Semaphore/api/helpers/helpers.go

package helpers

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/semaphoreui/semaphore/services/tasks"
	"net/http"
	"net/url"
	"runtime/debug"
	"strconv"
	"strings"

	"github.com/gorilla/context"
	log "github.com/sirupsen/logrus"

	"github.com/semaphoreui/semaphore/db"

	"github.com/gorilla/mux"
)

func Store(r *http.Request) db.Store {
	return context.Get(r, "store").(db.Store)
}

func TaskPool(r *http.Request) *tasks.TaskPool {
	return context.Get(r, "task_pool").(*tasks.TaskPool)
}

func isXHR(w http.ResponseWriter, r *http.Request) bool {
	accept := r.Header.Get("Accept")
	return !strings.Contains(accept, "text/html")
}

// GetStrParam fetches a parameter from the route variables as an integer
// redirects to a 404 or writes bad request state depending on error state
func GetStrParam(name string, w http.ResponseWriter, r *http.Request) (string, error) {
	strParam, ok := mux.Vars(r)[name]

	if !ok {
		if !isXHR(w, r) {
			http.Redirect(w, r, "/404", http.StatusFound)
		} else {
			w.WriteHeader(http.StatusBadRequest)
		}

		return "", fmt.Errorf("parameter missed")
	}

	return strParam, nil
}

// GetIntParam fetches a parameter from the route variables as an integer
// redirects to a 404 or writes bad request state depending on error state
func GetIntParam(name string, w http.ResponseWriter, r *http.Request) (int, error) {
	intParam, err := strconv.Atoi(mux.Vars(r)[name])

	if err != nil {
		if !isXHR(w, r) {
			http.Redirect(w, r, "/404", http.StatusFound)
		} else {
			w.WriteHeader(http.StatusBadRequest)
		}

		return 0, err
	}

	return intParam, nil
}

// H just a string-to-anything map
type H map[string]interface{}

// Bind decodes json into object
func Bind(w http.ResponseWriter, r *http.Request, out interface{}) bool {
	err := json.NewDecoder(r.Body).Decode(out)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
	}

	return err == nil
}

// WriteJSON writes object as JSON
func WriteJSON(w http.ResponseWriter, code int, out interface{}) {
	w.Header().Set("content-type", "application/json")
	w.WriteHeader(code)

	if err := json.NewEncoder(w).Encode(out); err != nil {
		log.Error(err)
		debug.PrintStack()
	}
}

func WriteErrorStatus(w http.ResponseWriter, err string, code int) {
	WriteJSON(w, code, map[string]string{
		"error": err,
	})
}

func WriteError(w http.ResponseWriter, err error) {
	if errors.Is(err, tasks.ErrInvalidSubscription) {
		WriteErrorStatus(w, "You have no subscription.", http.StatusForbidden)
		return
	}

	if errors.Is(err, db.ErrNotFound) {
		w.WriteHeader(http.StatusNotFound)
		return
	}

	if errors.Is(err, db.ErrInvalidOperation) {
		w.WriteHeader(http.StatusConflict)
		return
	}

	switch e := err.(type) {
	case *db.ValidationError:
		WriteErrorStatus(w, e.Error(), http.StatusBadRequest)
	default:
		log.Error(err)
		debug.PrintStack()
		w.WriteHeader(http.StatusBadRequest)
	}
}

func QueryParams(url *url.URL) db.RetrieveQueryParams {
	return db.RetrieveQueryParams{
		SortBy:       url.Query().Get("sort"),
		SortInverted: url.Query().Get("order") == "desc",
	}
}