protocol

		 Ricochet Robots Game Protocol (RRGP)
			   Version 0.1.2
			     2003-5-31
		
		  Keith Packard         Carl Worth
		keithp@keithp.com     cworth@isi.edu

Introduction

RRGP is a network protocol for playing the Ricochet Robots game.  It permits
a single server to host multiple games with named participants.  The
protocol is designed so that people can play using only telnet, but it is
expected that graphical interfaces will be able to drive the protocol as
well.

RRGP borrows ideas from other network protocols like SMTP using a
synchronous command interface.

Document Conventions

	All commands include a response (yeah, synchronous protocols are
	bad.  tough)

	<command> <args> 

	->

	<response>

	<response> is one of:

	<command> <args>
	ERROR <message>

1. Requests

1.1 Connection setup

    The RRGP server has no well defined port; agreement on which port to
    use must be done through some external mechanism.  Once connected,
    the client must identify itself:
    
    HELO <username>
    
    ->
    
    HELO <servername>

1.2. Global commands

    1.2.1 Listing available users

	WHO

	->

	WHO <username1> <games1> <username2> <games2> ...

	lists connected users and the number of games they've won.

    1.2.2. Listing available games

	GAMES

	->

	GAMES <game1> <game2> ...

    1.2.3. Message

	MESSAGE <text>

	->
	
	MESSAGE

    1.2.4. Help

	HELP { <command> }

	Displays help.  If <command> is provided, displays more
	detailed help on a specific command, otherwise displays an
	overview of all commands.

    1.2.5. Quit

	QUIT

	->

	QUIT

1.3. Game management commands

    1.3.1. Listing players in a game

	PLAYERS <game>

	->

	PLAYERS <username1> <score1> <username2> <score2> ...

	Possible errors: NOGAME

    1.3.2. Listing watchers of a game

	WATCHERS <game>

	->

	WATCERS <username1> <username2> ...

	Possible errors: NOGAME

    1.3.3. Get game information

	GAMEINFO <game>

	->

	GAMEINFO <turn> <color> <shape> <state> <time> <bid> <active>

	<turn> is a number from 1 to 17 indicating the current turn
	<color> <shape> indicate the active piece
	<state> is one of:
		new	Turn just started, no bids yet
		bid	Bidding opened.  <time> indicates time remaining,
			<bid> indicates the minimum bid
		show	Bidding closed and solution being demonstrated
			<active> indicates the person demonstrating
		done 	Current turn is over.  Either a solution
                        was demonstrated or the players have all
			given up trying to find a solution.
	<time> is valid only in BID state, else it's 0
	<bid> is valid in all but NEW state where it's 0
	<active> is valid in SHOW state, else it's ""

	Possible errors: NOGAME

    1.3.4. Creating a new game

	NEW <game-suggestion>

	->

	NEW <game>

    1.3.5. Joining an existing game

	JOIN <game>

	->

	JOIN

	Possible errors: NOGAME

    1.3.6. Watching an existing game

	WATCH <game>

	->

	WATCH

	The client will monitor the game, but not be listed in the
	userlist nor be allowed to make moves.

	Possible errors: NOGAME

    1.3.7. Dispose an empty game

	DISPOSE <game>

	->

	DISPOSE

	Disposes <game> unless it still has players associated.

	Possible errors: NOGAME NOTEMPTY

1.4. User information commands

    1.4.1. Get user information
    
	USERINFO <username>
    
	->
    
	USERINFO <game> <playing> <score> <bid>
    
	<game> is any currently associated game, else "".  If the user
	is not associated with any game, the remaining fields are
	false 0 0.
	
	<playing> is true if the user is playing and false if watching.
    
	<score> is a number from 0 to 17 indicating this players score
    
	<bid> is either "0" indicating no bid or a number indicating
	the users minimum bid.
	    
1.5. In-game commands

    1.5.1. Global game commands

	1.5.1.1 Get the game contents
    
	    SHOW
    
	    ->
    
	    SHOW <game-board>
    
	    <game-board> is a quoted multi-line string containing an
	    diagram of the game contents, (an array of cells). A single
	    cell and its surrounding are indicated as:
    
	     HHH 
	    VrcsV
	     HHH
    
	    H = ' ' or '='
	    V = ' ' or '|'
	    r = '.' or <robot-color>  (one of 'r', 'g', 'b', or 'y')
	    c = '.' or <target-color> (one of 'r', 'g', 'b', or 'y')
	    s = '.' or <target-shape> (one of 'c', 's', 'o', or 't')
    
	    The goal robot and target (color and shape) are indicated with
	    capital letters.
    
