<?php
declare(strict_types=1);

final class DirectAdminContext
{
    private function __construct(
        private string $username,
        private string $sourceHost,
        private string $serverName,
        private string $method
    ) {
    }

    /**
     * @param array<string,mixed> $server
     */
    public static function fromServer(array $server, Settings $settings): self
    {
        $username = trim((string)($server['USERNAME'] ?? ''));
        if (!preg_match('/^[A-Za-z0-9][A-Za-z0-9._-]{0,31}$/', $username)) {
            throw new InvalidArgumentException('Invalid DirectAdmin username');
        }
        $host = self::trustedSourceHost($server);
        if ($host === '') {
            throw new InvalidArgumentException('Missing source host');
        }
        $serverName = $settings->sourceServerName();
        if ($serverName === '') {
            $serverName = $settings->sanitizeServerName(explode('.', $host)[0] ?? '');
        }
        if ($serverName === '') {
            throw new InvalidArgumentException('Invalid source server name');
        }
        return new self($username, $host, $serverName, strtoupper((string)($server['REQUEST_METHOD'] ?? 'GET')));
    }

    /**
     * @param array<string,mixed> $server
     */
    private static function trustedSourceHost(array $server): string
    {
        return Settings::normalizeHost((string)($server['SERVER_NAME'] ?? ''));
    }

    public function username(): string
    {
        return $this->username;
    }

    public function sourceHost(): string
    {
        return $this->sourceHost;
    }

    public function serverName(): string
    {
        return $this->serverName;
    }

    public function auditServerName(): string
    {
        return $this->sourceHost;
    }

    public function method(): string
    {
        return $this->method;
    }
}