class Syntropy::RPCAPI

def __error_response__(err)
  http_status = err.respond_to?(:http_status) ? err.http_status : INTERNAL_SERVER_ERROR
  error_name = err.class.name.split('::').last
  [{ status: error_name, message: err.message }, http_status]
end

def __invoke__(req)
  q = req.validate_param(:q, String).to_sym
  response = case req.method
  when 'get'
    __invoke_get__(q, req)
  when 'post'
    __invoke_post__(q, req)
  else
    raise Syntropy::Error.method_not_allowed
  end
  [{ status: 'OK', response: response }, Qeweney::Status::OK]
rescue => e
  if !e.is_a?(Syntropy::Error)
    p e
    p e.backtrace
  end
  __error_response__(e)
end

def __invoke_get__(sym,  req)
  return send(sym, req) if respond_to?(sym)
  err = respond_to?(:"#{sym}!") ? Syntropy::Error.method_not_allowed : Syntropy::Error.not_found
  raise err
end

def __invoke_post__(sym, req)
  sym_post = :"#{sym}!"
  return send(sym_post, req) if respond_to?(sym_post)
  err = respond_to?(sym) ? Syntropy::Error.method_not_allowed : Syntropy::Error.not_found
  raise err
end

def call(req)
  response, status = __invoke__(req)
  req.respond(
    response.to_json,
    ':status'       => status,
    'Content-Type'  => 'application/json'
  )
end

def initialize(env)
  @env = env
end