	    For example:
    
	    SHOW "
	     ===
	    |R.. ... .gs
	    
	     byc|... .RT|
	     ===    ==="
    
	    R.. = 	Red robot (goal robot)
	    .gs = 	Green square target
	    byc = 	Blue robot on yellow circle target
	    .RT =	Red triangle (goal target)
    
	    Possible errors: NOTINGAME
    
	1.5.1.2. Next turn
    
	    TURN
    
	    ->
    
	    TURN
    
	    Advance the game to the next turn, (which will have a new
	    target square).  TURN is valid only when the game is in
	    the DONE state
		    
	    Possible errors: NOTINGAME, NOTDONE
    
	1.5.1.3. Part
    
	    PART
    
	    ->
    
	    PART
    
	    Departs the current game
    
    1.5.2. Bidding commands 

	1.5.2.1 Bid
    
	    BID <number>
    
	    ->
    
	    BID
    
	    Possible errors: NOTINGAME, NOTBIDDING, NOTNUMBER, NOTLOWER
    
	1.5.2.2. Revoke
    
	    REVOKE
    
	    ->
    
	    REVOKE
    
	    Possible errors: NOTINGAME, NOTBIDDING, NOBID
    
	1.5.2.3. Abandon
    
	    ABANDON
    
	    ->
    
	    ABANDON
    
	    Possible errors: NOTINGAME, NOTBIDDING
    
	    Mark this user as having abandoned this turn.  If all users
	    abandon, then the game state is switched to DONE.

	1.5.2.4. No more bids

	    NOBID

	    ->

	    NOBID

	    Possible errors: NOTINGAME, NOTBIDDING
    
	    Mark this user as done bidding.  If all users NOBID, then
	    the game state is switched to SHOW.
    
    1.5.3. Solving commands

	1.5.3.1. Move
    
	    MOVE <color> <dir1> <dir2> ...
    
	    ->
    
	    MOVE <count>
    
	    <color> is one of 'R', 'Y', 'G' or 'B', <dir> is one of 'N',
	    'E', 'S' or 'W'.
    
	    Possible errors: NOTINGAME, NOTACTIVE, BLOCKED, TOOMANYMOVES
    
	1.5.3.2. Undo
    
	    UNDO
    
	    ->
    
	    UNDO
    
	    Undoes the last move
    
	    Possible errors: NOTINGAME, NOTACTIVE
    
	    XXX: Do we add another error code for no further undo?
    
	1.5.3.3. Reset
    
	    RESET
    
	    ->
    
	    RESET
    
	    Resets robot positions to that at the start of the turn.
    
	    Possible errors: NOTINGAME, NOTACTIVE
    
	1.5.3.4. Pass the demonstration to the next lowest bidder
    
	    PASS
    
	    ->
    
	    PASS
    
	    Possible errors: NOTINGAME
	
2. Asynchronous notification.  

    The server will send notices to each user in a game whenever
    there is a move. It will also send notices to every connected
    client when additional people join or new games are
    started. These are of the form:

	NOTICE <notice-code> <args>

    Game-specific notices are sent to users involved in the related
    game, other notices are sent to all users.  Note that even the user
    originating the notice receives a copy.

2.1. Global notices

    These notices are sent to all connected clients

    2.1.1. New users
    
	NOTICE USER <username>
    
    2.1.2. Disconnected user
    
	NOTICE QUIT <username>
    
    2.1.3. New games
    
	NOTICE GAME <game>
    
    2.1.4. Terminated games
    
	NOTICE DISPOSE <game>
    
    2.1.5. Message

	NOTICE MESSAGE <username> <text>

2.2. Game notices

    These notices are sent to all players and watchers in
    the affected game

    2.2.1. Global game notices

	2.2.1.1 Game state change
	
	    NOTICE GAMESTATE <state>

	    Game state has changed to <state>

	2.2.1.2. Next turn (game)

	    NOTICE TURN <color> <shape>

	    Note that the game state is implicitly changed to New

	2.2.1.3. Next game (game)

	    NOTICE GAME

	2.2.1.4. Join game (game)
	
	    NOTICE JOIN <username>
	
	2.2.1.5. Watch game (game)
	
	    NOTICE WATCH <username>
	
	2.2.1.6. User departed game (game)
	
	    NOTICE PART <username>
	
    2.2.2. Bid notices

	Notices sent duing the bidding phase of a turn
    
	2.2.2.1. Bids (game)
	
	    NOTICE BID <username> <number>
	
	2.2.2.2. Revoke (game)
	
	    NOTICE REVOKE <username>

	    The specific user has revoked their bid. If there
	    are no other bids outstanding, the game state is
	    returned to New.
	
	2.2.2.3. Timer (game)
	
	    NOTICE TIME <seconds>
    
	    Timer ticks are sent every 10 seconds after the first
	    bid has been made

	2.2.2.4. Abandon request

	    NOTICE ABANDON <username>
    
	    <username> has requested that the current turn be abandoned
	    before bidding has closed.  If all players make such
	    a request, the TURN command may be used to move to the next
	    turn.

