libpurple/log.c

/* purple
 *
 * Purple is the legal property of its developers, whose names are too numerous
 * to list here.  Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
 */

#include "internal.h"
#include "account.h"
#include "debug.h"
#include "glibcompat.h" /* for purple_g_stat on win32 */
#include "image-store.h"
#include "log.h"
#include "prefs.h"
#include "util.h"
#include "time.h"

static GSList *loggers = NULL;

static PurpleLogLogger *html_logger;
static PurpleLogLogger *txt_logger;

struct _purple_logsize_user {
	char *name;
	PurpleAccount *account;
};
static GHashTable *logsize_users = NULL;
static GHashTable *logsize_users_decayed = NULL;

static void log_get_log_sets_common(GHashTable *sets);

static gsize html_logger_write(PurpleLog *log, PurpleMessageFlags type,
                               const char *from, GDateTime *time, const char *message);
static void html_logger_finalize(PurpleLog *log);
static GList *html_logger_list(PurpleLogType type, const char *sn, PurpleAccount *account);
static GList *html_logger_list_syslog(PurpleAccount *account);
static char *html_logger_read(PurpleLog *log, PurpleLogReadFlags *flags);
static int html_logger_total_size(PurpleLogType type, const char *name, PurpleAccount *account);

static gsize txt_logger_write(PurpleLog *log, PurpleMessageFlags type,
                              const char *from, GDateTime *time, const char *message);
static void txt_logger_finalize(PurpleLog *log);
static GList *txt_logger_list(PurpleLogType type, const char *sn, PurpleAccount *account);
static GList *txt_logger_list_syslog(PurpleAccount *account);
static char *txt_logger_read(PurpleLog *log, PurpleLogReadFlags *flags);
static int txt_logger_total_size(PurpleLogType type, const char *name, PurpleAccount *account);

/**************************************************************************
 * PUBLIC LOGGING FUNCTIONS ***********************************************
 **************************************************************************/

PurpleLog *purple_log_new(PurpleLogType type, const char *name, PurpleAccount *account,
                      PurpleConversation *conv, GDateTime *time)
{
	PurpleLog *log;

	/* IMPORTANT: Make sure to initialize all the members of PurpleLog */
	log = g_slice_new(PurpleLog);

	log->type = type;
	log->name = g_strdup(purple_normalize(account, name));
	log->account = account;
	log->conv = conv;
	if (time)
		log->time = g_date_time_ref(time);
	else
		log->time = NULL;
	log->logger = purple_log_logger_get();
	log->logger_data = NULL;

	if (log->logger && log->logger->create)
		log->logger->create(log);
	return log;
}

void purple_log_free(PurpleLog *log)
{
	g_return_if_fail(log);
	if (log->logger && log->logger->finalize)
		log->logger->finalize(log);
	g_free(log->name);
	if (log->time)
		g_date_time_unref(log->time);

	g_slice_free(PurpleLog, log);
}

void purple_log_write(PurpleLog *log, PurpleMessageFlags type,
                      const char *from, GDateTime *time, const char *message)
{
	struct _purple_logsize_user *lu;
	gsize written, total = 0;
	gpointer ptrsize;

	g_return_if_fail(log);
	g_return_if_fail(log->logger);
	g_return_if_fail(log->logger->write);

	written = (log->logger->write)(log, type, from, time, message);

	lu = g_new(struct _purple_logsize_user, 1);

	lu->name = g_strdup(purple_normalize(log->account, log->name));
	lu->account = log->account;

	if(g_hash_table_lookup_extended(logsize_users, lu, NULL, &ptrsize)) {
		char *tmp = lu->name;

		total = GPOINTER_TO_INT(ptrsize);
		total += written;
		g_hash_table_replace(logsize_users, lu, GINT_TO_POINTER(total));

		/* The hash table takes ownership of lu, so create a new one
		 * for the logsize_users_decayed check below. */
		lu = g_new(struct _purple_logsize_user, 1);
		lu->name = g_strdup(tmp);
		lu->account = log->account;
	}

	if(g_hash_table_lookup_extended(logsize_users_decayed, lu, NULL, &ptrsize)) {
		total = GPOINTER_TO_INT(ptrsize);
		total += written;
		g_hash_table_replace(logsize_users_decayed, lu, GINT_TO_POINTER(total));
	} else {
		g_free(lu->name);
		g_free(lu);
	}
}

char *purple_log_read(PurpleLog *log, PurpleLogReadFlags *flags)
{
	PurpleLogReadFlags mflags;
	g_return_val_if_fail(log && log->logger, NULL);
	if (log->logger->read) {
		char *ret = (log->logger->read)(log, flags ? flags : &mflags);
		purple_str_strip_char(ret, '\r');
		return ret;
	}
	return g_strdup(_("<b><font color=\"red\">The logger has no read function</font></b>"));
}

int purple_log_get_size(PurpleLog *log)
{
	g_return_val_if_fail(log && log->logger, 0);

	if (log->logger->size)
		return log->logger->size(log);
	return 0;
}

static guint _purple_logsize_user_hash(struct _purple_logsize_user *lu)
{
	return g_str_hash(lu->name);
}

static guint _purple_logsize_user_equal(struct _purple_logsize_user *lu1,
		struct _purple_logsize_user *lu2)
{
	return (lu1->account == lu2->account && purple_strequal(lu1->name, lu2->name));
}

static void _purple_logsize_user_free_key(struct _purple_logsize_user *lu)
{
	g_free(lu->name);
	g_free(lu);
}

int purple_log_get_total_size(PurpleLogType type, const char *name, PurpleAccount *account)
{
	gpointer ptrsize;
	int size = 0;
	GSList *n;
	struct _purple_logsize_user *lu;

