package webutility

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

// NotFoundHandlerFunc writes HTTP error 404 to w.
func NotFoundHandlerFunc(w http.ResponseWriter, req *http.Request) {
	SetDefaultHeaders(w)
	if req.Method == "OPTIONS" {
		return
	}
	NotFound(w, req, fmt.Sprintf("Resource you requested was not found: %s", req.URL.String()))
}

// SetDefaultHeaders set's default headers for an HTTP response.
func SetDefaultHeaders(w http.ResponseWriter) {
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Methods", "POST, GET, PUT, DELETE, OPTIONS")
	w.Header().Set("Access-Control-Allow-Headers", `Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization`)
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
}

func ReqLocale(req *http.Request, dflt string) string {
	loc := req.FormValue("locale")
	if loc == "" {
		return dflt
	}
	return loc
}

// 2xx
func Success(w http.ResponseWriter, payload interface{}, code int) {
	w.WriteHeader(code)
	if payload != nil {
		json.NewEncoder(w).Encode(payload)
	}
}

// 200
func OK(w http.ResponseWriter, payload interface{}) {
	Success(w, payload, http.StatusOK)
}

// 201
func Created(w http.ResponseWriter, payload interface{}) {
	Success(w, payload, http.StatusCreated)
}

type weberror struct {
	Request string `json:"request"`
	Error   string `json:"error"`
}

// 4xx; 5xx
func Error(w http.ResponseWriter, r *http.Request, code int, err string) {
	werr := weberror{Error: err, Request: r.Method + " " + r.RequestURI}
	w.WriteHeader(code)
	json.NewEncoder(w).Encode(werr)
}

// 400
func BadRequest(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusBadRequest, err)
}

// 401
func Unauthorized(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusUnauthorized, err)
}

// 403
func Forbidden(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusForbidden, err)
}

// 404
func NotFound(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusNotFound, err)
}

// 409
func Conflict(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusConflict, err)
}

// 500
func InternalServerError(w http.ResponseWriter, r *http.Request, err string) {
	Error(w, r, http.StatusInternalServerError, err)
}