/*
 * Copyright (c) 2009, Rambler media
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY Rambler media ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Rambler BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/***MODULE:fuzzy
 * rspamd module that checks fuzzy checksums for messages
 *
 * Allowed options:
 * - symbol (string): symbol to insert (default: 'R_FUZZY')
 * - max_score (double): maximum score to that weights of hashes would be normalized (default: 0 - no normalization)
 *
 * - fuzzy_map (string): a string that contains map in format { fuzzy_key => [ symbol, weight ] } where fuzzy_key is number of 
 *   fuzzy list. This string itself should be in format 1:R_FUZZY_SAMPLE1:10,2:R_FUZZY_SAMPLE2:1 etc, where first number is fuzzy
 *   key, second is symbol to insert and third - weight for normalization
 *
 * - min_length (integer): minimum length (in characters) for text part to be checked for fuzzy hash (default: 0 - no limit)
 * - whitelist (map string): map of ip addresses that should not be checked with this module
 * - servers (string): list of fuzzy servers in format "server1:port,server2:port" - these servers would be used for checking and storing
 *   fuzzy hashes
 */

#include "config.h"
#include "main.h"
#include "message.h"
#include "cfg_file.h"
#include "expressions.h"
#include "util.h"
#include "view.h"
#include "map.h"
#include "images.h"
#include "fuzzy_storage.h"
#include "cfg_xml.h"

#define DEFAULT_SYMBOL "R_FUZZY_HASH"
#define DEFAULT_UPSTREAM_ERROR_TIME 10
#define DEFAULT_UPSTREAM_DEAD_TIME 300
#define DEFAULT_UPSTREAM_MAXERRORS 10

#define DEFAULT_IO_TIMEOUT 500
#define DEFAULT_PORT 11335

struct storage_server {
	struct upstream                 up;
	gchar                           *name;
	struct in_addr                  addr;
	guint16                        port;
};

struct fuzzy_mapping {
	guint32                         fuzzy_flag;
	gchar                           *symbol;
	double weight;
};

struct fuzzy_mime_type {
	gchar                           *type;
	gchar                           *subtype;
};

struct fuzzy_ctx {
	gint                            (*filter) (struct worker_task * task);
	gchar                           *symbol;
	struct storage_server          *servers;
	gint                            servers_num;
	memory_pool_t                  *fuzzy_pool;
	double                          max_score;
	gint32                          min_hash_len;
	radix_tree_t                   *whitelist;
	GHashTable                     *mappings;
	GList                          *mime_types;
	gint32                          min_bytes;
	gint32                          min_height;
	gint32                          min_width;
	guint32                         io_timeout;
};

struct fuzzy_client_session {
	gint                            state;
	fuzzy_hash_t                   *h;
	struct event                    ev;
	struct timeval                  tv;
	struct worker_task             *task;
	struct storage_server          *server;
	gint                            fd;
};

struct fuzzy_learn_session {
	struct event                    ev;
	fuzzy_hash_t                   *h;
	gint                            cmd;
	gint                            value;
	gint                            flag;
	gint                            *saved;
	struct timeval                  tv;
	struct controller_session      *session;
	struct storage_server          *server;
	struct worker_task             *task;
	gint                            fd;
};

static struct fuzzy_ctx        *fuzzy_module_ctx = NULL;
static const gchar              hex_digits[] = "0123456789abcdef";

static gint                      fuzzy_mime_filter (struct worker_task *task);
static void                     fuzzy_symbol_callback (struct worker_task *task, void *unused);
static void                     fuzzy_add_handler (gchar **args, struct controller_session *session);
static void                     fuzzy_delete_handler (gchar **args, struct controller_session *session);

/* Flags string is in format <numeric_flag>:<SYMBOL>:weight[, <numeric_flag>:<SYMBOL>:weight...] */
static void
parse_flags_string (struct config_file *cfg, gchar *str)
{
	gchar                           **strvec, *item, *err_str, **map_str;
	gint                            num, i, t;
	struct fuzzy_mapping           *map;
	
	strvec = g_strsplit_set (str, ", ;", 0);
	num = g_strv_length (strvec);