	lu = g_new(struct _purple_logsize_user, 1);
	lu->name = g_strdup(purple_normalize(account, name));
	lu->account = account;

	if(g_hash_table_lookup_extended(logsize_users, lu, NULL, &ptrsize)) {
		size = GPOINTER_TO_INT(ptrsize);
		g_free(lu->name);
		g_free(lu);
	} else {
		for (n = loggers; n; n = n->next) {
			PurpleLogLogger *logger = n->data;

			if(logger->total_size){
				size += (logger->total_size)(type, name, account);
			} else if(logger->list) {
				GList *logs = (logger->list)(type, name, account);
				int this_size = 0;

				while (logs) {
					PurpleLog *log = (PurpleLog*)(logs->data);
					this_size += purple_log_get_size(log);
					purple_log_free(log);
					logs = g_list_delete_link(logs, logs);
				}

				size += this_size;
			}
		}

		g_hash_table_replace(logsize_users, lu, GINT_TO_POINTER(size));
	}
	return size;
}

gint purple_log_get_activity_score(PurpleLogType type, const char *name, PurpleAccount *account)
{
	gpointer ptrscore;
	int score;
	GSList *n;
	struct _purple_logsize_user *lu;

	lu = g_new(struct _purple_logsize_user, 1);
	lu->name = g_strdup(purple_normalize(account, name));
	lu->account = account;

	if(g_hash_table_lookup_extended(logsize_users_decayed, lu, NULL, &ptrscore)) {
		score = GPOINTER_TO_INT(ptrscore);
		g_free(lu->name);
		g_free(lu);
	} else {
		GDateTime *now = g_date_time_new_now_utc();
		double score_double = 0.0;
		for (n = loggers; n; n = n->next) {
			PurpleLogLogger *logger = n->data;

			if(logger->list) {
				GList *logs = (logger->list)(type, name, account);

				while (logs) {
					PurpleLog *log = (PurpleLog*)(logs->data);
					if (!log) {
						g_warn_if_reached();
						continue;
					}
					/* Activity score counts bytes in the log, exponentially
					   decayed with a half-life of 14 days. */
					score_double += purple_log_get_size(log) *
						pow(0.5, g_date_time_difference(now, log->time)/(14LL*G_TIME_SPAN_DAY));
					purple_log_free(log);
					logs = g_list_delete_link(logs, logs);
				}
			}
		}
		g_date_time_unref(now);

		score = (gint) ceil(score_double);
		g_hash_table_replace(logsize_users_decayed, lu, GINT_TO_POINTER(score));
	}
	return score;
}

gboolean purple_log_is_deletable(PurpleLog *log)
{
	g_return_val_if_fail(log != NULL, FALSE);
	g_return_val_if_fail(log->logger != NULL, FALSE);

	if (log->logger->remove == NULL)
		return FALSE;

	if (log->logger->is_deletable != NULL)
		return log->logger->is_deletable(log);

	return TRUE;
}

gboolean purple_log_delete(PurpleLog *log)
{
	g_return_val_if_fail(log != NULL, FALSE);
	g_return_val_if_fail(log->logger != NULL, FALSE);

	if (log->logger->remove != NULL)
		return log->logger->remove(log);

	return FALSE;
}

char *
purple_log_get_log_dir(PurpleLogType type, const char *name, PurpleAccount *account)
{
	PurpleProtocol *protocol;
	const char *protocol_name;
	char *acct_name;
	const char *target;
	char *dir;

	protocol = purple_protocols_find(purple_account_get_protocol_id(account));
	if (!protocol)
		return NULL;

	protocol_name = purple_protocol_class_list_icon(protocol, account, NULL);

	acct_name = g_strdup(purple_escape_filename(purple_normalize(account,
				purple_account_get_username(account))));

	if (type == PURPLE_LOG_CHAT) {
		char *temp = g_strdup_printf("%s.chat", purple_normalize(account, name));
		target = purple_escape_filename(temp);
		g_free(temp);
	} else if(type == PURPLE_LOG_SYSTEM) {
		target = ".system";
	} else {
		target = purple_escape_filename(purple_normalize(account, name));
	}

	dir = g_build_filename(purple_data_dir(), "logs", protocol_name, acct_name, target, NULL);

	g_free(acct_name);

	return dir;
}

/****************************************************************************
 * LOGGER FUNCTIONS *********************************************************
 ****************************************************************************/

static PurpleLogLogger *current_logger = NULL;

static void logger_pref_cb(const char *name, PurplePrefType type,
						   gconstpointer value, gpointer data)
{
	PurpleLogLogger *logger;
	GSList *l = loggers;
	while (l) {
		logger = l->data;
		if (purple_strequal(logger->id, value)) {
			purple_log_logger_set(logger);
			return;
		}
		l = l->next;
	}
	purple_log_logger_set(txt_logger);
}


PurpleLogLogger *purple_log_logger_new(const char *id, const char *name, int functions, ...)
{
	PurpleLogLogger *logger;
	va_list args;

	g_return_val_if_fail(id != NULL, NULL);
	g_return_val_if_fail(name != NULL, NULL);
	g_return_val_if_fail(functions >= 1, NULL);

	logger = g_new0(PurpleLogLogger, 1);
	logger->id = g_strdup(id);
	logger->name = g_strdup(name);

	va_start(args, functions);

	if (functions >= 1)
		logger->create = va_arg(args, void *);
	if (functions >= 2)
		logger->write = va_arg(args, void *);
	if (functions >= 3)
		logger->finalize = va_arg(args, void *);
	if (functions >= 4)
		logger->list = va_arg(args, void *);
	if (functions >= 5)
		logger->read = va_arg(args, void *);
	if (functions >= 6)
		logger->size = va_arg(args, void *);
	if (functions >= 7)
		logger->total_size = va_arg(args, void *);
	if (functions >= 8)
		logger->list_syslog = va_arg(args, void *);
	if (functions >= 9)
		logger->get_log_sets = va_arg(args, void *);
	if (functions >= 10)
		logger->remove = va_arg(args, void *);
	if (functions >= 11)
		logger->is_deletable = va_arg(args, void *);

