1package server
2
3import (
4 "context"
5 "encoding/json"
6 "errors"
7 "sync"
8 "time"
9
10 "github.com/gofrs/uuid"
11 "github.com/speps/go-hashids"
12 "github.com/zikaeroh/codies/internal/game"
13 "github.com/zikaeroh/codies/internal/protocol"
14 "github.com/zikaeroh/ctxjoin"
15 "github.com/zikaeroh/ctxlog"
16 "go.uber.org/atomic"
17 "go.uber.org/zap"
18 "golang.org/x/sync/errgroup"
19 "nhooyr.io/websocket"
20 "nhooyr.io/websocket/wsjson"
21)
22
23const maxRooms = 1000
24
25var (
26 ErrRoomExists = errors.New("server: rooms exist")
27 ErrTooManyRooms = errors.New("server: too many rooms")
28)
29
30type Server struct {
31 clientCount atomic.Int64
32 roomCount atomic.Int64
33 doPrune chan struct{}
34 ready chan struct{}
35
36 mu sync.Mutex
37
38 ctx context.Context
39 rooms map[string]*Room
40 roomIDs map[string]*Room
41
42 hid *hashids.HashID
43 nextID int64
44}
45
46func NewServer() *Server {
47 hd := hashids.NewData()
48 hd.MinLength = 8
49 hd.Salt = uuid.Must(uuid.NewV4()).String() // IDs are only valid for this server instance; ok to randomize salt.
50 hid, err := hashids.NewWithData(hd)
51 if err != nil {
52 panic(err)
53 }
54
55 return &Server{
56 ready: make(chan struct{}),
57 doPrune: make(chan struct{}, 1),
58 rooms: make(map[string]*Room),
59 roomIDs: make(map[string]*Room),
60 hid: hid,
61 }
62}
63
64func (s *Server) Run(ctx context.Context) error {
65 s.ctx = ctx
66
67 close(s.ready)
68 ticker := time.NewTicker(5 * time.Minute)
69 defer ticker.Stop()
70
71 for {
72 select {
73 case <-ctx.Done():
74 return ctx.Err()
75
76 case <-s.doPrune:
77 s.prune(ctx)
78
79 case <-ticker.C:
80 s.prune(ctx)
81 }
82 }
83}
84
85func (s *Server) FindRoom(name string) *Room {
86 <-s.ready
87
88 s.mu.Lock()
89 defer s.mu.Unlock()
90 return s.rooms[name]
91}
92
93func (s *Server) FindRoomByID(id string) *Room {
94 <-s.ready
95
96 s.mu.Lock()
97 defer s.mu.Unlock()
98 return s.roomIDs[id]
99}
100
101func (s *Server) CreateRoom(ctx context.Context, name, password string) (*Room, error) {
102 <-s.ready
103
104 s.mu.Lock()
105 defer s.mu.Unlock()
106
107 room := s.rooms[name]
108 if room != nil {
109 return nil, ErrRoomExists
110 }
111
112 if len(s.rooms) >= maxRooms {
113 return nil, ErrTooManyRooms
114 }
115
116 id, err := s.hid.EncodeInt64([]int64{s.nextID})
117 if err != nil {
118 return nil, err
119 }
120 s.nextID++
121
122 roomCtx, roomCancel := context.WithCancel(s.ctx)
123
124 room = &Room{
125 Name: name,
126 Password: password,
127 ID: id,
128 clientCount: &s.clientCount,
129 roomCount: &s.roomCount,
130 ctx: roomCtx,
131 cancel: roomCancel,
132 room: game.NewRoom(nil),
133 players: make(map[game.PlayerID]noteSender),
134 turnSeconds: 60,
135 }
136
137 room.lastSeen.Store(time.Now())
138
139 room.room.NewGame()
140
141 s.rooms[name] = room
142 s.roomIDs[room.ID] = room
143 s.roomCount.Inc()
144 metricRooms.Inc()
145
146 ctxlog.Info(ctx, "created new room", zap.String("name", name), zap.String("id", room.ID))
147
148 if s.nextID%100 == 0 {
149 s.triggerPrune()
150 }
151
152 return room, nil
153}
154
155func (s *Server) triggerPrune() {
156 select {
157 case s.doPrune <- struct{}{}:
158 default:
159 }
160}
161
162func (s *Server) prune(ctx context.Context) {
163 s.mu.Lock()
164 defer s.mu.Unlock()
165
166 toRemove := make([]string, 0, 1)
167
168 for name, room := range s.rooms {
169 lastSeen := room.lastSeen.Load().(time.Time)
170 if time.Since(lastSeen) > 10*time.Minute {
171 toRemove = append(toRemove, name)
172 }
173 }
174
175 if len(toRemove) == 0 {
176 return
177 }
178
179 for _, name := range toRemove {
180 room := s.rooms[name]
181 room.mu.Lock()
182 room.stopTimer()
183 room.mu.Unlock()
184
