    );
  }

  async findSubmittedRankingsByShareConfigId(
    shareConfigId: string,
  ): Promise<ShareParticipantRankingRow[]> {
    const rows = await this.repository
      .createQueryBuilder('participant')
      .where('participant.shareConfigId = :shareConfigId', { shareConfigId })
      .andWhere('participant.submittedAt IS NOT NULL')
      .orderBy('participant.correctCount', 'DESC')
      .addOrderBy('participant.totalTimeSpent', 'ASC')
      .addOrderBy('participant.submittedAt', 'ASC')
      .addOrderBy('participant.participantId', 'ASC')
      .getMany();

    return rows.map((row) => ({
      shareConfigId: row.shareConfigId,
      participantId: row.participantId,
      correctCount: row.correctCount,
      totalTimeSpent: row.totalTimeSpent,
      submittedAt: row.submittedAt!,
    }));
  }

  async findSubmittedRankingsByShareConfigIds(
    shareConfigIds: string[],
  ): Promise<ShareParticipantRankingRow[]> {
    if (shareConfigIds.length === 0) {
      return [];
    }

    const rows = await this.repository
      .createQueryBuilder('participant')
      .where('participant.shareConfigId IN (:...shareConfigIds)', {
        shareConfigIds,
      })
      .andWhere('participant.submittedAt IS NOT NULL')
      .orderBy('participant.shareConfigId', 'ASC')
      .addOrderBy('participant.correctCount', 'DESC')
      .addOrderBy('participant.totalTimeSpent', 'ASC')
      .addOrderBy('participant.submittedAt', 'ASC')
      .addOrderBy('participant.participantId', 'ASC')
      .getMany();

    return rows.map((row) => ({
      shareConfigId: row.shareConfigId,
      participantId: row.participantId,
      correctCount: row.correctCount,
      totalTimeSpent: row.totalTimeSpent,
      submittedAt: row.submittedAt!,
    }));
  }

  async existsByShareConfigAndParticipant(
    shareConfigId: string,
    participantId: string,
  ): Promise<boolean> {
    const count = await this.repository.count({
      where: { shareConfigId, participantId },
    });
    return count > 0;
  }
}