<?php

namespace PrestaShop\CircuitBreaker;

/**
 * Define the available transitions of the Circuit Breaker;.
 */
final class Transition
{
    /**
     * Happened only once when calling the Circuit Breaker.
     */
    const INITIATING_TRANSITION = 'INITIATING';

    /**
     * Happened when we open the Circuit Breaker.
     * This means once the Circuit Breaker is in failure.
     */
    const OPENING_TRANSITION = 'OPENING';

    /**
     * Happened once the conditions of retry are met
     * in OPEN state to move to HALF_OPEN state in the
     * Circuit Breaker.
     */
    const CHECKING_AVAILABILITY_TRANSITION = 'CHECKING AVAILABILITY';

    /**
     * Happened when we come back to OPEN state
     * in the Circuit Breaker from the HALF_OPEN state.
     */
    const REOPENING_TRANSITION = 'REOPENING';

    /**
     * Happened if the service is available again.
     */
    const CLOSING_TRANSITION = 'CLOSING';

    /**
     * Happened on each try to call the service.
     */
    const TRIAL_TRANSITION = 'TRIAL';
}