Validate moves

README.md

@@ -3,7 +3,7 @@
 [![Donate via LiberaPay](https://img.shields.io/liberapay/receives/rocket9labs.com.svg?logo=liberapay)](https://liberapay.com/rocket9labs.com)
 [![Donate via Patreon](https://img.shields.io/badge/dynamic/json?color=%23e85b46&label=Patreon&query=data.attributes.patron_count&suffix=%20patrons&url=https%3A%2F%2Fwww.patreon.com%2Fapi%2Fcampaigns%2F5252223)](https://www.patreon.com/rocketnine)
 
-**Note:** This is unfinished, alpha-quality software. Here be dragons.
+**Note:** This is unfinished alpha-quality software. Here be dragons.
 
 ## Play
 
@@ -28,3 +28,5 @@ See [bgammon-cli](https://code.rocket9labs.com/tslocum/bgammon-cli)
 Please share issues and suggestions [here](https://code.rocket9labs.com/tslocum/bgammon/issues).
 
 The bgammon protocol is specified in [PROTOCOL.md](https://code.rocket9labs.com/tslocum/bgammon/src/branch/main/PROTOCOL.md). 
+
+For information on how to play backgammon visit https://bkgm.com/rules.html

cmd/bgammon-server/client.go

@@ -106,7 +106,7 @@ func (c *serverClient) sendEvent(e interface{}) {
 	case *bgammon.EventFailedRoll:
 		c.Write([]byte(fmt.Sprintf("failedroll %s", ev.Reason)))
 	case *bgammon.EventMoved:
-		c.Write([]byte(fmt.Sprintf("moved %s %s", ev.Player, bgammon.FormatMoves(ev.Moves, c.playerNumber))))
+		c.Write([]byte(fmt.Sprintf("moved %s %s", ev.Player, bgammon.FormatAndFlipMoves(ev.Moves, c.playerNumber))))
 	case *bgammon.EventFailedMove:
 		c.Write([]byte(fmt.Sprintf("failedmove %d/%d %s", ev.From, ev.To, ev.Reason)))
 	case *bgammon.EventFailedOk:

cmd/bgammon-server/server.go

@@ -346,6 +346,16 @@ COMMANDS:
 				continue
 			}
 
+			// Set default game name.
+			if len(bytes.TrimSpace(gameName)) == 0 {
+				abbr := "'s"
+				lastLetter := cmd.client.name[len(cmd.client.name)-1]
+				if lastLetter == 's' || lastLetter == 'S' {
+					abbr = "'"
+				}
+				gameName = []byte(fmt.Sprintf("%s%s game", cmd.client.name, abbr))
+			}
+
 			g := newServerGame(<-s.newGameIDs)
 			g.name = gameName
 			g.password = gamePassword
@@ -480,6 +490,14 @@ COMMANDS:
 					continue COMMANDS
 				}
 
+				if !bgammon.ValidSpace(from) || !bgammon.ValidSpace(to) {
+					cmd.client.sendEvent(&bgammon.EventFailedMove{
+						From:   from,
+						To:     to,
+						Reason: "Illegal move.",
+					})
+				}
+
 				originalFrom, originalTo := from, to
 				from, to = bgammon.FlipSpace(from, cmd.client.playerNumber), bgammon.FlipSpace(to, cmd.client.playerNumber)
 				log.Printf("translated player %d %d-%d as %d-%d", cmd.client.playerNumber, originalFrom, originalTo, from, to)
@@ -496,9 +514,12 @@ COMMANDS:
 				continue
 			}
 			clientGame.eachClient(func(client *serverClient) {
-				client.sendEvent(&bgammon.EventMoved{
+				ev := &bgammon.EventMoved{
 					Moves: bgammon.FlipMoves(moves, client.playerNumber),
-				})
+				}
+				ev.Player = string(cmd.client.name)
+
+				client.sendEvent(ev)
 				clientGame.sendBoard(client)
 			})
 		case bgammon.CommandReset:
@@ -525,9 +546,12 @@ COMMANDS:
 				cmd.client.sendNotice("Failed to undo move: invalid move.")
 			} else {
 				clientGame.eachClient(func(client *serverClient) {
-					client.sendEvent(&bgammon.EventMoved{
+					ev := &bgammon.EventMoved{
 						Moves: bgammon.FlipMoves(undoMoves, client.playerNumber),
-					})
+					}
+					ev.Player = string(cmd.client.name)
+
+					client.sendEvent(ev)
 					clientGame.sendBoard(client)
 				})
 			}
@@ -544,7 +568,7 @@ COMMANDS:
 					playerNumber = 2
 				}
 				cmd.client.sendEvent(&bgammon.EventFailedOk{
-					Reason: fmt.Sprintf("The following legal moves are available: %s", bgammon.FormatMoves(legalMoves, playerNumber)),
+					Reason: fmt.Sprintf("The following legal moves are available: %s", bgammon.FormatAndFlipMoves(legalMoves, playerNumber)),
 				})
 				continue
 			}

game.go

@@ -592,7 +592,7 @@ func FlipSpace(space int, player int) int {
 		case SpaceBarOpponent:
 			return SpaceBarPlayer
 		default:
-			log.Panicf("unknown space %d", space)
+			return -1
 		}
 	}
 	return 24 - space + 1
@@ -606,18 +606,33 @@ func FlipMoves(moves [][]int, player int) [][]int {
 	return m
 }
 
-func FormatMoves(moves [][]int, player int) []byte {
+func FormatMoves(moves [][]int) []byte {
 	var out bytes.Buffer
 	for i := range moves {
 		if i != 0 {
 			out.WriteByte(' ')
 		}
-		// TODO
-		out.Write([]byte(fmt.Sprintf("{{%d/%d}}", FlipSpace(moves[i][0], player), FlipSpace(moves[i][1], player))))
+		out.Write([]byte(fmt.Sprintf("%d/%d", moves[i][0], moves[i][1])))
 	}
 	return out.Bytes()
 }
 
+func FormatAndFlipMoves(moves [][]int, player int) []byte {
+	return FormatMoves(FlipMoves(moves, player))
+}
+
+func ValidSpace(space int) bool {
+	if space < 1 || space > 24 {
+		return false
+	}
+	switch space {
+	case SpaceHomePlayer, SpaceHomeOpponent, SpaceBarPlayer, SpaceBarOpponent:
+		return true
+	default:
+		return false
+	}
+}
+
 const (
 	VerticalBar rune = '\u2502' // │
 )