/*
 *	INCLUDES
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <math.h>
#include <sys/wait.h>


/*
 *	GLOBALS
 */

int start_time;
bool pipe_logging = false;
int only_opening = -1;
FILE *pgn_log = NULL;
FILE *match_log = NULL;




/*
 *	Misc
 */

void strip_newline(char *s)
{
	int i;
	
	for (i = 0;; ++i)
		{
		if (!s[i] || s[i] == '\r' || s[i] == '\n')
			{
			s[i] = 0;
			return;
			}
		}
}

void copy_result(char *to, char *from)
{
	int i;
	
	for (i = 0; i < strlen(from); ++i)
		if (from[i] == '0' || from[i] == '1')
			break;
	strcpy(to, &from[i]);
	for (i = 0; i < strlen(to); ++i)
		if (to[i] == '}')
			break;
	to[i + 1] = 0;
}




/*
 *	MyLock
 */

#include <pthread.h>
#include <semaphore.h>

class MyLock
{
public:
	MyLock();
	void get();
	void release();

private:
	pthread_mutex_t the_lock;
};

MyLock::MyLock()
{
	pthread_mutex_init(&the_lock, NULL);
}

void MyLock::get()
{
	for (;;)
		{
		if (pthread_mutex_lock(&the_lock) == 0)  // EBUSY??
			break;
		usleep(1);
		}
}

void MyLock::release()
{
	pthread_mutex_unlock(&the_lock);
}

MyLock glock;




/*
 *	Settings
 */

class Settings
{
public:
	Settings() { count = 0; };
	bool read(char *filename);
	char * get(char *name);

private:
	char map[20][2][1000];
	int count;
};

Settings settings;

bool Settings::read(char *filename)
{
	FILE *f;
	char line[1000];
	char var[1000];

	printf("Reading settings file: %s\n", filename);
	count = 0;
	f = fopen(filename, "r");
	if (!f)
		{
		printf("Couldn't open file.\n");
		return false;
		}
	for (;;)
		{
		line[0] = 0;
		fgets(line, 1000, f);
		if (!line[0])
			break;
		strip_newline(line);
		sscanf(line, "%s", var);
		strcpy(map[count][0], var);
		strcpy(map[count][1], line + strlen(var) + 1);
		count++;
		}
	fclose(f);
	return true;
}

char * Settings::get(char *name)
{
	int i;
	
	for (i = 0; i < count; ++i)
		if (!strcmp(map[i][0], name))
			return map[i][1];
	printf("Setting not found: %s\n", name);
	exit(1);
}




/*
 *	ChildProc
 */

class ChildProc
{
public:
	ChildProc();
	virtual ~ChildProc();
	
	virtual void start(char *cmd_line);
	virtual void stop();
	void send(char *line);
	void receive(char *line, int size);
	bool poll();
	void flush();
	char * get_cmd() { return cmd; }
	
private:
	void init();

	char cmd[100];
	bool running;

	int pid;
	int to_prog[2];
	int from_prog[2];
	FILE *to;
	FILE *from;
};

ChildProc::ChildProc()
{
	init();
}

ChildProc::~ChildProc()
{
	stop();
}

void ChildProc::init()
{
	strcpy(cmd, "");
	pid = 0;
	to = NULL;
	from = NULL;
	running = false;
}

void ChildProc::start(char *cmd_line)
{
	char *argv[100];
	char arg_buff[100][100];
	int args = 0, i = 0, j = 0;

	argv[0] = arg_buff[0];
	for (;;)
		{
		argv[args][i] = cmd_line[j];
		if (!argv[args][i] || argv[args][i] == ' ')
			{
			argv[args][i] = 0;
			args++;
			argv[args] = arg_buff[args];
			i = -1;  // will get incremented to 0
			}
		if (!cmd_line[j])
			break;
		i++;
		j++;
		}
	argv[args] = NULL;
	
	stop();
	glock.get();
	pipe(to_prog);
	pipe(from_prog);
	if ((pid = fork()) == 0)  // what to do with glock here?
		{
		dup2(to_prog[0], 0);
		dup2(from_prog[1], 1);
		close(to_prog[0]);
		close(to_prog[1]);
		close(from_prog[0]);
		close(from_prog[1]);
		dup2(1, fileno(stderr));  // force stderr to the pipe
		execvp(argv[0], argv);
		perror(argv[0]);
		exit(1);
		}
	if (pid == -1)
		{
		printf("fork() failed, command line: %s\n", cmd_line);
		exit(1);
		}
	close(to_prog[0]);
	close(from_prog[1]);
	from = fdopen(from_prog[0], "r");
	to = fdopen(to_prog[1], "w");
	setbuf(from, NULL);
	setbuf(to, NULL);
	glock.release();

