/*
** Copyright (C) 2008-2011 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** 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 3, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/

#if HAVE_CONFIG_H
#include "config.h"
#endif /*HAVE_CONFIG_H*/

#include "mu-cmd.h"

#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <signal.h>
#include <unistd.h>

#include "mu-util.h"
#include "mu-msg.h"
#include "mu-index.h"
#include "mu-runtime.h"

static gboolean MU_CAUGHT_SIGNAL;

static void
update_warning (void)
{
	g_warning ("note: the database needs to be upgraded to version %s",
		   MU_XAPIAN_DB_VERSION);
	g_warning ("please run 'mu index --rebuild' (see the manpage)");
}

static void
sig_handler (int sig)
{
	if (!MU_CAUGHT_SIGNAL && sig == SIGINT) { /* Ctrl-C */
		g_print ("\n");
		g_warning ("shutting down gracefully, "
			   "press again to kill immediately");
	}
	
        MU_CAUGHT_SIGNAL = TRUE;
}

static void
install_sig_handler (void)
{
        struct sigaction action;
        int i, sigs[] = { SIGINT, SIGHUP, SIGTERM };
	
        MU_CAUGHT_SIGNAL = FALSE;

        action.sa_handler = sig_handler;
        sigemptyset(&action.sa_mask);
        action.sa_flags = SA_RESETHAND;

        for (i = 0; i != G_N_ELEMENTS(sigs); ++i)
                if (sigaction (sigs[i], &action, NULL) != 0)
                        g_critical ("set sigaction for %d failed: %s",
				    sigs[i], strerror (errno));;
}


static gboolean
check_index_or_cleanup_params (MuConfig *opts)
{
	/* param[0] == 'index' or 'cleanup', there should be no
	 * param[1] */
	if (opts->params[1]) {
		g_warning ("usage: mu %s [options]", opts->params[0]);
		return FALSE;
	}
		
	if (opts->linksdir) {
		g_warning ("invalid option(s) for command");
		return FALSE;
	}
	
	if (opts->xbatchsize < 0) {
		g_warning ("the Xapian batch size must be non-negative");
		return FALSE;
	}

	if (opts->max_msg_size < 0) {
		g_warning ("the maximum message size must be non-negative");
		return FALSE;
	}
	
	return TRUE;
}

static gboolean
check_maildir (const char *maildir)
{
	if (!maildir) {
		g_warning ("no maildir to work on; use --maildir= to set it explicitly");
		return FALSE;
	}
	
	if (!g_path_is_absolute (maildir)) {
		g_warning ("maildir path '%s' is not absolute", maildir);
		return FALSE;
	}
	
	if (!mu_util_check_dir (maildir, TRUE, FALSE)) {
		g_warning ("not a valid Maildir: %s", maildir);
		return FALSE;
	}

	return TRUE;
}


static MuResult
index_msg_silent_cb  (MuIndexStats* stats, void *user_data)
{
	return MU_CAUGHT_SIGNAL ? MU_STOP: MU_OK;
}

static void
print_stats (MuIndexStats* stats, gboolean clear)
{
	const char *kars="-\\|/";
	char output[120];
	
	static int i = 0;
	static unsigned len = 0;

	if (clear) {
		/* optimization, this function showed up in profiles */
		static const char *backspace =
			"\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b"
			"\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b"
			"\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b"
			"\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b";
		//backspace[len] = '\0';
		fputs (backspace, stdout);
		//backspace[len] = '\b';
	}
		
	len = (unsigned) snprintf (output, sizeof(output),
				   "%c processing mail; processed: %u; "
				   "updated/new: %u, cleaned-up: %u",
				   (unsigned)kars[++i % 4],
				   (unsigned)stats->_processed,
				   (unsigned)stats->_updated,
				   (unsigned)stats->_cleaned_up);
	fputs (output, stdout);
}


static MuResult
index_msg_cb  (MuIndexStats* stats, void *user_data)
{
	if (stats->_processed % 25)
	 	return MU_OK;
	
	print_stats (stats, TRUE);
		
	return MU_CAUGHT_SIGNAL ? MU_STOP: MU_OK;
}



static gboolean
database_version_check_and_update (MuConfig *opts)
{
	const gchar *xpath;

	xpath = mu_runtime_path (MU_RUNTIME_PATH_XAPIANDB);
	
	if (mu_util_xapian_is_empty (xpath))
		return TRUE;
	
