Add protocol specification

PROTOCOL.md

@@ -0,0 +1,82 @@
+# Secification of bgammon protocol
+
+## User commands
+
+Format: `command <required argument> [optional argument]`
+
+### `login [username] [password]`
+
+Log in to bgammon. A random username is assigned when none is provided.
+
+This must be the first command sent when a client connects to bgammon.
+
+### `help [command]`
+
+Request help for all commands, or optionally a specific command.
+
+### `list`
+
+List all games.
+
+### `create [public/private] [password]`
+
+List all games.
+
+### `join [ID] [password]`
+
+Join game.
+
+### `roll`
+
+Roll dice.
+
+### `move <from-to> [from-to]...`
+
+Move checkers.
+
+### `reset`
+
+Reset pending checker movement.
+
+### `ok`
+
+Confirm checker movement and pass turn to next player.
+
+### `disconnect`
+
+Disconnect from the server.
+
+## Server responses
+
+Data types:
+
+- `integer` a whole number
+- `boolean` - `0` (representing false) or `1` (representing true)
+- `text` - alphanumeric without spaces
+- `line` - alphanumeric with spaces
+
+### `hello <message:line>`
+
+Initial welcome message sent by the server. It provides instructions on how to log in.
+
+This message does not normally need to be displayed when using a graphical client.
+
+### `welcome <name:text> there are <clients:integer> clients playing <games:integer> games.`
+
+Initial message sent by the server.
+
+### `notice <message:line>`
+
+Server message. This should always be displayed to the user.
+
+### `liststart Games list:`
+
+Start of games list.
+
+### `game <ID:integer> <password:boolean> <players:integer> <name:line>`
+
+Game description.
+
+### `listend End of games list.`
+
+End of games list.

cmd/bgammon-server/server.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"math/rand"
 	"net"
+	"strconv"
 	"strings"
 	"time"
 
@@ -124,8 +125,18 @@ func (s *server) sendWelcome(c *serverClient) {
 	c.events <- []byte(fmt.Sprintf("welcome %s there are %d clients playing %d games.", c.name, len(s.clients), len(s.games)))
 }
 
+func (s *server) gameByClient(c *serverClient) *serverGame {
+	for _, g := range s.games {
+		if g.client1 == c || g.client2 == c {
+			return g
+		}
+	}
+	return nil
+}
+
 func (s *server) handleCommands() {
 	var cmd serverCommand
+COMMANDS:
 	for cmd = range s.commands {
 		if cmd.client == nil {
 			log.Panicf("nil client with command %s", cmd.command)
@@ -186,6 +197,11 @@ func (s *server) handleCommands() {
 		}
 
 		switch keyword {
+		case bgammon.CommandHelp:
+			// TODO get extended help by specifying a command after help
+			cmd.client.events <- []byte("helpstart Help text:")
+			cmd.client.events <- []byte("help Test help text")
+			cmd.client.events <- []byte("helpend End of help text.")
 		case bgammon.CommandSay:
 			if len(params) == 0 {
 				continue
@@ -196,13 +212,12 @@ func (s *server) handleCommands() {
 			password := 0
 			name := "game name"
 			for _, g := range s.games {
-				cmd.client.events <- []byte(fmt.Sprintf("game %d %d %d %s", g.id, players, password, name))
+				cmd.client.events <- []byte(fmt.Sprintf("game %d %d %d %s", g.id, password, players, name))
 			}
 			cmd.client.events <- []byte("listend End of games list.")
 		case bgammon.CommandCreate:
 			sendUsage := func() {
-				cmd.client.events <- []byte("notice To create a public game specify whether it is public or private.")
-				cmd.client.events <- []byte("notice When creating a private game, a password must be set.")
+				cmd.client.events <- []byte("notice To create a public game specify whether it is public or private. When creating a private game, a password must also be provided.")
 			}
 			if len(params) == 0 {
 				sendUsage()
@@ -232,10 +247,63 @@ func (s *server) handleCommands() {
 			g.name = gameName
 			g.password = gamePassword
 
