/*
 dcc.c : irssi

    Copyright (C) 1999-2001 Timo Sirainen

    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; either version 2 of the License, or
    (at your option) any later version.

    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 "module.h"
#include "signals.h"
#include "commands.h"
#include "network.h"
#include "net-sendbuffer.h"
#include "line-split.h"
#include "settings.h"

#include "irc.h"

#include "dcc-chat.h"
#include "dcc-get.h"

void dcc_send_init(void);
void dcc_send_deinit(void);

void dcc_resume_init(void);
void dcc_resume_deinit(void);

void dcc_autoget_init(void);
void dcc_autoget_deinit(void);

#define DCC_TYPES 5

static const char *dcc_types[] = {
	"CHAT",
	"SEND",
	"GET",
	"RESUME",
	"ACCEPT"
};

GSList *dcc_conns;

static int dcc_timeouttag;

/* Create new DCC record */
DCC_REC *dcc_create(int type, const char *nick, const char *arg,
		    IRC_SERVER_REC *server, DCC_REC *chat)
{
	DCC_REC *dcc;

	g_return_val_if_fail(nick != NULL, NULL);
	g_return_val_if_fail(arg != NULL, NULL);

	dcc = g_new0(DCC_REC, 1);
	dcc->mirc_ctcp = settings_get_bool("dcc_mirc_ctcp");
	dcc->created = time(NULL);
	dcc->chat = chat;
	dcc->type = type;
	dcc->arg = g_strdup(arg);
	dcc->nick = g_strdup(nick);
	dcc->fhandle = -1;
	dcc->tagconn = dcc->tagread = dcc->tagwrite = -1;
	dcc->server = server;
	dcc->mynick = g_strdup(server != NULL ? server->nick :
			       chat != NULL ? chat->nick : "??");

	dcc->ircnet = server == NULL ?
		(chat == NULL || chat->ircnet == NULL ? NULL : g_strdup(chat->ircnet)) :
		(server->connrec->chatnet == NULL ? NULL : g_strdup(server->connrec->chatnet));
	dcc_conns = g_slist_append(dcc_conns, dcc);

	signal_emit("dcc created", 1, dcc);
	return dcc;
}

static void dcc_remove_chat_refs(DCC_REC *dcc)
{
	GSList *tmp;

	g_return_if_fail(dcc != NULL);

	for (tmp = dcc_conns; tmp != NULL; tmp = tmp->next) {
		DCC_REC *rec = tmp->data;

		if (rec->chat == dcc)
			rec->chat = NULL;
	}
}

/* Destroy DCC record */
void dcc_destroy(DCC_REC *dcc)
{
	g_return_if_fail(dcc != NULL);
	if (dcc->destroyed) return;

	dcc_conns = g_slist_remove(dcc_conns, dcc);
	dcc_remove_chat_refs(dcc);

	dcc->destroyed = TRUE;
	signal_emit("dcc destroyed", 1, dcc);

	if (dcc->fhandle != -1) close(dcc->fhandle);
	if (dcc->handle != NULL) net_disconnect(dcc->handle);
	if (dcc->tagconn != -1) g_source_remove(dcc->tagconn);
	if (dcc->tagread != -1) g_source_remove(dcc->tagread);
	if (dcc->tagwrite != -1) g_source_remove(dcc->tagwrite);
	if (dcc->sendbuf != NULL) net_sendbuffer_destroy(dcc->sendbuf, FALSE);

	if (dcc->type == DCC_TYPE_CHAT)
		line_split_free((LINEBUF_REC *) dcc->databuf);
	else if (dcc->databuf != NULL)
		g_free(dcc->databuf);

	g_free_not_null(dcc->file);
	g_free_not_null(dcc->ircnet);
	g_free_not_null(dcc->chat_id);
	g_free_not_null(dcc->target);
	g_free(dcc->mynick);
	g_free(dcc->nick);
	g_free(dcc->arg);
	g_free(dcc);
}

void dcc_make_address(IPADDR *ip, char *host)
{
	unsigned long addr;

	if (is_ipv6_addr(ip)) {
		/* IPv6 */
		net_ip2host(ip, host);
	} else {
		memcpy(&addr, &ip->addr, 4);
		g_snprintf(host, MAX_IP_LEN, "%lu",
			   (unsigned long) htonl(addr));
	}
}