	if (functions >= 12)
		purple_debug_info("log", "Dropping new functions for logger: %s (%s)\n", name, id);

	va_end(args);

	return logger;
}

void purple_log_logger_free(PurpleLogLogger *logger)
{
	if (!logger)
		return;
	g_free(logger->name);
	g_free(logger->id);
	g_free(logger);
}

void purple_log_logger_add (PurpleLogLogger *logger)
{
	g_return_if_fail(logger);
	if (g_slist_find(loggers, logger))
		return;
	loggers = g_slist_append(loggers, logger);
	if (purple_strequal(purple_prefs_get_string("/purple/logging/format"), logger->id)) {
		purple_prefs_trigger_callback("/purple/logging/format");
	}
}

void purple_log_logger_remove (PurpleLogLogger *logger)
{
	g_return_if_fail(logger);
	loggers = g_slist_remove(loggers, logger);
}

void purple_log_logger_set (PurpleLogLogger *logger)
{
	g_return_if_fail(logger);
	current_logger = logger;
}

PurpleLogLogger *purple_log_logger_get()
{
	return current_logger;
}

GList *purple_log_logger_get_options(void)
{
	GSList *n;
	GList *list = NULL;
	PurpleLogLogger *data;

	for (n = loggers; n; n = n->next) {
		data = n->data;
		if (!data->write)
			continue;
		list = g_list_append(list, data->name);
		list = g_list_append(list, data->id);
	}

	return list;
}

gint purple_log_compare(gconstpointer y, gconstpointer z)
{
	const PurpleLog *a = y;
	const PurpleLog *b = z;

	/* Sort in reverse order. */
	return g_date_time_compare(b->time, a->time);
}

GList *purple_log_get_logs(PurpleLogType type, const char *name, PurpleAccount *account)
{
	GList *logs = NULL;
	GSList *n;
	for (n = loggers; n; n = n->next) {
		PurpleLogLogger *logger = n->data;
		if (!logger->list)
			continue;
		logs = g_list_concat(logger->list(type, name, account), logs);
	}

	return g_list_sort(logs, purple_log_compare);
}

gint purple_log_set_compare(gconstpointer y, gconstpointer z)
{
	const PurpleLogSet *a = y;
	const PurpleLogSet *b = z;
	gint ret = 0;

	/* This logic seems weird at first...
	 * If either account is NULL, we pretend the accounts are
	 * equal. This allows us to detect duplicates that will
	 * exist if one logger knows the account and another
	 * doesn't. */
	if (a->account != NULL && b->account != NULL) {
		ret = strcmp(purple_account_get_username(a->account), purple_account_get_username(b->account));
		if (ret != 0)
			return ret;
	}

	ret = strcmp(a->normalized_name, b->normalized_name);
	if (ret != 0)
		return ret;

	return (gint)b->type - (gint)a->type;
}

static guint
log_set_hash(gconstpointer key)
{
	const PurpleLogSet *set = key;

	/* The account isn't hashed because we need PurpleLogSets with NULL accounts
	 * to be found when we search by a PurpleLogSet that has a non-NULL account
	 * but the same type and name. */
	return g_int_hash(&set->type) + g_str_hash(set->name);
}

static gboolean
log_set_equal(gconstpointer a, gconstpointer b)
{
	/* I realize that the choices made for GList and GHashTable
	 * make sense for those data types, but I wish the comparison
	 * functions were compatible. */
	return !purple_log_set_compare(a, b);
}

static void
log_add_log_set_to_hash(GHashTable *sets, PurpleLogSet *set)
{
	PurpleLogSet *existing_set = g_hash_table_lookup(sets, set);

	if (existing_set == NULL)
		g_hash_table_insert(sets, set, set);
	else if (existing_set->account == NULL && set->account != NULL)
		g_hash_table_replace(sets, set, set);
	else
		purple_log_set_free(set);
}

GHashTable *purple_log_get_log_sets(void)
{
	GSList *n;
	GHashTable *sets = g_hash_table_new_full(log_set_hash, log_set_equal,
											 (GDestroyNotify)purple_log_set_free, NULL);

	/* Get the log sets from all the loggers. */
	for (n = loggers; n; n = n->next) {
		PurpleLogLogger *logger = n->data;

		if (!logger->get_log_sets)
			continue;

		logger->get_log_sets(log_add_log_set_to_hash, sets);
	}

	log_get_log_sets_common(sets);

	/* Return the GHashTable of unique PurpleLogSets. */
	return sets;
}

void purple_log_set_free(PurpleLogSet *set)
{
	g_return_if_fail(set != NULL);

	g_free(set->name);
	if (set->normalized_name != set->name)
		g_free(set->normalized_name);

	g_slice_free(PurpleLogSet, set);
}

GList *purple_log_get_system_logs(PurpleAccount *account)
{
	GList *logs = NULL;
	GSList *n;
	for (n = loggers; n; n = n->next) {
		PurpleLogLogger *logger = n->data;
		if (!logger->list_syslog)
			continue;
		logs = g_list_concat(logger->list_syslog(account), logs);
	}

	return g_list_sort(logs, purple_log_compare);
}

/****************************************************************************
 * LOG SUBSYSTEM ************************************************************
 ****************************************************************************/

void *
purple_log_get_handle(void)
{
	static int handle;

	return &handle;
}

void purple_log_init(void)
{
	void *handle = purple_log_get_handle();