	for (i = 0; i < num; i ++) {
		item = strvec[i];
		map_str = g_strsplit_set (item, ":", 3);
		t = g_strv_length (map_str);
		if (t != 3 && t != 2) {
			msg_err ("invalid fuzzy mapping: %s", item);
		}
		else {
			map = memory_pool_alloc (fuzzy_module_ctx->fuzzy_pool, sizeof (struct fuzzy_mapping));
			map->symbol = memory_pool_strdup (fuzzy_module_ctx->fuzzy_pool, map_str[1]);

			errno = 0;
			map->fuzzy_flag = strtol (map_str[0], &err_str, 10);
			if (errno != 0 || (err_str && *err_str != '\0')) {
				msg_info ("cannot parse flag %s: %s", map_str[0], strerror (errno));
				continue;
			}
			else if (t == 2) {
				/* Weight is skipped in definition */
				map->weight = fuzzy_module_ctx->max_score;
			}
			else {
				map->weight = strtol (map_str[2], &err_str, 10);

			}
			/* Add flag to hash table */
			g_hash_table_insert (fuzzy_module_ctx->mappings, GINT_TO_POINTER(map->fuzzy_flag), map);
			register_virtual_symbol (&cfg->cache, map->symbol, map->weight);
		}
		g_strfreev (map_str);
	}

	g_strfreev (strvec);
}

static GList *
parse_mime_types (const gchar *str)
{
	gchar                           **strvec, *p;
	gint                            num, i;
	struct fuzzy_mime_type         *type;
	GList                          *res = NULL;

	strvec = g_strsplit_set (str, ",", 0);
	num = g_strv_length (strvec);
	for (i = 0; i < num; i++) {
		g_strstrip (strvec[i]);
		if ((p = strchr (strvec[i], '/')) != NULL) {
			*p = 0;
			type = memory_pool_alloc (fuzzy_module_ctx->fuzzy_pool, sizeof (struct fuzzy_mime_type));
			type->type = memory_pool_strdup (fuzzy_module_ctx->fuzzy_pool, strvec[i]);
			type->subtype = memory_pool_strdup (fuzzy_module_ctx->fuzzy_pool, p + 1);
			res = g_list_prepend (res, type);
		}
		else {
			msg_info ("bad content type: %s", strvec[i]);
		}
	}

	if (res != NULL) {
		memory_pool_add_destructor (fuzzy_module_ctx->fuzzy_pool, (pool_destruct_func)g_list_free, res);
	}

	return res;
}

static gboolean
fuzzy_check_content_type (GMimeContentType *type)
{
	struct fuzzy_mime_type         *ft;
	GList                          *cur;

	cur = fuzzy_module_ctx->mime_types;
	while (cur) {
		ft = cur->data;
		if (g_mime_content_type_is_type (type, ft->type, ft->subtype)) {
			return TRUE;
		}
		cur = g_list_next (cur);
	}

	return FALSE;
}

static void
parse_servers_string (gchar *str)
{
	gchar                           **strvec, *p, portbuf[6], *name;
	gint                            num, i, j, port;
	struct hostent                 *hent;
	struct in_addr                  addr;

	strvec = g_strsplit_set (str, ",", 0);
	num = g_strv_length (strvec);

	fuzzy_module_ctx->servers = memory_pool_alloc0 (fuzzy_module_ctx->fuzzy_pool, sizeof (struct storage_server) * num);

	for (i = 0; i < num; i++) {
		g_strstrip (strvec[i]);

		if ((p = strchr (strvec[i], ':')) != NULL) {
			j = 0;
			p++;
			while (g_ascii_isdigit (*(p + j)) && j < sizeof (portbuf) - 1) {
				portbuf[j] = *(p + j);
				j++;
			}
			portbuf[j] = '\0';
			port = atoi (portbuf);
		}
		else {
			/* Default http port */
			port = DEFAULT_PORT;
		}
		name = memory_pool_alloc (fuzzy_module_ctx->fuzzy_pool, p - strvec[i]);
		rspamd_strlcpy (name, strvec[i], p - strvec[i]);
		if (!inet_aton (name, &addr)) {
			/* Resolve using dns */
			hent = gethostbyname (name);
			if (hent == NULL) {
				msg_info ("cannot resolve: %s", name);
				continue;
			}
			else {
				fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].port = port;
				fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].name = name;
				memcpy (&fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].addr, hent->h_addr, sizeof (struct in_addr));
				fuzzy_module_ctx->servers_num++;
			}
		}
		else {
			fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].port = port;
			fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].name = name;
			memcpy (&fuzzy_module_ctx->servers[fuzzy_module_ctx->servers_num].addr, &addr, sizeof (struct in_addr));
			fuzzy_module_ctx->servers_num++;
		}