DCC_REC *dcc_find_request_latest(int type)
{
	DCC_REC *latest;
        GSList *tmp;

        latest = NULL;
	for (tmp = dcc_conns; tmp != NULL; tmp = tmp->next) {
		DCC_REC *dcc = tmp->data;

		if (dcc->type == type && dcc_is_waiting_user(dcc))
			latest = dcc;
	}

        return latest;
}

DCC_REC *dcc_find_request(int type, const char *nick, const char *arg)
{
	GSList *tmp;

	g_return_val_if_fail(nick != NULL, NULL);

	for (tmp = dcc_conns; tmp != NULL; tmp = tmp->next) {
		DCC_REC *dcc = tmp->data;

		if (dcc->type == type && !dcc_is_connected(dcc) &&
		    g_strcasecmp(dcc->nick, nick) == 0 &&
		    (arg == NULL || strcmp(dcc->arg, arg) == 0))
			return dcc;
	}

	return NULL;
}

const char *dcc_type2str(int type)
{
	g_return_val_if_fail(type >= 1 && type <= DCC_TYPES, NULL);

	return dcc_types[type-1];
}

int dcc_str2type(const char *type)
{
	int num;

	for (num = 0; num < DCC_TYPES; num++) {
		if (g_strcasecmp(dcc_types[num], type) == 0)
			return num+1;
	}

	return 0;
}

GIOChannel *dcc_listen(GIOChannel *interface, IPADDR *ip, int *port)
{
	if (net_getsockname(interface, ip, NULL) == -1)
                return NULL;

	*port = settings_get_int("dcc_port");
	return net_listen(ip, port);
}

void dcc_get_address(const char *str, IPADDR *ip)
{
	unsigned long addr;

	if (strchr(str, ':') == NULL) {
		/* normal IPv4 address in 32bit number form */
                addr = strtoul(str, NULL, 10);
		ip->family = AF_INET;
		addr = (unsigned long) ntohl(addr);
		memcpy(&ip->addr, &addr, 4);
	} else {
		/* IPv6 - in standard form */
		net_host2ip(str, ip);
	}
}

void dcc_ctcp_message(IRC_SERVER_REC *server, const char *target,
		      DCC_REC *chat, int notice, const char *msg)
{
	char *str;

	if (chat != NULL && chat->sendbuf != NULL) {
		/* send it via open DCC chat */
		str = g_strdup_printf("%s\001%s\001", chat->mirc_ctcp ? "" :
				      notice ? "CTCP_REPLY " :
				      "CTCP_MESSAGE ", msg);
                dcc_chat_send(chat, str);
		g_free(str);
	} else {
		irc_send_cmdv(server, "%s %s :\001%s\001",
			      notice ? "NOTICE" : "PRIVMSG", target, msg);
	}
}

/* Server connected, check if there's any open dcc sessions for this ircnet.. */
static void dcc_server_connected(IRC_SERVER_REC *server)
{
	GSList *tmp;

	g_return_if_fail(server != NULL);

	if (server->connrec->chatnet == NULL)
		return;

	for (tmp = dcc_conns; tmp != NULL; tmp = tmp->next) {
		DCC_REC *dcc = tmp->data;

		if (dcc->server == NULL && dcc->ircnet != NULL &&
		    g_strcasecmp(dcc->ircnet, server->connrec->chatnet) == 0) {
			dcc->server = server;
			g_free(dcc->mynick);
			dcc->mynick = g_strdup(server->nick);
		}
	}
}

/* Server disconnected, remove it from all dcc records */
static void dcc_server_disconnected(IRC_SERVER_REC *server)
{
	GSList *tmp;

	g_return_if_fail(server != NULL);

	for (tmp = dcc_conns; tmp != NULL; tmp = tmp->next) {
		DCC_REC *dcc = tmp->data;

		if (dcc->server != server)
			continue;

		dcc->server = dcc->ircnet == NULL ? NULL :
			IRC_SERVER(server_find_chatnet(dcc->ircnet));
		if (dcc->server != NULL) {
			g_free(dcc->mynick);
			dcc->mynick = g_strdup(dcc->server->nick);
		}
	}
}

