Implement help command

Resolves #18.

PROTOCOL.md

@@ -68,14 +68,17 @@ formatted responses are more easily parsed by computers.
   - List all matches.
   - Aliases: `ls`
 
-- `create <public>/<private [password]> <points> <acey> [name]`
-  - Create a match. An `acey` value of 0 represents a standard game, while a value of 1 represents an acey-deucey game.
+- `create <public>/<private [password]> <points> <variant> [name]`
+  - Create a match. A `variant` value of 0 represents a standard game, a value of 1 represents an acey-deucey game and a value of 2 represents a tabula game.
   - Aliases: `c`
 
 - `join <id>/<username> [password]`
   - Join match by match ID or by player.
   - Aliases: `j`
 
+- `leave`
+  - Leave match.
+
 - `double`
   - Offer double to opponent.
   - Aliases: `d`
@@ -123,7 +126,11 @@ must write some data to the server at least once every 40 seconds.
 - `disconnect`
   - Disconnect from the server.
 
-- `broadcast`
+- `motd [message]`
+  - View (or set) message of the day.
+  - Specifying a new message of the day is only available to server administrators.
+
+- `broadcast <message>`
   - Send a message to all players.
   - This command is only available to server administrators.
 

command.go

@@ -58,3 +58,32 @@ const (
 	EventTypeReplay      = "replay"
 	EventTypeHistory     = "history"
 )
+
+var HelpText = map[string]string{
+	CommandLogin:         "[username] [password] - Log in. A random username is assigned when none is provided.",
+	CommandRegister:      "<email> <username> <password> - Register an account. A valid email address must be provided.",
+	CommandResetPassword: "<email> - Request a password reset link via email.",
+	CommandPassword:      "<old> <new> - Change account password.",
+	CommandSet:           "<name> <value> - Change account setting. Available settings: highlight, pips and moves.",
+	CommandReplay:        "<id> - Retrieve replay of the specified game.",
+	CommandHistory:       "<username> [page] - Retrieve match history of the specified player.",
+	CommandHelp:          "[command] - Request help for all commands, or optionally a specific command.",
+	CommandSay:           "<message> - Send a chat message. This command can only be used after creating or joining a match.",
+	CommandList:          "- List all matches.",
+	CommandCreate:        "<public>/<private [password]> <points> <variant> [name] - Create a match. A variant value of 0 represents a standard game, a value of 1 represents an acey-deucey game and a value of 2 represents a tabula game.",
+	CommandJoin:          "<id>/<username> [password] - Join match by match ID or by player.",
+	CommandLeave:         "- Leave match.",
+	CommandDouble:        "- Offer double to opponent.",
+	CommandResign:        "- Resign game. Resigning when a double is offered will decline the offer.",
+	CommandRoll:          "- Roll dice.",
+	CommandMove:          "<from-to> [from-to]... - Move checkers.",
+	CommandReset:         "- Reset pending checker movement.",
+	CommandOk:            "[1-6] - Accept double offer or confirm checker movement. The parameter for this command only applies in acey-deucey games.",
+	CommandRematch:       "- Request (or accept) a rematch after a match has been finished.",
+	CommandBoard:         "- Request current match state.",
+	CommandPong:          "<message> - Sent in response to server ping event to prevent the connection from timing out.",
+	CommandDisconnect:    "- Disconnect from the server.",
+	CommandMOTD:          "[message] - View (or set) message of the day. Specifying a new message of the day is only available to server administrators.",
+	CommandBroadcast:     "<message> - Send a message to all players. This command is only available to server administrators.",
+	CommandShutdown:      "<minutes> <reason> - Prevent the creation of new matches and periodically warn players about the server shutting down. This command is only available to server administrators.",
+}

event.go

@@ -24,12 +24,6 @@ type EventWelcome struct {
 	Games      int
 }
 
-type EventHelp struct {
-	Event
-	Topic   string
-	Message string
-}
-
 type EventPing struct {
 	Event
 	Message string
@@ -169,8 +163,6 @@ func DecodeEvent(message []byte) (interface{}, error) {
 	switch e.Type {
 	case EventTypeWelcome:
 		ev = &EventWelcome{}
-	case EventTypeHelp:
-		ev = &EventHelp{}
 	case EventTypePing:
 		ev = &EventPing{}
 	case EventTypeNotice:

pkg/server/client.go

@@ -95,8 +95,6 @@ func (c *serverClient) sendEvent(e interface{}) {
 		switch ev := e.(type) {
 		case *bgammon.EventWelcome:
 			ev.Type = bgammon.EventTypeWelcome
-		case *bgammon.EventHelp:
-			ev.Type = bgammon.EventTypeHelp
 		case *bgammon.EventPing:
 			ev.Type = bgammon.EventTypePing
 		case *bgammon.EventNotice:
@@ -149,10 +147,6 @@ func (c *serverClient) sendEvent(e interface{}) {
 	switch ev := e.(type) {
 	case *bgammon.EventWelcome:
 		c.Write([]byte(fmt.Sprintf("welcome %s there are %d clients playing %d matches.", ev.PlayerName, ev.Clients, ev.Games)))
-	case *bgammon.EventHelp:
-		c.Write([]byte("helpstart Help text:"))
-		c.Write([]byte(fmt.Sprintf("help %s", ev.Message)))
-		c.Write([]byte("helpend End of help text."))
 	case *bgammon.EventPing:
 		c.Write([]byte(fmt.Sprintf("ping %s", ev.Message)))
 	case *bgammon.EventNotice:

pkg/server/server.go

@@ -15,7 +15,9 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
+	"reflect"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -78,6 +80,8 @@ type server struct {
 
 	motd string
 
+	sortedCommands []string
+
 	mailServer   string
 	passwordSalt string
 	resetSalt    string
@@ -108,6 +112,13 @@ func NewServer(tz string, dataSource string, mailServer string, passwordSalt str
 	}
 	s.loadLocales()
 
+	keys := reflect.ValueOf(bgammon.HelpText).MapKeys()
+	sortKeys := func(i, j int) bool { return keys[i].Interface().(string) < keys[j].Interface().(string) }
+	sort.Slice(keys, sortKeys)
+	for _, key := range keys {
+		s.sortedCommands = append(s.sortedCommands, key.Interface().(string))
+	}
+
 	if tz != "" {
 		var err error
 		s.tz, err = time.LoadLocation(tz)

pkg/server/server_command.go

@@ -257,11 +257,21 @@ COMMANDS:
 
 		switch keyword {
 		case bgammon.CommandHelp, "h":
-			// TODO get extended help by specifying a command after help
-			cmd.client.sendEvent(&bgammon.EventHelp{
-				Topic:   "",
-				Message: "Test help text",
-			})
+			if len(params) > 0 {
+				command := string(bytes.ToLower(bytes.Join(params, []byte(" "))))
+				commandHelp := bgammon.HelpText[command]
+				if commandHelp != "" {
+					cmd.client.sendNotice("/" + command + " " + commandHelp)
+				} else {
+					cmd.client.sendNotice(fmt.Sprintf("Unknown command: %s", command))
+				}
+				continue
+			}
+
+			cmd.client.sendNotice("Available commands:")
+			for _, command := range s.sortedCommands {
+				cmd.client.sendNotice("/" + command + " " + bgammon.HelpText[command])
+			}
 		case bgammon.CommandJSON:
 			sendUsage := func() {
 				cmd.client.sendNotice("To enable JSON formatted messages, send 'json on'. To disable JSON formatted messages, send 'json off'.")