public interface IQueryContextFactory
{
    QueryContext Create(string query, HttpRequest request);
}

internal class HttpRequestQueryContextFactory : IQueryContextFactory
{
    public QueryContext Create(string query, HttpRequest request)
    {
        if (string.IsNullOrEmpty(query))
            throw new ArgumentNullException(nameof(query));
        if (request == null)
            throw new ArgumentNullException(nameof(request));

        return new QueryContext
        {
            Method = request.Method,
            QueryString = string.Concat(query, request.QueryString),
            Parameters = request.Query.ToDictionary(x => x.Key, x => x.Value.ToString().Replace(""", string.Empty)),
            Headers = request.Headers.ToDictionary(x => x.Key, x => x.Value.ToString())
        };
    }
}

[HttpGet]
    public IActionResult Process(string query)
    {
        (...)
        var ctx = _contextFactory.Create(query, Request);
    }