<?php
// ====================================================================
// 1. ENVIRONMENT CONFIGURATION & GLOBAL SETTINGS
// ====================================================================
// Set time zone and ensure clean error reporting for debugging development builds
date_default_timezone_set('UTC');
error_reporting(E_ALL);
ini_set('display_errors', 0); // Disabled in production builds so errors don't corrupt JSON payloads

// ====================================================================
// 2. DATABASE CONFIGURATION (Aiven Cloud Connection Matrix)
// ====================================================================
// Fall back to standard local development values if variables aren't injected by Vercel
$db_host = getenv('DB_HOST') ?: '127.0.0.1';
$db_port = getenv('DB_PORT') ?: '3306'; 
$db_user = getenv('DB_USER') ?: 'root';
$db_pass = getenv('DB_PASS') ?: '';
$db_name = 'defaultdb';

try {
    // Open a secure database link using the PHP Data Objects (PDO) framework
 $pdo = new PDO(
    "mysql:host=$db_host;port=$db_port;dbname=$db_name;charset=utf8mb4",
    $db_user,
    $db_pass,
    [
        PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
        PDO::ATTR_EMULATE_PREPARES   => false,
        PDO::MYSQL_ATTR_SSL_CA       => true, // Encapsulated correctly inside the array
    ]
);
} catch (PDOException $e) {
    // If the database connection drops, immediately return a clean JSON error response 
    header('Content-Type: application/json');
    http_response_code(500);
    echo json_encode([
        "error" => "Secure cloud database connection error.",
        "status" => "fail"
    ]);
    exit();
}

// ====================================================================
// 3. MEDIA UPLOAD & STORAGE CONFIGURATION (Cloudinary)
// ====================================================================
// Pull raw cloudinary:// URL string directly from Vercel's Environment Variables
$cloudinary_env = getenv('CLOUDINARY_URL') ?: 'cloudinary://LOCAL_MOCK_KEY_FOR_TESTING';

// Define it as a global constant so your existing media/upload scripts run unchanged
define('CLOUDINARY_URL', $cloudinary_env);


// ====================================================================
// 4. API UTILITY FUNCTIONS (Optional helper block for your endpoints)
// ====================================================================
/**
 * Standardized function to echo clean JSON responses back to the Instagram app
 */
function sendJsonResponse($data, $status_code = 200) {
    header('Content-Type: application/json');
    http_response_code($status_code);
    echo json_encode($data);
    exit();
}