+			if rand.Intn(2) == 0 { // Start as black.
+				g.client1 = cmd.client
+				g.Player1.Name = string(cmd.client.name)
+			} else { // Start as white.
+				g.client2 = cmd.client
+				g.Player2.Name = string(cmd.client.name)
+			}
+
 			s.games = append(s.games, g)
+
+			players := 1
+			password := 0
+			if len(gamePassword) != 0 {
+				password = 1
+			}
+			cmd.client.events <- []byte(fmt.Sprintf("joined %d %d %d %s", g.id, password, players, gameName))
 		case bgammon.CommandJoin:
+			if s.gameByClient(cmd.client) != nil {
+				cmd.client.events <- []byte("failedjoin Please leave the game you are in before joining another game.")
+				continue
+			}
+
+			sendUsage := func() {
+				cmd.client.events <- []byte("notice To join a public game specify its game ID. To join a private game, a password must also be specified.")
+			}
+
+			if len(params) == 0 {
+				sendUsage()
+				continue
+			}
+			gameID, err := strconv.Atoi(string(params[1]))
+			if err != nil || gameID < 1 {
+				sendUsage()
+				continue
+			}
+
+			for _, g := range s.games {
+				if g.id == gameID {
+					if len(g.password) != 0 && (len(params) < 2 || !bytes.Equal(g.password, bytes.Join(params[2:], []byte(" ")))) {
+						cmd.client.events <- []byte("failedjoin Invalid password.")
+						continue COMMANDS
+					}
+
+					log.Printf("join existing game %+v", g)
+					// cmd.client.events <- []byte(fmt.Sprintf("joined %d %d %d %s", g.id, players, password, gameName))
+					continue COMMANDS
+				}
+			}
+		case bgammon.CommandLeave:
 		case bgammon.CommandRoll:
 		case bgammon.CommandMove:
+		case bgammon.CommandDisconnect:
+			g := s.gameByClient(cmd.client)
+			if g != nil {
+				// todo leave game
+			}
+			cmd.client.Terminate("Client disconnected")
 		default:
 			log.Printf("unknown command %s", keyword)
 		}

command.go

@@ -5,11 +5,16 @@ package bgammon
 type Command string
 
 const (
-	CommandLogin  = "login"  // Log in with username and password, or as a guest.
-	CommandSay    = "say"    // Send chat message.
-	CommandList   = "list"   // List available games.
-	CommandCreate = "create" // Create game.
-	CommandJoin   = "join"   // Join game.
-	CommandRoll   = "roll"   // Roll dice.
-	CommandMove   = "move"   // Move checkers.
+	CommandLogin      = "login"      // Log in with username and password, or as a guest.
+	CommandHelp       = "help"       // Print help information.
+	CommandSay        = "say"        // Send chat message.
+	CommandList       = "list"       // List available games.
+	CommandCreate     = "create"     // Create game.
+	CommandJoin       = "join"       // Join game.
+	CommandLeave      = "leave"      // Leave game.
+	CommandRoll       = "roll"       // Roll dice.
+	CommandMove       = "move"       // Move checkers.
+	CommandReset      = "reset"      // Reset checker movement.
+	CommandOk         = "ok"         // Confirm checker movement and pass turn to next player.
+	CommandDisconnect = "disconnect" // Disconnect from server.
 )

game.go

@@ -13,7 +13,9 @@ type Game struct {
 
 func NewGame() *Game {
 	return &Game{
-		Board: NewBoard(),
+		Board:   NewBoard(),
+		Player1: NewPlayer(1),
+		Player2: NewPlayer(2),
 	}
 }
 

player.go

@@ -4,3 +4,9 @@ type Player struct {
 	Number int // 1 black, 2 white
 	Name   string
 }
+
+func NewPlayer(number int) *Player {
+	return &Player{
+		Number: number,
+	}
+}