/*

 * cmd.c                -- Send shell command output as messages

 *

 * Copyrigth (C) 2009      Myhailo Danylenko <isbear@ukrpost.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 <stdlib.h>

#include <glib.h>

#include <gmodule.h>

#include <unistd.h>

#include <errno.h>

#include "commands.h"

#include "logprint.h"

#include "utils.h"

#include "settings.h"

#include "hbuf.h"

#include "xmpp.h"

#include "roster.h"

typedef struct {

	gchar      *jid;

	GString    *input;

	guint       source;

	GIOChannel *channel;

} cmd_cb_t;

static GSList  *cmd_channels = NULL;

static gboolean cmd_reader (GIOChannel *channel, GIOCondition condition, gpointer data)

{

	cmd_cb_t *cb = (cmd_cb_t *) data;

	if (condition & (G_IO_IN|G_IO_PRI)) {

		GIOStatus    chstat;

		static gchar buf[HBB_BLOCKSIZE];

		gsize        endpos;

		chstat = g_io_channel_read_chars (channel, buf, HBB_BLOCKSIZE, &endpos, NULL);

		if (chstat == G_IO_STATUS_ERROR || chstat == G_IO_STATUS_EOF) {

			cb->source = 0;

			return FALSE; // XXX

		}

		if (endpos) {

			GString *input = cb->input;

			gsize    bread   = 0;

			gsize    written = 0;

			GError  *err     = NULL;

			gchar   *utf8    = NULL;

			g_string_append_len (input, buf, endpos);

			if (!lm_connection_is_authenticated (lconnection)) {

				scr_LogPrint (LPRINT_LOGNORM, "cmd: Connection is not ready, delaying data");

				return TRUE;

			}

			// usual g_locale_to_utf8 seem to be unable to detect locale charset

			// maybe, proper solution will be to call setlocale on module loading,

			// but mcabber already does this, and I do not want to mess with it

			utf8 = g_convert (input->str, input->len, LocaleCharSet, "UTF-8", &bread, &written, &err);

			if (err && err->code == G_CONVERT_ERROR_ILLEGAL_SEQUENCE && bread) {

				err     = NULL;

				written = 0;

				utf8 = g_convert (input->str, bread, LocaleCharSet, "UTF-8", &bread, &written, &err);

			}

			if (written) {

				gsize sent = 0;

				while (sent < written) {

					gint      crypted;

					gpointer  xep184  = NULL;

					gsize     len     = 0;

					gchar    *bbuf    = NULL;

					if (written - sent > HBB_BLOCKSIZE) {

						gchar *c = utf8 + sent + HBB_BLOCKSIZE;

						c = g_utf8_find_prev_char (utf8 + sent, c);

						if (!c) {

							scr_LogPrint (LPRINT_LOGNORM, "cmd: Cannot determine utf8 character end! End of data chunk will be discarded!");

							break;

						}

						len  = c - utf8 - sent;

						bbuf = g_strndup (utf8 + sent, len);

					}

					// XXX add command/sequence number as title?

					if (crypted == -1) {

						scr_LogPrint (LPRINT_LOGNORM, "cmd: Encryption error. Message not sent.");

						if (!len)

							break;

						g_free (bbuf);

						continue;

					}

					if (!len)

						break;

					g_free (bbuf);

					sent += len;

				}

				g_free (utf8);

				g_string_erase (input, 0, bread);

			} else {

				scr_LogPrint (LPRINT_LOGNORM, "cmd: Character conversion error: %s", err->message);

				cb->source = 0;

				return FALSE;

			}

		}

	} else if (condition & (G_IO_ERR|G_IO_NVAL|G_IO_HUP)) {

		cb->source = 0;

		return FALSE; // XXX

	}

	return TRUE;

}

static void cmd_destroy_data (gpointer data)

{

	cmd_cb_t *cb = (cmd_cb_t *) data;

	cmd_channels = g_slist_remove (cmd_channels, data);

	// May conflict - will be called during source removal?

//	if (cb->source)

//		g_source_remove (cb->source);

	if (cb->channel)

		g_io_channel_unref (cb->channel);

	g_free (cb->jid);

	g_free (cb);

}

static void do_cmd (char *arg)

{

	int         fd[2];

	const char *jid = CURRENT_JID;

	if (!*arg)

		return;

	if (!jid) {

		scr_LogPrint (LPRINT_LOGNORM, "Unsuitable buddy selected");

		return;

	}

	if (pipe (fd)) {

		scr_LogPrint (LPRINT_LOGNORM, "Cannot create pipe: %s", strerror (errno));

		return;

	}

	{

		int res = fork ();

		if (!res) {

			close (fd[0]);

			dup2 (fd[1], STDOUT_FILENO);

			if (settings_opt_get_int ("cmd_redirect_stderr"))

				dup2 (fd[1], STDERR_FILENO);

			else

				close (STDERR_FILENO);

			close (STDIN_FILENO);

			close (fd[1]);

			{

				const char *shell = settings_opt_get ("cmd_shell");

				if (!shell)

					shell = getenv ("SHELL");

				if (!shell)

					shell = "sh";

				execl (shell, shell, "-c", arg, NULL);

			}

		}

		if (res == -1) {

			scr_LogPrint (LPRINT_NORMAL, "Cannot fork child: %s", strerror (errno));

			close (fd[0]);

			close (fd[1]);

			return;

		}

		close (fd[1]);

		GIOChannel *channel = g_io_channel_unix_new (fd[0]);

		g_io_channel_set_flags (channel, G_IO_FLAG_NONBLOCK, NULL);

		g_io_channel_set_encoding (channel, NULL, NULL);

		g_io_channel_set_close_on_unref (channel, TRUE);

		g_io_channel_set_buffered (channel, FALSE);

		{

			cmd_cb_t *cb = g_new (cmd_cb_t, 1);

			cb->jid     = g_strdup (jid);

			cb->input   = g_string_new (NULL);

			cb->channel = channel;

			cb->source  = g_io_add_watch_full (channel, 0, G_IO_IN|G_IO_PRI|G_IO_ERR|G_IO_HUP|G_IO_NVAL,

		                                   cmd_reader, (gpointer) cb, cmd_destroy_data);

			cmd_channels = g_slist_append (cmd_channels, cb);

		}

	}

}

const gchar *g_module_check_init(GModule *module)

{

	cmd_add ("cmd", "", 0, 0, do_cmd, NULL);

	return NULL;

}

void g_module_unload(GModule *module)

{

	GSList *sel;

	cmd_del ("cmd");

	for (sel = cmd_channels; sel; sel = sel->next) {

		cmd_cb_t *cb = (cmd_cb_t *) sel->data;

		if (cb->source)

			g_source_remove (cb->source);

		if (cb->channel)

			g_io_channel_unref (cb->channel);

		g_free (cb->jid);

		g_free (cb);

	}

	g_slist_free (cmd_channels);

}

/* vim: se ts=4 sw=4: */