The REST API now allows specfiying the Lobby ID

The ID is limited to an unused valid UUIDv4.
This does not allow specifying a lobby owner as of now. However, due to
the recent changes to the start / restart system, this is not as much of
a hurdle as it used to be.

Fixes #207
Fixes #194

internal/api/v1.go

@@ -88,6 +88,22 @@ func (handler *V1Handler) postLobby(writer http.ResponseWriter, request *http.Re
 		return
 	}
 
+	var requestErrors []string
+
+	// The lobby ID is normally autogenerated and it isn't advisble to set it
+	// yourself, but for certain integrations / automations this can be useful.
+	// However, to avoid any kind of abuse, this needs to be a valid UUID at
+	// least.
+	desiredLobbyId := uuid.Nil
+	lobbyId := request.Form.Get("lobby_id")
+	if lobbyId != "" {
+		var err error
+		desiredLobbyId, err = uuid.FromString(lobbyId)
+		if err != nil {
+			requestErrors = append(requestErrors, err.Error())
+		}
+	}
+
 	languageData, languageKey, languageInvalid := ParseLanguage(request.Form.Get("language"))
 	drawingTime, drawingTimeInvalid := ParseDrawingTime(request.Form.Get("drawing_time"))
 	rounds, roundsInvalid := ParseRounds(request.Form.Get("rounds"))
@@ -104,7 +120,6 @@ func (handler *V1Handler) postLobby(writer http.ResponseWriter, request *http.Re
 	}
 	customWords, customWordsInvalid := ParseCustomWords(lowercaser, request.Form.Get("custom_words"))
 
-	var requestErrors []string
 	if languageInvalid != nil {
 		requestErrors = append(requestErrors, languageInvalid.Error())
 	}
@@ -136,14 +151,23 @@ func (handler *V1Handler) postLobby(writer http.ResponseWriter, request *http.Re
 	}
 
 	playerName := GetPlayername(request)
-	player, lobby, err := game.CreateLobby(playerName, languageKey,
-		publicLobby, drawingTime, rounds, maxPlayers, customWordsPerTurn,
-		clientsPerIPLimit, customWords)
+	player, lobby, err := game.CreateLobby(desiredLobbyId, playerName,
+		languageKey, publicLobby, drawingTime, rounds, maxPlayers,
+		customWordsPerTurn, clientsPerIPLimit, customWords)
 	if err != nil {
 		http.Error(writer, err.Error(), http.StatusBadRequest)
 		return
 	}
 
+	// Due to the fact the IDs can be chosen manually, there's a big clash
+	// potential! However, since we only allow specifying this via the rest API
+	// we treat this here. This can't be treated in the game package right now
+	// anyway though, as there'd be an import cycle.
+	if state.GetLobby(lobby.LobbyID) != nil {
+		http.Error(writer, "lobby id already in use", http.StatusBadRequest)
+		return
+	}
+
 	lobby.WriteObject = WriteObject
 	lobby.WritePreparedMessage = WritePreparedMessage
 	player.SetLastKnownAddress(GetIPAddressFromRequest(request))

internal/frontend/create.go

@@ -8,6 +8,7 @@ import (
 	"log"
 	"net/http"
 
+	"github.com/gofrs/uuid/v5"
 	"github.com/scribble-rs/scribble.rs/internal/api"
 	"github.com/scribble-rs/scribble.rs/internal/config"
 	"github.com/scribble-rs/scribble.rs/internal/game"
@@ -171,7 +172,7 @@ func (handler *SSRHandler) ssrCreateLobby(writer http.ResponseWriter, request *h
 
 	playerName := api.GetPlayername(request)
 
-	player, lobby, err := game.CreateLobby(playerName, languageKey,
+	player, lobby, err := game.CreateLobby(uuid.Nil, playerName, languageKey,
 		publicLobby, drawingTime, rounds, maxPlayers, customWordsPerTurn,
 		clientsPerIPLimit, customWords)
 	if err != nil {

internal/game/lobby.go

@@ -908,13 +908,17 @@ func (lobby *Lobby) selectWord(wordChoiceIndex int) {
 // CreateLobby creates a new lobby including the initial player (owner) and
 // optionally returns an error, if any occurred during creation.
 func CreateLobby(
+	desiredLobbyId uuid.UUID,
 	playerName, chosenLanguage string,
 	publicLobby bool,
 	drawingTime, rounds, maxPlayers, customWordsPerTurn, clientsPerIPLimit int,
 	customWords []string,
 ) (*Player, *Lobby, error) {
+	if desiredLobbyId == uuid.Nil {
+		desiredLobbyId = uuid.Must(uuid.NewV4())
+	}
 	lobby := &Lobby{
-		LobbyID: uuid.Must(uuid.NewV4()).String(),
+		LobbyID: desiredLobbyId.String(),
 		EditableLobbySettings: EditableLobbySettings{
 			Rounds:             rounds,
 			DrawingTime:        drawingTime,

internal/state/lobbies_test.go

@@ -3,6 +3,7 @@ package state
 import (
 	"testing"
 
+	"github.com/gofrs/uuid/v5"
 	"github.com/scribble-rs/scribble.rs/internal/config"
 	"github.com/scribble-rs/scribble.rs/internal/game"
 	"github.com/stretchr/testify/require"
@@ -13,7 +14,7 @@ func TestAddAndRemove(t *testing.T) {
 	require.Empty(t, lobbies, "Lobbies should be empty when test starts")
 
 	createLobby := func() *game.Lobby {
-		player, lobby, err := game.CreateLobby("player", "dutch", true, 100, 10, 10, 3, 1, nil)
+		player, lobby, err := game.CreateLobby(uuid.Nil, "player", "dutch", true, 100, 10, 10, 3, 1, nil)
 		require.NoError(t, err)
 		lobby.OnPlayerDisconnect(player)
 		return lobby