	/* when rebuilding, we empty the database before doing
	 * anything */
	if (opts->rebuild) {
		opts->reindex = TRUE;
		g_message ("clearing database %s", xpath);
		return mu_util_xapian_clear (xpath);
	}

	if (!mu_util_xapian_needs_upgrade (xpath))
		return TRUE; /* ok, nothing to do */
	
	/* ok, database is not up to date */
	if (opts->autoupgrade) {
		opts->reindex = TRUE;
		g_message ("auto-upgrade: clearing old database first");
		return mu_util_xapian_clear (xpath);
	}

	update_warning ();
	return FALSE;
}


static void
show_time (unsigned t, unsigned processed)
{
	if (t)
		g_message ("elapsed: %u second(s), ~ %u msg/s",
			   t, processed/t);
	else
		g_message ("elapsed: %u second(s)", t);
}


static gboolean
update_maildir_path_maybe (MuIndex *idx, MuConfig *opts)
{
	gchar *exp;
	
	/* if 'maildir_guessed' is TRUE, we can override it later
	 * with mu_index_last_used_maildir (in mu-cmd-index.c)
	 */
	if (!opts->maildir) {

		const char *tmp;

		/* try the last used one */
		tmp = mu_index_last_used_maildir (idx);
		if (tmp) 
			opts->maildir = g_strdup (tmp);
		else
			opts->maildir = mu_util_guess_maildir ();
	}
	
	if (opts->maildir) {
		exp = mu_util_dir_expand(opts->maildir);
		if (exp) {
			g_free(opts->maildir);
			opts->maildir = exp;
		}
	}		

	return check_maildir (opts->maildir);	
}


static MuExitCode
cmd_cleanup (MuIndex *midx, MuConfig *opts, MuIndexStats *stats,
	     gboolean show_progress)
{
	MuResult rv;
	time_t t;
	
	g_message ("cleaning up messages [%s]",
		   mu_runtime_path (MU_RUNTIME_PATH_XAPIANDB));
	
	t = time (NULL);
	rv = mu_index_cleanup (midx, stats,
			       show_progress ? index_msg_cb : index_msg_silent_cb,
			       NULL);
	
	if (!opts->quiet) {
		print_stats (stats, TRUE);
		g_print ("\n");
		show_time ((unsigned)(time(NULL)-t),stats->_processed);
	}
	
	return (rv == MU_OK || rv == MU_STOP) ?
		MU_EXITCODE_OK: MU_EXITCODE_ERROR;
}



static MuExitCode
cmd_index (MuIndex *midx, MuConfig *opts, MuIndexStats *stats,
	   gboolean show_progress)
{
	MuResult rv;
	time_t t;
	
	g_message ("indexing messages under %s [%s]", opts->maildir,
		   mu_runtime_path (MU_RUNTIME_PATH_XAPIANDB));
	
	t = time (NULL);
	rv = mu_index_run (midx, opts->maildir, opts->reindex, stats,
			   show_progress ? index_msg_cb:index_msg_silent_cb,
			   NULL, NULL);

	if (!opts->quiet) {
		print_stats (stats, TRUE);
		g_print ("\n");
		show_time ((unsigned)(time(NULL)-t),stats->_processed);
	}
	
	if (rv == MU_OK && !opts->nocleanup) {
		mu_index_stats_clear (stats);
		rv = cmd_cleanup (midx, opts, stats, show_progress);
	}
	
