<?php
require_once __DIR__. "/.env.php"; // DB_USER, DB_PASS, DB_NAME, DB_HOST
// Setup PDO
$dsn = "mysql:host=".DB_HOST.";dbname=SYS_PRD_BND;charset=utf8mb4";
$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
];

try {
    $pdo = new PDO($dsn, DB_USER, DB_PASS, $options);

    // Fetch dependencies from PyPi table
    // Note: We select LibName. If AliasName represents a specific version or URI, it can be appended.
    $stmt = $pdo->query("SELECT LibName, VersionOrTag FROM PyPi ORDER BY LibName");
    
    $requirements = [];
    foreach ($stmt as $row) {
        $line = $row['LibName'];
        if (!empty($row['VersionOrTag'])) {
            $line .= '==' . $row['VersionOrTag'];
        }
        $requirements[] = $line;
    }

    // Build requirements.txt content (Plain Text, one per line)
    $output = implode("\n", $requirements);

    // Write to file (stdout for Makefile redirection)
    file_put_contents('php://stdout', $output . "\n");
    file_put_contents("php://stderr", "✅ requirements.txt generated successfully.\n");

} catch (PDOException $e) {
    file_put_contents("php://stderr", "❌ Database error: " . $e->getMessage() . "\n");
}