package com.baiyue.common.event;

import java.util.Objects;

/** A consumer returns this only after its durable processing transaction commits. */
public record DeliveryAck(String eventId, String payloadHash, Outcome outcome) {
    public enum Outcome { APPLIED, DUPLICATE, STALE }

    public DeliveryAck {
        if (!EventIdentifiers.isSupported(eventId)) throw new IllegalArgumentException("Invalid ACK eventId");
        if (payloadHash == null || !payloadHash.matches("sha256:[0-9a-fA-F]{64}")) {
            throw new IllegalArgumentException("Invalid ACK payloadHash");
        }
        Objects.requireNonNull(outcome, "ACK outcome is required");
    }

    public static DeliveryAck of(EventEnvelope event, Outcome outcome) {
        return new DeliveryAck(event.eventId(), event.payloadHash(), outcome);
    }

    /** HTTP and ApiResponse status must also be checked by the transport. */
    public void requireMatches(EventEnvelope sent) {
        if (!eventId.equals(sent.eventId()) || !payloadHash.equalsIgnoreCase(sent.payloadHash())) {
            throw new IllegalArgumentException("Consumer ACK does not match the sent event identity and payload");
        }
        EventDeliveryRoute route = EventDeliveryRoute.forEventType(sent.eventType());
        if (outcome == Outcome.STALE && !route.acceptsStale()) {
            throw new IllegalArgumentException("STALE is not an allowed result for " + sent.eventType());
        }
    }
}