<?php
// webhook.php
$verifyToken = "YOUR_VERIFY_TOKEN"; // Replace with your verify token

$hubChallenge = isset($_GET['hub_challenge']) ? $_GET['hub_challenge'] : null;
$hubMode = isset($_GET['hub_mode']) ? $_GET['hub_mode'] : null;
$hubVerifyToken = isset($_GET['hub_verify_token']) ? $_GET['hub_verify_token'] : null;

if ($hubMode === 'subscribe' && $hubVerifyToken === $verifyToken) {
    echo $hubChallenge; // Respond with challenge to verify webhook
} else {
    http_response_code(403);
    echo "Verification failed.";
}
exit();
?>

<?php
// index.php
ini_set('display_errors', 1);
error_reporting(E_ALL);

// Log file path
$logFilePath = 'logs/webhook.log';
date_default_timezone_set('Africa/Nairobi');

// Decode incoming JSON from WhatsApp webhook
$data = json_decode(file_get_contents('php://input'), true);

if ($data['object'] == 'whatsapp_business_account' && isset($data['entry'][0]['changes'][0]['value']['messages'])) {
    $entry = $data['entry'][0];
    $from = $entry['changes'][0]['value']['messages'][0]['from'];
    $senderName = $entry['changes'][0]['value']['contacts'][0]['profile']['name'];
    $type = $entry['changes'][0]['value']['messages'][0]['type'];

    // Extract message text
    if ($type == 'text') {
        $text = $entry['changes'][0]['value']['messages'][0]['text']['body'];
    } elseif ($type == 'interactive') {
        $interactive = $entry['changes'][0]['value']['messages'][0]['interactive'];
        $interactive_type = $interactive['type'];
        $text = ($interactive_type == 'button_reply') ? $interactive['button_reply']['title'] : $interactive['list_reply']['title'];
    } else {
        $text = "Hello"; // Fallback for unsupported message types
    }

    // Process the message with ChatGPT
    getChatGPTResponse($text, $from);
}

// Fetch response from ChatGPT
function getChatGPTResponse($inputText, $from) {
    global $logFilePath;
    logMessage("GPT |: ", $inputText, $from);

    // Load conversation context
    $conversationContext = loadConversationContext($from);
    $conversationContext[] = ['role' => 'user', 'content' => $inputText];

    // ChatGPT API request
    $data = [
        'messages' => $conversationContext,
        'model' => 'gpt-4-turbo', // Replace with your model
        'temperature' => 0.7,
        'max_tokens' => 150
    ];

    $headers = [
        'Content-Type: application/json',
        'Authorization: Bearer YOUR_OPENAI_API_KEY'
    ];

    $ch = curl_init("https://api.openai.com/v1/chat/completions");
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

    $response = curl_exec($ch);
    curl_close($ch);

    $responseArr = json_decode($response, true);
    $reply = $responseArr['choices'][0]['message']['content'];

    // Save updated context
    $conversationContext[] = ['role' => 'system', 'content' => $reply];
    saveConversationContext($from, $conversationContext);

    // Send response to WhatsApp
    sendWhatsAppMessage($from, $reply);
    logMessage("OUT |: ", $reply, $from);
}

// Load conversation context
function loadConversationContext($userId) {
    $filePath = "conversations/$userId.json";
    if (file_exists($filePath)) {
        return json_decode(file_get_contents($filePath), true);
    }
    return [];
}

// Save conversation context
function saveConversationContext($userId, $context) {
    $filePath = "conversations/$userId.json";
    if (!file_exists(dirname($filePath))) {
        mkdir(dirname($filePath), 0755, true);
    }
    file_put_contents($filePath, json_encode($context));
}

// Send WhatsApp message
function sendWhatsAppMessage($recipientNumber, $message) {
    $accessToken = 'YOUR_META_ACCESS_TOKEN';
    $url = 'https://graph.facebook.com/v20.0/YOUR_PHONE_NUMBER_ID/messages';

    $_message = "*Ubuni AI*\n\n" . $message;
    $data = [
        'messaging_product' => 'whatsapp',
        'to' => $recipientNumber,
        'type' => 'text',
        'text' => ['body' => $_message]
    ];

    $headers = [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $accessToken
    ];

    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    $response = curl_exec($ch);
    curl_close($ch);

    $responseData = json_decode($response, true);
    if (isset($responseData['messages'][0]['message_status'])) {
        echo 'Message Status: ' . $responseData['messages'][0]['message_status'];
    } else {
        echo 'Unable to retrieve message status.';
    }
}

// Log messages
function logMessage($type, $message, $phone_number) {
    global $logFilePath;
    $logMessage = date('Y-m-d H:i:s') . ' | ' . $type . ' | ' . $phone_number . ' | ' . $message . PHP_EOL;
    file_put_contents($logFilePath, $logMessage, FILE_APPEND);
}
?>