import { Inject, Injectable } from '@nestjs/common';
import {
  COMMENT_REPOSITORY,
  type ICommentRepository,
} from '../../../domain/repositories/comment.repository.interface.js';
import {
  ISSUE_REPOSITORY,
  type IIssueRepository,
} from '../../../../issue/domain/repositories/issue.repository.interface.js';
import { IssueNotFoundException } from '../../../../issue/domain/exceptions/issue-not-found.exception.js';
import { ListCommentsQuery } from './list-comments.query.js';
import { CommentDto } from '../../dto/comment.dto.js';
import { CommentExpanderService } from '../../services/comment-expander.service.js';

@Injectable()
export class ListCommentsUseCase {
  constructor(
    @Inject(COMMENT_REPOSITORY)
    private readonly commentRepository: ICommentRepository,
    @Inject(ISSUE_REPOSITORY)
    private readonly issueRepository: IIssueRepository,
    private readonly commentExpander: CommentExpanderService,
  ) {}

  async execute(query: ListCommentsQuery): Promise<{ list: CommentDto[]; nextCursor: string | null }> {
    const issue = await this.issueRepository.findById(query.issueId, query.userId);
    if (!issue) {
      throw new IssueNotFoundException(query.issueId);
    }

    const { list, nextCursor } = await this.commentRepository.findByIssue({
      issueId: query.issueId,
      limit: query.limit,
      cursor: query.cursor,
      direction: query.direction,
    });

    return { list: await this.commentExpander.expandAll(list), nextCursor };
  }
}