	}

	g_strfreev (strvec);

}

static double
fuzzy_normalize (gint32 in, double weight)
{
	double ms = weight, ams = fabs (ms), ain = fabs (in);
	
	if (ams > 0.001) {
		if (ain < ams / 2.) {
			return in;
		}
		else if (ain < ams * 2.) {
			ain = ain / 3. + ams / 3.;
			return in > 0 ? ain : -(ain);
		}
		else {
			return in > 0 ? ms : -(ms);
		}
	}
	
	return (double)in;
}

static const gchar *
fuzzy_to_string (fuzzy_hash_t *h)
{
	static gchar strbuf [FUZZY_HASHLEN * 2 + 1];
	gint                            i;
	guint8 byte;

	for (i = 0; i < FUZZY_HASHLEN; i ++) {
		byte = h->hash_pipe[i];
		if (byte == '\0') {
			break;
		}
		strbuf[i * 2] = hex_digits[byte >> 4];
		strbuf[i * 2 + 1] = hex_digits[byte & 0xf];
	}

	strbuf[i * 2] = '\0';

	return strbuf;
}

gint
fuzzy_check_module_init (struct config_file *cfg, struct module_ctx **ctx)
{
	fuzzy_module_ctx = g_malloc0 (sizeof (struct fuzzy_ctx));

	fuzzy_module_ctx->filter = fuzzy_mime_filter;
	fuzzy_module_ctx->fuzzy_pool = memory_pool_new (memory_pool_get_size ());
	fuzzy_module_ctx->servers = NULL;
	fuzzy_module_ctx->servers_num = 0;
	fuzzy_module_ctx->mappings = g_hash_table_new (g_direct_hash, g_direct_equal);

	*ctx = (struct module_ctx *)fuzzy_module_ctx;
	/* Register module options */
	register_module_opt ("fuzzy_check", "symbol", MODULE_OPT_TYPE_STRING);
	register_module_opt ("fuzzy_check", "max_score", MODULE_OPT_TYPE_DOUBLE);
	register_module_opt ("fuzzy_check", "servers", MODULE_OPT_TYPE_STRING);
	register_module_opt ("fuzzy_check", "fuzzy_map", MODULE_OPT_TYPE_STRING);
	register_module_opt ("fuzzy_check", "whitelist", MODULE_OPT_TYPE_STRING);
	register_module_opt ("fuzzy_check", "mime_types", MODULE_OPT_TYPE_STRING);
	register_module_opt ("fuzzy_check", "min_length", MODULE_OPT_TYPE_UINT);
	register_module_opt ("fuzzy_check", "min_bytes", MODULE_OPT_TYPE_UINT);
	register_module_opt ("fuzzy_check", "min_height", MODULE_OPT_TYPE_UINT);
	register_module_opt ("fuzzy_check", "min_width", MODULE_OPT_TYPE_UINT);
	register_module_opt ("fuzzy_check", "min_symbols", MODULE_OPT_TYPE_UINT);
	register_module_opt ("fuzzy_check", "timeout", MODULE_OPT_TYPE_TIME);

	return 0;
}

gint
fuzzy_check_module_config (struct config_file *cfg)
{
	gchar                           *value;
	gint                            res = TRUE;

	if ((value = get_module_opt (cfg, "fuzzy_check", "symbol")) != NULL) {
		fuzzy_module_ctx->symbol = memory_pool_strdup (fuzzy_module_ctx->fuzzy_pool, value);
	}
	else {
		fuzzy_module_ctx->symbol = DEFAULT_SYMBOL;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "max_score")) != NULL) {
		fuzzy_module_ctx->max_score = strtod (value, NULL);
	}
	else {
		fuzzy_module_ctx->max_score = 0.;
	}

