SMS and WhatsApp driver abstraction

<?php

namespace App\Messaging;

use Closure;
use Illuminate\Support\Facades\Log;
use InvalidArgumentException;

final readonly class OutboundMessage
{
    public function __construct(public string $to, public string $body, public ?string $template = null) {}
}

interface Driver
{
    /** Returns the provider's message id. */
    public function send(OutboundMessage $message): string;
}

final class LogDriver implements Driver
{
    public function send(OutboundMessage $message): string
    {
        Log::info('message.sent', ['to' => substr($message->to, 0, 4).'***']);

        return 'log-'.uniqid();
    }
}

final class Messenger
{
    /** @var array<string, Closure(): Driver> */
    private array $factories = [];

    /** @var array<string, Driver> */
    private array $resolved = [];

    public function register(string $channel, Closure $factory): void
    {
        $this->factories[$channel] = $factory;
        unset($this->resolved[$channel]);
    }

    public function via(string $channel): object
    {
        $driver = $this->resolved[$channel] ??= ($this->factories[$channel] ?? throw new InvalidArgumentException("Unknown channel {$channel}"))();

        // Small wrapper that normalises the number before any driver sees it.
        return new class($driver) {
            public function __construct(private Driver $driver) {}

            public function send(OutboundMessage $message): string
            {
                $digits = preg_replace('/\D+/', '', $message->to);

                return $this->driver->send(new OutboundMessage('+'.$digits, $message->body, $message->template));
            }
        };
    }
}

<?php

namespace App\Messaging;

use Illuminate\Support\Facades\Http;

/** Bearer-token JSON provider for plain SMS. */
final class SmsDriver implements Driver
{
    public function __construct(private array $cfg) {}

    public function send(OutboundMessage $message): string
    {
        return Http::withToken($this->cfg['token'])->baseUrl($this->cfg['url'])
            ->post('/messages', ['from' => $this->cfg['sender'], 'to' => $message->to, 'text' => $message->body])
            ->throw()->json('id');
    }
}

/** WhatsApp needs an approved template outside the 24 hour customer window. */
final class WhatsappDriver implements Driver
{
    public function __construct(private array $cfg) {}

    public function send(OutboundMessage $message): string
    {
        $payload = $message->template
            ? ['type' => 'template', 'template' => ['name' => $message->template, 'params' => [$message->body]]]
            : ['type' => 'text', 'text' => ['body' => $message->body]];

        return Http::withToken($this->cfg['token'])->baseUrl($this->cfg['url'])
            ->post("/{$this->cfg['phone_id']}/messages", ['to' => ltrim($message->to, '+')] + $payload)
            ->throw()->json('messages.0.id');
    }
}