ajax_handler.php

<?php
// Include required files and establish the database connection
require_once 'lib.required.php';
require_once 'db.php';

#define('HARDCODED_DEPLOYMENT','azure-gpt35');
define('HARDCODED_DEPLOYMENT','azure-gpt3-16k');

$user = $_SESSION['user_data']['userid'] ?? null; // Assuming you have a session variable for username

// Check if the request method is POST
if ($_SERVER['REQUEST_METHOD'] === 'POST') {

    // Get the user's message from the POST data
    $user_message = base64_decode($_POST['message']); // Decode from Base64
    //$user_message = filter_input(INPUT_POST, 'message', FILTER_SANITIZE_STRING);

    $deployment = isset($_POST['deployment']) ? $_POST['deployment'] : 'default_deployment'; // Provide a default if needed


    // Retrieve the chat ID from the POST data
    $chat_id = filter_input(INPUT_POST, 'chat_id', FILTER_SANITIZE_STRING);

    // Initialize variables for new chat creation
    $new_chat_id = '';
    $document_name = $_SESSION['document_name'] ?? ''; // Use null coalescing operator for default values
    $document_text = $_SESSION['document_text'] ?? '';

    // Create a new chat session if no chat ID is provided
    if (empty($chat_id)) {
        $need_title = true;

        // The $new_chat_id will tell Javascript to reload the page to show the new title. 
        $id = $new_chat_id = create_chat($user, 'New auto-generated Chat', '', $_SESSION['deployment'], $document_name, $document_text);
    } else {
        $need_title = (get_new_title_status($user, $chat_id)) ? true : false;
  
        $id = $chat_id;
    }

    /*
    echo "THIS IS THE deployment: " . $deployment . "\n";
    echo "THIS IS THE config: " . print_r($config,1) . "\n";
    echo "THIS IS THE session: " . print_r($_SESSION,1) . "\n";
    echo "THIS IS THE AJAX HANDLER CHAT ID: " . $chat_id . "\n";
    echo "THIS IS THE AJAX HANDLER NEW CHAT ID: " . $new_chat_id . "\n";
    */

    // Get the GPT response to the user's message using the get_gpt_response() function
    $gpt_response = get_gpt_response($user_message, $id, $user, $deployment);
    #echo "THIS IS THE GPT Response: <pre>" . print_r($gpt_response,1)."</pre>"; die();

    if (!empty($gpt_response['error']) && $gpt_response['error'] == 1) {
        $gpt_response['message'] = preg_replace('/Please go here.*/','',$gpt_response['message']);
    }

    // Generate a concise chat title if a new chat was created and there were no errors in the GPT response
    if ($need_title && empty($gpt_response['error'])) {
        $chat_title = generate_chat_title($user_message, $gpt_response['message'], HARDCODED_DEPLOYMENT);
        
        // Update the chat title in the database if the title was successfully generated
        if ($chat_title !== null) {
            $chat_title = substringWords($chat_title,6); 
            update_chat_title($user, $id, $chat_title);
        }
    }

    // Prepare the response data to send back to the client
    $response = [
        'eid' => $gpt_response['eid'] ?? null,
        'deployment' => $deployment ?? null, 
        'error' => $gpt_response['error'] ?? null,
        'gpt_response' => $gpt_response['message'] ?? null,
        'chat_id' => $chat_id,
        'new_chat_id' => $new_chat_id,
        'image_gen_name' => $gpt_response['image_gen_name'] ?? null // Include image filename
    ];

    #echo "THIS IS THE GPT Response: " . print_r($response,1); die();

    // Send the JSON-encoded response and exit the script
    echo json_encode($response);
    exit();
}

/**
 * Generates a concise chat title using the Azure API.
 *
 * @param string $user_message The user's initial message in the chat.
 * @param string $gpt_response The GPT's response to the user's message.
 * @param array $active_config The active configuration settings for the API call.
 * @return string|null The generated chat title or null if an error occurs.
 */
function generate_chat_title($user_message, $gpt_response, $config_key) {
    // Prepare the message for generating a chat title
    $msg = [
        ["role" => "system", "content" => "You are an AI assistant that creates concise, friently, title summaries for chats. Use no more than 5 words. Never include code or punctuation. Never include mathematical notation. Only use words and if needed, numbers."],
        ["role" => "user", "content" =>  substringWords($user_message,300)],
        ["role" => "assistant", "content" => substringWords($gpt_response,300)],
        ["role" => "user", "content" => "Pleae create a concise, friently, title, summarizing this chat. Use no more than 5 words. Never include code or punctuation. Never include mathematical notation. Only use words and if needed, numbers."],
    ];
    $active_config = load_configuration($config_key);
    #die(print_r($msg,1));

    // Call Azure API to generate the chat title
    $title_response = call_azure_api($active_config, $msg);
    $title_response_data = json_decode($title_response, true);
    #die(print_r($title_response_data,1));

    // Check if the title generation was successful and return the generated title
    if (empty($title_response_data['error'])) {
        return substr($title_response_data['choices'][0]['message']['content'],0,254);
    } else {
        // Log the error and return null
        error_log("Error generating chat title: " . $title_response);
        return null;
    }
}