	if ((value = get_module_opt (cfg, "fuzzy_check", "min_length")) != NULL) {
		fuzzy_module_ctx->min_hash_len = strtoul (value, NULL, 10);
	}
	else {
		fuzzy_module_ctx->min_hash_len = 0;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "min_bytes")) != NULL) {
		fuzzy_module_ctx->min_bytes = strtoul (value, NULL, 10);
	}
	else {
		fuzzy_module_ctx->min_bytes = 0;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "min_height")) != NULL) {
		fuzzy_module_ctx->min_height = strtoul (value, NULL, 10);
	}
	else {
		fuzzy_module_ctx->min_height = 0;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "min_width")) != NULL) {
		fuzzy_module_ctx->min_width = strtoul (value, NULL, 10);
	}
	else {
		fuzzy_module_ctx->min_width = 0;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "timeout")) != NULL) {
		fuzzy_module_ctx->io_timeout = parse_time (value, TIME_SECONDS);
	}
	else {
		fuzzy_module_ctx->io_timeout = DEFAULT_IO_TIMEOUT;
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "mime_types")) != NULL) {
		fuzzy_module_ctx->mime_types = parse_mime_types (value);
	}

	if ((value = get_module_opt (cfg, "fuzzy_check", "whitelist")) != NULL) {
		fuzzy_module_ctx->whitelist = radix_tree_create ();
		if (!add_map (value, read_radix_list, fin_radix_list, (void **)&fuzzy_module_ctx->whitelist)) {
			msg_err ("cannot add whitelist '%s'", value);	
		}
	}
	else {
		fuzzy_module_ctx->whitelist = NULL;
	}

	if ((value = get_module_opt (cfg, "fuzzy_check", "servers")) != NULL) {
		parse_servers_string (value);
	}
	if ((value = get_module_opt (cfg, "fuzzy_check", "fuzzy_map")) != NULL) {
		parse_flags_string (cfg, value);
	}

	register_symbol (&cfg->cache, fuzzy_module_ctx->symbol, fuzzy_module_ctx->max_score, fuzzy_symbol_callback, NULL);

	register_custom_controller_command ("fuzzy_add", fuzzy_add_handler, TRUE, TRUE);
	register_custom_controller_command ("fuzzy_del", fuzzy_delete_handler, TRUE, TRUE);

	return res;
}

gint
fuzzy_check_module_reconfig (struct config_file *cfg)
{
	memory_pool_delete (fuzzy_module_ctx->fuzzy_pool);
	fuzzy_module_ctx->servers = NULL;
	fuzzy_module_ctx->servers_num = 0;
	fuzzy_module_ctx->fuzzy_pool = memory_pool_new (memory_pool_get_size ());
	
	g_hash_table_remove_all (fuzzy_module_ctx->mappings);
	return fuzzy_check_module_config (cfg);
}

/* Finalize IO */
static void
fuzzy_io_fin (void *ud)
{
	struct fuzzy_client_session    *session = ud;

	event_del (&session->ev);
	close (session->fd);
}

/* Call this whenever we got data from fuzzy storage */
static void
fuzzy_io_callback (gint fd, short what, void *arg)
{
	struct fuzzy_client_session    *session = arg;
	struct fuzzy_cmd                cmd;
	struct fuzzy_mapping           *map;
	gchar                           buf[62], *err_str, *symbol;
	gint                            value = 0, flag = 0, r;
	double                          nval;

	if (what == EV_WRITE) {
		/* Send command to storage */
		cmd.blocksize = session->h->block_size;
		cmd.value = 0;
		memcpy (cmd.hash, session->h->hash_pipe, sizeof (cmd.hash));
		cmd.cmd = FUZZY_CHECK;
		cmd.flag = 0;
		if (write (fd, &cmd, sizeof (struct fuzzy_cmd)) == -1) {
			goto err;
		}
		else {
			event_del (&session->ev);
			event_set (&session->ev, fd, EV_READ, fuzzy_io_callback, session);
			event_add (&session->ev, &session->tv);
		}
	}
	else if (what == EV_READ) {
		/* Got reply */
		if ((r = read (fd, buf, sizeof (buf) - 1)) == -1) {
			goto err;
		}
		else if (buf[0] == 'O' && buf[1] == 'K') {
			buf[r] = 0;
			/* Now try to get value */
			value = strtol (buf + 3, &err_str, 10);
			if (*err_str == ' ') {
				/* Now read flag */
				flag = strtol (err_str + 1, &err_str, 10);
			}
			*err_str = '\0';
			/* Get mapping by flag */
			if ((map = g_hash_table_lookup (fuzzy_module_ctx->mappings, GINT_TO_POINTER (flag))) == NULL) {
				/* Default symbol and default weight */
				symbol = fuzzy_module_ctx->symbol;
				nval = fuzzy_normalize (value, fuzzy_module_ctx->max_score);
			}
			else {
				/* Get symbol and weight from map */
				symbol = map->symbol;
				nval = fuzzy_normalize (value, map->weight);
			}
			msg_info ("<%s>, found fuzzy hash '%s' with weight: %.2f, in list: %d",
					session->task->message_id, fuzzy_to_string (session->h), flag, nval);
			rspamd_snprintf (buf, sizeof (buf), "%d: %d / %.2f", flag, value, nval);
			insert_result (session->task, symbol, nval, g_list_prepend (NULL, 
						memory_pool_strdup (session->task->task_pool, buf)));
		}
		goto ok;
	}
	else {
		errno = ETIMEDOUT;
		goto err;	
	}

