roomescape-refactored/src/main/java/roomescape/theme/service/ThemeService.java

package roomescape.theme.service;

import java.time.LocalDate;
import java.util.List;

import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import roomescape.common.exception.ErrorType;
import roomescape.common.exception.RoomescapeException;
import roomescape.reservation.domain.repository.ReservationRepository;
import roomescape.theme.domain.Theme;
import roomescape.theme.domain.repository.ThemeRepository;
import roomescape.theme.dto.ThemeRequest;
import roomescape.theme.dto.ThemeResponse;
import roomescape.theme.dto.ThemesResponse;

@Service
@Transactional
public class ThemeService {

	private final ThemeRepository themeRepository;

	public ThemeService(ThemeRepository themeRepository) {
		this.themeRepository = themeRepository;
	}

	@Transactional(readOnly = true)
	public Theme findThemeById(Long id) {
		return themeRepository.findById(id)
			.orElseThrow(() -> new RoomescapeException(ErrorType.THEME_NOT_FOUND,
				String.format("[themeId: %d]", id), HttpStatus.BAD_REQUEST));
	}

	@Transactional(readOnly = true)
	public ThemesResponse findAllThemes() {
		List<ThemeResponse> response = themeRepository.findAll()
			.stream()
			.map(ThemeResponse::from)
			.toList();

		return new ThemesResponse(response);
	}

	@Transactional(readOnly = true)
	public ThemesResponse getMostReservedThemesByCount(int count) {
		LocalDate today = LocalDate.now();
		LocalDate startDate = today.minusDays(7);
		LocalDate endDate = today.minusDays(1);

		List<ThemeResponse> response = themeRepository.findTopNThemeBetweenStartDateAndEndDate(startDate, endDate,
				count)
			.stream()
			.map(ThemeResponse::from)
			.toList();

		return new ThemesResponse(response);
	}

	public ThemeResponse addTheme(ThemeRequest request) {
		validateIsSameThemeNameExist(request.name());
		Theme theme = themeRepository.save(new Theme(request.name(), request.description(), request.thumbnail()));

		return ThemeResponse.from(theme);
	}

	private void validateIsSameThemeNameExist(String name) {
		if (themeRepository.existsByName(name)) {
			throw new RoomescapeException(ErrorType.THEME_DUPLICATED,
				String.format("[name: %s]", name), HttpStatus.CONFLICT);
		}
	}

	public void removeThemeById(Long id) {
		if (themeRepository.isReservedTheme(id)) {
			throw new RoomescapeException(ErrorType.THEME_IS_USED_CONFLICT,
				String.format("[themeId: %d]", id), HttpStatus.CONFLICT);
		}
		themeRepository.deleteById(id);
	}
}