<?php

namespace App\SendingServers\Identities;

/**
 * Lifecycle discriminator on `sending_identities` rows.
 *
 * Determined automatically (never user-chosen) by:
 *   - server null              → LOCAL_DKIM
 *   - server's driver implements SupportsIdentitySync → VENDOR_SYNC
 *   - otherwise                → MANUAL
 *
 * Constraints (validated in SendingIdentity::booted):
 *   LOCAL_DKIM   : sending_server_id NULL,    customer_id NOT NULL, dkim_* populated, kind=domain
 *   VENDOR_SYNC  : sending_server_id NOT NULL,                       dkim_* NULL,     last_synced_at NOT NULL
 *   MANUAL       : sending_server_id NOT NULL,                       dkim_* NULL,     last_synced_at NULL
 */
enum ManagementMode: string
{
    case LOCAL_DKIM  = 'local_dkim';
    case VENDOR_SYNC = 'vendor_sync';
    case MANUAL      = 'manual';
}