fathom/pkg/api/http.go

package api

import (
	"encoding/json"
	"net/http"

	"github.com/gobuffalo/packr"
	log "github.com/sirupsen/logrus"
)

// Handler is our custom HTTP handler with error returns
type Handler func(w http.ResponseWriter, r *http.Request) error

type envelope struct {
	Data  interface{} `json:",omitempty"`
	Error interface{} `json:",omitempty"`
}

func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if err := h(w, r); err != nil {
		HandleError(w, r, err)
	}
}

// HandlerFunc takes a custom Handler func and converts it to http.HandlerFunc
func HandlerFunc(fn Handler) http.HandlerFunc {
	return http.HandlerFunc(Handler(fn).ServeHTTP)
}

// HandleError handles errors
func HandleError(w http.ResponseWriter, r *http.Request, err error) {
	log.WithFields(log.Fields{
		"request": r.Method + " " + r.RequestURI,
		"error":   err,
	}).Error("error handling request")

	w.WriteHeader(http.StatusInternalServerError)
	w.Header().Set("Content-Type", "application/json")
	w.Write([]byte("false"))
}

func respond(w http.ResponseWriter, statusCode int, d interface{}) error {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(statusCode)
	err := json.NewEncoder(w).Encode(d)
	return err
}

func serveFileHandler(box *packr.Box, filename string) http.Handler {
	return HandlerFunc(serveFile(box, filename))
}

func serveFile(box *packr.Box, filename string) Handler {
	return func(w http.ResponseWriter, r *http.Request) error {
		f, err := box.Open(filename)
		if err != nil {
			return err
		}
		defer f.Close()

		d, err := f.Stat()
		if err != nil {
			return err
		}

		http.ServeContent(w, r, filename, d.ModTime(), f)
		return nil
	}
}

func NotFoundHandler(box *packr.Box) http.Handler {
	return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
		w.WriteHeader(http.StatusNotFound)
		w.Write(box.Bytes("404.html"))
		return nil
	})
}