Paging

@Repository
abstract class CustomQuerydslRepositorySupport (domainClass: Class<*>?) : QuerydslRepositorySupport(domainClass!!) {
    @PersistenceContext
    override fun setEntityManager(entityManager: EntityManager) {
        super.setEntityManager(entityManager)
    }
}

@RestController
@RequestMapping("/${Application.VERSION}/area")
class AreaEndpoint(private val areaCommand: AreaCommand) {
    /**
     * 지역 목록 조회
     * @param areaReqeust
     * @return ResponseEntity<Page<AreaResponse>>
     */
    @GetMapping
    fun getAreas(areaReqeust: AreaReqeust, @PageableDefault(size = 30, page = 0, sort = ["id"], direction = Sort.Direction.DESC) pageable: Pageable): ResponseEntity<Page<Area>> {
        return ResponseEntity.ok(areaCommand.getAreas(areaReqeust, pageable))
    }

    data class AreaReqeust(
        override val id: Long? = null,
        override val city: String? = null,
        override val district: String? = null,
        override val deposit: Long? = null,
        override val rentalPrice: Long? = null,
        override val managementCost: Long? = null,
        override val areaWeighted: Long? = null,
        override val createdAt: LocalDateTime? = null,
        override val updatedAt: LocalDateTime? = null,
    ) : Area
}


@Component
class AreaRepositoryAdaptor(
    private val query: JPAQueryFactory,
) : CustomQuerydslRepositorySupport(AreaEntity::class.java), AreaQueryRepository {
    override fun getAreas(areaRequest: Area, pageable: Pageable): Page<Area> = query
        .selectFrom(area)
        .applyFilter(areaRequest)
        .let { baseQuery ->
            val list = querydsl!!.applyPagination(pageable, baseQuery).fetch().map { it.toDto() }

            val count = baseQuery.select(area.id.count()).fetchFirst() ?: 0L

            PageableExecutionUtils.getPage(list, pageable) { count }
        }

    fun AreaEntity.toDto() = AreaResponse(
        id = id,
        city = city,
        district = district,
        deposit = deposit,
        rentalPrice = rentalPrice,
        managementCost = managementCost,
        areaWeighted = areaWeighted,
        createdAt = createdAt,
        updatedAt = updatedAt,
    )

    private fun JPAQuery<AreaEntity>.applyFilter(areaRequest: Area): JPAQuery<AreaEntity> = where(
        BooleanBuilder().apply {
            areaRequest.run {
                city?.let { and(area.city.eq(it)) }
                district?.let { and(area.district.eq(it)) }
                deposit?.let { and(area.deposit.eq(it)) }
                rentalPrice?.let { and(area.rentalPrice.eq(it)) }
                managementCost?.let { and(area.managementCost.eq(it)) }
                areaWeighted?.let { and(area.areaWeighted.eq(it)) }
            }
        },
    )
}

data class AreaResponse(
    override val id: Long? = null,
    override val city: String? = null,
    override val district: String? = null,
    override val deposit: Long? = null,
    override val rentalPrice: Long? = null,
    override val managementCost: Long? = null,
    override val areaWeighted: Long? = null,
    override val createdAt: LocalDateTime? = null,
    override val updatedAt: LocalDateTime? = null,
) : Area