<?php
declare(strict_types=1);

final class Settings
{
    /** @var array<string,string> */
    private array $values;

    private function __construct(array $values)
    {
        $this->values = $values;
    }

    public static function load(string $path): self
    {
        $values = [];
        if (is_readable($path)) {
            $lines = file($path, FILE_IGNORE_NEW_LINES);
            if ($lines !== false) {
                foreach ($lines as $line) {
                    $line = trim($line);
                    if ($line === '' || $line[0] === '#') {
                        continue;
                    }

                    if (!preg_match('/^([A-Za-z0-9_]+)=(.*)$/', $line, $m)) {
                        continue;
                    }

                    $values[$m[1]] = self::parseShValue((string)$m[2]);
                }
            }
        }

        return new self($values);
    }

    public static function loadPostgresqlCredentials(string $path): array
    {
        if (!is_readable($path)) {
            throw new RuntimeException('Brak pliku z danymi PostgreSQL: ' . $path);
        }

        $lines = file($path, FILE_IGNORE_NEW_LINES);
        if ($lines === false) {
            throw new RuntimeException('Nie można odczytać pliku: ' . $path);
        }

        $kv = [];
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line === '' || $line[0] === '#') {
                continue;
            }

            if (strpos($line, '=') !== false) {
                [$k, $v] = array_map('trim', explode('=', $line, 2));
                if ($k !== '') {
                    $kv[strtoupper($k)] = self::parseShValue($v);
                }
                continue;
            }

            $parts = explode(':', $line);
            if (count($parts) >= 5) {
                return [
                    'host' => trim($parts[0]) !== '' ? trim($parts[0]) : 'localhost',
                    'port' => (int)(trim($parts[1]) !== '' ? trim($parts[1]) : '5432'),
                    'database' => trim($parts[2]) !== '' ? trim($parts[2]) : 'postgres',
                    'user' => trim($parts[3]),
                    'password' => trim(implode(':', array_slice($parts, 4))),
                ];
            }
        }

        if (!empty($kv['PG_HOST']) || !empty($kv['PG_USER']) || !empty($kv['PG_PASSWORD'])) {
            return [
                'host' => $kv['PG_HOST'] ?? 'localhost',
                'port' => (int)($kv['PG_PORT'] ?? '5432'),
                'database' => $kv['PG_DATABASE'] ?? ($kv['PG_DBNAME'] ?? 'postgres'),
                'user' => $kv['PG_USER'] ?? 'postgres',
                'password' => $kv['PG_PASSWORD'] ?? '',
            ];
        }

        throw new RuntimeException('Niepoprawny format pliku danych PostgreSQL: ' . $path);
    }

    public function getString(string $key, string $default = ''): string
    {
        return isset($this->values[$key]) ? trim($this->values[$key]) : $default;
    }

    public function getInt(string $key, int $default = 0): int
    {
        if (!isset($this->values[$key])) {
            return $default;
        }

        $value = trim($this->values[$key]);
        if ($value === '' || !preg_match('/^-?[0-9]+$/', $value)) {
            return $default;
        }

        return (int)$value;
    }

    public function getBool(string $key, bool $default = false): bool
    {
        if (!isset($this->values[$key])) {
            return $default;
        }

        return self::toBool($this->values[$key], $default);
    }

    public function defaultDatabasesLimit(): int
    {
        $limit = $this->getInt('PG_PLUGIN_DEFAULT_DB_LIMIT', 5);
        return $limit < 0 ? 0 : $limit;
    }

    public function maxHostsPerUser(): int
    {
        $limit = $this->getInt('PG_PLUGIN_MAX_HOSTS_PER_USER', 30);
        return $limit < 1 ? 1 : $limit;
    }

    public function allowRemoteHosts(): bool
    {
        if (array_key_exists('allow_remote_hosts', $this->values)) {
            return self::toBool($this->values['allow_remote_hosts'], true);
        }

        return $this->getBool('PG_PLUGIN_ALLOW_REMOTE_HOSTS', true);
    }

    public function hbaSyncScript(): string
    {
        $path = $this->getString('PG_PLUGIN_SUDO_SYNC_HBA', '/usr/local/directadmin/plugins/da-postgresql/scripts/setup/pg_hba_sync.sh');
        return $path !== '' ? $path : '/usr/local/directadmin/plugins/da-postgresql/scripts/setup/pg_hba_sync.sh';
    }

    public function enableBackup(): bool
    {
        return $this->getBool('ENABLE_BACKUP', true);
    }

    public function enableUploadBackup(): bool
    {
        return $this->getBool('ENABLE_UPLOAD_BACKUP', true);
    }

    public function enableAdminer(): bool
    {
        if (!$this->getBool('ENABLE_ADMINER', false)) {
            return false;
        }

        return $this->isAdminerInstalled();
    }

    public function adminerUrlPath(): string
    {
        $path = trim($this->getString('ADMINER_URL_PATH', '/adminer'));
        if ($path === '') {
            return '/adminer';
        }

        if ($path[0] !== '/') {
            $path = '/' . $path;
        }

        $path = rtrim($path, '/');
        return $path !== '' ? $path : '/adminer';
    }

    public function adminerPublicBaseUrl(): string
    {
        $url = trim($this->getString('ADMINER_PUBLIC_BASE_URL', ''));
        if ($url === '') {
            return '';
        }

