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, playerID uuid.UUID, nickname string, c *websocket.Conn) {
228 ctx, cancel := ctxjoin.AddCancel(ctx, r.ctx)
229 defer cancel()
230
231 ctx = ctxlog.With(ctx, zap.String("roomName", r.Name), zap.String("roomID", r.ID), zap.String("nickname", nickname))
232
233 metricClients.Inc()
234 defer metricClients.Dec()
235
236 clientCount := r.clientCount.Inc()
237 ctxlog.Info(ctx, "client connected", zap.Int64("clientCount", clientCount), zap.Int64("roomCount", r.roomCount.Load()))
238
239 defer func() {
240 clientCount := r.clientCount.Dec()
241 ctxlog.Info(ctx, "client disconnected", zap.Int64("clientCount", clientCount), zap.Int64("roomCount", r.roomCount.Load()))
242 }()
243
244 defer c.Close(websocket.StatusGoingAway, "going away")
245
246 g, ctx := errgroup.WithContext(ctx)
247
248 r.mu.Lock()
249 r.players[playerID] = func(s protocol.ServerNote) {
250 if ctx.Err() != nil {
251 return
252 }
253
254 // It's not safe to start more group goroutines concurrently; just use a regular
255 // goroutine and hope that errors here will be reflected later via ping/receive failures.
256 go func() {
257 ctx, cancel := context.WithTimeout(ctx, time.Second)
258 defer cancel()
259 if err := wsjson.Write(ctx, c, &s); err != nil {
260 return
261 }
262 metricSent.Inc()
263 }()
264 }
265 r.room.AddPlayer(playerID, nickname)
266 r.sendAll()
267 r.mu.Unlock()
268
269 defer func() {
270 r.mu.Lock()
271 defer r.mu.Unlock()
272 delete(r.players, playerID)
273 r.room.RemovePlayer(playerID)
274 r.sendAll()
275 }()
276
277 g.Go(func() error {
278 <-ctx.Done()
279 return c.Close(websocket.StatusGoingAway, "going away")
280 })
281
282 g.Go(func() error {
283 ticker := time.NewTicker(time.Minute)
284 defer ticker.Stop()
285
286 for {
287 select {
288 case <-ctx.Done():
289 return ctx.Err()
290 case <-ticker.C:
291 }
292
293 if err := c.Ping(ctx); err != nil {
294 return err
295 }
296
297 r.lastSeen.Store(time.Now())
298 }
299 })
300
301 g.Go(func() error {
302 for {
303 var note protocol.ClientNote
304
305 if err := wsjson.Read(ctx, c, ¬e); err != nil {
306 return err
307 }
308
309 ctx = ctxlog.With(ctx, zap.String("method", string(note.Method)))
310
311 r.lastSeen.Store(time.Now())
312 metricReceived.Inc()
313
314 if err := r.handleNote(ctx, playerID, ¬e); err != nil {
315 metricHandleErrors.Inc()
316 ctxlog.Error(ctx, "error handling note", zap.Error(err))
317 return err
318 }
319 }
320 })
321
322 _ = g.Wait()
323}
324
325var errMissingPlayer = errors.New("missing player during handleNote")
326
327func (r *Room) handleNote(ctx context.Context, playerID game.PlayerID, note *protocol.ClientNote) error {
328 r.mu.Lock()
329 defer r.mu.Unlock()
330
331 // The client's version was wrong; reject and send them the current state.
