database.php

<?php

// 1. Read and parse the local .env file line by line
$envFile = __DIR__ . '/.env';
if (file_exists($envFile)) {
    $lines = file($envFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
    foreach ($lines as $line) {
        // Skip comment lines
        if (strpos(trim($line), '#') === 0) continue;
        
        // Split each line by the first '=' character
        list($name, $value) = explode('=', $line, 2);
        $_ENV[trim($name)] = trim($value);
    }
}

// 2. Extract database connection parameters from $_ENV
$host = $_ENV['DB_HOST'] ?? null;
$port = $_ENV['DB_PORT'] ?? null;
$db   = $_ENV['DB_NAME'] ?? null;
$user = $_ENV['DB_USER'] ?? null;
$pass = $_ENV['DB_PASS'] ?? null;

if (!$host || !$port || !$db || !$user || !$pass) {
    header('Content-Type: application/json', true, 500);
    echo json_encode(["error" => "Critical server configuration error: Missing database environment variables."]);
    exit;
}

// 3. Construct the Data Source Name (DSN) string
$dsn = "pgsql:host=$host;port=$port;dbname=$db;";

// 4. Set secure execution attributes for the PDO instance
$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];

try {
    // 5. Instantiate the PDO object to establish the network socket connection
    $pdo = new PDO($dsn, $user, $pass, $options);
} catch (\PDOException $e) {
    // If connection fails, catch the error and stop execution safely
    header('Content-Type: application/json', true, 500);
    echo json_encode(["error" => "Database connection failed: " . $e->getMessage()]);
    exit;
}