/***************************************************************************
 *   Copyright (C) 05/2009 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; version 2 of the License                *
 *                                                                         *
 *   This program 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <sys/stat.h>

#include "configfile.h"
#include "event.h"
#include "list.h"
#include "logging.h"
#include "process.h"
#include "torrentfile.h"

LIST_HEAD(torrent_list);

struct torrent_file * find_create_torrent(const char *fullpath)
{
	/* strip directory from filename */
	const char *filename = strrchr(fullpath, '/');
	if (filename == NULL || *(filename +1) == '\0')
		filename = fullpath;
	else
		filename++;

	/* search for this torrent */
	struct torrent_file *torrent;
	list_for_each_entry(torrent, &torrent_list, list) {
		if (strcmp(torrent->name, filename) == 0)
			return torrent;
	}

	/* create a new one */
	torrent = malloc(sizeof(struct torrent_file) + strlen(filename));
	if (torrent == NULL) {
		log_print(LOG_WARN, "find_create_torrent(): out of memory");
		return NULL;
	}

	/* init fields */
	INIT_LIST_HEAD(&torrent->client_list);
	torrent->name = strdup(filename);
	torrent->destroy = 0;
	torrent->child = NULL;

	/* keep torrent list sorted by name */
	struct torrent_file *search;
	list_for_each_entry(search, &torrent_list, list)
		if (strcmp(search->name, torrent->name) > 0)
			break;

	list_add_tail(&torrent->list, &search->list);
	return torrent;
}

int destroy_torrent(struct torrent_file *torrent)
{
	/* remove us from list */
	list_del(&torrent->list);

	/* check if we're seeding, destroy after sigchld */
	if (torrent->child != NULL) {
		torrent->destroy = 1;
		kill(SIGTERM, torrent->child->pid);
		return 0;
	}

	free(torrent->name);
	free(torrent);
	return 0;
}

static void child_exit(struct child_process *child, int exit_code, void *privdata)
{
	struct torrent_file *torrent = (struct torrent_file *)privdata;
	log_print(LOG_INFO, "ctorrent [pid:%d] was killed (exit:%d)", child->pid, exit_code);
	torrent->child = NULL;

	close(child->fd[STDIN_FILENO]);
	close(child->fd[STDOUT_FILENO]);
	close(child->fd[STDERR_FILENO]);

	if (torrent->destroy)
		destroy_torrent(torrent);
}

static int null_read(int fd, void *privdata)
{
	char buf[256];

	int len = read(fd, buf, sizeof(buf));
	return !(len > 0);
}

int seed_torrent(struct torrent_file *torrent)
{
	const char *path = config_get_string("global", "search-path", NULL);
	if (path == NULL) {
		log_print(LOG_WARN, "requesting torrentfile, but no search path given");
		return -1;
	}

	char buf[256];
	int len = snprintf(buf, sizeof(buf), "%s/%s", path, torrent->name);
	if (len < 0 || len >= sizeof(buf)) {
		log_print(LOG_WARN, "filename > max");
		return -1;
	}

	struct stat statbuf;
	if (stat(buf, &statbuf) < 0) {
		log_print(LOG_WARN, "torrent file not found: %s", buf);
		return -1;
	}

	const char *ctorrent_bin = config_get_string("global", "ctorrent-bin", "/usr/bin/ctorrent");
	const char *statserv = config_get_string("global", "statserv", "127.0.0.1:2780");
	char *const args[] = { (char *)ctorrent_bin, "-S", (char *)statserv, "-f", buf, NULL };

	torrent->child = childproc_alloc(args, path);
	if (childproc_fork(torrent->child, child_exit, torrent) < 0) {
		log_print(LOG_ERROR, "spawn_child(%s)", args[0]);
		childproc_free(torrent->child);
		torrent->child = NULL;
		return -1;
	}

	log_print(LOG_INFO, "spawned ctorrent for %s [pid:%d]", torrent->name, torrent->child->pid);

	/* just read all output from ctorrent to /dev/null */
	event_add_readfd(NULL, torrent->child->fd[STDOUT_FILENO], null_read, NULL);
	event_add_readfd(NULL, torrent->child->fd[STDERR_FILENO], null_read, NULL);

	return 0;
}