pw_less http handler

handler.go

package user

import (
    "errors"
    "io/ioutil"
    "net/http"
)

type UserHandler struct {
    Controller UserController
}

var ErrUnprocessableInput = errors.New("unprocessable input")
var ErrUnexpectedError = errors.New("unexpected error")
var ErrNotFound = errors.New("not found")

func NewHandler(c UserController) {
    uh := UserHandler{Controller: c}
    http.Handle("/users", http.HandlerFunc(uh.handleUsers))
}

func (u UserHandler) handleUsers(w http.ResponseWriter, r *http.Request) {
    var (
        resp []byte
        err  error
    )
    switch r.Method {
    case http.MethodGet:
        email := r.URL.Query().Get("email")
        token := r.URL.Query().Get("token")
        resp, err = u.Controller.ValidateUserToken(email, token)
    case http.MethodPost:
        b, _ := ioutil.ReadAll(r.Body)
        resp, err = u.Controller.CreateUser(b)
    default:
        w.WriteHeader(http.StatusMethodNotAllowed)
        w.Write([]byte("Method not allowed"))
    }
    if err != nil {
        handleErr(w, err)
    } else {
        w.Header().Add("content-type", "application/json")
        w.WriteHeader(http.StatusOK)
        w.Write(resp)
    }
}

func handleErr(w http.ResponseWriter, err error) {
    switch err {
    case ErrUnexpectedError:
        w.WriteHeader(http.StatusInternalServerError)
    case ErrUnprocessableInput:
        w.WriteHeader(http.StatusBadRequest)
    case ErrNotFound:
        w.WriteHeader(http.StatusNotFound)
    default:
        w.WriteHeader(http.StatusInternalServerError)
    }
    w.Write([]byte(err.Error()))
}