	running = true;
	strcpy(cmd, argv[0]);	
}

void ChildProc::stop()
{
	int x;
	
	if (!running)
		return;
	glock.get();
	fclose(to);
	fclose(from);
	close(to_prog[1]);
	close(from_prog[0]);
	glock.release();
	kill(pid, SIGTERM);
	waitpid(pid, &x, 0);
	init();
}

void ChildProc::send(char *line)
{
	char temp[1000];
	int i;
	
	if (!running)
		return;
	strcpy(temp, line);
	strip_newline(temp);
	glock.get();
	fprintf(to, "%s\n", temp);
	glock.release();
	if (pipe_logging)
		printf("%s send: %s\n", cmd, temp);
}

void ChildProc::receive(char *line, int size)
{
	int i;
	
	line[0] = 0;
	if (!running)
		return;
	if (!poll())
		return;
	glock.get();
	fgets(line, size, from);
	glock.release();
	strip_newline(line);
	if (pipe_logging)
		printf("%s recv: %s\n", cmd, line);
}

bool ChildProc::poll()
{
	fd_set myset;
	timeval mytime;
	int r;
	
	FD_ZERO(&myset);
	FD_SET(from_prog[0], &myset);
	mytime.tv_sec = 0;
	mytime.tv_usec = 0;
	glock.get();
	r = select(from_prog[0] + 1, &myset, NULL, NULL, &mytime);
	glock.release();
	return (r > 0) ? true : false;
}

void ChildProc::flush()
{
	char line[1000];
	
	while (poll())
		{
		receive(line, 1000);
		if (!line[0])
			break;
		}
}




/*
 *	ChessEngine
 */

class ChessEngine : private ChildProc
{
public:
	void start(char *cmd_line, char *init_str_arg);
	void stop();
	void new_game();
	void send_move(char *move);
	void get_move(char *move);
	bool is_game_over() { return game_over; }
	char * get_result() { return result; }
	
private:
	bool game_over;
	char result[100];
	char init_str[1000];
};

void ChessEngine::start(char *cmd_line, char *init_str_arg)
{
	ChildProc::start(cmd_line);
	send("xboard\n");
	strcpy(init_str, init_str_arg);
}

void ChessEngine::stop()
{
	send("quit\n");
	ChildProc::stop();
}

void ChessEngine::new_game()
{
	char temp[1000];
	
	// stop the engine and flush leftover output
	// only necessary when reusing the engine
	/*send("?\n");
	usleep(100000);
	flush();*/

	send("new\n");
	send("easy\n");
	sprintf(temp, "%s\n", init_str);
	send(temp);
	send("force\n");

	game_over = false;
}

void ChessEngine::send_move(char *move)
{
	char s[100];
	
	if (game_over)
		return;
	sprintf(s, "%s\n", move);
	send(s);
}

void ChessEngine::get_move(char *move)
{
	char line[1000];
	char tok[1000];
	
	move[0] = 0;
	while (poll())  // does the engine think the game is over?
		{
		receive(line, 1000);
		if (strchr(line, '{'))
			{
			game_over = true;
			copy_result(result, line);
			}
		}
	if (game_over)
		return;
	send("go\n");
	for (;;)
		{
		receive(line, 1000);
		if (!line[0])
			{
			usleep(1000);
			continue;
			}		
		if (strchr(line, '{'))
			{
			game_over = true;
			copy_result(result, line);
			break;
			}
		sscanf(line, "%s", tok);
		if (!strcmp(tok, "move"))
			{
			sscanf(line, "move %s", move);
			break;
			}
		}
	if (!game_over)
		send("force\n");
}




/*
 *	WorkItems
 */

const int max_work_items = 5000;
const int max_game_ply = 400;

struct WorkItem
{
	volatile int status;
	bool printed;
	
	int white_engine;
	int opening_id;
	char opening[200];
	char move[max_game_ply + 2][10];
	int moves;
	char result[100];
};

WorkItem *work_item[max_work_items];
int work_items;

bool make_work_items(char *filename)
{
	FILE *f;
	char line[1000];
	int openings = 0;
	WorkItem *w;

	printf("Creating work items from file: %s\n", filename);
	work_items = 0;
	f = fopen(filename, "r");
	if (!f)
		{
		printf("Couldn't open file.\n");
		return false;
		}
	for (;;)
		{
		line[0] = 0;
		fgets(line, 1000, f);
		if (!line[0])
			break;
		strip_newline(line);
		openings++;
		
		if (only_opening != -1 && openings != only_opening)
			continue;
		
		w = new WorkItem;
		w->status = 0;
		w->opening_id = openings;
		strcpy(w->opening, line);
		w->white_engine = 1;
		work_item[work_items++] = w;

