get_config.php

<?php
/**
 * get_config.php
 *
 * Chooses the correct INI file based on where the code is running:
 *   • Web request → look at $_SERVER['REQUEST_URI']
 *   • CLI / cron   → look at the script directory (__DIR__)
 *
 * Results:
 *   /etc/apps/chatdev_config.ini   (environment = dev)
 *   /etc/apps/chattest_config.ini  (environment = test)
 *   /etc/apps/chatprod_config.ini  (environment = prod, default)
 */

# 1.  Default to production
$environment = '';

# 2.  If we're in a web context, key off REQUEST_URI
if (!empty($_SERVER['REQUEST_URI'])) {
    $uri = $_SERVER['REQUEST_URI'];
    if (strpos($uri, 'chatdev')  !== false) {
        $environment = 'dev';
    } elseif (strpos($uri, 'chattest') !== false) {
        $environment = 'test';
    }

# 3.  Otherwise (CLI / cron), look at the directory path of this file
} else {
    $dir = __DIR__;                                 // e.g. /var/www/ai.nhlbi.nih.gov/chatdev
    if (strpos($dir, 'chatdev')  !== false) {
        $environment = 'dev';
    } elseif (strpos($dir, 'chattest') !== false) {
        $environment = 'test';
    }
}

# 4.  Load the appropriate INI file first
$config_file = "/etc/apps/chat{$environment}_config.ini";

if (!is_readable($config_file)) {
    $explicit_path = getenv('CHAT_CONFIG_PATH');
    if ($explicit_path === false || $explicit_path === '') {
        if (defined('CHAT_CONFIG_PATH') && CHAT_CONFIG_PATH !== '') {
            $explicit_path = CHAT_CONFIG_PATH;
        }
    }

    if ($explicit_path !== false && $explicit_path !== '') {
        $config_file = $explicit_path;
        $environment = 'custom';
    } else {
        throw new RuntimeException("Config file not found for environment '{$environment}': {$config_file}");
    }
}

$config = parse_ini_file($config_file, true);