/*
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Mate Library.
 *
 * The Mate Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The Mate Library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Mate Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
/*
  @NOTATION@
 */

/*
 * mate-score.c
 * originally by Elliot Lee, subsequently bashed around by Nathan Bryant
 */

#include <config.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <glib/gstdio.h>
#include <locale.h>

#ifdef HAVE_SYS_FSUID_H
	#ifdef HAVE_SETFSGID
		#include <sys/fsuid.h>
	#endif
#endif

#include <glib/gi18n-lib.h>

#include "mate-i18n.h"
#include "mate-score.h"
#include "mate-util.h"

#ifdef G_OS_WIN32
	#include <fcntl.h>
	#include <io.h>

	#define pipe(fds) _pipe(fds, 4096, _O_BINARY)

	/* Microsoft's strtok() *is* thread-safe, it uses a thread-local
	 * buffer. "Use" the third argument to this macro so gcc doesn't
	 * complain about an unused variable, and we don't have to ifdef out
	 * the definition.
	 */
	#define strtok_r(s, delim, ptrptr) (*(ptrptr) = strtok(s, delim))
#endif

#include "libmate-private.h"

#ifndef NSCORES
	#define NSCORES 10
#endif

struct command {
	gfloat score;
	int level; /* length of level arg to mate_score_log including null term */
	gboolean ordering;
};

struct ascore_t {
	gchar* username;
	time_t scoretime;
	gfloat score;
};

static int outfd = -1, infd = -1;
static const gchar* defgamename;

/********************** internal functions ***********************************/

static gchar* mate_get_score_file_name(const gchar* progname, const gchar* level)
{
	if (level)
	{
		return g_strconcat(LIBMATE_LOCALSTATEDIR, G_DIR_SEPARATOR_S "games" G_DIR_SEPARATOR_S, progname, ".", level, ".scores", NULL);
	}
	else
	{
		return g_strconcat(LIBMATE_LOCALSTATEDIR, G_DIR_SEPARATOR_S "games" G_DIR_SEPARATOR_S, progname, ".scores", NULL);
	}
}

/* This must be wrapped in push_c_locale on the caller */
static void print_ascore(struct ascore_t* ascore, FILE* outfile)
{
	/* make sure we write values to files in a consistent manner */
	fprintf(outfile, "%f %ld %s\n", ascore->score, (long int) ascore->scoretime, ascore->username);
}

static void free_ascore(struct ascore_t* data)
{
	g_free(data->username);
	g_free(data);
}

/** log_score
 *
 * Inputs:
 *   'progname' - the program to log a score for
 *   'level' - the freeform level identifier
 *   'username' - the username that this score is logged under
 *   'score' - the game score
 *   'ordering' - whether lower scores are better.
 *
 * Outputs:
 *   'retval' - Whether the score got onto the highscore list
 *
 * Description:
 *   Loads all the existing scores into the 'scores'
 *   list.  Goes through and finds out whether there's a
 *   place for the new score on the high-score list, and
 *   if so, inserts it. Writes out the new high-score list.
 */
static gint log_score(const gchar* progname, const gchar* level, gchar* username, gfloat score, gboolean ordering)
{
	FILE* infile;
	FILE* outfile;
	gchar buf[512], *buf2;
	GList* scores = NULL, *anode;
	gchar* game_score_file;
	gfloat ascore;
	struct ascore_t* anitem, *curscore;
	int i;
	gint retval = 1;
	gint pos;

	game_score_file = mate_get_score_file_name(progname, level);

	infile = g_fopen(game_score_file, "r");
	if (infile)
	{
		/* make sure we read values from files in a consistent manner */
		mate_i18n_push_c_numeric_locale();

		while (fgets(buf, sizeof(buf), infile))
		{
			long ltime;
			i = strlen (buf) - 1;	/* Chomp */
			while (g_ascii_isspace (buf[i]))
				buf[i--] = '\0';

