<?php

declare(strict_types=1);

namespace Abovault\Retention;

use Abovault\Model\Subscription;

defined('ABSPATH') || exit;

/**
 * Retention trigger registry — the entry layer of the trigger→enrollment→execution
 * engine ported from famos.fans (ReEngagementTriggerService).
 *
 * Triggers map lifecycle EVENTS to retention SEQUENCES:
 *   - payment_failed   → dunning sequence (reminder + retry + "update your card")
 *   - period_ending    → renewal-reminder sequence
 *   - cancel_requested → win-back offer (pause / discount / downgrade) BEFORE hard cancel
 *   - canceled         → win-back sequence (last shot)
 *   - anniversary      → loyalty sequence
 *
 * This is the differentiator: WCS/Milo/Sublium have (at best) linear dunning emails;
 * this is an event-driven sequence engine with retention offers.
 */
final class TriggerRegistry
{
    private static ?TriggerRegistry $instance = null;

    /** @var array<string, string> event → sequence key */
    private array $map = [
        'payment_failed'   => 'dunning',
        'period_ending'    => 'renewal_reminder',
        'cancel_requested' => 'win_back_offer',
        'canceled'         => 'win_back',
        'anniversary'      => 'loyalty',
    ];

    public static function instance(): TriggerRegistry
    {
        return self::$instance ??= new self();
    }

    public function register(): void
    {
        if (get_option('abovault_retention_enabled', 'yes') !== 'yes') {
            return;
        }

        add_action('abovault_payment_failed', function (int $id): void {
            $this->enroll($id, 'payment_failed');
        });

        // Every status transition can seed a trigger (canceled → win_back, etc.).
        add_action('abovault_subscription_transitioned', function (int $id, string $to): void {
            if ($to === Subscription::STATUS_CANCELED) {
                $this->enroll($id, 'canceled');
            }
        }, 10, 2);

        // period_ending + anniversary are evaluated by ExecutionService's daily sweep.
    }

    /** @return array<string, string> */
    public function sequences(): array
    {
        return $this->map;
    }

    private function enroll(int $subscriptionId, string $event): void
    {
        $sequence = $this->map[$event] ?? null;
        if ($sequence === null) {
            return;
        }
        EnrollmentService::enroll($subscriptionId, $sequence, $event);
    }
}