implement game turn logic

2026-11-02 21:24:32 +03:00
parent 153dc74ff6
commit 189b027a11
7 changed files with 896 additions and 13 deletions
@@ -23,6 +23,7 @@ var (
 	ErrUnexpectedState    = errors.New("unexpected state for placing ships")
 	ErrShipsAlreadyPlaced = errors.New("ships already placed")
 	ErrInvalidSlot        = errors.New("invalid slot index")
+	ErrNotYourTurn        = errors.New("not your turn")
 )

 // BoardSize is the width and height of the Sea Battle board.
@@ -99,9 +100,11 @@ type PlayerSlot struct {
 	lastState     int  // last state sent to this player, 0 if none
 	everConnected bool // true after the first successful join

-	ships       []protocol.Ship
-	board       Board
-	shipsPlaced bool
+	ships          []protocol.Ship
+	board          Board
+	shipsPlaced    bool
+	struck         [BoardSize][BoardSize]bool
+	shipsRemaining int
 }

 // Match is the state of a single game of sea battle.
@@ -156,6 +159,26 @@ func (m *Match) Board(slotIdx int) (Board, bool) {
 	return m.slots[slotIdx].board, m.slots[slotIdx].shipsPlaced
 }

+// Struck returns a copy of the struck grid for the player in slotIdx.
+func (m *Match) Struck(slotIdx int) ([BoardSize][BoardSize]bool, bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if slotIdx < 0 || slotIdx >= len(m.slots) {
+		return [BoardSize][BoardSize]bool{}, false
+	}
+	return m.slots[slotIdx].struck, true
+}
+
+// ShipsRemaining returns the number of unsunk ships for the player in slotIdx.
+func (m *Match) ShipsRemaining(slotIdx int) int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if slotIdx < 0 || slotIdx >= len(m.slots) {
+		return -1
+	}
+	return m.slots[slotIdx].shipsRemaining
+}
+
 func (m *Match) slotIndex(userID int64) int {
 	switch userID {
 	case m.playerIDs[0]:
@@ -395,11 +418,119 @@ func (m *Manager) PlaceShips(ctx context.Context, match *Match, slotIdx int, shi
 	copy(slot.ships, ships)
 	slot.board = NewBoard(ships)
 	slot.shipsPlaced = true
+	slot.shipsRemaining = len(ships)
+	slot.struck = [BoardSize][BoardSize]bool{}

 	m.setStateLocked(ctx, match, nextState)
 	return nil
 }

+// Fire processes a shot from the player at slotIdx towards opponent's board (1 - slotIdx).
+// If the player does not have the right of turn, the message is ignored and ErrNotYourTurn is returned.
+// If the position is out of bounds or already struck, FireResultInvalidPosition is sent to the shooter.
+// Otherwise:
+// - Miss: marks cell as struck, sends FireResultMiss to shooter, turn passes to opponent.
+// - Hit: marks cell as struck, sends FireResultHit to shooter, turn does not pass.
+// - Sunk: marks ship and all surrounding cells (including diagonals) as struck, sends FireResultSunk to shooter.
+//   If all opponent ships are destroyed, match finishes: END messages (victory/defeat) are sent to both players,
+//   and connections are closed immediately.
+//   Otherwise, turn does not pass.
+func (m *Manager) Fire(ctx context.Context, match *Match, slotIdx int, x, y int) (int, error) {
+	res, won, matchID, err := m.fireLocked(ctx, match, slotIdx, x, y)
+	if won {
+		// TODO: Report match result to main-server once endpoint is ready.
+		m.finishGame(matchID, slotIdx)
+	}
+	return res, err
+}
+
+func (m *Manager) fireLocked(ctx context.Context, match *Match, slotIdx int, x, y int) (res int, won bool, matchID string, err error) {
+	match.mu.Lock()
+	defer match.mu.Unlock()
+
+	if match.ended {
+		return 0, false, "", ErrMatchFinished
+	}
+	if !match.started {
+		return 0, false, "", ErrMatchNotStarted
+	}
+	if slotIdx < 0 || slotIdx >= len(match.slots) {
+		return 0, false, "", ErrInvalidSlot
+	}
+
+	var isTurn bool
+	switch match.state {
+	case StatePlayer1Turn:
+		isTurn = (slotIdx == 0)
+	case StatePlayer2Turn:
+		isTurn = (slotIdx == 1)
+	}
+	if !isTurn {
+		return 0, false, "", ErrNotYourTurn
+	}
+
+	shooter := match.slots[slotIdx]
+	target := match.slots[1-slotIdx]
+
+	if x < 0 || x >= BoardSize || y < 0 || y >= BoardSize || target.struck[y][x] {
+		m.queueFireResultLocked(ctx, shooter, protocol.FireResultInvalidPosition)
+		return protocol.FireResultInvalidPosition, false, "", nil
+	}
+
+	shipID := target.board[y][x]
+	if shipID == 0 {
+		target.struck[y][x] = true
+		m.queueFireResultLocked(ctx, shooter, protocol.FireResultMiss)
+
+		var nextState int
+		if slotIdx == 0 {
+			nextState = StatePlayer2Turn
+		} else {
+			nextState = StatePlayer1Turn
+		}
+		m.setStateLocked(ctx, match, nextState)
+		return protocol.FireResultMiss, false, "", nil
+	}
+
+	target.struck[y][x] = true
+	shipIdx := int(shipID - 1)
+	ship := target.ships[shipIdx]
+
+	sunk := true
+	for _, c := range ship.Cells() {
+		if !target.struck[c.Y][c.X] {
+			sunk = false
+			break
+		}
+	}
+
+	if !sunk {
+		m.queueFireResultLocked(ctx, shooter, protocol.FireResultHit)
+		return protocol.FireResultHit, false, "", nil
+	}
+
+	for _, c := range ship.Cells() {
+		for dy := -1; dy <= 1; dy++ {
+			for dx := -1; dx <= 1; dx++ {
+				nx, ny := c.X+dx, c.Y+dy
+				if nx >= 0 && nx < BoardSize && ny >= 0 && ny < BoardSize {
+					target.struck[ny][nx] = true
+				}
+			}
+		}
+	}
+	target.shipsRemaining--
+
+	m.queueFireResultLocked(ctx, shooter, protocol.FireResultSunk)
+
+	if target.shipsRemaining == 0 {
+		match.state = 0
+		return protocol.FireResultSunk, true, match.ID, nil
+	}
+
+	return protocol.FireResultSunk, false, "", nil
+}
+
 // SetState moves the match into a new server-side state and notifies both players.
 func (m *Manager) SetState(ctx context.Context, match *Match, state int) {
 	match.mu.Lock()
@@ -433,6 +564,18 @@ func (m *Manager) queueStateLocked(ctx context.Context, slot *PlayerSlot, state
 	}
 }

