/**
 * @file dcc_send.c Functions used in sending files with DCC SEND
 *
 * gaim
 *
 * Copyright (C) 2004, Timothy T Ringenbach <omarvo@hotmail.com>
 * Copyright (C) 2003, Robbert Haarman <gaim@inglorion.net>
 *
 * 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 "internal.h"
#include "irc.h"
#include "debug.h"
#include "ft.h"
#include "notify.h"
#include "network.h"

/***************************************************************************
 * Functions related to receiving files via DCC SEND
 ***************************************************************************/

struct irc_xfer_rx_data {
	gchar *ip;
};

static void irc_dccsend_recv_destroy(GaimXfer *xfer)
{
	struct irc_xfer_rx_data *xd = xfer->data;

	if (xd->ip != NULL)
		g_free(xd->ip);

	g_free(xd);
}

/*
 * This function is called whenever data is received.
 * It sends the acknowledgement (in the form of a total byte count as an
 * unsigned 4 byte integer in network byte order)
 */
static void irc_dccsend_recv_ack(GaimXfer *xfer, const char *data, size_t size) {
	unsigned long l;

	l = htonl(xfer->bytes_sent);
	write(xfer->fd, &l, sizeof(l));
}

static void irc_dccsend_recv_init(GaimXfer *xfer) {
	struct irc_xfer_rx_data *xd = xfer->data;

	gaim_xfer_start(xfer, -1, xd->ip, xfer->remote_port);
	g_free(xd->ip);
	xd->ip = NULL;
}

/* This function makes the necessary arrangements for receiving files */
void irc_dccsend_recv(struct irc_conn *irc, const char *from, const char *msg) {
	GaimXfer *xfer;
	struct irc_xfer_rx_data *xd;
	gchar **token;
	struct in_addr addr;
	GString *filename;
	int i = 0;
	guint32 nip;

	token = g_strsplit(msg, " ", 0);
	if (!token[0] || !token[1] || !token[2]) {
		g_strfreev(token);
		return;
	}

	filename = g_string_new("");
	if (token[0][0] == '"') {
		if (!strchr(&(token[0][1]), '"')) {
			g_string_append(filename, &(token[0][1]));
			for (i = 1; token[i]; i++)
				if (!strchr(token[i], '"')) {
					g_string_append_printf(filename, " %s", token[i]);
				} else {
					g_string_append_len(filename, token[i], strlen(token[i]) - 1);
					break;
				}
		} else {
			g_string_append_len(filename, &(token[0][1]), strlen(&(token[0][1])) - 1);
		}
	} else {
		g_string_append(filename, token[0]);
	}

	if (!token[i] || !token[i+1] || !token[i+2]) {
		g_strfreev(token);
		g_string_free(filename, TRUE);
		return;
	}
	i++;

	xfer = gaim_xfer_new(irc->account, GAIM_XFER_RECEIVE, from);
	xd = g_new0(struct irc_xfer_rx_data, 1);
	xfer->data = xd;

	gaim_xfer_set_filename(xfer, filename->str);
	xfer->remote_port = atoi(token[i+1]);

	nip = strtoul(token[i], NULL, 10);
	if (nip) {
		addr.s_addr = htonl(nip);
		xd->ip = g_strdup(inet_ntoa(addr));
	} else {
		xd->ip = g_strdup(token[i]);
	}
	gaim_debug(GAIM_DEBUG_INFO, "irc", "Receiving file from %s\n",
		xd->ip);
	gaim_xfer_set_size(xfer, token[i+2] ? atoi(token[i+2]) : 0);

	gaim_xfer_set_init_fnc(xfer, irc_dccsend_recv_init);
	gaim_xfer_set_ack_fnc(xfer, irc_dccsend_recv_ack);

	gaim_xfer_set_end_fnc(xfer, irc_dccsend_recv_destroy);
	gaim_xfer_set_request_denied_fnc(xfer, irc_dccsend_recv_destroy);
	gaim_xfer_set_cancel_send_fnc(xfer, irc_dccsend_recv_destroy);

	gaim_xfer_request(xfer);
	g_strfreev(token);
	g_string_free(filename, TRUE);
}

/*******************************************************************
 * Functions related to sending files via DCC SEND
 *******************************************************************/

struct irc_xfer_send_data {
	gint inpa;
	int fd;
	guchar *rxqueue;
	guint rxlen;
};

static void irc_dccsend_send_destroy(GaimXfer *xfer)
{
	struct irc_xfer_send_data *xd = xfer->data;

	if (xd == NULL)
		return;

	if (xd->inpa > 0)
		gaim_input_remove(xd->inpa);
	if (xd->fd != -1)
		close(xd->fd);

	if (xd->rxqueue)
		g_free(xd->rxqueue);

	g_free(xd);
}

/* just in case you were wondering, this is why DCC is gay */
static void irc_dccsend_send_read(gpointer data, int source, GaimInputCondition cond)
{
	GaimXfer *xfer = data;
	struct irc_xfer_send_data *xd = xfer->data;
	char *buffer[16];
	int len;

