go-calc-local-handlers.go

func notFoundHandler(w http.ResponseWriter, r *http.Request) {
	writeRawBody(w, r, notFoundResponse, http.StatusNotFound)
}

func doHandler() http.HandlerFunc {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req Request
		if err := unmarshalBody(r, &req); err != nil {
			log.Println(err)
			response := NewErrorResponse(err)
			writeBody(w, r, response, http.StatusBadRequest)
			return
		}

		if err := req.Validate(); err != nil {
			log.Println(err)
			response := NewErrorResponse(err)
			writeBody(w, r, response, http.StatusUnprocessableEntity)
			return
		}

		operation := Operations[req.Operation]
		result := Do(operation.lambda, req.Arguments)

		response := Response{
			Operation: req.Operation,
			Arguments: req.Arguments,
			Result:    result,
		}

		writeBody(w, r, response, http.StatusOK)
	})
}