/*
File: MBCEngine.mm
Contains: An agent representing the sjeng chess engine
Version: 1.0
Copyright: © 2002-2011 by Apple Computer, Inc., all rights reserved.
*/
#import "MBCEngine.h"
#import "MBCEngineCommands.h"
#import "MBCController.h"
#include <unistd.h>
#include <algorithm>
//
// Paradoxically enough, moving as quickly as possible is
// not necessarily desirable. Users tend to get frustrated
// once they realize how little time their Mac really spends
// to crush them at low levels. In the interest of promoting
// harmonious Human - Machine relations, we enforce minimum
// response times.
//
const NSTimeInterval kInteractiveDelay = 2.0;
const NSTimeInterval kAutomaticDelay = 4.0;
using std::max;
@implementation MBCEngine
- (id) init
{
fEngineEnabled = false;
fSetPosition = false;
fTakeback = false;
fNeedsGo = false;
fLastMove = nil;
fLastPonder = nil;
fLastEngineMove = nil;
fDontMoveBefore = [NSDate timeIntervalSinceReferenceDate];
fMainRunLoop = [NSRunLoop currentRunLoop];
fEngineMoves = [[NSPort port] retain];
[fEngineMoves setDelegate:self];
fMove = [[NSPortMessage alloc] initWithSendPort: fEngineMoves
receivePort: fEngineMoves
components: [NSArray array]];
[self enableEngineMoves:YES];
fEngineTask = [[NSTask alloc] init];
fToEnginePipe = [[NSPipe alloc] init];
fFromEnginePipe = [[NSPipe alloc] init];
[fEngineTask setStandardInput:fToEnginePipe];
[fEngineTask setStandardOutput:fFromEnginePipe];
[fEngineTask setLaunchPath:
[[NSBundle mainBundle] pathForResource:@"sjeng"
ofType:@"ChessEngine"]];
[fEngineTask setArguments: [NSArray arrayWithObject:@"sjeng (Chess Engine)"]];
[self performSelector:@selector(launchEngine:) withObject:nil afterDelay:0.001];
fToEngine = [fToEnginePipe fileHandleForWriting];
fFromEngine = [fFromEnginePipe fileHandleForReading];
[NSThread detachNewThreadSelector:@selector(runEngine:) toTarget:self
withObject:nil];
[self writeToEngine:@"xboard\nconfirm_moves\n"];
return self;
}
- (void) launchEngine:(id)arg
{
[fEngineTask launch];
}
- (void) shutdown
{
//
// Since there is only one Engine per app run, we don't bother
// deallocating all the resources.
//
[self writeToEngine:@"?exit\n"];
}
- (void) writeToEngine:(NSString *)string
{
NSData * data = [string dataUsingEncoding:NSASCIIStringEncoding];
[[MBCController controller] logToEngine:string];
[fToEngine writeData:data];
}
- (void) interruptEngine
{
[self writeToEngine:@"?"];
}
- (void) setSearchTime:(int)time
{
fSearchTime = time;
if (fSearchTime < 0)
[self writeToEngine:[NSString stringWithFormat:@"sd %d\n",
4+fSearchTime]];
else
[self writeToEngine:[NSString stringWithFormat:@"sd 40\nst %d\n",
fSearchTime]];
}
- (MBCMove *) lastPonder
{
return fLastPonder;
}
- (MBCMove *) lastEngineMove
{
return fLastEngineMove;
}
- (void) runEngine:(id) sender
{
unsigned cmd;
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
[[[NSThread currentThread] threadDictionary]
setObject:fFromEngine forKey:@"InputHandle"];
while (cmd = yylex()) {
[fMove setMsgid:cmd];
[fMove sendBeforeDate:[NSDate distantFuture]];
[pool release];
pool = [[NSAutoreleasePool alloc] init];
}
}
- (void) enableEngineMoves:(BOOL)enable
{
if (enable != fEngineEnabled)
if (fEngineEnabled = enable)
[fMainRunLoop addPort:fEngineMoves forMode:NSDefaultRunLoopMode];
else
[fMainRunLoop removePort:fEngineMoves forMode:NSDefaultRunLoopMode];
}
- (void) takebackNow
{
[fLastPonder release];
fLastPonder = nil;
[self writeToEngine:@"remove\n"];
