import { Injectable, NotFoundException } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';

@Injectable()
export class GalleryService {
  constructor(private prisma: PrismaService) {}

  /** 作品广场列表（已审核通过的公开作品） */
  async getGalleryList(params: {
    page?: number;
    pageSize?: number;
    tagId?: number;
    category?: string;
    sortBy?: string;
    keyword?: string;
  }) {
    const { page = 1, pageSize = 12, tagId, category, sortBy = 'latest', keyword } = params;
    const skip = (page - 1) * pageSize;

    const where: any = {
      status: 'published',
      visibility: 'public',
      isDeleted: 0,
    };

    if (keyword) {
      where.OR = [
        { title: { contains: keyword } },
        { description: { contains: keyword } },
      ];
    }

    if (tagId) {
      where.tags = { some: { tagId } };
    }

    if (category) {
      where.tags = {
        ...where.tags,
        some: { ...where.tags?.some, tag: { category } },
      };
    }

    const orderBy: any = sortBy === 'hot'
      ? [{ likeCount: 'desc' }, { viewCount: 'desc' }]
      : sortBy === 'views'
        ? { viewCount: 'desc' }
        : { publishTime: 'desc' };

    const [list, total] = await Promise.all([
      this.prisma.userWork.findMany({
        where,
        skip,
        take: pageSize,
        orderBy,
        include: {
          creator: { select: { id: true, nickname: true, avatar: true } },
          tags: { include: { tag: { select: { id: true, name: true } } } },
          _count: { select: { pages: true, likes: true, comments: true } },
        },
      }),
      this.prisma.userWork.count({ where }),
    ]);

    return { list, total, page, pageSize };
  }

  /** 广场作品详情（增加浏览量） */
  async getGalleryDetail(id: number) {
    const work = await this.prisma.userWork.findFirst({
      where: { id, status: 'published', visibility: 'public', isDeleted: 0 },
      include: {
        pages: { orderBy: { pageNo: 'asc' } },
        creator: { select: { id: true, nickname: true, avatar: true, username: true } },
        tags: { include: { tag: true } },
        _count: { select: { pages: true, likes: true, favorites: true, comments: true } },
      },
    });

    if (!work) throw new NotFoundException('作品不存在');

    // 异步增加浏览量
    this.prisma.userWork.update({
      where: { id },
      data: { viewCount: { increment: 1 } },
    }).catch(() => {});

    return work;
  }

  /** 推荐作品列表 */
  async getRecommendedWorks(limit = 10) {
    return this.prisma.userWork.findMany({
      where: {
        isRecommended: true,
        status: 'published',
        visibility: 'public',
        isDeleted: 0,
      },
      take: limit,
      orderBy: [{ likeCount: 'desc' }, { publishTime: 'desc' }],
      include: {
        creator: { select: { id: true, nickname: true, avatar: true } },
      },
    });
  }

  /** 某用户的公开作品列表 */
  async getUserPublicWorks(userId: number, params: { page?: number; pageSize?: number }) {
    const { page = 1, pageSize = 12 } = params;
    const skip = (page - 1) * pageSize;

    const where = {
      userId,
      status: 'published',
      visibility: 'public',
      isDeleted: 0,
    };

    const [list, total] = await Promise.all([
      this.prisma.userWork.findMany({
        where,
        skip,
        take: pageSize,
        orderBy: { publishTime: 'desc' },
        include: {
          tags: { include: { tag: { select: { id: true, name: true } } } },
          _count: { select: { pages: true, likes: true } },
        },
      }),
      this.prisma.userWork.count({ where }),
    ]);

    return { list, total, page, pageSize };
  }
}