module Excon

def stub_for(request_params={})
  if (method = request_params.delete(:method))
    request_params[:method] = method.to_s.downcase.to_sym
  end
  request_params[:query] = Utils.query_string(request_params)[1...] if request_params.key?(:query)
  Excon.stubs.each do |stub, response_params|
    captures = { headers: {} }
    headers_match = !stub.key?(:headers) || stub[:headers].keys.all? do |key|
      case value = stub[:headers][key]
      when Regexp
        case request_params[:headers][key]
        when String
          if (match = value.match(request_params[:headers][key]))
            captures[:headers][key] = match.captures
          end
        when Regexp # for unstub on regex params
          match = (value == request_params[:headers][key])
        end
        match
      else
        value == request_params[:headers][key]
      end
    end
    non_headers_match = (stub.keys - [:headers]).all? do |key|
      case value = stub[key]
      when Regexp
        case request_params[key]
        when String
          if (match = value.match(request_params[key]))
            captures[key] = match.captures
          end
        when Regexp # for unstub on regex params
          match = (value == request_params[key])
        end
        match
      else
        value == request_params[key]
      end
    end
    if headers_match && non_headers_match
      request_params[:captures] = captures
      return [stub, response_params]
    end
  end
  nil
end