[[NSNotificationCenter defaultCenter]
postNotificationName:MBCTakebackNotification
object:nil];
}
- (void) executeMove:(MBCMove *) move;
{
[self flipSide];
[fLastPonder release];
fLastPonder = nil;
[fLastEngineMove release];
fLastEngineMove = [move retain];
[[NSNotificationCenter defaultCenter]
postNotificationName:[self notificationForSide]
object:move];
}
- (void) handlePortMessage:(NSPortMessage *)message
{
MBCMove * move = [MBCMove moveFromCompactMove:[message msgid]];
if (fWaitForStart) { // Suppress all commands until next start
if (move->fCommand == kCmdStartGame) {
fWaitForStart = false;
}
return;
}
//
// Otherwise, handle move confirmations or rejections here and
// broadcast the rest of the moves
//
switch (move->fCommand) {
case kCmdUndo:
//
// Last unchecked move was rejected
//
fThinking = false;
[[NSNotificationCenter defaultCenter]
postNotificationName:MBCIllegalMoveNotification
object:move];
break;
case kCmdMoveOK:
if (fLastMove) { // Ignore confirmations of game setup moves
[self flipSide];
//
// Suspend processing until move performed on board
//
[self enableEngineMoves:NO];
[[NSNotificationCenter defaultCenter]
postNotificationName:[self notificationForSide]
object:fLastMove];
if (fNeedsGo) {
fNeedsGo = false;
[self writeToEngine:@"go\n"];
}
}
break;
case kCmdPMove:
case kCmdPDrop:
[fLastPonder release];
fLastPonder = [move retain];
break;
case kCmdWhiteWins:
case kCmdBlackWins:
case kCmdDraw:
[[NSNotificationCenter defaultCenter]
postNotificationName:MBCGameEndNotification
object:move];
break;
default:
if (fSide == kBothSides)
[self writeToEngine:@"go\n"]; // Trigger next move
else
fThinking = false;
//
// After the engine moved, we defer further moves until the
// current move is executed on the board
//
[self enableEngineMoves:NO];
NSTimeInterval now = [NSDate timeIntervalSinceReferenceDate];
[self performSelector:@selector(executeMove:) withObject:move
afterDelay: fDontMoveBefore-now];
if (fSide == kBothSides)
fDontMoveBefore = max(now,fDontMoveBefore)+kAutomaticDelay;
break;
}
}
- (void) flipSide
{
fLastSide = (fLastSide == kBlackSide) ? kWhiteSide : kBlackSide;
}
- (NSString *) notificationForSide
{
return (fLastSide==kWhiteSide)
? MBCWhiteMoveNotification
: MBCBlackMoveNotification;
}
- (void) initGame:(MBCVariant)variant
{
[self writeToEngine:@"?new\n"];
switch (variant) {
case kVarCrazyhouse:
[self writeToEngine:@"variant crazyhouse\n"];
break;
case kVarSuicide:
[self writeToEngine:@"variant suicide\n"];
break;
case kVarLosers:
[self writeToEngine:@"variant losers\n"];
break;
default:
// Regular Chess
break;
}
[self setSearchTime:fSearchTime];
fTakeback = false;
}
- (void) setGame:(MBCVariant)variant fen:(NSString *)fen holding:(NSString *)holding moves:(NSString *)moves
{
[self initGame:variant];
fSetPosition = true;
[fLastMove release];
fLastMove = nil;
const char * s = [fen UTF8String];
while (isspace(*s))
++s;
while (!isspace(*s))
++s;
while (isspace(*s))
++s;
fLastSide = *s == 'w' ? kBlackSide : kWhiteSide;
if (moves) {
[self writeToEngine:@"force\n"];
[self writeToEngine:moves];
} else {
if (*s == 'b')
[self writeToEngine:@"black\n"];
[self writeToEngine:
[NSString stringWithFormat:@"setboard %@\n", fen]];
if (variant == kVarCrazyhouse)
[self writeToEngine:
[NSString stringWithFormat:@"holding %@\n", holding]];
}
}
- (void) startGame:(MBCVariant)variant playing:(MBCSide)sideToPlay
{
//
// <rdar://problem/5844722> Get rid of queued up move notifications