	return;

  err:
	msg_err ("got error on IO with server %s:%d, %d, %s", session->server->name, session->server->port, errno, strerror (errno));
  ok:
	remove_normal_event (session->task->s, fuzzy_io_fin, session);

	session->task->save.saved--;
	if (session->task->save.saved == 0) {
		/* Call other filters */
		session->task->save.saved = 1;
		process_filters (session->task);
	}
}

static void
fuzzy_learn_fin (void *arg)
{
	struct fuzzy_learn_session     *session = arg;

	event_del (&session->ev);
	close (session->fd);
}

static void
fuzzy_learn_callback (gint fd, short what, void *arg)
{
	struct fuzzy_learn_session     *session = arg;
	struct fuzzy_cmd                cmd;
	gchar                           buf[64];
	gint                            r;

	if (what == EV_WRITE) {
		/* Send command to storage */
		cmd.blocksize = session->h->block_size;
		memcpy (cmd.hash, session->h->hash_pipe, sizeof (cmd.hash));
		cmd.cmd = session->cmd;
		cmd.value = session->value;
		cmd.flag = session->flag;
		if (write (fd, &cmd, sizeof (struct fuzzy_cmd)) == -1) {
			goto err;
		}
		else {
			event_del (&session->ev);
			event_set (&session->ev, fd, EV_READ, fuzzy_learn_callback, session);
			event_add (&session->ev, &session->tv);
		}
	}
	else if (what == EV_READ) {
		if (read (fd, buf, sizeof (buf)) == -1) {
			goto err;
		}
		else if (buf[0] == 'O' && buf[1] == 'K') {
			msg_info ("added fuzzy hash '%s' to list: %d for message <%s>",
					fuzzy_to_string (session->h), session->flag, session->task->message_id);
			r = rspamd_snprintf (buf, sizeof (buf), "OK" CRLF "END" CRLF);
			if (! rspamd_dispatcher_write (session->session->dispatcher, buf, r, FALSE, FALSE)) {
				return;
			}
			goto ok;
		}
		else {
			msg_info ("cannot add fuzzy hash for message <%s>", session->task->message_id);
			r = rspamd_snprintf (buf, sizeof (buf), "ERR" CRLF "END" CRLF);
			if (! rspamd_dispatcher_write (session->session->dispatcher, buf, r, FALSE, FALSE)) {
				return;
			}
			goto ok;
		}
	}
	else {
		errno = ETIMEDOUT;
		goto err;	
	}

	return;

  err:
	msg_err ("got error in IO with server %s:%d, %d, %s", session->server->name, session->server->port, errno, strerror (errno));
	r = rspamd_snprintf (buf, sizeof (buf), "Error" CRLF "END" CRLF);
	if (! rspamd_dispatcher_write (session->session->dispatcher, buf, r, FALSE, FALSE)) {
		return;
	}
  ok:
	remove_normal_event (session->session->s, fuzzy_learn_fin, session);

	(*session->saved)--;
	if (*session->saved == 0) {
		session->session->state = STATE_REPLY;
		session->session->dispatcher->write_callback (session->session);
	}
}

static inline void
register_fuzzy_call (struct worker_task *task, fuzzy_hash_t *h)
{
	struct fuzzy_client_session    *session;
	struct storage_server          *selected;
	gint                            sock;