	purple_prefs_add_none("/purple/logging");
	purple_prefs_add_bool("/purple/logging/log_ims", TRUE);
	purple_prefs_add_bool("/purple/logging/log_chats", TRUE);
	purple_prefs_add_bool("/purple/logging/log_system", FALSE);

	purple_prefs_add_string("/purple/logging/format", "html");

	html_logger = purple_log_logger_new("html", _("HTML"), 11,
									  NULL,
									  html_logger_write,
									  html_logger_finalize,
									  html_logger_list,
									  html_logger_read,
									  purple_log_common_sizer,
									  html_logger_total_size,
									  html_logger_list_syslog,
									  NULL,
									  purple_log_common_deleter,
									  purple_log_common_is_deletable);
	purple_log_logger_add(html_logger);

	txt_logger = purple_log_logger_new("txt", _("Plain text"), 11,
									 NULL,
									 txt_logger_write,
									 txt_logger_finalize,
									 txt_logger_list,
									 txt_logger_read,
									 purple_log_common_sizer,
									 txt_logger_total_size,
									 txt_logger_list_syslog,
									 NULL,
									 purple_log_common_deleter,
									 purple_log_common_is_deletable);
	purple_log_logger_add(txt_logger);

	purple_signal_register(handle, "log-timestamp",
			     purple_marshal_POINTER__POINTER_POINTER_BOOLEAN,
	                     G_TYPE_STRING, 3,
	                     PURPLE_TYPE_LOG,
	                     G_TYPE_OBJECT,
	                     G_TYPE_BOOLEAN);

	purple_prefs_connect_callback(NULL, "/purple/logging/format",
							    logger_pref_cb, NULL);
	purple_prefs_trigger_callback("/purple/logging/format");

	logsize_users = g_hash_table_new_full((GHashFunc)_purple_logsize_user_hash,
			(GEqualFunc)_purple_logsize_user_equal,
			(GDestroyNotify)_purple_logsize_user_free_key, NULL);
	logsize_users_decayed = g_hash_table_new_full((GHashFunc)_purple_logsize_user_hash,
				(GEqualFunc)_purple_logsize_user_equal,
				(GDestroyNotify)_purple_logsize_user_free_key, NULL);
}

void
purple_log_uninit(void)
{
	purple_signals_unregister_by_instance(purple_log_get_handle());

	purple_log_logger_remove(html_logger);
	purple_log_logger_free(html_logger);
	html_logger = NULL;

	purple_log_logger_remove(txt_logger);
	purple_log_logger_free(txt_logger);
	txt_logger = NULL;

	g_hash_table_destroy(logsize_users);
	g_hash_table_destroy(logsize_users_decayed);
}

static PurpleLog *
purple_log_copy(PurpleLog *log)
{
	PurpleLog *log_copy;

	g_return_val_if_fail(log != NULL, NULL);

	log_copy = g_new(PurpleLog, 1);
	*log_copy = *log;

	return log_copy;
}

GType
purple_log_get_type(void)
{
	static GType type = 0;

	if (type == 0) {
		type = g_boxed_type_register_static("PurpleLog",
				(GBoxedCopyFunc)purple_log_copy,
				(GBoxedFreeFunc)g_free);
	}

	return type;
}

/****************************************************************************
 * LOGGERS ******************************************************************
 ****************************************************************************/

static char *log_get_timestamp(PurpleLog *log, GDateTime *when)
{
	gboolean show_date;
	char *date;
	GDateTime *dt;

	dt = g_date_time_new_now_utc();
	show_date = (log->type == PURPLE_LOG_SYSTEM) || (g_date_time_difference(dt, when) > 20L * G_TIME_SPAN_MINUTE);
	g_date_time_unref(dt);

	date = purple_signal_emit_return_1(purple_log_get_handle(),
	                          "log-timestamp",
	                          log, when, show_date);
	if (date != NULL)
		return date;

	dt = g_date_time_to_local(when);
	if (show_date)
		date = g_date_time_format(dt, _("%x %X"));
	else
		date = g_date_time_format(dt, "%X");
	g_date_time_unref(dt);

	return date;
}

/* NOTE: This can return msg (which you may or may not want to g_free())
 * NOTE: or a newly allocated string which you MUST g_free().
 * TODO: XXX: does it really works?
 */
static char *
convert_image_tags(const PurpleLog *log, const char *msg)
{
	const char *tmp;
	const char *start;
	const char *end;
	GData *attributes;
	GString *newmsg = NULL;

	tmp = msg;

	while (purple_markup_find_tag("img", tmp, &start, &end, &attributes)) {
		int imgid = 0;
		char *idstr = NULL;

		if (newmsg == NULL)
			newmsg = g_string_new("");

		/* copy any text before the img tag */
		if (tmp < start)
			g_string_append_len(newmsg, tmp, start - tmp);

		if ((idstr = g_datalist_get_data(&attributes, "id")) != NULL)
			imgid = atoi(idstr);

		if (imgid != 0)
		{
			FILE *image_file;
			char *dir;
			PurpleImage *image;
			gconstpointer image_data;
			const gchar *new_filename = NULL;
			char *path = NULL;
			size_t image_byte_count;

			image = purple_image_store_get(imgid);
			if (image == NULL)
			{
				/* This should never happen. */
				/* This *does* happen for failed Direct-IMs -DAA */
				g_string_free(newmsg, TRUE);
				g_return_val_if_reached((char *)msg);
			}

			image_data       = purple_image_get_data(image);
			image_byte_count = purple_image_get_data_size(image);
			dir              = purple_log_get_log_dir(log->type, log->name, log->account);
			new_filename = purple_image_generate_filename(image);

			path = g_build_filename(dir, new_filename, NULL);