185 room.cancel()
186 delete(s.rooms, name)
187 delete(s.roomIDs, room.ID)
188 s.roomCount.Dec()
189 metricRooms.Dec()
190 }
191
192 ctxlog.Info(ctx, "pruned rooms", zap.Int("count", len(toRemove)))
193}
194
195func (s *Server) Stats() (rooms, clients int) {
196 s.mu.Lock()
197 defer s.mu.Unlock()
198 return len(s.rooms), int(s.clientCount.Load())
199}
200
201type Room struct {
202 Name string
203 Password string
204 ID string
205
206 ctx context.Context
207 cancel context.CancelFunc
208 clientCount *atomic.Int64
209 roomCount *atomic.Int64
210
211 mu sync.Mutex
212 room *game.Room
213 players map[game.PlayerID]noteSender
214 state *stateCache
215 lastSeen atomic.Value
216
217 timed bool
218 turnSeconds int
219 turnDeadline *time.Time
220 turnTimer *time.Timer
221
222 hideBomb bool
223}
224
225type noteSender func(protocol.ServerNote)
226
227func (r *Room) HandleConn(ctx context.Context, nickname string, c *websocket.Conn) {
228 playerID := uuid.Must(uuid.NewV4())
229
230 ctx, cancel := ctxjoin.AddCancel(ctx, r.ctx)
231 defer cancel()
232
233 ctx = ctxlog.With(ctx, zap.String("roomName", r.Name), zap.String("roomID", r.ID), zap.String("nickname", nickname))
234
235 metricClients.Inc()
236 defer metricClients.Dec()
237
238 clientCount := r.clientCount.Inc()
239 ctxlog.Info(ctx, "client connected", zap.Int64("clientCount", clientCount), zap.Int64("roomCount", r.roomCount.Load()))
240
241 defer func() {
242 clientCount := r.clientCount.Dec()
243 ctxlog.Info(ctx, "client disconnected", zap.Int64("clientCount", clientCount), zap.Int64("roomCount", r.roomCount.Load()))
244 }()
245
246 defer c.Close(websocket.StatusGoingAway, "going away")
247
248 g, ctx := errgroup.WithContext(ctx)
249
250 r.mu.Lock()
251 r.players[playerID] = func(s protocol.ServerNote) {
252 if ctx.Err() != nil {
253 return
254 }
255
256 // It's not safe to start more group goroutines concurrently; just use a regular
257 // goroutine and hope that errors here will be reflected later via ping/receive failures.
258 go func() {
259 ctx, cancel := context.WithTimeout(ctx, time.Second)
260 defer cancel()
261 if err := wsjson.Write(ctx, c, &s); err != nil {
262 return
263 }
264 metricSent.Inc()
265 }()
266 }
267 r.room.AddPlayer(playerID, nickname)
268 r.sendAll()
269 r.mu.Unlock()
270
271 defer func() {
272 r.mu.Lock()
273 defer r.mu.Unlock()
274 delete(r.players, playerID)
275 r.room.RemovePlayer(playerID)
276 r.sendAll()
277 }()
278
279 g.Go(func() error {
280 <-ctx.Done()
281 return c.Close(websocket.StatusGoingAway, "going away")
282 })
283
284 g.Go(func() error {
285 ticker := time.NewTicker(time.Minute)
286 defer ticker.Stop()
287
288 for {
289 select {
290 case <-ctx.Done():
291 return ctx.Err()
292 case <-ticker.C:
293 }
294
295 if err := c.Ping(ctx); err != nil {
296 return err
297 }
298
299 r.lastSeen.Store(time.Now())
300 }
301 })
302
303 g.Go(func() error {
304 for {
305 var note protocol.ClientNote
306
307 if err := wsjson.Read(ctx, c, ¬e); err != nil {
308 return err
309 }
310
311 ctx = ctxlog.With(ctx, zap.String("method", string(note.Method)))
312
313 r.lastSeen.Store(time.Now())
314 metricReceived.Inc()
315
316 if err := r.handleNote(ctx, playerID, ¬e); err != nil {
317 metricHandleErrors.Inc()
318 ctxlog.Error(ctx, "error handling note", zap.Error(err))
319 return err
320 }
321 }
322 })
323
324 _ = g.Wait()
325}
326
327var errMissingPlayer = errors.New("missing player during handleNote")
328
329func (r *Room) handleNote(ctx context.Context, playerID game.PlayerID, note *protocol.ClientNote) error {
330 r.mu.Lock()
331 defer r.mu.Unlock()
332
333 // The client's version was wrong; reject and send them the current state.
