package roomescape.theme.business

import org.springframework.data.repository.findByIdOrNull
import org.springframework.stereotype.Service
import org.springframework.transaction.annotation.Transactional
import roomescape.theme.exception.ThemeErrorCode
import roomescape.theme.exception.ThemeException
import roomescape.theme.infrastructure.persistence.ThemeEntity
import roomescape.theme.infrastructure.persistence.ThemeRepository
import roomescape.theme.web.*
import java.time.LocalDate

@Service
class ThemeService(
        private val themeRepository: ThemeRepository
) {
    @Transactional(readOnly = true)
    fun findById(id: Long): ThemeEntity = themeRepository.findByIdOrNull(id)
            ?: throw ThemeException(ThemeErrorCode.THEME_NOT_FOUND)

    @Transactional(readOnly = true)
    fun findThemes(): ThemeRetrieveListResponse = themeRepository.findAll()
            .toResponse()

    @Transactional(readOnly = true)
    fun findMostReservedThemes(count: Int): ThemeRetrieveListResponse {
        val today = LocalDate.now()
        val startDate = today.minusDays(7)
        val endDate = today.minusDays(1)

        return themeRepository.findPopularThemes(startDate, endDate, count)
                .toResponse()
    }

    @Transactional
    fun createTheme(request: ThemeCreateRequest): ThemeRetrieveResponse {
        if (themeRepository.existsByName(request.name)) {
            throw ThemeException(ThemeErrorCode.THEME_NAME_DUPLICATED)
        }

        val theme: ThemeEntity = request.toEntity()
        return themeRepository.save(theme).toResponse()
    }

    @Transactional
    fun deleteTheme(id: Long) {
        if (themeRepository.isReservedTheme(id)) {
            throw ThemeException(ThemeErrorCode.THEME_ALREADY_RESERVED)
        }

        themeRepository.deleteById(id)
    }
}