        $url = rtrim($url, '/');
        if (!preg_match('#^https?://#i', $url)) {
            return '';
        }

        return $url;
    }

    public function adminerPublic(): bool
    {
        return $this->getBool('ADMINER_PUBLIC', false);
    }

    public function adminerSsoDir(): string
    {
        $path = trim($this->getString('ADMINER_SSO_DIR', '/var/www/html/adminer/runtime'));
        if ($path === '') {
            $path = '/var/www/html/adminer/runtime';
        }
        return rtrim($path, '/');
    }

    public function adminerTicketTtl(): int
    {
        $ttl = $this->getInt('ADMINER_TICKET_TTL', 120);
        if ($ttl < 10) {
            return 10;
        }
        if ($ttl > 300) {
            return 300;
        }
        return $ttl;
    }

    public function adminerSessionTtl(): int
    {
        $ttl = $this->getInt('ADMINER_SESSION_TTL', 900);
        if ($ttl < 60) {
            return 60;
        }
        if ($ttl > 3600) {
            return 3600;
        }
        return $ttl;
    }

    public function adminerRoleTtl(): int
    {
        $ttl = $this->getInt('ADMINER_ROLE_TTL', 1200);
        if ($ttl < 120) {
            return 120;
        }
        if ($ttl > 7200) {
            return 7200;
        }
        return $ttl;
    }

    private function isAdminerInstalled(): bool
    {
        $indexFile = '/var/www/html/adminer/index.php';
        $coreFile = '/var/www/html/adminer/adminer-core.php';

        return is_file($indexFile) && is_readable($indexFile)
            && is_file($coreFile) && is_readable($coreFile);
    }

    public function allowRestoreToOtherDatabase(): bool
    {
        return $this->getBool('ALLOW_RESTORE_TO_OTHER_DATABASE', true);
    }

    public function enableTableCount(): bool
    {
        return $this->getBool('ENABLE_TABLE_COUNT', true);
    }

    public function countDatabaseSize(): bool
    {
        return $this->getBool('COUNT_DATABASE_SIZE', true);
    }

    public function compressBackup(): bool
    {
        return $this->getBool('COMPRESS_BACKUP', true);
    }

    public function hitmeBackupLocation(string $daUser = ''): string
    {
        $path = $this->getString('HITME_BACKUP_LOCATION', '/home/admin/postgres_backup');
        if ($path === '') {
            $path = '/home/admin/postgres_backup';
        }

        if ($daUser !== '') {
            $path = str_replace(['DA_USER', 'da_user'], $daUser, $path);
        }

        return rtrim($path, '/');
    }

    public function userBaseBackupDir(string $daUser = ''): string
    {
        $path = $this->getString('USER_BASE_BACKUP_DIR', '/home/DA_USER/postgres_backup');
        if ($path === '') {
            $path = '/home/DA_USER/postgres_backup';
        }

        if ($daUser !== '') {
            $path = str_replace(['DA_USER', 'da_user'], $daUser, $path);
        }

        return rtrim($path, '/');
    }

    public function userBackupDateFormat(): string
    {
        $format = $this->getString('USER_BACKUP_DATE_FORMAT', 'd.m.Y-H.i');
        return $format !== '' ? $format : 'd.m.Y-H.i';
    }

    public function loadOrCreateSecret(string $path): string
    {
        if (is_readable($path)) {
            $value = trim((string)file_get_contents($path));
            if ($value !== '') {
                return $value;
            }
        }

        $secret = bin2hex(random_bytes(32));
        $dir = dirname($path);
        if (!is_dir($dir)) {
            @mkdir($dir, 0700, true);
        }

        if (@file_put_contents($path, $secret) !== false) {
            @chmod($path, 0600);
            return $secret;
        }

        return hash('sha256', __FILE__ . '|' . php_uname('n') . '|' . $path . '|da-postgresql');
    }

    public static function toBool(string $value, bool $default = false): bool
    {
        $v = strtolower(trim($value));
        if ($v === '') {
            return $default;
        }

        if (in_array($v, ['1', 'true', 'yes', 'y', 'on', 'checked'], true)) {
            return true;
        }

        if (in_array($v, ['0', 'false', 'no', 'n', 'off', 'unchecked'], true)) {
            return false;
        }

        return $default;
    }

    private static function parseShValue(string $value): string
    {
        $value = trim($value);
        if ($value === '') {
            return '';
        }

        if ($value[0] === '\'' && substr($value, -1) === '\'') {
            return substr($value, 1, -1);
        }

        if ($value[0] === '"' && substr($value, -1) === '"') {
            return stripcslashes(substr($value, 1, -1));
        }

        $value = preg_replace('/\s+#.*$/', '', $value);
        return trim((string)$value);
    }
}