import { describe, it, expect, beforeEach, vi, Mock } from 'vitest';
import {
  PreviewLeagueScheduleUseCase,
  type PreviewLeagueScheduleResult,
  type PreviewLeagueScheduleInput,
  type PreviewLeagueScheduleErrorCode,
} from './PreviewLeagueScheduleUseCase';
import type { Logger } from '@core/shared/application';
import type { UseCaseOutputPort } from '@core/shared/application/UseCaseOutputPort';
import type { ApplicationErrorCode } from '@core/shared/errors/ApplicationErrorCode';
 
 describe('PreviewLeagueScheduleUseCase', () => {
  let useCase: PreviewLeagueScheduleUseCase;
  let logger: {
    debug: Mock;
    info: Mock;
    warn: Mock;
    error: Mock;
  };
  let output: { present: Mock } &
    UseCaseOutputPort<PreviewLeagueScheduleResult>;
 
   beforeEach(() => {
    logger = {
      debug: vi.fn(),
      info: vi.fn(),
      warn: vi.fn(),
      error: vi.fn(),
    };
    output = {
      present: vi.fn(),
    } as unknown as typeof output;
    useCase = new PreviewLeagueScheduleUseCase(
      undefined,
      logger as unknown as Logger,
      output,
    );
  });
 
  it('should preview schedule successfully', async () => {
    const params: PreviewLeagueScheduleInput = {
      schedule: {
        seasonStartDate: '2024-01-01',
        recurrenceStrategy: 'weekly',
        weekdays: ['Mon'],
        raceStartTime: '20:00',
        timezoneId: 'UTC',
        plannedRounds: 5,
      },
      maxRounds: 3,
    };
 
    const result = await useCase.execute(params);
 
    expect(result.isOk()).toBe(true);
    expect(result.unwrap()).toBeUndefined();
    expect(output.present).toHaveBeenCalledTimes(1);
    const presentedRaw = output.present.mock.calls[0]?.[0];
    expect(presentedRaw).toBeDefined();
    const presented = presentedRaw as PreviewLeagueScheduleResult;
    expect(presented.rounds.length).toBeGreaterThan(0);
    expect(presented.summary).toContain('Every Mon');
  });
 
 it('should return error for invalid schedule', async () => {
   const params: PreviewLeagueScheduleInput = {
     schedule: {
       seasonStartDate: 'invalid',
       recurrenceStrategy: 'weekly',
       weekdays: ['Mon'],
       raceStartTime: '20:00',
       timezoneId: 'UTC',
       plannedRounds: 5,
     },
   };

   const result = await useCase.execute(params);

   expect(result.isErr()).toBe(true);
   const err = result.unwrapErr() as ApplicationErrorCode<
     PreviewLeagueScheduleErrorCode,
     { message: string }
   >;
   expect(err.code).toBe('INVALID_SCHEDULE');
   expect(err.details.message).toBe('Invalid schedule data');
   expect(output.present).not.toHaveBeenCalled();
 });

 it('should return REPOSITORY_ERROR when generator throws', async () => {
   const throwingGenerator = {
     generateSlotsUpTo: vi.fn(() => {
       throw new Error('boom');
     }),
   } as unknown as Pick<
     typeof import('../../domain/services/SeasonScheduleGenerator').SeasonScheduleGenerator,
     'generateSlotsUpTo'
   >;

   const throwingUseCase = new PreviewLeagueScheduleUseCase(
     throwingGenerator,
     logger as unknown as Logger,
     output,
   );

   const params: PreviewLeagueScheduleInput = {
     schedule: {
       seasonStartDate: '2024-01-01',
       recurrenceStrategy: 'weekly',
       weekdays: ['Mon'],
       raceStartTime: '20:00',
       timezoneId: 'UTC',
       plannedRounds: 5,
     },
     maxRounds: 3,
   };

   const result = await throwingUseCase.execute(params);

   expect(result.isErr()).toBe(true);
   const err = result.unwrapErr() as ApplicationErrorCode<
     PreviewLeagueScheduleErrorCode,
     { message: string }
   >;
   expect(err.code).toBe('REPOSITORY_ERROR');
   expect(err.details.message).toBe('boom');
   expect(output.present).not.toHaveBeenCalled();
 });
});