334 if note.Version != r.room.Version {
335 p := r.players[playerID]
336 if p == nil {
337 return errMissingPlayer
338 }
339 r.sendOne(playerID, p)
340 return nil
341 }
342
343 before := r.room.Version
344 resetTimer := false
345
346 defer func() {
347 if r.room.Version != before {
348 if r.timed && resetTimer {
349 r.startTimer()
350 }
351 r.sendAll()
352 }
353 }()
354
355 switch note.Method {
356 case protocol.RevealMethod:
357 var params protocol.RevealParams
358 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
359 return err
360 }
361 prevTurn := r.room.Turn
362 r.room.Reveal(playerID, params.Row, params.Col)
363 resetTimer = prevTurn != r.room.Turn
364
365 case protocol.NewGameMethod:
366 var params protocol.NewGameParams
367 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
368 return err
369 }
370 resetTimer = true
371 r.room.NewGame()
372
373 case protocol.EndTurnMethod:
374 var params protocol.EndTurnParams
375 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
376 return err
377 }
378 resetTimer = true
379 r.room.EndTurn(playerID)
380
381 case protocol.RandomizeTeamsMethod:
382 var params protocol.RandomizeTeamsParams
383 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
384 return err
385 }
386 r.room.RandomizeTeams()
387
388 case protocol.ChangeTeamMethod:
389 var params protocol.ChangeTeamParams
390 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
391 return err
392 }
393 r.room.ChangeTeam(playerID, params.Team)
394
395 case protocol.ChangeNicknameMethod:
396 var params protocol.ChangeNicknameParams
397 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
398 return err
399 }
400
401 // Sync with protocol.go's validation method.
402 if len(params.Nickname) == 0 || len(params.Nickname) > 16 {
403 return nil
404 }
405
406 r.room.AddPlayer(playerID, params.Nickname)
407
408 case protocol.ChangeRoleMethod:
409 var params protocol.ChangeRoleParams
410 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
411 return err
412 }
413 r.room.ChangeRole(playerID, params.Spymaster)
414
415 case protocol.ChangePackMethod:
416 var params protocol.ChangePackParams
417 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
418 return err
419 }
420 r.room.ChangePack(params.Num, params.Enable)
421
422 case protocol.ChangeTurnModeMethod:
423 var params protocol.ChangeTurnModeParams
424 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
425 return err
426 }
427 r.changeTurnMode(params.Timed)
428
429 case protocol.ChangeTurnTimeMethod:
430 var params protocol.ChangeTurnTimeParams
431 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
432 return err
433 }
434 r.changeTurnTime(params.Seconds)
435
436 case protocol.AddPacksMethod:
437 var params protocol.AddPacksParams
438 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
439 return err
440 }
441 for _, p := range params.Packs {
442 if len(p.Words) < 25 {
443 continue
444 }
445 r.room.AddPack(p.Name, p.Words)
446 }
447
448 case protocol.RemovePackMethod:
449 var params protocol.RemovePackParams
450 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
451 return err
452 }
453 r.room.RemovePack(params.Num)
454
455 case protocol.ChangeHideBombMethod:
456 var params protocol.ChangeHideBombParams
457 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
458 return err
459 }
460 r.changeHideBomb(params.HideBomb)
461
462 default:
463 ctxlog.Warn(ctx, "unhandled method")
464 }
465
466 return nil
467}
468
469// Must be called with r.mu locked.
470func (r *Room) sendAll() {
471 for playerID, sender := range r.players {
472 r.sendOne(playerID, sender)
473 }
474}
475
476// Must be called with r.mu locked.
477func (r *Room) sendOne(playerID game.PlayerID, sender noteSender) {
478 state := r.createStateFor(playerID)
479 note := protocol.NewStateNote(playerID, state)
480 sender(note)
481}
482
483// Must be called with r.mu locked.
484func (r *Room) createStateFor(playerID game.PlayerID) *protocol.RoomState {
485 if r.state == nil || r.state.version != r.room.Version {
486 r.state = r.createStateCache()
487 }
488
489 // Temporary verbose access to attempt to figure out which of these is (impossibly) failing.