	/* Get upstream */
#ifdef HAVE_CLOCK_GETTIME
	selected = (struct storage_server *)get_upstream_by_hash (fuzzy_module_ctx->servers, fuzzy_module_ctx->servers_num,
			sizeof (struct storage_server), task->ts.tv_sec,
			DEFAULT_UPSTREAM_ERROR_TIME, DEFAULT_UPSTREAM_DEAD_TIME, DEFAULT_UPSTREAM_MAXERRORS, h->hash_pipe, sizeof (h->hash_pipe));
#else
	selected = (struct storage_server *)get_upstream_by_hash (fuzzy_module_ctx->servers, fuzzy_module_ctx->servers_num,
			sizeof (struct storage_server), task->tv.tv_sec,
			DEFAULT_UPSTREAM_ERROR_TIME, DEFAULT_UPSTREAM_DEAD_TIME, DEFAULT_UPSTREAM_MAXERRORS, h->hash_pipe, sizeof (h->hash_pipe));
#endif
	if (selected) {
		if ((sock = make_udp_socket (&selected->addr, selected->port, FALSE, TRUE)) == -1) {
			msg_warn ("cannot connect to %s, %d, %s", selected->name, errno, strerror (errno));
		}
		else {
			/* Create session for a socket */
			session = memory_pool_alloc (task->task_pool, sizeof (struct fuzzy_client_session));
			event_set (&session->ev, sock, EV_WRITE, fuzzy_io_callback, session);
			msec_to_tv (fuzzy_module_ctx->io_timeout, &session->tv);
			session->state = 0;
			session->h = h;
			session->task = task;
			session->fd = sock;
			session->server = selected;
			event_add (&session->ev, &session->tv);
			register_async_event (task->s, fuzzy_io_fin, session, FALSE);
			task->save.saved++;
		}
	}
}

/* This callback is called when we check message via fuzzy hashes storage */
static void
fuzzy_symbol_callback (struct worker_task *task, void *unused)
{
	struct mime_text_part          *part;
	struct mime_part               *mime_part;
	struct rspamd_image            *image;
	gchar                           *checksum;
	GList                          *cur;
	fuzzy_hash_t                   *fake_fuzzy;


	/* Check whitelist */
	if (fuzzy_module_ctx->whitelist && task->from_addr.s_addr != 0) {
		if (radix32tree_find (fuzzy_module_ctx->whitelist, ntohl ((guint32) task->from_addr.s_addr)) != RADIX_NO_VALUE) {
			msg_info ("<%s>, address %s is whitelisted, skip fuzzy check",
					task->message_id, inet_ntoa (task->from_addr));
			return;
		}
	}

	cur = task->text_parts;

	while (cur) {
		part = cur->data;
		if (part->is_empty) {
			cur = g_list_next (cur);
			continue;
		}

		/* Check length of hash */
		if (fuzzy_module_ctx->min_hash_len != 0 && 
				strlen (part->fuzzy->hash_pipe) * part->fuzzy->block_size < fuzzy_module_ctx->min_hash_len) {
			msg_info ("<%s>, part hash is shorter than %d symbols, skip fuzzy check",
					task->message_id, fuzzy_module_ctx->min_hash_len);
			cur = g_list_next (cur);
			continue;
		}

		register_fuzzy_call (task, part->fuzzy);
		register_fuzzy_call (task, part->double_fuzzy);

		cur = g_list_next (cur);
	}
	/* Process images */
	cur = task->images;
	while (cur) {
		image = cur->data;
		if (image->data->len > 0) {
			if (fuzzy_module_ctx->min_height <= 0 || image->height >= fuzzy_module_ctx->min_height) {
				if (fuzzy_module_ctx->min_width <= 0 || image->width >= fuzzy_module_ctx->min_width) {
					checksum = g_compute_checksum_for_data (G_CHECKSUM_MD5, image->data->data, image->data->len);
					/* Construct fake fuzzy hash */
					fake_fuzzy = memory_pool_alloc0 (task->task_pool, sizeof (fuzzy_hash_t));
					rspamd_strlcpy (fake_fuzzy->hash_pipe, checksum, sizeof (fake_fuzzy->hash_pipe));
					register_fuzzy_call (task, fake_fuzzy);
					g_free (checksum);
				}
			}
		}
		cur = g_list_next (cur);
	}
	/* Process other parts */
	cur = task->parts;
	while (cur) {
		mime_part = cur->data;
		if (mime_part->content->len > 0 && fuzzy_check_content_type (mime_part->type)) {
			if (fuzzy_module_ctx->min_bytes <= 0 || mime_part->content->len >= fuzzy_module_ctx->min_bytes) {
					checksum = g_compute_checksum_for_data (G_CHECKSUM_MD5, mime_part->content->data, mime_part->content->len);
					/* Construct fake fuzzy hash */
					fake_fuzzy = memory_pool_alloc0 (task->task_pool, sizeof (fuzzy_hash_t));
					rspamd_strlcpy (fake_fuzzy->hash_pipe, checksum, sizeof (fake_fuzzy->hash_pipe));
					register_fuzzy_call (task, fake_fuzzy);
					g_free (checksum);
			}
		}
		cur = g_list_next (cur);
	}
}