	if (rv == MU_OK || rv == MU_STOP) {
		MU_WRITE_LOG ("processed: %u; updated/new: %u, "
			      "cleaned-up: %u",
			      stats->_processed, stats->_updated,
			      stats->_cleaned_up);
		return MU_EXITCODE_OK;
	}
	
	return MU_EXITCODE_ERROR;
}

static MuExitCode
handle_index_error_and_free (GError *err)
{
	MuExitCode code;
	
	if (!err)
		return MU_EXITCODE_ERROR;

	switch (err->code) {

	case MU_ERROR_XAPIAN_CANNOT_GET_WRITELOCK:
		g_warning ("cannot get Xapian writelock");
		g_warning ("maybe mu index is already running?");
		code = MU_EXITCODE_DB_LOCKED;
		break;

	case MU_ERROR_XAPIAN_CORRUPTION:
		g_warning ("xapian database seems to be corrupted");
		g_warning ("try 'mu index --rebuild");
		code = MU_EXITCODE_DB_CORRUPTED;
		break;
	default:
		g_warning ("indexing error: %s",
			   err->message ? err->message : "");
		code = MU_EXITCODE_ERROR;
	}

	g_error_free (err);
	return code;
}

static MuIndex*
init_mu_index (MuConfig *opts, MuExitCode *code)
{
	MuIndex *midx;
	GError *err;
	
	if (!check_index_or_cleanup_params (opts) ||
	    !database_version_check_and_update(opts)) {
		*code = MU_EXITCODE_ERROR;
		return NULL;
	}
	
	err = NULL;
	midx = mu_index_new (mu_runtime_path (MU_RUNTIME_PATH_XAPIANDB),
			     mu_runtime_path (MU_RUNTIME_PATH_CONTACTS),
			     &err);
	if (!midx) {
		*code = handle_index_error_and_free (err);
		return NULL;
	}
	
	mu_index_set_max_msg_size (midx, opts->max_msg_size); 
	mu_index_set_xbatch_size (midx, opts->xbatchsize);
	
	return midx;
}


static MuExitCode
cmd_index_or_cleanup (MuConfig *opts)
{
	MuIndex *midx;
	MuIndexStats stats;
	gboolean rv, show_progress;
	MuExitCode code;

	/* create, and do error handling if needed */
	midx = init_mu_index (opts, &code);
	if (!midx)
		return code;
	
	/* we determine the maildir path only here, as it may depend on
         * mu_index_last_used_maildir
         */
	if (!update_maildir_path_maybe (midx, opts))
		return MU_EXITCODE_ERROR;		
	
	/* note, 'opts->quiet' already cause g_message output not to
	 * be shown; here, we make sure we only print progress info if
	 * opts->quiet is false case and when stdout is a tty */
	show_progress = !opts->quiet && isatty(fileno(stdout));

	mu_index_stats_clear (&stats);
	install_sig_handler ();

	switch (opts->cmd) {
	case MU_CONFIG_CMD_INDEX:
		rv = cmd_index (midx, opts, &stats, show_progress); break;
	case MU_CONFIG_CMD_CLEANUP:
	 	rv = cmd_cleanup (midx, opts, &stats, show_progress);  break;
	default:
		rv = MU_EXITCODE_ERROR;
		g_assert_not_reached ();
	}
	
	mu_index_destroy (midx);		
	return rv;
}


MuExitCode
mu_cmd_index (MuConfig *opts)
{
	g_return_val_if_fail (opts, FALSE);
	g_return_val_if_fail (opts->cmd == MU_CONFIG_CMD_INDEX,
			      FALSE);
	
	return cmd_index_or_cleanup (opts);
}

MuExitCode
mu_cmd_cleanup (MuConfig *opts)
{
	g_return_val_if_fail (opts, MU_EXITCODE_ERROR);
	g_return_val_if_fail (opts->cmd != MU_CONFIG_CMD_CLEANUP,
			      MU_EXITCODE_ERROR);
	
	return cmd_index_or_cleanup (opts);
}