package roomescape.reservation.business

import org.springframework.data.repository.findByIdOrNull
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.infrastructure.persistence.ReservationEntity
import roomescape.reservation.infrastructure.persistence.ReservationRepository
import roomescape.reservation.infrastructure.persistence.ReservationTimeEntity
import roomescape.reservation.infrastructure.persistence.ReservationTimeRepository
import roomescape.reservation.web.*
import java.time.LocalDate
import java.time.LocalTime

@Service
class ReservationTimeService(
        private val reservationTimeRepository: ReservationTimeRepository,
        private val reservationRepository: ReservationRepository
) {
    @Transactional(readOnly = true)
    fun findTimeById(id: Long): ReservationTimeEntity = reservationTimeRepository.findByIdOrNull(id)
            ?: throw RoomescapeException(
                    ErrorType.RESERVATION_TIME_NOT_FOUND,
                    "[reservationTimeId: $id]",
                    HttpStatus.BAD_REQUEST
            )


    @Transactional(readOnly = true)
    fun findAllTimes(): ReservationTimesResponse = reservationTimeRepository.findAll()
            .toResponses()

    @Transactional
    fun addTime(reservationTimeRequest: ReservationTimeRequest): ReservationTimeResponse {
        val startAt: LocalTime = reservationTimeRequest.startAt

        if (reservationTimeRepository.existsByStartAt(startAt)) {
            throw RoomescapeException(
                    ErrorType.TIME_DUPLICATED, "[startAt: $startAt]", HttpStatus.CONFLICT
            )
        }

        return ReservationTimeEntity(startAt = startAt)
                .also { reservationTimeRepository.save(it) }
                .toResponse()
    }

    @Transactional
    fun removeTimeById(id: Long) {
        val reservationTime: ReservationTimeEntity = findTimeById(id)
        reservationRepository.findByReservationTime(reservationTime)
                .also {
                    if (it.isNotEmpty()) {
                        throw RoomescapeException(
                                ErrorType.TIME_IS_USED_CONFLICT, "[timeId: $id]", HttpStatus.CONFLICT
                        )
                    }
                    reservationTimeRepository.deleteById(id)
                }
    }

    @Transactional(readOnly = true)
    fun findAllAvailableTimesByDateAndTheme(date: LocalDate, themeId: Long): ReservationTimeInfosResponse {
        val allTimes = reservationTimeRepository.findAll()
        val reservations: List<ReservationEntity> = reservationRepository.findByDateAndThemeId(date, themeId)

        return ReservationTimeInfosResponse(allTimes.map { time ->
            val alreadyBooked: Boolean = reservations.any { reservation -> reservation.reservationTime.id == time.id }
            time.toInfoResponse(alreadyBooked)
        })
    }
}