package main

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

	"github.com/google/uuid"
)

type signupHandler int
type whoAmIHandler int

type User struct {
	Username string `json:"username"`
	Nickname string `json:"nickname"`
	Admin    bool   `json:"admin"`
}

var Users map[string]User

func (a signupHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Methods", "POST")
	w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
	var user User
	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
		http.Error(w, "Daten konnten nicht verarbeitet werden.", http.StatusBadRequest)
		return
	}
	uuid := uuid.New().String()
	Users[uuid] = user
	w.WriteHeader(http.StatusOK)
	w.Write([]byte("Registrierung erfolgreich"))
	cookie := &http.Cookie{Name: "uuid", Value: uuid}
	http.SetCookie(w, cookie)
}

func (b whoAmIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	cookie, err := r.Cookie("uuid")
	if err != nil {
		w.Write([]byte("Keinen Login Cookie gefunden."))
		return
	}
	if user, ok := Users[cookie.Value]; ok {
		nickname := user.Nickname
		admin := user.Admin

		var status string
		if admin {
			status = "Admin"
		} else {
			status = "normaler Benutzer"
		}

		w.Write([]byte("Hallo " + nickname + "!\nDu bist als " + status + " registriert."))

	} else {
		w.Write([]byte("User nicht gefunden!"))
	}

}

func main() {
	Users = make(map[string]User)
	var a signupHandler
	var b whoAmIHandler
	mux := http.NewServeMux()
	mux.Handle("/signup", a)
	mux.Handle("/whoami", b)
	http.ListenAndServe("localhost:8080", mux)
}