/* Handle incoming DCC CTCP messages - either from IRC server or DCC chat */
static void ctcp_msg_dcc(IRC_SERVER_REC *server, const char *data,
			 const char *nick, const char *addr,
			 const char *target, DCC_REC *chat)
{
	char *args, *str;

	str = g_strconcat("ctcp msg dcc ", data, NULL);
	args = strchr(str+13, ' ');
	if (args != NULL) *args++ = '\0'; else args = "";

	g_strdown(str+13);
	if (!signal_emit(str, 6, server, args, nick, addr, target, chat)) {
		signal_emit("default ctcp msg dcc", 6,
			    server, data, nick, addr, target, chat);
	}
	g_free(str);
}

/* Handle incoming DCC CTCP replies - either from IRC server or DCC chat */
static void ctcp_reply_dcc(IRC_SERVER_REC *server, const char *data,
			   const char *nick, const char *addr,
			   const char *target)
{
	char *args, *str;

	str = g_strconcat("ctcp reply dcc ", data, NULL);
	args = strchr(str+15, ' ');
	if (args != NULL) *args++ = '\0'; else args = "";

	g_strdown(str+15);
	if (!signal_emit(str, 5, server, args, nick, addr, target)) {
		signal_emit("default ctcp reply dcc", 5,
			    server, data, nick, addr, target);
	}
	g_free(str);
}

/* CTCP REPLY: REJECT */
static void ctcp_reply_dcc_reject(IRC_SERVER_REC *server, const char *data,
				  const char *nick, const char *addr,
				  DCC_REC *chat)
{
        DCC_REC *dcc;
	char *typestr, *args;
        int type;

	typestr = g_strdup(data);
	args = strchr(typestr, ' ');
        if (args != NULL) *args++ = '\0'; else args = "";

	type = dcc_str2type(typestr);
	dcc = dcc_find_request(type, nick,
			       type == DCC_TYPE_CHAT ? NULL : args);
	if (dcc != NULL) {
		signal_emit("dcc closed", 1, dcc);
		dcc_destroy(dcc);
	}

        g_free(typestr);
}

/* Reject a DCC request */
void dcc_reject(DCC_REC *dcc, IRC_SERVER_REC *server)
{
	g_return_if_fail(dcc != NULL);

	if (dcc->server != NULL) server = dcc->server;
	if (server != NULL && (dcc->type != DCC_TYPE_CHAT ||
			       dcc->starttime == 0)) {
		signal_emit("dcc rejected", 1, dcc);
		irc_send_cmdv(server, "NOTICE %s :\001DCC REJECT %s %s\001",
			      dcc->nick, dcc_type2str(SWAP_SENDGET(dcc->type)),
			      dcc->arg);
	}

	signal_emit("dcc closed", 1, dcc);
	dcc_destroy(dcc);
}

static int dcc_timeout_func(void)
{
	GSList *tmp, *next;
	time_t now;

	now = time(NULL)-settings_get_int("dcc_timeout");
	for (tmp = dcc_conns; tmp != NULL; tmp = next) {
		DCC_REC *rec = tmp->data;

		next = tmp->next;
		if (rec->tagread == -1 && now > rec->created) {
			/* timed out. */
			dcc_reject(rec, NULL);
		}
	}
	return 1;
}

static void event_no_such_nick(IRC_SERVER_REC *server, char *data)
{
	char *params, *nick;
	GSList *tmp, *next;

	g_return_if_fail(data != NULL);

	params = event_get_params(data, 2, NULL, &nick);