			/* Only save unique files. */
			if (!g_file_test(path, G_FILE_TEST_EXISTS))
			{
				if ((image_file = g_fopen(path, "wb")) != NULL)
				{
					if (!fwrite(image_data, image_byte_count, 1, image_file))
					{
						purple_debug_error("log", "Error writing %s: %s\n",
						                   path, g_strerror(errno));
						fclose(image_file);

						/* Attempt to not leave half-written files around. */
						if (g_unlink(path)) {
							purple_debug_error("log", "Error deleting partial "
									"file %s: %s\n", path, g_strerror(errno));
						}
					}
					else
					{
						purple_debug_info("log", "Wrote image file: %s\n", path);
						fclose(image_file);
					}
				}
				else
				{
					purple_debug_error("log", "Unable to create file %s: %s\n",
					                   path, g_strerror(errno));
				}
			}

			/* Write the new image tag */
			g_string_append_printf(newmsg, "<img src=\"%s\">", new_filename);
			g_free(path);
			g_free(dir);
		}

		/* Continue from the end of the tag */
		tmp = end + 1;
	}

	if (newmsg == NULL)
	{
		/* No images were found to change. */
		return (char *)msg;
	}

	/* Append any remaining message data */
	g_string_append(newmsg, tmp);

	return g_string_free(newmsg, FALSE);
}

void purple_log_common_writer(PurpleLog *log, const char *ext)
{
	PurpleLogCommonLoggerData *data = log->logger_data;

	if (data == NULL)
	{
		/* This log is new */
		char *dir;
		GDateTime *dt;
		const char *tz;
		gchar *date;
		char *filename;
		char *path;

		dir = purple_log_get_log_dir(log->type, log->name, log->account);
		if (dir == NULL)
			return;

		g_mkdir_with_parents(dir, S_IRUSR | S_IWUSR | S_IXUSR);

		dt = g_date_time_to_local(log->time);
		tz = purple_escape_filename(g_date_time_get_timezone_abbreviation(dt));
		date = g_date_time_format(dt, "%Y-%m-%d.%H%M%S%z");
		g_date_time_unref(dt);

		filename = g_strdup_printf("%s%s%s", date, tz, ext ? ext : "");

		path = g_build_filename(dir, filename, NULL);
		g_free(dir);
		g_free(date);
		g_free(filename);

		log->logger_data = data = g_slice_new0(PurpleLogCommonLoggerData);

		data->file = g_fopen(path, "a");
		if (data->file == NULL)
		{
			purple_debug(PURPLE_DEBUG_ERROR, "log",
					"Could not create log file %s\n", path);

			if (log->conv != NULL)
				purple_conversation_write_system_message(log->conv,
					_("Logging of this conversation failed."),
					PURPLE_MESSAGE_ERROR);

			g_free(path);
			return;
		}
		g_free(path);
	}
}

GList *purple_log_common_lister(PurpleLogType type, const char *name, PurpleAccount *account, const char *ext, PurpleLogLogger *logger)
{
	GDir *dir;
	GList *list = NULL;
	const char *filename;
	char *path;

	if(!account)
		return NULL;

	path = purple_log_get_log_dir(type, name, account);
	if (path == NULL)
		return NULL;

	if (!(dir = g_dir_open(path, 0, NULL)))
	{
		g_free(path);
		return NULL;
	}

	while ((filename = g_dir_read_name(dir)))
	{
		if (g_str_has_suffix(filename, ext) &&
		    strlen(filename) >= (17 + strlen(ext))) {
			PurpleLog *log;
			PurpleLogCommonLoggerData *data;
			GDateTime *stamp = purple_str_to_date_time(purple_unescape_filename(filename), FALSE);

			log = purple_log_new(type, name, account, NULL, stamp);
			log->logger = logger;
			log->logger_data = data = g_slice_new0(PurpleLogCommonLoggerData);

			data->path = g_build_filename(path, filename, NULL);
			list = g_list_prepend(list, log);

			g_date_time_unref(stamp);
		}
	}
	g_dir_close(dir);
	g_free(path);
	return list;
}

int purple_log_common_total_sizer(PurpleLogType type, const char *name, PurpleAccount *account, const char *ext)
{
	GDir *dir;
	int size = 0;
	const char *filename;
	char *path;

	if(!account)
		return 0;

	path = purple_log_get_log_dir(type, name, account);
	if (path == NULL)
		return 0;

	if (!(dir = g_dir_open(path, 0, NULL)))
	{
		g_free(path);
		return 0;
	}

	while ((filename = g_dir_read_name(dir)))
	{
		if (g_str_has_suffix(filename, ext) &&
		    strlen(filename) >= (17 + strlen(ext))) {
			char *tmp = g_build_filename(path, filename, NULL);
			GStatBuf st;
			if (g_stat(tmp, &st))
			{
				purple_debug_error("log", "Error stating log file: %s\n", tmp);
				g_free(tmp);
				continue;
			}
			g_free(tmp);
			size += st.st_size;
		}
	}
	g_dir_close(dir);
	g_free(path);
	return size;
}

int purple_log_common_sizer(PurpleLog *log)
{
	GStatBuf st;
	PurpleLogCommonLoggerData *data = log->logger_data;

	g_return_val_if_fail(data != NULL, 0);

	if (!data->path || g_stat(data->path, &st))
		st.st_size = 0;

	return st.st_size;
}

/* This will build log sets for all loggers that use the common logger
 * functions because they use the same directory structure. */
static void log_get_log_sets_common(GHashTable *sets)
{
	gchar *log_path = g_build_filename(purple_data_dir(), "logs", NULL);
	GDir *log_dir = g_dir_open(log_path, 0, NULL);
	const gchar *protocol;

	if (log_dir == NULL) {
		g_free(log_path);
		return;
	}

	while ((protocol = g_dir_read_name(log_dir)) != NULL) {
		gchar *protocol_path = g_build_filename(log_path, protocol, NULL);
		GDir *protocol_dir;
		const gchar *username;
		gchar *protocol_unescaped;
		GList *account_iter;
		GList *accounts = NULL;

		if ((protocol_dir = g_dir_open(protocol_path, 0, NULL)) == NULL) {
			g_free(protocol_path);
			continue;
		}