	if ((len = read(source, buffer, sizeof(buffer))) <= 0) {
		gaim_input_remove(xd->inpa);
		xd->inpa = 0;
		return;
	}

	xd->rxqueue = g_realloc(xd->rxqueue, len + xd->rxlen);
	memcpy(xd->rxqueue + xd->rxlen, buffer, len);
	xd->rxlen += len;

	while (1) {
		int acked;

		if (xd->rxlen < 4)
			break;

		acked = ntohl(*((gint32 *)xd->rxqueue));

		xd->rxlen -= 4;
		if (xd->rxlen) {
			char *tmp = g_memdup(xd->rxqueue + 4, xd->rxlen);
			g_free(xd->rxqueue);
			xd->rxqueue = tmp;
		} else {
			g_free(xd->rxqueue);
			xd->rxqueue = NULL;
		}

		if (acked >= gaim_xfer_get_size(xfer)) {
			gaim_input_remove(xd->inpa);
			xd->inpa = 0;
			gaim_xfer_set_completed(xfer, TRUE);
			gaim_xfer_end(xfer);
			return;
		}


	}
}

ssize_t irc_dccsend_send_write(const char *buffer, size_t size, GaimXfer *xfer)
{
	ssize_t s;

	s = MIN(gaim_xfer_get_bytes_remaining(xfer), size);
	if (!s)
		return 0;

	return write(xfer->fd, buffer, s);
}

static void irc_dccsend_send_connected(gpointer data, int source, GaimInputCondition cond) {
	GaimXfer *xfer = (GaimXfer *) data;
	struct irc_xfer_send_data *xd = xfer->data;
	int conn;

	conn = accept(xd->fd, NULL, 0);
	if (conn == -1) {
		/* Accepting the connection failed. This could just be related
		 * to the nonblocking nature of the listening socket, so we'll
		 * just try again next time */
		/* Let's print an error message anyway */
		gaim_debug_warning("irc", "accept: %s\n", strerror(errno));
		return;
	}

	gaim_input_remove(xfer->watcher);
	xfer->watcher = 0;
	close(xd->fd);
	xd->fd = -1;

	xd->inpa = gaim_input_add(conn, GAIM_INPUT_READ, irc_dccsend_send_read, xfer);
	/* Start the transfer */
	gaim_xfer_start(xfer, conn, NULL, 0);
}

/*
 * This function is called after the user has selected a file to send.
 */
static void irc_dccsend_send_init(GaimXfer *xfer) {
	struct irc_xfer_send_data *xd = xfer->data;
	GaimConnection *gc = gaim_account_get_connection(gaim_xfer_get_account(xfer));
	struct irc_conn *irc = gc->proto_data;
	int sock;
	const char *arg[2];
	char *tmp;
	struct in_addr addr;
	unsigned short int port;

	xfer->filename = g_path_get_basename(xfer->local_filename);

	/* Create a listening socket */
	sock = gaim_network_listen_range(0, 0);

	if (sock < 0) {
		gaim_notify_error(gc, NULL, _("File Transfer Aborted"),
		                  _("Gaim could not open a listening port."));
		gaim_xfer_cancel_local(xfer);
		return;
	}

	xd->fd = sock;

	port = gaim_network_get_port_from_fd(sock);
	gaim_debug_misc("irc", "port is %hu\n", port);
	/* Monitor the listening socket */
	xfer->watcher = gaim_input_add(sock, GAIM_INPUT_READ,
	                               irc_dccsend_send_connected, xfer);

	/* Send the intended recipient the DCC request */
	arg[0] = xfer->who;
	inet_aton(gaim_network_get_my_ip(irc->fd), &addr);
	arg[1] = tmp = g_strdup_printf("\001DCC SEND \"%s\" %u %hu %u\001",
	                         xfer->filename, ntohl(addr.s_addr),
	                         port, xfer->size);

	irc_cmd_privmsg(xfer->account->gc->proto_data, "msg", NULL, arg);
	g_free(tmp);
}

/**
 * Gaim calls this function when the user selects Send File from the
 * buddy menu
 * It sets up the GaimXfer struct and tells Gaim to go ahead
 */
void irc_dccsend_send_file(GaimConnection *gc, const char *who, const char *file) {
	GaimXfer *xfer;
	struct irc_xfer_send_data *xd;

	/* Build the file transfer handle */
	xfer = gaim_xfer_new(gaim_connection_get_account(gc), GAIM_XFER_SEND, who);


	xd = g_new0(struct irc_xfer_send_data, 1);
	xd->fd = -1;
	xfer->data = xd;

	 /* Setup our I/O op functions */
	gaim_xfer_set_init_fnc(xfer, irc_dccsend_send_init);
	gaim_xfer_set_write_fnc(xfer, irc_dccsend_send_write);
	gaim_xfer_set_end_fnc(xfer, irc_dccsend_send_destroy);
	gaim_xfer_set_request_denied_fnc(xfer, irc_dccsend_send_destroy);
	gaim_xfer_set_cancel_send_fnc(xfer, irc_dccsend_send_destroy);
	/* Now perform the request */
	if (file)
		gaim_xfer_request_accepted(xfer, file);
	else
		gaim_xfer_request(xfer);
}