<?php
function env_first_db(array $keys, string $default = ''): string {
    foreach ($keys as $key) {
        $value = getenv($key);
        if ($value !== false && $value !== '') return $value;
    }
    return $default;
}

define('DB_HOST', env_first_db(['DB_HOST', 'MYSQL_HOST', 'MARIADB_HOST'], 'database'));
define('DB_NAME', env_first_db(['WEBGIS_V3_DB_NAME', 'DB_NAME'], 'webgis_kemiskinan'));
define('DB_USER', env_first_db(['DB_USER', 'MYSQL_USER', 'MARIADB_USER'], 'root'));
define('DB_PASS', env_first_db(['DB_PASSWORD', 'MYSQL_PASSWORD', 'MARIADB_PASSWORD'], ''));
define('DB_CHAR', getenv('DB_CHAR') ?: 'utf8mb4');

function getDB(): PDO {
    static $pdo = null;
    if ($pdo === null) {
        $serverDsn = "mysql:host=".DB_HOST.";charset=".DB_CHAR;
        $server = new PDO($serverDsn, DB_USER, DB_PASS, [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES => false,
        ]);

        $safeDb = preg_replace('/[^a-zA-Z0-9_]/', '', DB_NAME);
        $server->exec("CREATE DATABASE IF NOT EXISTS `$safeDb` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci");

        $dsn = "mysql:host=".DB_HOST.";dbname=".$safeDb.";charset=".DB_CHAR;
        $pdo = new PDO($dsn, DB_USER, DB_PASS, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => false,
        ]);

        ensureWebgisV3Schema($pdo);
    }
    return $pdo;
}

function ensureWebgisV3Schema(PDO $pdo): void {
    $stmt = $pdo->query("SHOW TABLES LIKE 'role'");
    if ($stmt->fetch()) return;

    $schemaFile = __DIR__ . '/../sql/schema.sql';
    if (!is_file($schemaFile)) return;

    $sql = file_get_contents($schemaFile);
    $sql = preg_replace('/CREATE DATABASE IF NOT EXISTS\s+`?webgis_kemiskinan`?.*?;/is', '', $sql);
    $sql = preg_replace('/USE\s+`?webgis_kemiskinan`?\s*;/i', '', $sql);
    $sql = preg_replace('/^\s*--.*$/m', '', $sql);

    foreach (array_filter(array_map('trim', explode(';', $sql))) as $statement) {
        if ($statement === '') continue;
        $pdo->exec($statement);
    }
}