<?php

/**
 * POASMS PHP client — single file, no dependencies (needs ext-curl + ext-json).
 * Works in plain PHP, Laravel, WHMCS hooks/modules.
 *
 *   require_once 'PoaSms.php';
 *   $sms = new PoaSms(getenv('POASMS_API_KEY'));
 *   $res = $sms->send('0712345678', 'Habari! Malipo yamepokelewa.');
 *   if ($res['ok']) { ... $res['data']['messages'][0]['id'] ... } else { error_log($res['error']); }
 *
 * Methods never throw on API/network errors; they return
 *   ['ok' => bool, 'status' => int, 'data' => array|null, 'error' => ?string, 'code' => ?string]
 */
class PoaSms
{
    private string $apiKey;

    private string $baseUrl;

    private int $timeout;

    public function __construct(string $apiKey, string $baseUrl = 'https://poasms.com/api/v1', int $timeout = 20)
    {
        $this->apiKey = $apiKey;
        $this->baseUrl = rtrim($baseUrl, '/');
        $this->timeout = $timeout;
    }

    /**
     * @param  string|string[]  $to
     * @param  array  $options  from, type (transactional|promotional|otp), reference, schedule_at, app
     */
    public function send($to, string $message, array $options = []): array
    {
        return $this->request('POST', '/sms/send', array_merge(['to' => $to, 'message' => $message], $options));
    }

    public function otp(string $to, string $message, ?string $reference = null): array
    {
        return $this->send($to, $message, array_filter(['type' => 'otp', 'reference' => $reference]));
    }

    public function status(string $messageId): array
    {
        return $this->request('GET', '/sms/'.rawurlencode($messageId));
    }

    public function messages(array $filters = []): array
    {
        return $this->request('GET', '/sms', $filters);
    }

    public function balance(): array
    {
        return $this->request('GET', '/balance');
    }

    /** @param string $groupBy app|day|month|status|network|type|sender */
    public function usage(?string $from = null, ?string $to = null, string $groupBy = 'app'): array
    {
        return $this->request('GET', '/usage', array_filter(['from' => $from, 'to' => $to, 'group_by' => $groupBy]));
    }

    // --- WhatsApp -------------------------------------------------------------

    /**
     * Send an approved WhatsApp template.
     *
     * @param  string|string[]  $to
     * @param  string[]  $params  values for {{1}}, {{2}}…
     * @param  array  $options  header (type,url|id,filename), buttons, reference, app, schedule_at, language
     */
    public function whatsapp($to, string $template, array $params = [], array $options = []): array
    {
        return $this->request('POST', '/whatsapp/send', array_merge(['to' => $to, 'template' => $template, 'params' => $params], $options));
    }

    /** Free-text WhatsApp reply — only within 24h of the customer's last message. */
    public function whatsappReply(string $to, string $message, ?string $reference = null): array
    {
        return $this->request('POST', '/whatsapp/send', array_filter(['to' => $to, 'message' => $message, 'reference' => $reference]));
    }

    public function whatsappTemplates(): array
    {
        return $this->request('GET', '/whatsapp/templates');
    }

    public function createWhatsappTemplate(array $template): array
    {
        return $this->request('POST', '/whatsapp/templates', $template);
    }

    public function whatsappInbox(array $filters = []): array
    {
        return $this->request('GET', '/whatsapp/inbox', $filters);
    }

    public function senderIds(): array
    {
        return $this->request('GET', '/sender-ids');
    }

    /** One sender ID's approval status: pending | approved | rejected. */
    public function senderId(string $name): array
    {
        return $this->request('GET', '/sender-ids/'.rawurlencode($name));
    }

    /**
     * Request a sender ID. $options: use_case, reference, document (path to a PDF/JPG/PNG ≤ 5 MB).
     * A name already requested returns ok=false with code 'sender_exists'.
     */
    public function requestSenderId(string $name, string $sampleMessage, array $options = []): array
    {
        $data = array_filter([
            'name' => $name,
            'sample_message' => $sampleMessage,
            'use_case' => $options['use_case'] ?? 'transactional',
            'reference' => $options['reference'] ?? null,
        ], fn ($v) => $v !== null);
        $doc = $options['document'] ?? null;
        if ($doc && is_readable($doc)) {
            $data['document'] = new CURLFile($doc);
        }

        return $this->request('POST', '/sender-ids', $data);
    }

    public function addContact(string $phone, ?string $name = null, array $groups = []): array
    {
        return $this->request('POST', '/contacts', array_filter(['phone' => $phone, 'name' => $name, 'groups' => $groups]));
    }

    public function optOut(string $phone): array
    {
        return $this->request('POST', '/opt-outs', ['phone' => $phone]);
    }

    /** Verify a webhook from POASMS. Pass the raw request body and the X-PoaSMS-Signature header. */
    public static function verifyWebhook(string $rawBody, ?string $signatureHeader, string $secret): bool
    {
        if (! $signatureHeader) {
            return false;
        }

        return hash_equals('sha256='.hash_hmac('sha256', $rawBody, $secret), $signatureHeader);
    }

    private function request(string $method, string $path, array $data = []): array
    {
        $url = $this->baseUrl.$path;
        if ($method === 'GET' && $data) {
            $url .= '?'.http_build_query($data);
        }
        $ch = curl_init($url);
        $headers = ['Authorization: Bearer '.$this->apiKey, 'Accept: application/json', 'User-Agent: poasms-php/1.0'];
        $multipart = (bool) array_filter($data, fn ($v) => $v instanceof CURLFile);
        if ($method !== 'GET' && $multipart) {
            curl_setopt($ch, CURLOPT_POSTFIELDS, $data);   // curl sets multipart/form-data
        } elseif ($method !== 'GET') {
            $headers[] = 'Content-Type: application/json';
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
        }
        curl_setopt_array($ch, [
            CURLOPT_CUSTOMREQUEST => $method,
            CURLOPT_HTTPHEADER => $headers,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_CONNECTTIMEOUT => 8,
        ]);
        $raw = curl_exec($ch);
        $status = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $err = curl_error($ch);
        if (PHP_VERSION_ID < 80000) {
            curl_close($ch);
        }

        if ($raw === false || $status === 0) {
            return ['ok' => false, 'status' => 0, 'data' => null, 'error' => 'Network error: '.$err, 'code' => 'network_error'];
        }
        $json = json_decode((string) $raw, true);
        $ok = $status >= 200 && $status < 300;

        return [
            'ok' => $ok,
            'status' => $status,
            'data' => $ok ? ($json['data'] ?? $json) : null,
            'error' => $ok ? null : ($json['error']['message'] ?? $json['message'] ?? "HTTP $status"),
            'code' => $ok ? null : ($json['error']['code'] ?? null),
        ];
    }
}