			{
				char *tokp;

				if((buf2 = strtok_r (buf, " ", &tokp)) == NULL)
					break;
				ascore = atof (buf2);
				if((buf2 = strtok_r (NULL, " ", &tokp)) == NULL)
					break;
				ltime = atoi (buf2);
				if((buf2 = strtok_r (NULL, "\n", &tokp)) == NULL)
				break;
			}

			anitem = g_new(struct ascore_t, 1);
			anitem->score = ascore;
			anitem->username = g_strdup(buf2);
			anitem->scoretime = (time_t) ltime;
			scores = g_list_append(scores, (gpointer) anitem);
		}

		mate_i18n_pop_c_numeric_locale();

		fclose(infile);
	}

	anitem = g_new(struct ascore_t, 1);
	anitem->score = score;
	anitem->username = g_strdup(username);
	anitem->scoretime = time(NULL);

	for (pos = 0, anode = scores; pos < NSCORES && anode; pos++, anode = anode->next)
	{
		curscore = anode->data;

		if (ordering)
		{
			if (curscore->score < anitem->score)
			{
				break;
			}
		}
		else
		{
			if (curscore->score > anitem->score)
			{
				break;
			}
		}
	}

	if (pos < NSCORES)
	{
		scores = g_list_insert(scores, anitem, pos);

		if ((anode = g_list_nth(scores, NSCORES)))
		{
			free_ascore(anode->data);
			scores = g_list_remove_link(scores, g_list_nth(scores, NSCORES));
		}

		retval = pos + 1;
	}
	else
	{
		retval = 0;
	}

	/* we dont create the file; it must already exist */
	outfile = g_fopen(game_score_file, "r+");

	#ifndef G_OS_WIN32
		ftruncate(fileno(outfile), 0);
	#else
		_chsize(fileno(outfile), 0);
	#endif

	if (outfile)
	{
		mate_i18n_push_c_numeric_locale();
		g_list_foreach(scores, (GFunc) print_ascore, outfile);
		mate_i18n_pop_c_numeric_locale();
		fclose(outfile);
	}
	else
	{
		perror(game_score_file);
	}

	g_free(game_score_file);

	g_list_foreach(scores, (GFunc) free_ascore, NULL);
	g_list_free(scores);

	return retval;
}

static int mate_score_child(int infileno, int outfileno)
{
	struct command cmd;
	gchar* level;
	gchar* realname;
	gint retval;

	#ifdef HAVE_SETFSGID
	   gid_t gid;

	   gid = getegid();
	   setgid(getgid());
	   setfsgid(gid);
	#endif

	realname = g_strdup(g_get_real_name());

	if (strcmp(realname, "Unknown") == 0)
	{
		g_free(realname);
		realname = g_strdup(g_get_user_name());
	}

	while (read(infileno, &cmd, sizeof cmd) == sizeof(cmd))
	{
		level = g_new (char, cmd.level);

		if (read(infileno, level, cmd.level) != cmd.level)
		{
			g_free(realname);

			return EXIT_FAILURE;
		}

		if (!*level)
		{
			g_free(level);
			level = NULL;
		}

		retval = log_score(defgamename, level, realname, cmd.score, cmd.ordering);

		if (write(outfileno, &retval, sizeof retval) != sizeof retval)
		{
			g_free(realname);
			return EXIT_FAILURE;
		}

		g_free(level);
	}

	g_free(realname);

	return EXIT_SUCCESS;
}

#ifdef G_OS_WIN32

static gpointer mate_score_child_thread(gpointer data)
{
	int* a = data;

	mate_score_child(a[0], a[1]);

	return NULL;
}

#endif

static void drop_perms(void)
{
	#ifndef G_OS_WIN32
		gid_t gid = getegid();

		setregid(getgid(), getgid());
		/* on some os'es (eg linux) this
		 * incantation will also drop the
		 * saved gid
		 */

		/* see if we can set it back -- if we can, saved id wasnt dropped */
		if (gid != getgid() && !setgid(gid))
		{
			if (getuid())
				g_warning("losing saved gid implementation detected, get a real OS :)\n");

			setgid(getgid());
		}
	#endif
}

/*********************** external functions **********************************/

/**
 * mate_score_init:
 * @gamename: Identifies the game name.
 *
 * MATE games should call this routine as the first statement
 * in main() if they have been installed setgid to the "games" group. It
 * performs the intialization required to later record information in the
 * scores table and then drops the groups privileges.
 *
 * Returns: %0 on success, returns %-1 on failure.
 */

gint mate_score_init(const gchar* gamename)
{
   int inpipe[2], outpipe[2];

	/*
	*creates a child process with which we communicate through a pair of pipes,
	* then drops privileges.
	*/
	if (!gamename)
		gamename = "";

	if (!(defgamename = g_strdup(gamename)) || pipe(inpipe))
	{
		drop_perms();
		return -1;
	}

	if (pipe (outpipe))
	{
		close(inpipe[0]);
		close(inpipe[1]);
		drop_perms();
		return -1;
	}

	outfd = outpipe[1];
	infd = inpipe[0];