+// queueFireResultLocked appends a FIRE_RESULT message to the player's unacknowledged
+// queue and sends it right away if the player is connected.
+// match.mu must be held.
+func (m *Manager) queueFireResultLocked(ctx context.Context, slot *PlayerSlot, result int) {
+	slot.seq++
+	data := protocol.BuildFireResult(slot.seq, result)
+	slot.unacked = append(slot.unacked, queuedMessage{seq: slot.seq, data: data})
+	if slot.conn != nil {
+		_ = slot.conn.Send(ctx, data)
+	}
+}
+
 // replayLocked re-sends everything the connected player has not
 // acknowledged yet; if there is nothing pending, the current state is sent
 // anew so a reconnected client can catch up.
@@ -483,10 +626,25 @@ func (m *Manager) onJoinTimeout(matchID string) {
 	m.finishMatchLocked(match, protocol.EndCodeJoinTimeout, "join timeout exceeded")
 }

+type playerEnd struct {
+	code   int
+	reason string
+}
+
 // finishMatchLocked tears down a match, removes it from m.matches, records it in m.finished,
-// and sends END notifications to connected players. Both m.mu and match.mu must be held
+// and sends identical END notifications to all players. Both m.mu and match.mu must be held
 // upon entry; both are unlocked by this function.
 func (m *Manager) finishMatchLocked(match *Match, code int, reason string) {
+	m.finishMatchWithEndsLocked(match, [2]playerEnd{
+		{code: code, reason: reason},
+		{code: code, reason: reason},
+	})
+}
+
+// finishMatchWithEndsLocked tears down a match, removes it from m.matches, records it in m.finished,
+// and sends per-player END notifications to connected players. Both m.mu and match.mu must be held
+// upon entry; both are unlocked by this function.
+func (m *Manager) finishMatchWithEndsLocked(match *Match, endsPerSlot [2]playerEnd) {
 	match.ended = true
 	if match.joinTimer != nil {
 		match.joinTimer.Stop()
@@ -499,9 +657,10 @@ func (m *Manager) finishMatchLocked(match *Match, code int, reason string) {
 		data []byte
 	}
 	var notify []notification
-	for _, slot := range match.slots {
+	for i, slot := range match.slots {
 		slot.seq++
-		data := protocol.BuildEnd(slot.seq, code, reason)
+		end := endsPerSlot[i]
+		data := protocol.BuildEnd(slot.seq, end.code, end.reason)
 		slot.unacked = append(slot.unacked, queuedMessage{seq: slot.seq, data: data})
 		ends[slot.UserID] = data
 		if slot.conn != nil {
@@ -529,8 +688,43 @@ func (m *Manager) finishMatchLocked(match *Match, code int, reason string) {
 	// Network I/O happens outside of any lock.
 	for _, n := range notify {
 		_ = n.conn.Send(context.Background(), n.data)
-		_ = n.conn.Close(protocol.CloseCodeNormal, "match ended")
 	}
+	var wg sync.WaitGroup
+	for _, n := range notify {
+		wg.Add(1)
+		go func(c Sender) {
+			defer wg.Done()
+			_ = c.Close(protocol.CloseCodeNormal, "match ended")
+		}(n.conn)
+	}
+	wg.Wait()
+}
+
+// finishGame completes a match due to all opponent ships being sunk.
+// winnerSlot is the slot index of the winning player (0 or 1).
+func (m *Manager) finishGame(matchID string, winnerSlot int) {
+	m.mu.Lock()
+	match, ok := m.matches[matchID]
+	if !ok {
+		m.mu.Unlock()
+		return
+	}
+	match.mu.Lock()
+	if match.ended {
+		match.mu.Unlock()
+		m.mu.Unlock()
+		return
+	}
+
+	endsPerSlot := [2]playerEnd{
+		{code: protocol.EndCodeVictory, reason: "victory"},
+		{code: protocol.EndCodeDefeat, reason: "defeat"},
+	}
+	if winnerSlot == 1 {
+		endsPerSlot[0], endsPerSlot[1] = endsPerSlot[1], endsPerSlot[0]
+	}
+
+	m.finishMatchWithEndsLocked(match, endsPerSlot)
 }

 // Shutdown closes all active player connections across all matches with code 1001 (going away)