<?php
// PHP 8.1+ with HTTPS stream support. No Composer packages.
// Sending is disabled at this docs release; production activation is separate.
// Persist this idempotency key with the application event before sending.
// Reuse key + unchanged payload after an uncertain HTTP result. Save the
// returned id on the same event. Never resend an ambiguous message blindly.
declare(strict_types=1);

$apiKey = getenv('MAILCORE_API_KEY') ?: '';
$key = getenv('MAILCORE_IDEMPOTENCY_KEY') ?: '';
if ($apiKey === '' || preg_match('/[\r\n]/', $apiKey)) {
    fwrite(STDERR, "Set MAILCORE_API_KEY on your server\n");
    exit(1);
}
if (!preg_match('/^[A-Za-z0-9._:-]{16,128}$/D', $key)) {
    fwrite(STDERR, "Set the idempotency key saved with this application event\n");
    exit(1);
}
$payload = [
    'from' => getenv('MAILCORE_FROM') ?: 'Example Shop <orders@notify.example>',
    'to' => getenv('MAILCORE_TO') ?: 'customer@recipient.example',
    'subject' => 'Order #8421 completed',
    'text' => 'Your order has been completed.',
    'tags' => ['order_id' => '8421'],
];
if (str_contains($payload['from'], '.example') || str_ends_with($payload['to'], '.example')) {
    fwrite(STDERR, "Set MAILCORE_FROM to your approved sender and MAILCORE_TO to the recipient\n");
    exit(1);
}
$context = stream_context_create(['http' => [
    'method' => 'POST',
    'header' => "Authorization: Bearer {$apiKey}\r\nIdempotency-Key: {$key}\r\nContent-Type: application/json\r\n",
    'content' => json_encode($payload, JSON_THROW_ON_ERROR),
    'timeout' => 30,
    'ignore_errors' => true,
    'follow_location' => 0, // Do not forward the Bearer key on redirects.
], 'ssl' => ['verify_peer' => true, 'verify_peer_name' => true]]);
$result = @file_get_contents('https://mailcore.uz/api/email/v1/emails', false, $context, 0, 1048577);
if ($result === false) {
    fwrite(STDERR, "No usable HTTP result. Reconcile with the saved event key and unchanged payload.\n");
    exit(1);
}
$status = 0;
foreach ($http_response_header ?? [] as $header) {
    if (preg_match('/^HTTP\/\S+ (\d{3})/', $header, $match)) $status = (int) $match[1];
}
try {
    $document = json_decode($result, true, 512, JSON_THROW_ON_ERROR);
    if (!is_array($document)) throw new RuntimeException('Unexpected response');
    if ($status !== 202) {
        fwrite(STDERR, json_encode(['httpStatus' => $status] + $document, JSON_THROW_ON_ERROR) . "\n");
        exit(1);
    }
    echo json_encode($document, JSON_THROW_ON_ERROR) . "\n";
} catch (Throwable $error) {
    fwrite(STDERR, "No usable JSON result. Reconcile with the saved event key and unchanged payload.\n");
    exit(1);
}