neko/server/internal/http/endpoint/endpoint.go

package endpoint

import (
	"encoding/json"
	"fmt"
	"net/http"
	"runtime/debug"

	"github.com/go-chi/chi/middleware"
	"github.com/rs/zerolog/log"
)

type (
	Endpoint func(http.ResponseWriter, *http.Request) error

	ErrResponse struct {
		Status    int    `json:"status,omitempty"`
		Err       string `json:"error,omitempty"`
		Message   string `json:"message,omitempty"`
		Details   string `json:"details,omitempty"`
		Code      string `json:"code,omitempty"`
		RequestID string `json:"request,omitempty"`
	}
)

func Handle(handler Endpoint) http.HandlerFunc {
	fn := func(w http.ResponseWriter, r *http.Request) {
		if err := handler(w, r); err != nil {
			WriteError(w, r, err)
		}
	}

	return http.HandlerFunc(fn)
}

var nonErrorsCodes = map[int]bool{
	404: true,
}

func errResponse(input interface{}) *ErrResponse {
	var res *ErrResponse
	var err interface{}

	switch input.(type) {
	case *HandlerError:
		e := input.(*HandlerError)
		res = &ErrResponse{
			Status:  e.Status,
			Err:     http.StatusText(e.Status),
			Message: e.Message,
		}
		err = e.Err
	default:
		res = &ErrResponse{
			Status: http.StatusInternalServerError,
			Err:    http.StatusText(http.StatusInternalServerError),
		}
		err = input
	}

	if err != nil {
		switch err.(type) {
		case *error:
			e := err.(error)
			res.Details = e.Error()
			break
		default:
			res.Details = fmt.Sprintf("%+v", err)
			break
		}
	}

	return res
}

func WriteError(w http.ResponseWriter, r *http.Request, err interface{}) {
	hlog := log.With().
		Str("module", "http").
		Logger()

	res := errResponse(err)

	if reqID := middleware.GetReqID(r.Context()); reqID != "" {
		res.RequestID = reqID
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(res.Status)

	if err := json.NewEncoder(w).Encode(res); err != nil {
		hlog.Warn().Err(err).Msg("Failed writing json error response")
	}

	if !nonErrorsCodes[res.Status] {
		logEntry := middleware.GetLogEntry(r)
		if logEntry != nil {
			logEntry.Panic(err, debug.Stack())
		} else {
			hlog.Error().Str("stack", string(debug.Stack())).Msgf("%+v", err)
		}
	}
}