		/* Using g_strdup() to cover the one-in-a-million chance that a
		 * protocol's list_icon function uses purple_unescape_filename(). */
		protocol_unescaped = g_strdup(purple_unescape_filename(protocol));

		/* Find all the accounts for protocol. */
		for (account_iter = purple_accounts_get_all() ; account_iter != NULL ; account_iter = account_iter->next) {
			PurpleProtocol *protocol;

			protocol = purple_protocols_find(purple_account_get_protocol_id((PurpleAccount *)account_iter->data));
			if (!protocol)
				continue;

			if (purple_strequal(protocol_unescaped, purple_protocol_class_list_icon(protocol, (PurpleAccount *)account_iter->data, NULL)))
				accounts = g_list_prepend(accounts, account_iter->data);
		}
		g_free(protocol_unescaped);

		while ((username = g_dir_read_name(protocol_dir)) != NULL) {
			gchar *username_path = g_build_filename(protocol_path, username, NULL);
			GDir *username_dir;
			const gchar *username_unescaped;
			PurpleAccount *account = NULL;
			gchar *name;

			if ((username_dir = g_dir_open(username_path, 0, NULL)) == NULL) {
				g_free(username_path);
				continue;
			}

			/* Find the account for username in the list of accounts for protocol. */
			username_unescaped = purple_unescape_filename(username);
			for (account_iter = g_list_first(accounts) ; account_iter != NULL ; account_iter = account_iter->next) {
				if (purple_strequal(purple_account_get_username((PurpleAccount *)account_iter->data), username_unescaped)) {
					account = account_iter->data;
					break;
				}
			}

			/* Don't worry about the cast, name will point to dynamically allocated memory shortly. */
			while ((name = (gchar *)g_dir_read_name(username_dir)) != NULL) {
				size_t len;
				PurpleLogSet *set;

				/* IMPORTANT: Always initialize all members of PurpleLogSet */
				set = g_slice_new(PurpleLogSet);

				/* Unescape the filename. */
				name = g_strdup(purple_unescape_filename(name));

				/* Get the (possibly new) length of name. */
				len = strlen(name);

				set->type = PURPLE_LOG_IM;
				set->name = name;
				set->account = account;
				/* set->buddy is always set below */
				set->normalized_name = g_strdup(purple_normalize(account, name));

				/* Check for .chat or .system at the end of the name to determine the type. */
				if (len >= 7) {
					gchar *tmp = &name[len - 7];
					if (purple_strequal(tmp, ".system")) {
						set->type = PURPLE_LOG_SYSTEM;
						*tmp = '\0';
					}
				}
				if (len > 5) {
					gchar *tmp = &name[len - 5];
					if (purple_strequal(tmp, ".chat")) {
						set->type = PURPLE_LOG_CHAT;
						*tmp = '\0';
					}
				}

				/* Determine if this (account, name) combination exists as a buddy. */
				if (account != NULL && *name != '\0')
					set->buddy = (purple_blist_find_buddy(account, name) != NULL);
				else
					set->buddy = FALSE;

				log_add_log_set_to_hash(sets, set);
			}
			g_free(username_path);
			g_dir_close(username_dir);
		}
		g_free(protocol_path);
		g_list_free(accounts);
		g_dir_close(protocol_dir);
	}
	g_free(log_path);
	g_dir_close(log_dir);
}

gboolean purple_log_common_deleter(PurpleLog *log)
{
	PurpleLogCommonLoggerData *data;
	int ret;

	g_return_val_if_fail(log != NULL, FALSE);

	data = log->logger_data;
	if (data == NULL)
		return FALSE;

	if (data->path == NULL)
		return FALSE;

	ret = g_unlink(data->path);
	if (ret == 0)
		return TRUE;
	else if (ret == -1)
	{
		purple_debug_error("log", "Failed to delete: %s - %s\n", data->path, g_strerror(errno));
	}
	else
	{
		/* I'm not sure that g_unlink() will ever return
		 * something other than 0 or -1. -- rlaager */
		purple_debug_error("log", "Failed to delete: %s\n", data->path);
	}

	return FALSE;
}

gboolean purple_log_common_is_deletable(PurpleLog *log)
{
	PurpleLogCommonLoggerData *data;
#ifndef _WIN32
	gchar *dirname;
#endif

	g_return_val_if_fail(log != NULL, FALSE);

	data = log->logger_data;
	if (data == NULL)
		return FALSE;

	if (data->path == NULL)
		return FALSE;

#ifndef _WIN32
	dirname = g_path_get_dirname(data->path);
	if (g_access(dirname, W_OK) == 0)
	{
		g_free(dirname);
		return TRUE;
	}
	purple_debug_info("log", "access(%s) failed: %s\n", dirname, g_strerror(errno));
	g_free(dirname);
#else
	/* Unless and until someone writes equivalent win32 code,
	 * we'll assume the file is deletable. */
	return TRUE;
#endif

	return FALSE;
}

static char *process_txt_log(char *txt, char *to_free)
{
	char *tmp;

	/* The to_free argument allows us to save a
	 * g_strdup() in some cases. */

	if (to_free == NULL)
		to_free = txt;

