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