		w = new WorkItem;
		w->status = 0;
		w->opening_id = openings;
		strcpy(w->opening, line);
		w->white_engine = 2;
		work_item[work_items++] = w;
		}
	fclose(f);
	printf("%d work items created.\n", work_items);
	return true;
}

void print_game(WorkItem *w)
{
	char white_name[100];
	char black_name[100];
	char line[1000];
	char short_result[100];
	char *temp;
	int m, i, line_break;
	
	if (w->white_engine == 1)
		{
		strcpy(white_name, settings.get("engine1"));
		strcpy(black_name, settings.get("engine2"));
		}
	else
		{
		strcpy(white_name, settings.get("engine2"));
		strcpy(black_name, settings.get("engine1"));
		}
	sprintf(line, "Opening: %d, %s vs. %s, result: %s\n",
			w->opening_id,
			white_name,
			black_name,
			w->result);
	printf(line);
	fprintf(match_log, line);
	fflush(match_log);
	
	strcpy(short_result, w->result);
	temp = strchr(short_result, ' ');
	if (temp)
		*temp = 0;
	fprintf(pgn_log, "[Round \"%d.%d\"]\n", w->opening_id, w->white_engine);
	fprintf(pgn_log, "[White \"%s\"]\n", white_name);
	fprintf(pgn_log, "[Black \"%s\"]\n", black_name);
	fprintf(pgn_log, "[Result \"%s\"]\n", short_result);
	fprintf(pgn_log, "\n");
	m = 0;
	line_break = 0;
	for (i = 1;; ++i)
		{
		if (m == w->moves)
			{
			fprintf(pgn_log, "%s\n", w->result);
			break;
			}
		fprintf(pgn_log, "%d. %s ", i, w->move[m++]);
		if (m < w->moves)
			fprintf(pgn_log, "%s ", w->move[m++]);
		if (m > line_break + 8)
			{
			fprintf(pgn_log, "\n");
			line_break = m;
			}
		}
	fprintf(pgn_log, "\n");
	fflush(pgn_log);
	
	w->printed = true;
}

void print_stats(int items)
{
	int i;
	int win = 0, lose = 0, draw = 0;
	int games = 0;
	double percent;
	double elo;
	char elo_sign = '+';
	int elapsed_time;
	int min, sec;
	double spg = 10.0;
	double percent_done;
	double eta;
	int eta_min, eta_sec;
	
	for (i = 0; i < items; ++i)
		{
		if (work_item[i]->status != 2)  // shouldn't happen
			break;
		if (strstr(work_item[i]->result, "1-0"))
			{
			if (work_item[i]->white_engine == 1)
				win++;
			else
				lose++;
			}
		if (strstr(work_item[i]->result, "0-1"))
			{
			if (work_item[i]->white_engine == 1)
				lose++;
			else
				win++;
			}
		if (strstr(work_item[i]->result, "1/2-1/2"))
			draw++;
		}
	games = win + lose + draw;
	
	percent = (double)win + (0.5 * (double)draw);
	percent /= (double)games;
	if (percent > 0.99999)
		elo = 400.0;
	else if (percent < 0.00001)
		elo = -400.0;
	else
		elo = -400.0 * log(1.0 / percent - 1.0) / log(10.0);
	if (elo < 0.0)
		{
		elo_sign = '-';
		elo = -elo;
		}
	elapsed_time = time(NULL) - start_time;
	sec = elapsed_time;
	min = sec / 60;
	sec -= min * 60;
	if (elapsed_time)
		spg = (double)(time(NULL) - start_time) / (double)games;
	percent_done = (double)games / (double)work_items;
	eta = (double)work_items - (double)games;
	eta *= spg;
	eta_sec = (int)eta;
	eta_min = eta_sec / 60;
	eta_sec -= eta_min * 60;
	
	printf("%s vs. %s: +%d -%d =%d, %.2f%c, ELO: %c%d\n",
			settings.get("engine1"),
			settings.get("engine2"),
			win, lose, draw,
			(float)(percent * 100.0), '%',
			elo_sign, (int)elo);
	printf("%d games in %d:%02d, %.2f seconds/game, %.1f%c done, ETA: %d:%02d\n",
			games, min, sec, (float)spg,
			(float)(percent_done * 100.0), '%',
			eta_min, eta_sec);
	printf("\n");
}