//
[self enableEngineMoves:NO];
if ([fEngineTask isRunning])
[NSObject cancelPreviousPerformRequestsWithTarget:self];
if (!fSetPosition) {
[self initGame:variant];
fLastSide = kBlackSide;
fNeedsGo = false;
} else {
fNeedsGo = sideToPlay != kNeitherSide;
fSetPosition = false;
}
[[NSNotificationCenter defaultCenter] removeObserver:self];
switch (fSide = sideToPlay) {
case kWhiteSide:
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(opponentMoved:)
name:MBCUncheckedBlackMoveNotification
object:nil];
break;
case kBothSides:
[self writeToEngine:@"go\n"];
fThinking = true;
break;
case kNeitherSide:
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(opponentMoved:)
name:MBCUncheckedWhiteMoveNotification
object:nil];
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(opponentMoved:)
name:MBCUncheckedBlackMoveNotification
object:nil];
[self writeToEngine:@"force\n"];
fThinking = false;
break;
default:
// Engine plays black
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(opponentMoved:)
name:MBCUncheckedWhiteMoveNotification
object:nil];
break;
}
if (fSide == kWhiteSide || fSide == kBlackSide)
if (fThinking = (fSide != fLastSide)) {
fNeedsGo = false;
[self writeToEngine:@"go\n"];
}
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(moveDone:)
name:MBCEndMoveNotification
object:nil];
fWaitForStart = true; // Suppress further moves until start
[self enableEngineMoves:YES];
}
- (void) moveDone:(NSNotification *)notification
{
[fLastPonder release];
fLastPonder = nil;
if (fTakeback) {
fTakeback = false;
[self takebackNow];
}
[self enableEngineMoves:YES];
}
- (void) takeback
{
if (fThinking) {
//
// Defer
//
fTakeback = true;
[self interruptEngine];
} else if (!fEngineEnabled) {
//
// Move yet to be executed
//
fTakeback = true;
} else
[self takebackNow];
}
- (id)retain
{
return [super retain];
}
- (void) opponentMoved:(NSNotification *)notification
{
//
// Got a human move, ask engine to verify it
//
const char * piece = " KQBNRP kqbnrp ";
MBCMove * move = reinterpret_cast<MBCMove *>([notification object]);
[fLastMove release];
fLastMove = [move retain];
switch (move->fCommand) {
case kCmdMove:
if (move->fPromotion)
[self writeToEngine:
[NSString stringWithFormat:@"%@%@%c\n",
[self squareToCoord:move->fFromSquare],
[self squareToCoord:move->fToSquare],
piece[move->fPromotion]]];
else
[self writeToEngine:
[NSString stringWithFormat:@"%@%@\n",
[self squareToCoord:move->fFromSquare],
[self squareToCoord:move->fToSquare]]];
fThinking = fSide != kNeitherSide;
break;
case kCmdDrop:
[self writeToEngine:
[NSString stringWithFormat:@"%c@%@\n",
piece[move->fPiece],
[self squareToCoord:move->fToSquare]]];
fThinking = fSide != kNeitherSide;
break;
default:
break;
}
fDontMoveBefore = [NSDate timeIntervalSinceReferenceDate]+kInteractiveDelay;
}
- (NSString *) squareToCoord:(MBCSquare)square
{
const char * row = "12345678";
const char * col = "abcdefgh";
return [NSString stringWithFormat:@"%c%c",
col[square % 8], row[square / 8]];
}
@end
void MBCIgnoredText(const char * text)
{
// fprintf(stderr, "* %s", text);
}
int MBCReadInput(char * buf, int max_size)
{
NSFileHandle * f =
[[[NSThread currentThread] threadDictionary]
objectForKey:@"InputHandle"];
ssize_t sz = read([f fileDescriptor], buf, max_size);
if (sz > 0)
[[MBCController controller]
logFromEngine: [NSString stringWithFormat:@"%.*s", sz, buf]];
return sz;
}
// Local Variables:
// mode:ObjC
// End: