<?php
/**
 * ==============================================================================
 * SAQEL ENTERPRISE (EDTECH 2.0) - NABEH WHATSAPP & GUARDIAN NOTIFICATION SERVICE
 * ==============================================================================
 * 
 * ملف: NabehService.php
 * الهدف المعماري:
 * بوابة التكامل الرسمية مع خدمة نبّه (Nabeh Gateway) لإرسال رسائل وإشعارات الواتساب:
 * 1. إرسال بطاقات رموز التحقق الفاخرة (Luxury Image OTP Cards) أو الرسائل النصية المباشرة.
 * 2. إرسال الإشعارات التوجيهية الهادئة لأولياء الأمور (Guardian Remedial Alerts) عند تعثر الطالب
 *    في أي مفهوم دراسي أو فحص سقراطي لمتابعة رحلة تعليمه دون قلق.
 * 3. إدارة الجلسات والمصادقة المؤقتة مع Nabeh API والتخزين المؤقت للتوكن في Redis لمدة 24 ساعة.
 */

namespace App\Services;

use App\Core\RedisClient;

class NabehService
{
    private string $authUrl;
    private string $sendUrl;
    private string $email;
    private string $password;
    private string $defaultType;

    public function __construct()
    {
        $this->authUrl     = (string)getenv('NABEH_AUTH_URL');
        $this->sendUrl     = (string)getenv('NABEH_SEND_URL');
        $this->email       = (string)getenv('NABEH_EMAIL');
        $this->password    = (string)getenv('NABEH_PASSWORD');
        $this->defaultType = (string)(getenv('NABEH_OTP_TYPE') ?: 'image'); // Default: Luxury Image Card

        $missing = [];
        if (empty($this->authUrl))  $missing[] = 'NABEH_AUTH_URL';
        if (empty($this->sendUrl))  $missing[] = 'NABEH_SEND_URL';
        if (empty($this->email))    $missing[] = 'NABEH_EMAIL';
        if (empty($this->password)) $missing[] = 'NABEH_PASSWORD';

        if (!empty($missing)) {
            throw new \RuntimeException("Nabeh Service configuration error: Missing environment variable(s): " . implode(', ', $missing));
        }
    }

    /**
     * Retrieve Nabeh JWT Bearer Token, caching it in Redis for 24 hours.
     */
    public function getBearerToken(): ?string
    {
        // 1. Try fetching from Redis first
        try {
            $redis = RedisClient::getInstance();
            $cachedToken = $redis->get('nabeh_bearer_token');
            if ($cachedToken && strlen((string)$cachedToken) > 20) {
                return (string)$cachedToken;
            }
        } catch (\Exception $e) {
            error_log("⚠️ [Nabeh Auth Redis] Error reading token: " . $e->getMessage());
        }

        // 2. Token not cached, authenticate via Nabeh Login API
        $payload = json_encode([
            'email'    => $this->email,
            'password' => $this->password,
        ]);

        $ch = curl_init($this->authUrl);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 30,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json'],
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
        ]);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);

        if ($curlError) {
            error_log("❌ [Nabeh Auth cURL Error] " . $curlError);
            return null;
        }

        if ($httpCode === 200 && $response) {
            $decoded = json_decode($response, true);
            $token = $decoded['token'] ?? $decoded['message']['token'] ?? $decoded['jwt'] ?? $decoded['access_token'] ?? null;

            if ($token) {
                // Cache token in Redis for 24h (86400 seconds)
                try {
                    $redis = RedisClient::getInstance();
                    $redis->setex('nabeh_bearer_token', 86400, (string)$token);
                    error_log("✅ [Nabeh Auth] Token cached in Redis successfully.");
                } catch (\Exception $e) {
                    error_log("⚠️ [Nabeh Auth Redis Cache Save] Error saving token: " . $e->getMessage());
                }
                return (string)$token;
            }
        }

        error_log("❌ [Nabeh Auth Login Failed] Code: {$httpCode} | Response: {$response}");
        return null;
    }

    /**
     * Send OTP via Nabeh JWT Auth Gateway (WhatsApp image/text OTP)
     */
    public function sendOtp(string $receiver, string $otp, ?string $method = null, string $appName = 'منصة صَقِل'): array
    {
        $bearerToken = $this->getBearerToken();
        if (!$bearerToken) {
            return [
                'success' => false,
                'error'   => 'فشل الحصول على توكن المصادقة من منصة نبيه. تأكد من صحة NABEH_EMAIL و NABEH_PASSWORD في .env.'
            ];
        }

        // Clean phone format: ensure Jordan numbers are standardized (9627XXXXXXXX)
        $phoneRaw = preg_replace('/\D+/', '', $receiver);
        if (str_starts_with($phoneRaw, '07')) {
            $phoneRaw = '962' . substr($phoneRaw, 1);
        } elseif (str_starts_with($phoneRaw, '7') && strlen($phoneRaw) === 9) {
            $phoneRaw = '962' . $phoneRaw;
        }

        $selectedType = $method ?: $this->defaultType;
        if (!in_array($selectedType, ['text', 'voice', 'image'], true)) {
            $selectedType = 'image';
        }

        // 1. Attempt with selected type (image card)
        $result = $this->attemptSend($phoneRaw, $selectedType, $otp, $appName, $bearerToken);
        if ($result['success']) {
            return $result;
        }

