/*

 * 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 <unistd.h>

#include <errno.h>

#include <string.h>

#include <mcabber/commands.h>

#include <mcabber/logprint.h>

#include <mcabber/utils.h>

#include <mcabber/settings.h>

#include <mcabber/hbuf.h>

#include <mcabber/xmpp.h>

#include <mcabber/roster.h>

#include <mcabber/modules.h>

#include <mcabber/hooks.h>

#include "config.h"

void mcmd_init   (void);

void mcmd_uninit (void);

#define DESCRIPTION ( \

	"Sends output of command to buddy\n" \

	"Provides command /cmd" )

module_info_t info_cmd = {

	.branch          = MCABBER_BRANCH,

	.api             = MCABBER_API_VERSION,

	.version         = PROJECT_VERSION,

	.description     = DESCRIPTION,

	.requires        = NULL,

	.init            = mcmd_init,

	.uninit          = mcmd_uninit,

	.next            = NULL,

};

typedef struct {

	gchar      *jid;

	GString    *input;

	gchar      *subject;

	guint       seq;

	guint       source;

	GIOChannel *channel;

} cmd_cb_t;

#ifdef MCABBER_API_HAVE_CMD_ID

static gpointer mcmd_cmid = NULL;

#endif

static GSList *cmd_channels = NULL;

static gboolean is_room (const gchar *jid)

{

	return roster_find (jid, jidsearch, ROSTER_TYPE_ROOM) ? TRUE : FALSE;

}

static gboolean cmd_send_msg (const gchar *to, const gchar *subject, const gchar *body)

{

	gboolean room    = is_room (to);

	gpointer xep184  = NULL;

	gint     crypted;

	xmpp_send_msg (to, body, room ? ROSTER_TYPE_ROOM : ROSTER_TYPE_USER, room ? NULL : subject, FALSE /* ? */, &crypted, LM_MESSAGE_SUB_TYPE_NOT_SET, &xep184);

	if (crypted == -1) {

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

		return FALSE;

	}

	if (!room) {

		if (subject) {

			gchar *hbody = g_strdup_printf ("[%s]\n%s", subject, body);

			hk_message_out (to, NULL, 0, hbody, crypted, xep184);

			g_free (hbody);

		} else

			hk_message_out (to, NULL, 0, body, crypted, xep184);

	}

	return TRUE;

}

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;

		GError       *error              = NULL;

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

		if (error) {

			scr_log_print (LPRINT_DEBUG, "cmd: Reading error: %s.", error -> message);

			g_clear_error (&error);

		}

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

			return FALSE; // XXX

		}

		if (endpos) {

			GString *input = cb->input;

			gsize    bread   = 0;

			gsize    written = 0;

			gchar   *utf8    = NULL;

			g_string_append_len (input, buf, endpos);

			if (!xmpp_is_online ()) {

				scr_log_print (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, &error);

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

				written = 0;

				g_clear_error (&error);

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

			}

			if (written) {

				gsize sent = 0;

				while (sent < written) {

					gsize     len     = 0;

					gchar    *bbuf    = NULL;

					gchar    *subject = NULL;

					if (written - sent > HBB_BLOCKSIZE) {

						gchar *c = utf8 + sent + HBB_BLOCKSIZE;

						c = g_utf8_find_prev_char (utf8 + sent, c);

						if (!c) {

							scr_log_print (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);

					}

					cb -> seq += 1;

					if (cb -> subject)

						subject = g_strdup_printf (cb -> subject, cb -> seq);

					if (!cmd_send_msg (cb->jid, subject, len ? bbuf : (utf8 + sent)))

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

					if (subject)

						g_free (subject);

					if (!len)

						break;

					g_free (bbuf);

					sent += len;

				}

				g_free (utf8);

				g_string_erase (input, 0, bread);

			} else {

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

				g_error_free (error);

				return FALSE;

			}

		}

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

		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);

	if (cb -> subject)

		g_free (cb -> subject);

	g_free (cb->jid);

	g_slice_free (cmd_cb_t, cb);

}

static void do_cmd (char *arg)

{

	int         fd[2];

	const char *jid = CURRENT_JID;

	if (!*arg)

		return;

	if (!jid) {

		scr_log_print (LPRINT_LOGNORM, "Unsuitable buddy selected.");

		return;

	}

	if (pipe (fd)) {

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

		return;

	}

	{

		GIOChannel *channel;

		int         res     = fork ();

		if (!res) {

			close (fd[0]);

			dup2 (fd[1], STDOUT_FILENO);

			if (settings_opt_get_int ( OPT_CMD_REDIRECT_STDERR ))

				dup2 (fd[1], STDERR_FILENO);

			else

				close (STDERR_FILENO);

			close (STDIN_FILENO);

			close (fd[1]);

			{

				const char *shell = settings_opt_get ( OPT_CMD_SHELL );

				if (!shell)

					shell = getenv ("SHELL");

				if (!shell)

					shell = "sh";

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

			}

		}

		if (res == -1) {

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

			close (fd[0]);

			close (fd[1]);

			return;

		}

		close (fd[1]);

		{

			GError *error = NULL;

			channel = g_io_channel_unix_new (fd[0]);

			g_io_channel_set_encoding (channel, NULL, &error);

			if (error) {

				scr_log_print (LPRINT_DEBUG, "cmd: Cannot unset channel encoding: %s.", error -> message);

				g_clear_error (&error);

			}

			g_io_channel_set_buffered (channel, FALSE);

			g_io_channel_set_flags (channel, G_IO_FLAG_NONBLOCK, &error);

			if (error) {

				scr_log_print (LPRINT_DEBUG, "cmd: Cannot set nonblocking flag on channel: %s.", error -> message);

				g_error_free (error);

			}

			g_io_channel_set_close_on_unref (channel, TRUE);

		}

		{

			cmd_cb_t *cb = g_slice_new (cmd_cb_t);

			if (settings_opt_get_int ( OPT_CMD_HEADER )) {

				if (settings_opt_get_int ( OPT_CMD_HEADER_INLINE ) || is_room (jid)) {

					gchar *mesg = g_strdup_printf ("$ %s", arg);

					gchar *utf  = to_utf8 (mesg);

					g_free (mesg);

					cmd_send_msg (jid, NULL, utf);

					g_free (utf);

					cb -> subject = NULL;

				} else {

					gchar *header = g_strdup_printf ("[%%02d] $ %s", arg);

					cb -> subject = to_utf8 (header);

					g_free (header);

				}

			}

			cb -> jid     = g_strdup (jid);

			cb -> input   = g_string_new (NULL);

			cb -> seq     = 0;

			cb -> channel = channel;

			cmd_channels  = g_slist_append (cmd_channels, cb);

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

			                                     cmd_reader, (gpointer) cb, cmd_destroy_data);

			g_io_channel_unref ( channel );

		}

	}

}

void mcmd_init (void)

{

#ifndef MCABBER_API_HAVE_CMD_ID

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

#else

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

#endif

}

void mcmd_uninit (void)

{

	GSList *sel;

#ifndef MCABBER_API_HAVE_CMD_ID

	cmd_del ("cmd");

#else

	if (mcmd_cmid)

		cmd_del (mcmd_cmid);

#endif

	for (sel = cmd_channels; sel; ) {

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

		sel = sel -> next;

		if (cb->source)

			g_source_remove (cb->source);

	}

}

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