	/* g_markup_escape_text requires valid UTF-8 */
	if (!g_utf8_validate(txt, -1, NULL))
	{
		tmp = purple_utf8_salvage(txt);
		g_free(to_free);
		to_free = txt = tmp;
	}

	tmp = g_markup_escape_text(txt, -1);
	g_free(to_free);
	txt = purple_markup_linkify(tmp);
	g_free(tmp);

	return txt;
}

/****************************
 ** HTML LOGGER *************
 ****************************/

static gsize html_logger_write(PurpleLog *log, PurpleMessageFlags type,
                               const char *from, GDateTime *time, const char *message)
{
	char *msg_fixed;
	char *image_corrected_msg;
	char *date;
	char *header;
	char *escaped_from;
	PurpleProtocol *protocol =
			purple_protocols_find(purple_account_get_protocol_id(log->account));
	PurpleLogCommonLoggerData *data = log->logger_data;
	gsize written = 0;

	if(!data) {
		const char *proto = purple_protocol_class_list_icon(protocol, log->account, NULL);
		GDateTime *dt;
		gchar *date;
		purple_log_common_writer(log, ".html");

		data = log->logger_data;

		/* if we can't write to the file, give up before we hurt ourselves */
		if (!data || !data->file) {
			return 0;
		}

		dt = g_date_time_to_local(log->time);
		date = g_date_time_format(dt, "%c");
		g_date_time_unref(dt);

		written += fprintf(data->file, "<html><head>");
		written += fprintf(data->file, "<meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">");
		written += fprintf(data->file, "<title>");
		if (log->type == PURPLE_LOG_SYSTEM)
			header = g_strdup_printf("System log for account %s (%s) connected at %s",
					purple_account_get_username(log->account), proto, date);
		else
			header = g_strdup_printf("Conversation with %s at %s on %s (%s)",
					log->name, date, purple_account_get_username(log->account), proto);

		written += fprintf(data->file, "%s", header);
		written += fprintf(data->file, "</title></head><body>");
		written += fprintf(data->file, "<h3>%s</h3>\n", header);
		g_free(date);
		g_free(header);
	}

	/* if we can't write to the file, give up before we hurt ourselves */
	if(!data->file)
		return 0;

	escaped_from = g_markup_escape_text(from != NULL ? from : "<NULL>",
			-1);

	image_corrected_msg = convert_image_tags(log, message);
	purple_markup_html_to_xhtml(image_corrected_msg, &msg_fixed, NULL);

	/* Yes, this breaks encapsulation.  But it's a static function and
	 * this saves a needless strdup(). */
	if (image_corrected_msg != message)
		g_free(image_corrected_msg);

	date = log_get_timestamp(log, time);

	if(log->type == PURPLE_LOG_SYSTEM){
		written += fprintf(data->file, "---- %s @ %s ----<br/>\n", msg_fixed, date);
	} else {
		if (type & PURPLE_MESSAGE_SYSTEM)
			written += fprintf(data->file, "<font size=\"2\">(%s)</font><b> %s</b><br/>\n", date, msg_fixed);
		else if (type & PURPLE_MESSAGE_RAW)
			written += fprintf(data->file, "<font size=\"2\">(%s)</font> %s<br/>\n", date, msg_fixed);
		else if (type & PURPLE_MESSAGE_ERROR)
			written += fprintf(data->file, "<font color=\"#FF0000\"><font size=\"2\">(%s)</font><b> %s</b></font><br/>\n", date, msg_fixed);
		else if (type & PURPLE_MESSAGE_AUTO_RESP) {
			if (type & PURPLE_MESSAGE_SEND)
				written += fprintf(data->file, _("<font color=\"#16569E\"><font size=\"2\">(%s)</font> <b>%s &lt;AUTO-REPLY&gt;:</b></font> %s<br/>\n"), date, escaped_from, msg_fixed);
			else if (type & PURPLE_MESSAGE_RECV)
				written += fprintf(data->file, _("<font color=\"#A82F2F\"><font size=\"2\">(%s)</font> <b>%s &lt;AUTO-REPLY&gt;:</b></font> %s<br/>\n"), date, escaped_from, msg_fixed);
		} else if (type & PURPLE_MESSAGE_RECV) {
			if(purple_message_meify(msg_fixed, -1))
				written += fprintf(data->file, "<font color=\"#062585\"><font size=\"2\">(%s)</font> <b>***%s</b></font> %s<br/>\n",
						date, escaped_from, msg_fixed);
			else
				written += fprintf(data->file, "<font color=\"#A82F2F\"><font size=\"2\">(%s)</font> <b>%s:</b></font> %s<br/>\n",
						date, escaped_from, msg_fixed);
		} else if (type & PURPLE_MESSAGE_SEND) {
			if(purple_message_meify(msg_fixed, -1))
				written += fprintf(data->file, "<font color=\"#062585\"><font size=\"2\">(%s)</font> <b>***%s</b></font> %s<br/>\n",
						date, escaped_from, msg_fixed);
			else
				written += fprintf(data->file, "<font color=\"#16569E\"><font size=\"2\">(%s)</font> <b>%s:</b></font> %s<br/>\n",
						date, escaped_from, msg_fixed);
		} else {
			purple_debug_error("log", "Unhandled message type.\n");
			written += fprintf(data->file, "<font size=\"2\">(%s)</font><b> %s:</b></font> %s<br/>\n",
						date, escaped_from, msg_fixed);
		}
	}
	g_free(date);
	g_free(msg_fixed);
	g_free(escaped_from);
	fflush(data->file);

	return written;
}

static void html_logger_finalize(PurpleLog *log)
{
	PurpleLogCommonLoggerData *data = log->logger_data;
	if (data) {
		if(data->file) {
			fprintf(data->file, "</body></html>\n");
			fclose(data->file);
		}
		g_free(data->path);

		g_slice_free(PurpleLogCommonLoggerData, data);
	}
}

static GList *html_logger_list(PurpleLogType type, const char *sn, PurpleAccount *account)
{
	return purple_log_common_lister(type, sn, account, ".html", html_logger);
}

