lab-development-imb/web/08/labor/loesungen/04/uebung04.go

86 lines
1.7 KiB
Go

package main
import (
"encoding/json"
"errors"
"fmt"
"net/http"
"sync"
"github.com/google/uuid"
)
type UserData struct {
Username string `json:"username"`
Nickname string `json:"nickname"`
Admin bool `json:"admin"`
}
var (
sessions = make(map[string]UserData)
mu sync.Mutex
)
func checkSessionID(r *http.Request) (string, error) {
cookie, err := r.Cookie("session_id")
if err != nil {
return "", errors.New("keine session-ID")
}
return cookie.Value, nil
}
func getSessionID(w http.ResponseWriter, r *http.Request) string {
sessionID, err := checkSessionID(r)
if err != nil {
newID := uuid.New().String()
newCookie := http.Cookie{
Name: "session_id",
Value: newID,
}
http.SetCookie(w, &newCookie)
mu.Lock()
sessions[newID] = UserData{}
mu.Unlock()
return newID
}
return sessionID
}
func signup(w http.ResponseWriter, r *http.Request) {
sessionID := getSessionID(w, r)
var user UserData
err := json.NewDecoder(r.Body).Decode(&user)
if err != nil {
http.Error(w, "Daten konnten nicht verarbeitet werden.", http.StatusBadRequest)
return
}
if user.Nickname == "" || user.Username == "" {
http.Error(w, "Daten unvollständig.", http.StatusBadRequest)
return
}
sessions[sessionID] = user
}
func whoami(w http.ResponseWriter, r *http.Request) {
sessionID, err := checkSessionID(r)
if err != nil {
fmt.Fprintf(w, "Du bist noch niemand.")
} else {
user := sessions[sessionID]
fmt.Fprintf(w, "Hallo %s!\n", user.Nickname)
if user.Admin {
fmt.Fprintln(w, "Du bist als Admin registriert.")
} else {
fmt.Fprintln(w, "Du bist nicht als Admin registriert.")
}
}
}
func main() {
http.HandleFunc("/signup", signup)
http.HandleFunc("/whoami", whoami)
http.ListenAndServe("localhost:8080", nil)
}