	/* check if we've send any dcc requests to this nick.. */
	for (tmp = dcc_conns; tmp != NULL; tmp = next) {
		DCC_REC *dcc = tmp->data;

		next = tmp->next;
		if (!dcc_is_connected(dcc) && dcc->server == server &&
		    g_strcasecmp(dcc->nick, nick) == 0) {
			signal_emit("dcc closed", 1, dcc);
			dcc_destroy(dcc);
		}
	}

	g_free(params);
}

/* SYNTAX: DCC CLOSE <type> <nick> [<file>] */
static void cmd_dcc_close(char *data, IRC_SERVER_REC *server)
{
	GSList *tmp, *next;
	char *typestr, *nick, *arg;
	void *free_arg;
	int found, type;

	g_return_if_fail(data != NULL);

	if (!cmd_get_params(data, &free_arg, 3, &typestr, &nick, &arg))
		return;

	if (*nick == '\0') cmd_param_error(CMDERR_NOT_ENOUGH_PARAMS);

	g_strup(typestr);
	type = dcc_str2type(typestr);
	if (type == 0) {
		signal_emit("dcc error unknown type", 1, typestr);
		cmd_params_free(free_arg);
		return;
	}

	found = FALSE;
	for (tmp = dcc_conns; tmp != NULL; tmp = next) {
		DCC_REC *dcc = tmp->data;

		next = tmp->next;
		if (dcc->type == type &&
		    g_strcasecmp(dcc->chat_id != NULL ?
				 dcc->chat_id : dcc->nick, nick) == 0 &&
		    (*arg == '\0' || strcmp(dcc->arg, arg) == 0)) {
			dcc_reject(dcc, server);
			found = TRUE;
		}
	}

	if (!found) {
		signal_emit("dcc error close not found", 3,
			    typestr, nick, arg);
	}

	cmd_params_free(free_arg);
}

static void cmd_dcc(const char *data, IRC_SERVER_REC *server, void *item)
{
	command_runsub("dcc", data, server, item);
}

void irc_dcc_init(void)
{
	dcc_conns = NULL;
	dcc_timeouttag = g_timeout_add(1000, (GSourceFunc) dcc_timeout_func, NULL);

	settings_add_bool("dcc", "dcc_mirc_ctcp", FALSE);
	settings_add_int("dcc", "dcc_port", 0);
	settings_add_int("dcc", "dcc_timeout", 300);
	settings_add_int("dcc", "dcc_block_size", 2048);

	signal_add("server connected", (SIGNAL_FUNC) dcc_server_connected);
	signal_add("server disconnected", (SIGNAL_FUNC) dcc_server_disconnected);
	signal_add("ctcp msg dcc", (SIGNAL_FUNC) ctcp_msg_dcc);
	signal_add("ctcp reply dcc", (SIGNAL_FUNC) ctcp_reply_dcc);
	signal_add("ctcp reply dcc reject", (SIGNAL_FUNC) ctcp_reply_dcc_reject);
	command_bind("dcc", NULL, (SIGNAL_FUNC) cmd_dcc);
	command_bind("dcc close", NULL, (SIGNAL_FUNC) cmd_dcc_close);
	signal_add("event 401", (SIGNAL_FUNC) event_no_such_nick);

	dcc_chat_init();
	dcc_get_init();
	dcc_send_init();
	dcc_resume_init();
	dcc_autoget_init();
}

void irc_dcc_deinit(void)
{
	dcc_chat_deinit();
	dcc_get_deinit();
	dcc_send_deinit();
	dcc_resume_deinit();
	dcc_autoget_deinit();

	signal_remove("server connected", (SIGNAL_FUNC) dcc_server_connected);
	signal_remove("server disconnected", (SIGNAL_FUNC) dcc_server_disconnected);
	signal_remove("ctcp msg dcc", (SIGNAL_FUNC) ctcp_msg_dcc);
	signal_remove("ctcp reply dcc", (SIGNAL_FUNC) ctcp_reply_dcc);
	signal_remove("ctcp reply dcc reject", (SIGNAL_FUNC) ctcp_reply_dcc_reject);
	command_unbind("dcc", (SIGNAL_FUNC) cmd_dcc);
	command_unbind("dcc close", (SIGNAL_FUNC) cmd_dcc_close);
	signal_remove("event 401", (SIGNAL_FUNC) event_no_such_nick);

	g_source_remove(dcc_timeouttag);

	while (dcc_conns != NULL)
		dcc_destroy(dcc_conns->data);
}