import { Injectable } from '@nestjs/common';
import { EntityManager, EntityRepository } from '@mikro-orm/postgresql';
import { FilterQuery } from '@mikro-orm/core';
import { Review } from '../entities/review.entity';
import { PaginatedResult } from 'src/common/interfaces/pagination.interface';
import { ReviewStatus } from '../enums/review-status.enum';

type FindReviewsOpts = {
  page?: number;
  limit?: number;
  foodId?: string;
  userId?: string;
  status?: ReviewStatus;
  orderBy?: string;
  restId?: string;
  order?: 'asc' | 'desc';
  parentId?: string;
  topLevel?: boolean;
};

@Injectable()
export class ReviewRepository extends EntityRepository<Review> {
  constructor(readonly em: EntityManager) {
    super(em, Review);
  }

  /**
   * Find reviews with pagination and optional filters.
   * Supports: foodId, userId, status, ordering.
   */
  async findAllPaginated(opts: FindReviewsOpts = {}): Promise<PaginatedResult<Review>> {
    const { page = 1, limit = 10, parentId, topLevel,
      foodId, restId, userId, status, orderBy = 'createdAt', order = 'desc' } = opts;

    const offset = (page - 1) * limit;

    // Only list top-level reviews; replies are nested under their parent
    const where: FilterQuery<Review> = {};
    if (topLevel) {
      where.parent = null;
    }

    if (parentId) {
      where.parent = { id: parentId };
    }

    if (foodId) {
      where.food = { id: foodId };
    }

    if (restId) {
      where.food = { restaurant: { id: restId } };
    }

    if (userId) {
      where.user = { id: userId };
    }

    if (status) {
      where.status = status;
    }

    const [data, total] = await this.findAndCount(where, {
      limit,
      offset,
      orderBy: { [orderBy]: order.toLowerCase() as 'asc' | 'desc' },
      populate: ['user', 'admin', 'parent', 'parent.user'],
    });

    const totalPages = Math.ceil(total / limit);

    return {
      data,
      meta: {
        total,
        page,
        limit,
        totalPages,
      },
    };
  }
}