<?php
/**
 * WamyClient — drop this one file into any of our PHP apps.
 *
 *   $wamy = new WamyClient('https://wamy.example.com', getenv('WAMY_KEY'));
 *   $url = $wamy->linkUrl($user->id, $user->email, $user->name);   // "Get alerts on Wamy" button
 *   $wamy->send(['external_id' => $user->id], ['ar' => 'تم تأكيد طلبك', 'en' => 'Your order is confirmed'], ['ref' => 'order-123']);
 *
 * Every method throws WamyError on failure, so a Wamy problem never breaks the caller silently.
 */
final class WamyError extends RuntimeException
{
    public function __construct(public readonly string $codeName, public readonly int $status, string $message = '')
    {
        parent::__construct($message !== '' ? $message : $codeName, $status);
    }
}

final class WamyClient
{
    public function __construct(private string $baseUrl, private string $apiKey, private int $timeout = 10)
    {
        $this->baseUrl = rtrim($baseUrl, '/');
    }

    /** One-time sign-in link for your user (open it from a button in your app). */
    /** $sender: open that sender's chat (see send). $days: 1-60 for a printed invitation; default is the short link setting. */
    public function linkUrl(string $externalId, ?string $email = null, ?string $name = null, ?array $sender = null, ?int $days = null): string
    {
        return $this->call('POST', 'link.php', array_filter(['external_id' => $externalId, 'email' => $email, 'name' => $name, 'sender' => $sender, 'days' => $days], fn($v) => $v !== null))['url'];
    }

    /**
     * @param array $to   ['external_id' => '42'] or ['email' => 'a@b.com'] (or both: links them)
     * @param string|array $text  "…" or ['ar' => '…', 'en' => '…']
     * @param array $opts title, image_url, buttons, ref (same ref = same message, safe to retry), email_fallback,
     *                    sender ['id' => 'school-12', 'name' => …, 'logo_url' => …] to send as one of your senders (its own chat)
     * @return array id, status, pushed_devices, emailed, …
     */
    public function send(array $to, string|array $text, array $opts = []): array
    {
        return $this->call('POST', 'send.php', ['to' => $to, 'text' => $text] + $opts);
    }

    /**
     * A file to attach: $wamy->send($to, 'Your invoice', ['file' => WamyClient::file('/path/invoice.pdf')]).
     * Photos (jpg, png, webp) and documents (pdf, doc(x), xls(x), ppt(x), txt, csv), 10 MB at most.
     */
    public static function file(string $path, ?string $name = null): array
    {
        $data = @file_get_contents($path);
        if ($data === false) throw new WamyError('file_unreadable', 0, "Cannot read $path");
        return ['name' => $name ?? basename($path), 'data' => base64_encode($data)];
    }

    /** status of a message you sent: sent | delivered | read */
    public function status(int|string $idOrRef): array
    {
        $q = is_int($idOrRef) ? 'id=' . $idOrRef : 'ref=' . rawurlencode($idOrRef);
        return $this->call('GET', 'message.php?' . $q);
    }

    /** linked, notifications (devices), blocked, muted, last_seen_at — decide the channel before sending */
    public function user(string $externalId, ?string $senderId = null): array
    {
        return $this->call('GET', 'user.php?external_id=' . rawurlencode($externalId) . ($senderId !== null ? '&sender_id=' . rawurlencode($senderId) : ''));
    }

    /**
     * Put a person on the team that answers in Wamy's reply inbox (staff, a teacher…), or take them off ($active = false).
     * $sender: answer for that sender's chat. $title: shown on their replies. $people: only these external_ids (null = everyone).
     * $guestsOnly: only visitors who are not your users yet (your own users you answer yourself, e.g. through the webhook).
     */
    public function agent(string $externalId, ?array $sender = null, ?string $title = null, ?array $people = null, bool $active = true, ?string $name = null, bool $guestsOnly = false): array
    {
        return $this->call('POST', 'agent.php', array_filter(['external_id' => $externalId, 'sender' => $sender, 'title' => $title, 'people' => $people, 'name' => $name, 'scope' => $guestsOnly ? 'guests' : null], fn($v) => $v !== null) + ['active' => $active]);
    }

    /** The contact link of your app or of one sender (like a WhatsApp number): ['url' => …, 'open' => bool]. */
    public function contact(?array $sender = null): array
    {
        return $this->call('POST', 'contact.php', $sender !== null ? ['sender' => $sender] : []);
    }

    /** you read the user's reply: their ticks turn blue */
    public function markRead(int $replyId): void
    {
        $this->call('POST', 'read.php', ['id' => $replyId]);
    }

    /** Check a webhook call came from Wamy. Pass the raw body and the request headers. */
    public static function verifyWebhook(string $rawBody, string $timestamp, string $signature, string $secret, int $tolerance = 300): bool
    {
        if (!ctype_digit($timestamp) || abs(time() - (int) $timestamp) > $tolerance) return false;
        return hash_equals('sha256=' . hash_hmac('sha256', $timestamp . '.' . $rawBody, $secret), $signature);
    }

    private function call(string $method, string $path, ?array $body = null): array
    {
        $ch = curl_init($this->baseUrl . '/api/v1/' . $path);
        $headers = ['Authorization: Bearer ' . $this->apiKey, 'Accept: application/json'];
        if ($body !== null) {
            $headers[] = 'Content-Type: application/json';
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
        }
        curl_setopt_array($ch, [CURLOPT_CUSTOMREQUEST => $method, CURLOPT_HTTPHEADER => $headers, CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => $this->timeout, CURLOPT_CONNECTTIMEOUT => 5]);
        $raw = curl_exec($ch);
        $status = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $err = curl_error($ch);
        curl_close($ch);
        if ($raw === false) throw new WamyError('network', 0, $err);
        $data = json_decode((string) $raw, true);
        if ($status >= 400 || !is_array($data)) throw new WamyError((string) ($data['error'] ?? 'http_' . $status), $status, (string) ($data['message'] ?? ''));
        return $data;
    }
}