	#ifndef G_OS_WIN32
		switch (fork())
		{
			case 0:

				if (dup2 (outpipe[0], STDIN_FILENO) == -1 || dup2 (inpipe[1], STDOUT_FILENO) == -1)
					exit (EXIT_FAILURE);

				close(inpipe[0]);
				close(inpipe[1]);
				close(outpipe[0]);
				close(outpipe[1]);

				exit(mate_score_child(STDIN_FILENO, STDOUT_FILENO));

			case -1:
				close(inpipe[0]);
				close(inpipe[1]);
				close(outpipe[0]);
				close(outpipe[1]);
				infd = outfd = -1;
				drop_perms();
				return -1;
		}

		close(outpipe[0]);
		close(inpipe[1]);
		drop_perms();
	#else
	{
		int a[2] = {outpipe[0], inpipe[1]};
		g_thread_create(mate_score_child_thread, a, FALSE, NULL);
	}
	#endif

	return 0;
}

/**
 * mate_score_log:
 * @score: The score achieved by the user in this game
 * @level: The level on which the score was obtained
 * @higher_to_lower_score_order: Set to %TRUE if high scores are better than
 * low scores.
 *
 * Logs a score entry for the user. You should call this every time a game
 * ends.  This function takes care of working out whether the user's score made
 * it into the ten best scores and, if so, records it in the table.
 *
 * Returns: %0 on failure and the number of bytes written otherwise.
 */
gint mate_score_log(gfloat score, const gchar* level, gboolean higher_to_lower_score_order)
{
	struct command cmd;
	gint retval;

	#ifndef G_OS_WIN32
		if (getgid() != getegid())
		{
			g_error("mate_score_init must be called first thing in main()\n");
			abort();
		}
	#endif

	if (infd == -1 || outfd == -1)
		return 0;

	cmd.score = score;

	if (!level)
		level = "";

	cmd.level = strlen (level) + 1;
	cmd.ordering = higher_to_lower_score_order;

	if (write(outfd, &cmd, sizeof cmd) != sizeof(cmd) || write(outfd, level, cmd.level) != cmd.level || read(infd, &retval, sizeof retval) != sizeof(retval))
	{
		close(outfd);
		close(infd);
		infd = outfd = -1;
		return 0;
	}

	return retval;
}

/**
 * mate_score_get_notable:
 * @gamename:   The name of the game we want to fetch information from.
 * @level:      The level for which we want to pull information.
 * @names:      An array of strings is returned at the address pointed here
 * @scores:     An array of gfloats is returned at the address pointed here
 * @scoretimes: An array of time_t is returned at the address pointed here
 *
 * Fetches the most notable players on @gamename at level @level.
 *
 * Returns: The number of scores returned.  The @names, @scores and @scoretime
 * pointers point to regions that were allocated with g_malloc() with the
 * contents.
 */
gint mate_score_get_notable (const gchar* gamename, const gchar* level, gchar*** names, gfloat** scores, time_t** scoretimes)
{
	const gchar* realname;
	gchar buf[512], *buf2;
	gchar* infile_name;
	FILE* infile;
	gint retval;

	g_return_val_if_fail(names != NULL, 0);
	g_return_val_if_fail(scores != NULL, 0);

	if (gamename == NULL)
	{
		realname = defgamename;
	}
	else
	{
		realname = gamename;
	}

	infile_name = mate_get_score_file_name(realname, level);

	infile = g_fopen(infile_name, "r");
	g_free (infile_name);

	if (infile)
	{
		*names = g_malloc((NSCORES + 1) * sizeof(gchar *));
		*scores = g_malloc((NSCORES + 1) * sizeof(gfloat));
		*scoretimes = g_malloc((NSCORES + 1) * sizeof(time_t));

		mate_i18n_push_c_numeric_locale();

		for (retval = 0; fgets(buf, sizeof(buf), infile) && retval < NSCORES; retval++)
		{
			char* tokp;

			buf[strlen(buf) - 1] = 0;
			buf2 = strtok_r(buf, " ", &tokp);
			(*scores)[retval] = atof(buf2);
			buf2 = strtok_r(NULL, " ", &tokp);
			(*scoretimes)[retval] = atoi(buf2);
			buf2 = strtok_r(NULL, "\n", &tokp);
			(*names)[retval] = g_strdup(buf2);
		}

		(*names)[retval] = NULL;
		(*scores)[retval] = 0.0;

		mate_i18n_pop_c_numeric_locale();

		fclose(infile);
	}
	else
	{
		*names = NULL;
		*scores = NULL;
		*scoretimes = NULL;
		retval = 0;
	}

	return retval;
}