static GList *html_logger_list_syslog(PurpleAccount *account)
{
	return purple_log_common_lister(PURPLE_LOG_SYSTEM, ".system", account, ".html", html_logger);
}

static char *html_logger_read(PurpleLog *log, PurpleLogReadFlags *flags)
{
	char *read;
	PurpleLogCommonLoggerData *data = log->logger_data;
	*flags = PURPLE_LOG_READ_NO_NEWLINE;
	if (!data || !data->path)
		return g_strdup(_("<font color=\"red\"><b>Unable to find log path!</b></font>"));
	if (g_file_get_contents(data->path, &read, NULL, NULL)) {
		char *minus_header = strchr(read, '\n');

		if (!minus_header)
			return read;

		minus_header = g_strdup(minus_header + 1);
		g_free(read);

		return minus_header;
	}
	return g_strdup_printf(_("<font color=\"red\"><b>Could not read file: %s</b></font>"), data->path);
}

static int html_logger_total_size(PurpleLogType type, const char *name, PurpleAccount *account)
{
	return purple_log_common_total_sizer(type, name, account, ".html");
}


/****************************
 ** PLAIN TEXT LOGGER *******
 ****************************/

static gsize txt_logger_write(PurpleLog *log, PurpleMessageFlags type,
                              const char *from, GDateTime *time, const char *message)
{
	char *date;
	PurpleProtocol *protocol =
			purple_protocols_find(purple_account_get_protocol_id(log->account));
	PurpleLogCommonLoggerData *data = log->logger_data;
	char *stripped = NULL;

	gsize written = 0;

	if (data == NULL) {
		/* This log is new.  We could use the loggers 'new' function, but
		 * creating a new file there would result in empty files in the case
		 * that you open a convo with someone, but don't say anything.
		 */
		const char *proto = purple_protocol_class_list_icon(protocol, log->account, NULL);
		GDateTime *dt;
		gchar *date;
		purple_log_common_writer(log, ".txt");

		data = log->logger_data;

		/* if we can't write to the file, give up before we hurt ourselves */
		if(!data || !data->file)
			return 0;

		dt = g_date_time_to_local(log->time);
		date = g_date_time_format(dt, "%c");
		if (log->type == PURPLE_LOG_SYSTEM)
			written += fprintf(data->file, "System log for account %s (%s) connected at %s\n",
				purple_account_get_username(log->account), proto,
				date);
		else
			written += fprintf(data->file, "Conversation with %s at %s on %s (%s)\n",
				log->name, date,
				purple_account_get_username(log->account), proto);
		g_free(date);
		g_date_time_unref(dt);
	}

	/* if we can't write to the file, give up before we hurt ourselves */
	if(!data->file)
		return 0;

	stripped = purple_markup_strip_html(message);
	date = log_get_timestamp(log, time);

	if(log->type == PURPLE_LOG_SYSTEM){
		written += fprintf(data->file, "---- %s @ %s ----\n", stripped, date);
	} else {
		if (type & PURPLE_MESSAGE_SEND ||
			type & PURPLE_MESSAGE_RECV) {
			if (type & PURPLE_MESSAGE_AUTO_RESP) {
				written += fprintf(data->file, _("(%s) %s <AUTO-REPLY>: %s\n"), date,
						from, stripped);
			} else {
				if(purple_message_meify(stripped, -1))
					written += fprintf(data->file, "(%s) ***%s %s\n", date, from,
							stripped);
				else
					written += fprintf(data->file, "(%s) %s: %s\n", date, from,
							stripped);
			}
		} else if (type & PURPLE_MESSAGE_SYSTEM ||
			type & PURPLE_MESSAGE_ERROR ||
			type & PURPLE_MESSAGE_RAW)
			written += fprintf(data->file, "(%s) %s\n", date, stripped);
		else if (type & PURPLE_MESSAGE_NO_LOG) {
			/* This shouldn't happen */
			g_free(stripped);
			return written;
		} else
			written += fprintf(data->file, "(%s) %s%s %s\n", date, from ? from : "",
					from ? ":" : "", stripped);
	}
	g_free(date);
	g_free(stripped);
	fflush(data->file);

	return written;
}

static void txt_logger_finalize(PurpleLog *log)
{
	PurpleLogCommonLoggerData *data = log->logger_data;
	if (data) {
		if(data->file)
			fclose(data->file);
		g_free(data->path);

		g_slice_free(PurpleLogCommonLoggerData, data);
	}
}

static GList *txt_logger_list(PurpleLogType type, const char *sn, PurpleAccount *account)
{
	return purple_log_common_lister(type, sn, account, ".txt", txt_logger);
}

static GList *txt_logger_list_syslog(PurpleAccount *account)
{
	return purple_log_common_lister(PURPLE_LOG_SYSTEM, ".system", account, ".txt", txt_logger);
}

static char *txt_logger_read(PurpleLog *log, PurpleLogReadFlags *flags)
{
	char *read, *minus_header;
	PurpleLogCommonLoggerData *data = log->logger_data;
	*flags = 0;
	if (!data || !data->path)
		return g_strdup(_("<font color=\"red\"><b>Unable to find log path!</b></font>"));
	if (g_file_get_contents(data->path, &read, NULL, NULL)) {
		minus_header = strchr(read, '\n');

		if (minus_header)
			return process_txt_log(minus_header + 1, read);
		else
			return process_txt_log(read, NULL);
	}
	return g_strdup_printf(_("<font color=\"red\"><b>Could not read file: %s</b></font>"), data->path);
}

static int txt_logger_total_size(PurpleLogType type, const char *name, PurpleAccount *account)
{
	return purple_log_common_total_sizer(type, name, account, ".txt");
}