package roomescape.time.business

import org.springframework.data.repository.findByIdOrNull
import org.springframework.stereotype.Service
import org.springframework.transaction.annotation.Transactional
import roomescape.reservation.infrastructure.persistence.ReservationEntity
import roomescape.reservation.infrastructure.persistence.ReservationRepository
import roomescape.time.exception.TimeErrorCode
import roomescape.time.exception.TimeException
import roomescape.time.infrastructure.persistence.TimeEntity
import roomescape.time.infrastructure.persistence.TimeRepository
import roomescape.time.web.*
import java.time.LocalDate
import java.time.LocalTime

@Service
class TimeService(
        private val timeRepository: TimeRepository,
        private val reservationRepository: ReservationRepository
) {
    @Transactional(readOnly = true)
    fun findById(id: Long): TimeEntity = timeRepository.findByIdOrNull(id)
            ?: throw TimeException(TimeErrorCode.TIME_NOT_FOUND)

    @Transactional(readOnly = true)
    fun findTimes(): TimeRetrieveListResponse = timeRepository.findAll()
            .toResponse()

    @Transactional
    fun createTime(request: TimeCreateRequest): TimeCreateResponse {
        val startAt: LocalTime = request.startAt
        if (timeRepository.existsByStartAt(startAt)) {
            throw TimeException(TimeErrorCode.TIME_DUPLICATED)
        }

        val time: TimeEntity = request.toEntity()

        return timeRepository.save(time).toCreateResponse()
    }

    @Transactional
    fun deleteTime(id: Long) {
        val time: TimeEntity = findById(id)
        val reservations: List<ReservationEntity> = reservationRepository.findAllByTime(time)

        if (reservations.isNotEmpty()) {
            throw TimeException(TimeErrorCode.TIME_ALREADY_RESERVED)
        }
        timeRepository.delete(time)
    }

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

        return TimeWithAvailabilityListResponse(allTimes.map { time ->
            val isAvailable: Boolean = reservations.none { reservation -> reservation.time.id == time.id }
            TimeWithAvailabilityResponse(time.id!!, time.startAt, isAvailable)
        })
    }
}