/*
 *	WorkerThread
 */

class WorkerThread
{
public:
	void do_work(int id_arg);
	void do_item(WorkItem *w);

private:
	void do_opening(WorkItem *w);
	void add_move(WorkItem *w, char *move);

	int id;
	ChessEngine engine1, engine2;
};

void WorkerThread::do_work(int id_arg)
{
	int i;
	
	id = id_arg;
	for (;;)
		{
		glock.get();
		for (i = 0; i < work_items; ++i)
			if (work_item[i]->status == 0)
				break;
		if (i != work_items)
			work_item[i]->status = 1;
		glock.release();

		if (i == work_items)
			break;
		do_item(work_item[i]);
		}
}

void WorkerThread::do_item(WorkItem *w)
{
	char move[100];
	ChessEngine *etm;  // engine to move
	ChessEngine *etw;  // engine to wait
	ChessEngine *temp;

	w->printed = false;
	w->moves = 0;
	
	engine1.start(settings.get("cmd1"), settings.get("init1"));
	engine2.start(settings.get("cmd2"), settings.get("init2"));
	engine1.new_game();
	engine2.new_game();
	do_opening(w);
	
	etm = &engine1;
	etw = &engine2;
	if ((w->moves & 1) == 1 && w->white_engine == 1)
		{
		etm = &engine2;
		etw = &engine1;
		}
	if ((w->moves & 1) == 0 && w->white_engine == 2)
		{
		etm = &engine2;
		etw = &engine1;
		}
	for (;;)
		{
		etm->get_move(move);
		if (etm->is_game_over())
			{
			strcpy(w->result, etm->get_result());
			break;
			}
		etw->send_move(move);
		add_move(w, move);
		if (w->moves >= max_game_ply)
			{
			strcpy(w->result, "1/2-1/2 {Game too long}");
			break;
			}
		temp = etm;
		etm = etw;
		etw = temp;
		}
	
	engine1.stop();
	engine2.stop();
	w->status = 2;
}

void WorkerThread::do_opening(WorkItem *w)
{
	char move[100];
	int i = 0, j = 0;
	
	for (;;)
		{
		move[i] = w->opening[j];
		if (!move[i] || move[i] == ' ')
			{
			move[i] = 0;
			engine1.send_move(move);
			engine2.send_move(move);
			add_move(w, move);
			i = -1;
			}
		if (!w->opening[j])
			break;
		i++;
		j++;
		}
}

void WorkerThread::add_move(WorkItem *w, char *move)
{
	strcpy(w->move[w->moves++], move);
}




/*
 *	threads
 */

WorkerThread *worker[100];
pthread_t *mythread[100];
volatile int thread_count = 0;

void * thread_proc(void *arg)
{
	int id;
	
	glock.get();
	id = thread_count++;
	glock.release();
	worker[id] = new WorkerThread;
	worker[id]->do_work(id);
	delete worker[id];
	pthread_exit(&mythread[id]);
	delete mythread[id];  // ?
}

void start_threads(int count)
{
	int i;
	int x = 0;

	printf("Starting threads...\n");
	for (i = 0; i < count; ++i)
		{
		mythread[i] = new pthread_t;
		pthread_create(mythread[i], NULL, thread_proc, (void *)&x);
		}
	printf("Started %d threads.\n", i);
}




/*
 *	main
 */

main(int argc, char *argv[])
{
	int i;
	char settings_filename[100];
	int threads = 1;
	
	start_time = time(NULL);
	strcpy(settings_filename, "settings.txt");

	for (i = 1;;)
		{
		if (i >= argc)
			break;
		if (!strcmp(argv[i], "-l"))
			{
			pipe_logging = true;
			}
		else if (!strcmp(argv[i], "-o"))
			{
			only_opening = atoi(argv[++i]);
			}
		else if (!strcmp(argv[i], "-t"))
			{
			threads = atoi(argv[++i]);
			}
		else if (argv[i][0] == '-')
			{
			printf("Usage: shiai [options] [settings file]\n");
			printf("\n");
			printf(" -h   : Display this screen\n");
			printf(" -l   : Display I/O with engines (\"log\")\n");
			printf(" -o # : Run opening number #\n");
			printf(" -t # : Run with # threads\n");
			printf("\n");
			exit(0);
			}
		else
			{
			strcpy(settings_filename, argv[i]);
			}
		i++;
		}
	
	if (!settings.read(settings_filename))
		exit(1);
	if (!make_work_items(settings.get("openings")))
		exit(1);
	
	pgn_log = fopen(settings.get("pgnlog"), "w");
	if (!pgn_log)
		{
		printf("Couldn't open %s for writing.\n", settings.get("pgnlog"));
		exit(1);
		}
	match_log = fopen(settings.get("matchlog"), "w");
	if (!match_log)
		{
		printf("Couldn't open %s for writing.\n", settings.get("matchlog"));
		exit(1);
		}
	
	if (threads <= 0 || threads > 16)
		threads = 1;
	start_threads(threads);
	for (i = 0; i < work_items; ++i)
		{
		while (work_item[i]->status != 2)
			sleep(1);
		print_game(work_item[i]);
		print_stats(i + 1);
		}
	
	fclose(pgn_log);
	fclose(match_log);
	return 0;
}