card-jong-be/controller/lobby.go

package controller

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

	"github.com/nrednav/cuid2"
)

// TODO: This struct should have a creation time
type Lobby struct {
	LobbyOwner   string
	LobbyPlayers []string
}

type LobbyResult struct {
	LobbyId string
}

type LobbyCreateInput struct {
	UserId string
}

// TODO: We should remove entries from this map when they expire.
// TODO: Define how long lobbies last
var lobbies = make(map[string]Lobby)

func CreateLobby(writer http.ResponseWriter, request *http.Request) {
	writer.Header().Set("Content-Type", "application/json")

	authOk := AuthHeaderIsValid(request.Header.Get("Authorization"))
	if !authOk {
		writer.WriteHeader(http.StatusUnauthorized)
		return
	}

	// Get the UserId from the JSON payload
	decoder := json.NewDecoder(request.Body)
	var data LobbyCreateInput
	err := decoder.Decode(&data)
	if err != nil {
		fmt.Printf("Error in JSON decoding: %s\n", err)
		writer.WriteHeader(http.StatusInternalServerError)
		fmt.Fprintf(writer, "{\"error\": \"%s\"}", err)
		return
	}

	lobbyId := cuid2.Generate()

	result := LobbyResult{LobbyId: lobbyId}
	lobbies[lobbyId] = Lobby{
		LobbyOwner:   data.UserId,
		LobbyPlayers: make([]string, 3),
	}
	log.Printf("Created lobby with id %s/%s", lobbyId, data.UserId)

	jsonData, err := json.Marshal(result)
	if err != nil {
		fmt.Printf("Error in JSON marshal: %s\n", err)
		writer.WriteHeader(http.StatusInternalServerError)
		fmt.Fprintf(writer, "{\"error\": \"%s\"}", err)
		return
	}

	fmt.Fprintf(writer, "%s", jsonData)
}

// Verifies that the userId has access to the lobbyId
func VerifyLobbyAccess(userId, lobbyId string) bool {
	lobby, ok := lobbies[lobbyId]
	if !ok {
		return false
	}

	if lobby.LobbyOwner == userId {
		return true
	}

	for _, playerId := range lobby.LobbyPlayers {
		if playerId == userId {
			return true
		}
	}

	return false
}