static inline gboolean
register_fuzzy_controller_call (struct controller_session *session, struct worker_task *task, fuzzy_hash_t *h,
		gint                            cmd, gint value, gint flag, gint *saved)
{
	struct fuzzy_learn_session     *s;
	struct storage_server          *selected;
	gint                            sock, r;
	gchar                           out_buf[BUFSIZ];

	/* Get upstream */
#ifdef HAVE_CLOCK_GETTIME
	selected = (struct storage_server *)get_upstream_by_hash (fuzzy_module_ctx->servers, fuzzy_module_ctx->servers_num,
			sizeof (struct storage_server), task->ts.tv_sec,
			DEFAULT_UPSTREAM_ERROR_TIME, DEFAULT_UPSTREAM_DEAD_TIME, DEFAULT_UPSTREAM_MAXERRORS, h->hash_pipe, sizeof (h->hash_pipe));
#else
	selected = (struct storage_server *)get_upstream_by_hash (fuzzy_module_ctx->servers, fuzzy_module_ctx->servers_num,
			sizeof (struct storage_server), task->tv.tv_sec,
			DEFAULT_UPSTREAM_ERROR_TIME, DEFAULT_UPSTREAM_DEAD_TIME, DEFAULT_UPSTREAM_MAXERRORS, h->hash_pipe, sizeof (h->hash_pipe));
#endif
	if (selected) {
		/* Create UDP socket */
		if ((sock = make_udp_socket (&selected->addr, selected->port, FALSE, TRUE)) == -1) {
			msg_warn ("cannot connect to %s, %d, %s", selected->name, errno, strerror (errno));
			session->state = STATE_REPLY;
			r = rspamd_snprintf (out_buf, sizeof (out_buf), "no hashes written" CRLF "END" CRLF);
			if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
				return FALSE;
			}
			free_task (task, FALSE);
			return FALSE;
		}
		else {
			/* Socket is made, create session */
			s = memory_pool_alloc (session->session_pool, sizeof (struct fuzzy_learn_session));
			event_set (&s->ev, sock, EV_WRITE, fuzzy_learn_callback, s);
			msec_to_tv (fuzzy_module_ctx->io_timeout, &s->tv);
			s->task = task;
			s->h = memory_pool_alloc (session->session_pool, sizeof (fuzzy_hash_t));
			memcpy (s->h, h, sizeof (fuzzy_hash_t));
			s->session = session;
			s->server = selected;
			s->cmd = cmd;
			s->value = value;
			s->flag = flag;
			s->saved = saved;
			s->fd = sock;
			event_add (&s->ev, &s->tv);
			(*saved)++;
			register_async_event (session->s, fuzzy_learn_fin, s, FALSE);
			return TRUE;
		}
	}
	return FALSE;
}

static void
fuzzy_process_handler (struct controller_session *session, f_str_t * in)
{
	struct worker_task             *task;
	struct mime_text_part          *part;
	struct mime_part               *mime_part;
	struct rspamd_image            *image;
	GList                          *cur;
	gint                            r, cmd = 0, value = 0, flag = 0, *saved, *sargs;
	gchar                           out_buf[BUFSIZ], *checksum;
	fuzzy_hash_t                    fake_fuzzy;

	/* Extract arguments */
	if (session->other_data) {
		sargs = session->other_data;
		cmd = sargs[0];
		value = sargs[1];
		flag = sargs[2];
	}
	
	/* Prepare task */
	task = construct_task (session->worker);
	session->other_data = task;
	session->state = STATE_WAIT;
	
