import { beforeEach, describe, expect, it, vi } from 'vitest';
import type { IIssueRepository } from '../../../../issue/domain/repositories/issue.repository.interface.js';
import { IssueNotFoundException } from '../../../../issue/domain/exceptions/issue-not-found.exception.js';
import { CommentEventsService, type CommentEvent } from '../../services/comment-events.service.js';
import { CommentApplicationMapper } from '../../mappers/comment-application.mapper.js';
import { WatchIssueCommentsUseCase } from './watch-issue-comments.use-case.js';
import { WatchIssueCommentsQuery } from './watch-issue-comments.query.js';
import { buildComment, buildIssue, mockIssueRepository } from '../test-helpers.js';

const dtoForIssue = (issueId: number) =>
  CommentApplicationMapper.toDto(buildComment({ id: `comment-of-${issueId}`, issueId }), new Map());

describe('WatchIssueCommentsUseCase', () => {
  let issueRepository: IIssueRepository;
  let commentEventsService: CommentEventsService;
  let useCase: WatchIssueCommentsUseCase;

  beforeEach(() => {
    issueRepository = mockIssueRepository();
    commentEventsService = new CommentEventsService();
    useCase = new WatchIssueCommentsUseCase(issueRepository, commentEventsService);
  });

  it('streams only events of the requested issue', async () => {
    vi.mocked(issueRepository.findById).mockResolvedValue(buildIssue());
    const received: CommentEvent[] = [];

    const events$ = await useCase.execute(new WatchIssueCommentsQuery(1, 'user-1'));
    events$.subscribe((event) => received.push(event));

    commentEventsService.emit('comment.created', dtoForIssue(1));
    commentEventsService.emit('comment.created', dtoForIssue(2));

    expect(received.map((event) => event.comment.id)).toEqual(['comment-of-1']);
  });

  it('throws IssueNotFoundException when the issue is not visible to the user', async () => {
    vi.mocked(issueRepository.findById).mockResolvedValue(null);

    await expect(useCase.execute(new WatchIssueCommentsQuery(1, 'user-2'))).rejects.toThrow(IssueNotFoundException);
  });
});