490 room := r.room
491 players := room.Players
492 player := players[playerID]
493 spymaster := player.Spymaster
494
495 if spymaster {
496 return r.state.spymaster
497 }
498 return r.state.guesser
499}
500
501type stateCache struct {
502 version int
503 guesser *protocol.RoomState
504 spymaster *protocol.RoomState
505}
506
507func (r *Room) createStateCache() *stateCache {
508 return &stateCache{
509 version: r.room.Version,
510 guesser: r.createRoomState(false),
511 spymaster: r.createRoomState(true),
512 }
513}
514
515func (r *Room) createRoomState(spymaster bool) *protocol.RoomState {
516 room := r.room
517
518 s := &protocol.RoomState{
519 Version: room.Version,
520 Teams: make([][]*protocol.StatePlayer, len(room.Teams)),
521 Turn: room.Turn,
522 Winner: room.Winner,
523 Board: make([][]*protocol.StateTile, room.Board.Rows),
524 WordsLeft: room.Board.WordCounts,
525 Lists: make([]*protocol.StateWordList, len(room.WordLists)),
526 HideBomb: r.hideBomb,
527 }
528
529 if r.turnDeadline != nil {
530 s.Timer = &protocol.StateTimer{
531 TurnTime: r.turnSeconds,
532 TurnEnd: *r.turnDeadline,
533 }
534 }
535
536 for team, members := range room.Teams {
537 for _, id := range members {
538 p := room.Players[id]
539 s.Teams[team] = append(s.Teams[team], &protocol.StatePlayer{
540 PlayerID: id,
541 Nickname: p.Nickname,
542 Spymaster: p.Spymaster,
543 })
544 }
545
546 if s.Teams[team] == nil {
547 s.Teams[team] = []*protocol.StatePlayer{}
548 }
549 }
550
551 for row := range s.Board {
552 tiles := make([]*protocol.StateTile, room.Board.Cols)
553 for col := range tiles {
554 tile := room.Board.Get(row, col)
555 sTile := &protocol.StateTile{
556 Word: tile.Word,
557 Revealed: tile.Revealed,
558 }
559
560 if spymaster || tile.Revealed || room.Winner != nil {
561 view := &protocol.StateView{
562 Team: tile.Team,
563 Neutral: tile.Neutral,
564 Bomb: tile.Bomb,
565 }
566
567 if view.Bomb && !tile.Revealed && room.Winner == nil && r.hideBomb {
568 view.Neutral = true
569 view.Bomb = false
570 }
571
572 sTile.View = view
573 }
574
575 tiles[col] = sTile
576 }
577
578 s.Board[row] = tiles
579 }
580
581 for i, wl := range room.WordLists {
582 s.Lists[i] = &protocol.StateWordList{
583 Name: wl.Name,
584 Count: wl.List.Len(),
585 Custom: wl.Custom,
586 Enabled: wl.Enabled,
587 }
588 }
589
590 return s
591}
592
593// Must be called with r.mu locked.
594func (r *Room) changeTurnMode(timed bool) {
595 if r.timed == timed {
596 return
597 }
598
599 r.timed = timed
600
601 if timed {
602 r.startTimer()
603 } else {
604 r.stopTimer()
605 }
606
607 r.room.Version++
608}
609
610// Must be called with r.mu locked.
611func (r *Room) changeTurnTime(seconds int) {
612 if seconds <= 0 || r.turnSeconds == seconds {
613 return
614 }
615
616 r.turnSeconds = seconds
617
618 if r.timed {
619 r.startTimer()
620 }
621
622 r.room.Version++
623}
624
625func (r *Room) timerEndTurn() {
626 r.mu.Lock()
627 defer r.mu.Unlock()
628
629 stopped := r.stopTimer()
630 if !stopped {
631 // Room was pruned.
632 return
633 }
634
635 r.turnTimer = nil
636 r.turnDeadline = nil
637
638 if r.room.Winner != nil || r.turnSeconds == 0 {
639 return
640 }
641
642 r.room.ForceEndTurn()
643 r.startTimer()
644 r.sendAll()
645}
646
647// Must be called with r.mu locked.
648func (r *Room) stopTimer() (stopped bool) {
649 if r.turnTimer != nil {
650 r.turnTimer.Stop()
651 stopped = true
652 }
653 r.turnTimer = nil
654 r.turnDeadline = nil
655 return stopped
656}
657
658// Must be called with r.mu locked.
659func (r *Room) startTimer() {
660 if !r.timed {
661 panic("startTimer called on non-timed room")
662 }
663
664 if r.turnTimer != nil {
665 r.turnTimer.Stop()
666 }
667
668 dur := time.Second * time.Duration(r.turnSeconds)
669 deadline := time.Now().Add(dur)
670 r.turnDeadline = &deadline
671 r.turnTimer = time.AfterFunc(dur, r.timerEndTurn)
672}
673
674// Must be called with r.mu locked.
675func (r *Room) changeHideBomb(HideBomb bool) {
676 if r.hideBomb == HideBomb {
677 return
678 }
679
680 r.hideBomb = HideBomb
681 r.room.Version++
682}