        // 2. If image failed, fallback to text mode
        if ($selectedType === 'image') {
            error_log("ℹ️ [Nabeh OTP Fallback] Image card attempt failed for {$phoneRaw}. Retrying with text mode...");
            $textResult = $this->attemptSend($phoneRaw, 'text', $otp, $appName, $bearerToken);
            if ($textResult['success']) {
                $textResult['note'] = 'Delivered via text fallback';
                return $textResult;
            }
            return $textResult;
        }

        return $result;
    }

    private function attemptSend(string $phone, string $type, string $otp, string $appName, string $bearerToken): array
    {
        $payload = json_encode([
            'phone'   => $phone,
            'type'    => $type,
            'code'    => $otp,
            'message' => "رمز التحقق الخاص بك لمنصة {$appName} هو: *{$otp}* \n الرجاء عدم مشاركته مع أي شخص لحماية حسابك.",
        ]);

        $timeout = ($type === 'image') ? 45 : 20;

        $ch = curl_init($this->sendUrl);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => $timeout,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
            CURLOPT_HTTPHEADER     => [
                'Content-Type: application/json',
                "Authorization: Bearer {$bearerToken}",
            ],
        ]);

        $startTime = microtime(true);
        $response = curl_exec($ch);
        $duration = round(microtime(true) - $startTime, 2);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);

        if ($curlError) {
            error_log("❌ [Nabeh OTP cURL Error (type={$type}, duration={$duration}s)] " . $curlError);
            return [
                'success'   => false,
                'type_used' => $type,
                'duration'  => "{$duration}s",
                'http_code' => $httpCode,
                'error'     => 'cURL Error: ' . $curlError,
                'response'  => null
            ];
        }

        error_log("ℹ️ [Nabeh OTP Response (type={$type}, duration={$duration}s, HTTP {$httpCode})] " . $response);

        if ($httpCode === 200 && $response) {
            $decoded = json_decode($response, true);
            if ($decoded) {
                $statusStr = strtolower((string)($decoded['status'] ?? ''));
                $msgStr    = strtolower((string)($decoded['message'] ?? ''));
                $errStr    = strtolower((string)($decoded['error'] ?? ''));

                if (
                    !empty($decoded['success']) ||
                    in_array($statusStr, ['success', 'ok', 'true', '200', 'sent', 'queued', '1'], true) ||
                    ($decoded['status'] ?? false) === true ||
                    ($decoded['code'] ?? 0) === 200 ||
                    !empty($decoded['message_id']) ||
                    !empty($decoded['id']) ||
                    !empty($decoded['token']) ||
                    str_contains($msgStr, 'success') ||
                    str_contains($msgStr, 'sent') ||
                    str_contains($msgStr, 'تم') ||
                    str_contains($errStr, 'via gateway')
                ) {
                    return [
                        'success'   => true,
                        'type_used' => $type,
                        'duration'  => "{$duration}s",
                        'http_code' => 200,
                        'message'   => 'تم إرسال رمز التحقق بنجاح عبر الواتساب',
                        'raw'       => $decoded
                    ];
                }
            }
        }

        return [
            'success'   => false,
            'type_used' => $type,
            'duration'  => "{$duration}s",
            'http_code' => $httpCode,
            'error'     => 'Nabeh Gateway rejected request (HTTP ' . $httpCode . ')',
            'response'  => $response
        ];
    }

    /**
     * Send direct WhatsApp text notification via Nabeh Gateway
     */
    public function sendMessage(string $receiver, string $message): array
    {
        $bearerToken = $this->getBearerToken();
        if (!$bearerToken) {
            return [
                'success' => false,
                'error'   => 'فشل الحصول على توكن المصادقة من منصة نبيه.'
            ];
        }

        $phoneRaw = preg_replace('/\D+/', '', $receiver);
        if (str_starts_with($phoneRaw, '07')) {
            $phoneRaw = '962' . substr($phoneRaw, 1);
        } elseif (str_starts_with($phoneRaw, '7') && strlen($phoneRaw) === 9) {
            $phoneRaw = '962' . $phoneRaw;
        }

        $payload = json_encode([
            'phone'   => $phoneRaw,
            'type'    => 'text',
            'message' => $message,
        ]);

        $ch = curl_init($this->sendUrl);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 25,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
            CURLOPT_HTTPHEADER     => [
                'Content-Type: application/json',
                "Authorization: Bearer {$bearerToken}",
            ],
        ]);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);

        if ($curlError) {
            return ['success' => false, 'error' => $curlError];
        }

        return ['success' => $httpCode === 200, 'response' => $response];
    }

    /**
     * Send Guardian Remedial Alert via WhatsApp
     */
    public function sendGuardianRemedialAlert(
        string $guardianPhone,
        string $studentName,
        string $subjectName,
        string $weakTopic,
        string $portalUrl = 'https://saqel.intaleqapp.com/guardian'
    ): array {
        $message = "🔔 *تنبيه متابعة دراسية من منصة صَقِل* 🧠\n\n"
                 . "ولي أمر الطالب/ـة: *{$studentName}* المحترم،\n"
                 . "نحيطكم علماً بأنه أثناء فحص الاستيعاب السقراطي في مادة *{$subjectName}*، تم رصد تعثر في مفهوم:\n"
                 . "📌 *[{$weakTopic}]*\n\n"
                 . "✅ *الإجراء المتخذ من المنصة:* تم إرجاع الطالب تلقائياً لمشاهدة المقطع الشارح للمفهوم بدقة لترسيخ الفهم.\n\n"
                 . "📊 يمكنكم متابعة جاهزية الطالب والتقرير التشخيصي المفصل عبر بوابة ولي الأمر:\n"
                 . "{$portalUrl}\n\n"
                 . "مع تحيات فريق الدعم الأكاديمي لمنصة صَقِل ✨";

        return $this->sendMessage($guardianPhone, $message);
    }
}