332 if note.Version != r.room.Version {
333 p := r.players[playerID]
334 if p == nil {
335 return errMissingPlayer
336 }
337 r.sendOne(playerID, p)
338 return nil
339 }
340
341 before := r.room.Version
342 resetTimer := false
343
344 defer func() {
345 if r.room.Version != before {
346 if r.timed && resetTimer {
347 r.startTimer()
348 }
349 r.sendAll()
350 }
351 }()
352
353 switch note.Method {
354 case protocol.RevealMethod:
355 var params protocol.RevealParams
356 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
357 return err
358 }
359 prevTurn := r.room.Turn
360 r.room.Reveal(playerID, params.Row, params.Col)
361 resetTimer = prevTurn != r.room.Turn
362
363 case protocol.NewGameMethod:
364 var params protocol.NewGameParams
365 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
366 return err
367 }
368 resetTimer = true
369 r.room.NewGame()
370
371 case protocol.EndTurnMethod:
372 var params protocol.EndTurnParams
373 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
374 return err
375 }
376 resetTimer = true
377 r.room.EndTurn(playerID)
378
379 case protocol.RandomizeTeamsMethod:
380 var params protocol.RandomizeTeamsParams
381 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
382 return err
383 }
384 r.room.RandomizeTeams()
385
386 case protocol.ChangeTeamMethod:
387 var params protocol.ChangeTeamParams
388 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
389 return err
390 }
391 r.room.ChangeTeam(playerID, params.Team)
392
393 case protocol.ChangeNicknameMethod:
394 var params protocol.ChangeNicknameParams
395 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
396 return err
397 }
398
399 // Sync with protocol.go's validation method.
400 if len(params.Nickname) == 0 || len(params.Nickname) > 16 {
401 return nil
402 }
403
404 r.room.AddPlayer(playerID, params.Nickname)
405
406 case protocol.ChangeRoleMethod:
407 var params protocol.ChangeRoleParams
408 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
409 return err
410 }
411 r.room.ChangeRole(playerID, params.Spymaster)
412
413 case protocol.ChangePackMethod:
414 var params protocol.ChangePackParams
415 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
416 return err
417 }
418 r.room.ChangePack(params.Num, params.Enable)
419
420 case protocol.ChangeTurnModeMethod:
421 var params protocol.ChangeTurnModeParams
422 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
423 return err
424 }
425 r.changeTurnMode(params.Timed)
426
427 case protocol.ChangeTurnTimeMethod:
428 var params protocol.ChangeTurnTimeParams
429 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
430 return err
431 }
432 r.changeTurnTime(params.Seconds)
433
434 case protocol.AddPacksMethod:
435 var params protocol.AddPacksParams
436 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
437 return err
438 }
439 for _, p := range params.Packs {
440 if len(p.Words) < 25 {
441 continue
442 }
443 r.room.AddPack(p.Name, p.Words)
444 }
445
446 case protocol.RemovePackMethod:
447 var params protocol.RemovePackParams
448 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
449 return err
450 }
451 r.room.RemovePack(params.Num)
452
453 case protocol.ChangeHideBombMethod:
454 var params protocol.ChangeHideBombParams
455 if err := json.Unmarshal(note.Params, ¶ms); err != nil {
456 return err
457 }
458 r.changeHideBomb(params.HideBomb)
459
460 default:
461 ctxlog.Warn(ctx, "unhandled method")
462 }
463
464 return nil
465}
466
467// Must be called with r.mu locked.
468func (r *Room) sendAll() {
469 for playerID, sender := range r.players {
470 r.sendOne(playerID, sender)
471 }
472}
473
474// Must be called with r.mu locked.
475func (r *Room) sendOne(playerID game.PlayerID, sender noteSender) {
476 state := r.createStateFor(playerID)
477 note := protocol.StateNote(state)
478 sender(note)
479}
480
481// Must be called with r.mu locked.
482func (r *Room) createStateFor(playerID game.PlayerID) *protocol.State {
483 if r.state == nil || r.state.version != r.room.Version {
484 r.state = r.createStateCache()
485 }
486
487 // Temporary verbose access to attempt to figure out which of these is (impossibly) failing.
