package eventDemo.libs.event

import io.github.oshai.kotlinlogging.KotlinLogging
import java.util.Queue
import java.util.concurrent.ConcurrentLinkedQueue
import kotlin.reflect.KClass

/**
 * An In-Memory implementation of an event stream.
 *
 * All methods are implemented.
 */
class EventStreamInMemory<E : Event<ID>, ID : AggregateId> : EventStream<E, ID> {
    private val logger = KotlinLogging.logger {}
    private val events: Queue<E> = ConcurrentLinkedQueue()

    override fun publish(event: E) {
        events.add(event)
        logger.atInfo {
            message = "Event published: $event"
            payload = mapOf("event" to event)
        }
    }

    override fun publish(vararg events: E) {
        events.forEach { publish(it) }
    }

    override fun readLast(aggregateId: ID): E? = events.lastOrNull()

    override fun <R : E> readLastOf(
        aggregateId: ID,
        eventType: KClass<out R>,
    ): R? =
        events
            .filterIsInstance(eventType.java)
            .lastOrNull { it.aggregateId == aggregateId }

    override fun readAll(aggregateId: ID): Set<E> =
        events
            .filter { it.aggregateId == aggregateId }
            .toSet()
}

inline fun <reified R : E, E : Event<ID>, ID : AggregateId> EventStream<E, ID>.readLastOf(aggregateId: ID): R? =
    readLastOf(aggregateId, R::class)