import { UseCase } from '../../../../shared/application/UseCase';
import { Result, Ok, Err } from '../../../../shared/domain/Result';
import { EventBus } from '../../../../shared/application/EventBus';
import { IReportRepository } from '../../domain/ports/IReportRepository';
import { Report, ReportFilters } from '../../domain/entities/Report';
import { ReportFormat } from '../../domain/value-objects/ReportFormat';

export interface GenerateReportRequest {
  title: string;
  format: 'html' | 'json' | 'pdf';
  filters?: ReportFilters;
}

export interface GenerateReportResponse {
  reportId: string;
  status: string;
}

export class GenerateReportCommand
  implements UseCase<GenerateReportRequest, GenerateReportResponse, string>
{
  constructor(
    private readonly reportRepository: IReportRepository,
    private readonly eventBus: EventBus
  ) {}

  async execute(request: GenerateReportRequest): Promise<Result<GenerateReportResponse, string>> {
    let format: ReportFormat;
    try {
      format = ReportFormat.fromString(request.format);
    } catch {
      return Err(`Invalid format: ${request.format}`);
    }

    const report = Report.create({
      title: request.title,
      format,
      filters: request.filters ?? {},
    });

    await this.reportRepository.save(report);

    const events = report.clearEvents();
    for (const event of events) {
      await this.eventBus.publish(event);
    }

    return Ok({ reportId: report.id.toString(), status: report.status.value });
  }
}