488 room := r.room
489 players := room.Players
490 player := players[playerID]
491 spymaster := player.Spymaster
492
493 if spymaster {
494 return r.state.spymaster
495 }
496 return r.state.guesser
497}
498
499type stateCache struct {
500 version int
501 guesser *protocol.State
502 spymaster *protocol.State
503}
504
505func (r *Room) createStateCache() *stateCache {
506 return &stateCache{
507 version: r.room.Version,
508 guesser: r.createRoomState(false),
509 spymaster: r.createRoomState(true),
510 }
511}
512
513func (r *Room) createRoomState(spymaster bool) *protocol.State {
514 room := r.room
515
516 s := &protocol.State{
517 Version: room.Version,
518 Teams: make([][]*protocol.StatePlayer, len(room.Teams)),
519 Turn: room.Turn,
520 Winner: room.Winner,
521 Board: make([][]*protocol.StateTile, room.Board.Rows),
522 WordsLeft: room.Board.WordCounts,
523 Lists: make([]*protocol.StateWordList, len(room.WordLists)),
524 HideBomb: r.hideBomb,
525 }
526
527 if r.turnDeadline != nil {
528 s.Timer = &protocol.StateTimer{
529 TurnTime: r.turnSeconds,
530 TurnEnd: *r.turnDeadline,
531 }
532 }
533
534 for team, members := range room.Teams {
535 for _, id := range members {
536 p := room.Players[id]
537 s.Teams[team] = append(s.Teams[team], &protocol.StatePlayer{
538 PlayerID: id,
539 Nickname: p.Nickname,
540 Spymaster: p.Spymaster,
541 })
542 }
543
544 if s.Teams[team] == nil {
545 s.Teams[team] = []*protocol.StatePlayer{}
546 }
547 }
548
549 for row := range s.Board {
550 tiles := make([]*protocol.StateTile, room.Board.Cols)
551 for col := range tiles {
552 tile := room.Board.Get(row, col)
553 sTile := &protocol.StateTile{
554 Word: tile.Word,
555 Revealed: tile.Revealed,
556 }
557
558 if spymaster || tile.Revealed || room.Winner != nil {
559 view := &protocol.StateView{
560 Team: tile.Team,
561 Neutral: tile.Neutral,
562 Bomb: tile.Bomb,
563 }
564
565 if view.Bomb && !tile.Revealed && room.Winner == nil && r.hideBomb {
566 view.Neutral = true
567 view.Bomb = false
568 }
569
570 sTile.View = view
571 }
572
573 tiles[col] = sTile
574 }
575
576 s.Board[row] = tiles
577 }
578
579 for i, wl := range room.WordLists {
580 s.Lists[i] = &protocol.StateWordList{
581 Name: wl.Name,
582 Count: wl.List.Len(),
583 Custom: wl.Custom,
584 Enabled: wl.Enabled,
585 }
586 }
587
588 return s
589}
590
591// Must be called with r.mu locked.
592func (r *Room) changeTurnMode(timed bool) {
593 if r.timed == timed {
594 return
595 }
596
597 r.timed = timed
598
599 if timed {
600 r.startTimer()
601 } else {
602 r.stopTimer()
603 }
604
605 r.room.Version++
606}
607
608// Must be called with r.mu locked.
609func (r *Room) changeTurnTime(seconds int) {
610 if seconds <= 0 || r.turnSeconds == seconds {
611 return
612 }
613
614 r.turnSeconds = seconds
615
616 if r.timed {
617 r.startTimer()
618 }
619
620 r.room.Version++
621}
622
623func (r *Room) timerEndTurn() {
624 r.mu.Lock()
625 defer r.mu.Unlock()
626
627 stopped := r.stopTimer()
628 if !stopped {
629 // Room was pruned.
630 return
631 }
632
633 r.turnTimer = nil
634 r.turnDeadline = nil
635
636 if r.room.Winner != nil || r.turnSeconds == 0 {
637 return
638 }
639
640 r.room.ForceEndTurn()
641 r.startTimer()
642 r.sendAll()
643}
644
645// Must be called with r.mu locked.
646func (r *Room) stopTimer() (stopped bool) {
647 if r.turnTimer != nil {
648 r.turnTimer.Stop()
649 stopped = true
650 }
651 r.turnTimer = nil
652 r.turnDeadline = nil
653 return stopped
654}
655
656// Must be called with r.mu locked.
657func (r *Room) startTimer() {
658 if !r.timed {
659 panic("startTimer called on non-timed room")
660 }
661
662 if r.turnTimer != nil {
663 r.turnTimer.Stop()
664 }
665
666 dur := time.Second * time.Duration(r.turnSeconds)
667 deadline := time.Now().Add(dur)
668 r.turnDeadline = &deadline
669 r.turnTimer = time.AfterFunc(dur, r.timerEndTurn)
670}
671
672// Must be called with r.mu locked.
673func (r *Room) changeHideBomb(HideBomb bool) {
674 if r.hideBomb == HideBomb {
675 return
676 }
677
678 r.hideBomb = HideBomb
679 r.room.Version++
680}