package world.respect.datalayer.school

import io.ktor.util.StringValues
import kotlinx.coroutines.flow.Flow
import kotlinx.datetime.LocalDate
import world.respect.datalayer.DataLayerParams
import world.respect.datalayer.DataLoadParams
import world.respect.datalayer.DataLoadState
import world.respect.datalayer.school.model.ChangeHistoryEntry
import world.respect.datalayer.school.model.EnrollmentRoleEnum
import world.respect.datalayer.school.model.Person
import world.respect.datalayer.school.model.PersonRoleEnum
import world.respect.datalayer.school.model.PersonStatusEnum
import world.respect.datalayer.school.model.composites.PersonListDetails
import world.respect.datalayer.shared.WritableDataSource
import world.respect.datalayer.shared.paging.IPagingSourceFactory
import world.respect.datalayer.shared.params.GetListCommonParams

interface PersonDataSource: WritableDataSource<Person> {

    /**
     * @param includeRelated if true, then include all Persons related (as per
     *        Person.relatedPersonUids) to those that match the other criteria.
     * @param inClassOnDay: when using filterByClazzUid, we often want to limit this to only those
     *        that have an active enrollment (e.g. are currently members of the class).
     *
     *        a) the startDate is null, today, or any earlier date
     *        and b) the endDate is null, today, or any later date
     *        and c) the removedAt is null or an instant > Clock.System.now().
     *
     *        If common.includeDeleted is true, then the dates will be ignored (ensuring that repo
     *        queries fetch all updated data).
     */
    data class GetListParams(
        val common: GetListCommonParams = GetListCommonParams(),
        val filterByClazzUid: String? = null,
        val filterByEnrolmentRole: EnrollmentRoleEnum? = null,
        val filterByName: String? = null,
        val filterByPersonStatus: PersonStatusEnum? = null,
        val filterByPersonRole: PersonRoleEnum? = null,
        val includeRelated: Boolean = false,
        val inClassOnDay: LocalDate? = null,
    ) {

        companion object {
            fun fromParams(stringValues: StringValues) : GetListParams {
                return GetListParams(
                    common = GetListCommonParams.fromParams(stringValues),
                    filterByClazzUid = stringValues[DataLayerParams.FILTER_BY_CLASS_UID],
                    filterByEnrolmentRole = stringValues[DataLayerParams.FILTER_BY_ENROLLMENT_ROLE]?.let {
                        EnrollmentRoleEnum.fromValue(it)
                    },
                    inClassOnDay = stringValues[DataLayerParams.IN_CLASS_ON_DAY]?.let {
                        LocalDate.parse(it)
                    },
                    filterByPersonStatus = stringValues[DataLayerParams.FILTER_BY_PERSON_STATUS]?.let {
                        PersonStatusEnum.fromValue(it)
                    },
                    filterByName = stringValues[DataLayerParams.SEARCH_QUERY],
                    filterByPersonRole = stringValues[FILTER_BY_PERSON_ROLE]?.let {
                        PersonRoleEnum.fromValue(it)
                    },
                    includeRelated = stringValues[DataLayerParams.INCLUDE_RELATED]?.toBoolean() ?: false,

                )
            }
        }

    }

    suspend fun findByUsername(username: String): Person?

    suspend fun findByGuid(loadParams: DataLoadParams, guid: String): DataLoadState<Person>

    fun findByGuidAsFlow(guid: String): Flow<DataLoadState<Person>>

    fun listAsFlow(
        loadParams: DataLoadParams,
        params: GetListParams = GetListParams(),
    ): Flow<DataLoadState<List<Person>>>

    suspend fun list(
        loadParams: DataLoadParams,
        params: GetListParams = GetListParams(),
    ): DataLoadState<List<Person>>

    fun listAsPagingSource(
        loadParams: DataLoadParams,
        params: GetListParams,
    ): IPagingSourceFactory<Int, Person>


    fun listDetailsAsPagingSource(
        loadParams: DataLoadParams,
        listParams: GetListParams,
    ): IPagingSourceFactory<Int, PersonListDetails>

    /**
     * Persists the list to the DataSource. The underlying DataSource WILL set the stored time on
     * the data. It WILL NOT set the last-modified time (this should be done by the ViewModel or
     * UseCase actually changing the data).
     */
    override suspend fun store(
        list: List<Person>
    )


    companion object {

        const val ENDPOINT_NAME = "person"


        const val FILTER_BY_PERSON_ROLE = "filterByPersonRole"


    }

}