package io.apicurio.registry.metrics.health.liveness;

import javax.annotation.PostConstruct;
import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.inject.Default;
import javax.inject.Inject;

import io.apicurio.common.apps.config.Info;
import io.apicurio.registry.metrics.health.AbstractErrorCounterHealthCheck;
import org.eclipse.microprofile.config.inject.ConfigProperty;
import org.eclipse.microprofile.health.HealthCheck;
import org.eclipse.microprofile.health.HealthCheckResponse;
import org.eclipse.microprofile.health.Liveness;
import org.slf4j.Logger;

/**
 * @author Jakub Senko <em>m@jsenko.net</em>
 */
@ApplicationScoped
@Liveness
@Default
public class ResponseErrorLivenessCheck extends AbstractErrorCounterHealthCheck implements HealthCheck, LivenessCheck {

    @Inject
    Logger log;

    /**
     * Maximum number of HTTP 5xx errors returned to the user
     * as captured by {@link io.apicurio.registry.rest.RegistryExceptionMapper}
     * before the liveness check fails.
     */
    @ConfigProperty(name = "registry.metrics.ResponseErrorLivenessCheck.errorThreshold", defaultValue = "1")
    @Info(category = "health", description = "Error threshold of response liveness check", availableSince = "1.0.2.Final")
    Integer configErrorThreshold;

    /**
     * The counter is reset after some time without errors.
     * i.e. to fail the check after 2 errors in a minute, set the threshold to 1 and this configuration option
     * to 60.
     * TODO report the absolute count as a metric?
     */
    @ConfigProperty(name = "registry.metrics.ResponseErrorLivenessCheck.counterResetWindowDurationSec", defaultValue = "60")
    @Info(category = "health", description = "Counter reset window duration of response liveness check", availableSince = "1.0.2.Final")
    Integer configCounterResetWindowDurationSec;

    /**
     * If set to a positive value, reset the liveness status after this time window passes without any further errors.
     */
    @ConfigProperty(name = "registry.metrics.ResponseErrorLivenessCheck.statusResetWindowDurationSec", defaultValue = "300")
    @Info(category = "health", description = "Status reset window duration of response liveness check", availableSince = "1.0.2.Final")
    Integer configStatusResetWindowDurationSec;

    @ConfigProperty(name = "registry.metrics.ResponseErrorLivenessCheck.disableLogging", defaultValue = "false")
    @Info(category = "health", description = "Disable logging of response liveness check", availableSince = "2.0.0.Final")
    Boolean disableLogging;

    @PostConstruct
    void init() {
        init(configErrorThreshold, configCounterResetWindowDurationSec, configStatusResetWindowDurationSec);
    }

    @Override
    public synchronized HealthCheckResponse call() {
        callSuper();
        return HealthCheckResponse.builder()
                .name("ResponseErrorLivenessCheck")
                .withData("errorCount", errorCounter)
                .up()
                .build();
    }

    @Override
    public void suspect(String reason) {
        if (disableLogging != Boolean.TRUE) {
            log.warn("Liveness problem suspected in ResponseErrorLivenessCheck: {}", reason);
        }
        super.suspectSuper();
        if (disableLogging != Boolean.TRUE) {
            log.info("After this event, the error counter is {} (out of the maximum {} allowed).", errorCounter, configErrorThreshold);
        }
    }

    @Override
    public void suspectWithException(Throwable reason) {
        if (disableLogging != Boolean.TRUE) {
            log.warn("Liveness problem suspected in ResponseErrorLivenessCheck because of an exception: ", reason);
        }
        super.suspectSuper();
        if (disableLogging != Boolean.TRUE) {
            log.info("After this event, the error counter is {} (out of the maximum {} allowed).", errorCounter, configErrorThreshold);
        }
    }
}