	2.2.2.5. Nobid request

	    NOTICE NOBID <username>

	    <username> has announced that they plan on making no more bids
	    in the current turn.  If all players make such a request,
	    the game moves to the SHOW state.

   2.2.3. Solving notices

	Notices sent during the solving phase of a turn
	    	
	2.2.3.1. Select active player (game)

	    NOTICE ACTIVE <username> <bid>

	    Only the active player may move the robots

	2.2.3.2. Move notice (game)

	    NOTICE MOVE <count> <color> <dir>

	2.2.3.3. Undo (game)

	    NOTICE UNDO

	2.2.3.4. Reset (game)

	    NOTICE RESET

	2.2.3.5. Position (after move/undo/reset)

	    NOTICE POSITION <color> <x> <y>

	    The indicated robot has moved to the indicated position.
	    The board is 0-based with the origin in the upper left
	    corner.

	2.2.3.6. Score (game)

	    NOTICE SCORE <username> <score>

	    The indicated user has demonstrated a solution and
	    received a point.

3. Errors

    The following error codes may be returned.

3.1. Connection setup errors

    These errors occur during connection setup.

    3.1.1. No name set
    
	ERROR NONAMESET
    
	'helo' must be sent before any command other than 'quit'.
    
    3.1.2. Invalid name
    
	ERROR INVALIDNAME
    
	All names must be unique.

3.2. Command format errors

    Errors caused by ill-formed commands
    
    3.2.1. Command
    
	ERROR COMMAND
    
	An invalid command was specified
    
    3.2.2. Syntax
    
	ERROR SYNTAX
    
	A syntax error was detected
    
    3.2.3. Not number
    
	ERROR NOTNUMBER
    
	A non-numeric value was supplied where a number was required
	
    3.2.4. Not color
    
	ERROR NOTCOLOR
    
	The color name specified in the command was invalid
    
    3.2.5. Not shape
    
	ERROR NOTSHAPE
    
	The shape name specified in the command was invalid
    
    3.2.6. Not direction
    
	ERROR NOTDIRECTION
    
	The direction name specified in the command was invalid

3.3. Global command errors.

    There are no errors from any of the global commands

3.4. Game management errors.

    Errors from game management commands
    
    3.3.1. No such game
	
	ERROR NOGAME
	
	A game name was provided that does not exist.
	
    3.3.2. Not empty
	
	ERROR NOTEMPTY
	
	DISPOSE was requested for a game with active players
	
3.5. User information errors

    3.5.1. No such user
    
	ERROR NOUSER

	A user name was provided that does not exist.

3.6. In-game errors

    3.6.1. Global game errors
    
	3.6.1.1. Not in game
    
	    ERROR NOTINGAME
    
	    A game playing command was made, but the user is not a
	    particpant of any game.
    
	    Possibly returned by: SHOW, MOVE, RESET, UNDO, TURN, PASS,
	    MESSAGE.

	3.6.1.2. Not playing

	    ERROR NOTPLAYING

	    A command was executed by a watching user that is
	    permitted only to players

	3.6.1.3. Not done
    
	    ERROR NOTDONE
    
	    TURN was requested and the game is not in DONE state.
    
    3.6.2. Bidding errors 
    
	3.6.2.1. Not bidding

	    ERROR NOTBIDDING
    
	    A bid was submitted after the bidding closed
    
	    Possibly returned by: BID
    
	3.6.2.2. Not lower

	    ERROR NOTLOWER
    
	    A bid was submitted that was higher than previous bid.
    
	    Possibly returned by: BID
    
	3.6.2.3. No bid

	    ERROR NOBID
    
	    A revoke was requested when no bid had been entered
    
	    Possibly returned by: REVOKE
	    
    3.6.3. Solving mode errors
    
	3.6.3.1. Not active

	    ERROR NOTACTIVE
	
	    A move, undo or reset was submitted by other than the
	    active user.
	    
	    Possibly returned by: MOVE, RESET, UNDO
	
	3.6.3.2. Blocked
	
	    ERROR BLOCKED
	
	    The robot cannot move the requested direction.
	
	    Possibly returned by: MOVE
	
	3.6.3.3. TOOMANYMOVES
	
	    ERROR TOOMANYMOVES
	
	    An attempt was made to make more moves than the users bid
	
	    Possibly returned by: MOVE
	

Some comments/questions
-----------------------

The server manages ACTIVE based on bids, scores, and PASS
requests. Once a turn is over, (solution demonstrated or all bidding
users PASS), it would be nice to allow others to show alternate
solutions, failed attempts, etc. Shall we provide a way for the ACTIVE
user to pass control to another, (only when a turn is over)? Or maybe
since the turn is over we just let any user move the pieces?