Bounce and complaint webhook processing

<?php

namespace App\Mail;

use Illuminate\Support\Facades\Cache;

class ProcessDeliveryEvent
{
    private const SOFT_LIMIT = 3;

    /** @param array{type: string, address: string, permanent?: bool, reason?: string} $event */
    public static function handle(array $event): void
    {
        $address = $event['address'];

        match (true) {
            $event['type'] === 'complaint' => SuppressionList::add($address, 'complaint'),
            $event['type'] === 'bounce' && ($event['permanent'] ?? false) => SuppressionList::add($address, 'hard_bounce'),
            $event['type'] === 'bounce' => self::softBounce($address, $event['reason'] ?? ''),
            default => null,
        };
    }

    private static function softBounce(string $address, string $reason): void
    {
        $key = 'soft-bounce:'.SuppressionList::key($address);

        Cache::add($key, 0, now()->addWeek()); // rolling window starts at the first strike

        if (Cache::increment($key) >= self::SOFT_LIMIT) {
            SuppressionList::add($address, 'soft_bounce: '.mb_substr($reason, 0, 80));
        }
    }
}

<?php

namespace App\Mail;

use Illuminate\Support\Facades\DB;

final class SuppressionList
{
    /** Hashed, so the block outlives deleting the contact. */
    public static function key(string $address): string
    {
        return hash('sha256', mb_strtolower(trim($address)));
    }

    public static function add(string $address, string $reason): void
    {
        DB::table('suppressions')->upsert(
            [['address_hash' => self::key($address), 'reason' => $reason, 'created_at' => now()]],
            ['address_hash'],
            ['reason'],
        );
    }

    public static function blocks(string $address): bool
    {
        return DB::table('suppressions')->where('address_hash', self::key($address))->exists();
    }
}