	/* Allocate message from string */
	task->msg = memory_pool_alloc (task->task_pool, sizeof (f_str_t));
	task->msg->begin = in->begin;
	task->msg->len = in->len;
	

	saved = memory_pool_alloc0 (session->session_pool, sizeof (gint));
	r = process_message (task);
	if (r == -1) {
		msg_warn ("processing of message failed");
		free_task (task, FALSE);
		session->state = STATE_REPLY;
		r = rspamd_snprintf (out_buf, sizeof (out_buf), "cannot process message" CRLF "END" CRLF);
		if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
			msg_warn ("write error");
		}
		return;
	}
	else {
		/* Plan new event for writing */
		cur = task->text_parts;

		while (cur) {
			part = cur->data;
			if (part->is_empty) {
				cur = g_list_next (cur);
				continue;
			}
			if (! register_fuzzy_controller_call (session, task, part->fuzzy, cmd, value, flag, saved)) {
				/* Cannot write hash */
				session->state = STATE_REPLY;
				r = rspamd_snprintf (out_buf, sizeof (out_buf), "cannot write fuzzy hash" CRLF "END" CRLF);
				if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
					return;
				}
				free_task (task, FALSE);
				return;
			}
			if (! register_fuzzy_controller_call (session, task, part->double_fuzzy, cmd, value, flag, saved)) {
				/* Cannot write hash */
				session->state = STATE_REPLY;
				r = rspamd_snprintf (out_buf, sizeof (out_buf), "cannot write fuzzy hash" CRLF "END" CRLF);
				if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
					return;
				}
				free_task (task, FALSE);
				return;
			}
			cur = g_list_next (cur);
		}
		/* Process images */
		cur = task->images;
		while (cur) {
			image = cur->data;
			if (image->data->len > 0) {
				if (fuzzy_module_ctx->min_height <= 0 || image->height >= fuzzy_module_ctx->min_height) {
					if (fuzzy_module_ctx->min_width <= 0 || image->width >= fuzzy_module_ctx->min_width) {
						checksum = g_compute_checksum_for_data (G_CHECKSUM_MD5, image->data->data, image->data->len);
						/* Construct fake fuzzy hash */
						fake_fuzzy.block_size = 0;
						bzero (fake_fuzzy.hash_pipe, sizeof (fake_fuzzy.hash_pipe));
						rspamd_strlcpy (fake_fuzzy.hash_pipe, checksum, sizeof (fake_fuzzy.hash_pipe));
						if (! register_fuzzy_controller_call (session, task, &fake_fuzzy, cmd, value, flag, saved)) {
							/* Cannot write hash */
							session->state = STATE_REPLY;
							r = rspamd_snprintf (out_buf, sizeof (out_buf), "cannot write fuzzy hash" CRLF "END" CRLF);
							if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
								return;
							}
							g_free (checksum);
							free_task (task, FALSE);
							return;
						}

						msg_info ("save hash of image: [%s] to list: %d", checksum, flag);
						g_free (checksum);
					}
				}
			}
			cur = g_list_next (cur);
		}
		/* Process other parts */
		cur = task->parts;
		while (cur) {
			mime_part = cur->data;
			if (mime_part->content->len > 0 && fuzzy_check_content_type (mime_part->type)) {
				if (fuzzy_module_ctx->min_bytes <= 0 || mime_part->content->len >= fuzzy_module_ctx->min_bytes) {
						checksum = g_compute_checksum_for_data (G_CHECKSUM_MD5, mime_part->content->data, mime_part->content->len);
						/* Construct fake fuzzy hash */
						fake_fuzzy.block_size = 0;
						bzero (fake_fuzzy.hash_pipe, sizeof (fake_fuzzy.hash_pipe));
						rspamd_strlcpy (fake_fuzzy.hash_pipe, checksum, sizeof (fake_fuzzy.hash_pipe));
						if (! register_fuzzy_controller_call (session, task, &fake_fuzzy, cmd, value, flag, saved)) {
							/* Cannot write hash */
							session->state = STATE_REPLY;
							r = rspamd_snprintf (out_buf, sizeof (out_buf), "cannot write fuzzy hash" CRLF "END" CRLF);
							if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
								return;
							}
							g_free (checksum);
							free_task (task, FALSE);
							return;
						}
						msg_info ("save hash of part of type: %s/%s: [%s] to list %d",
								mime_part->type->type, mime_part->type->subtype,
								checksum, flag);
						g_free (checksum);
				}
			}
			cur = g_list_next (cur);
		}
	}

	memory_pool_add_destructor (session->session_pool, (pool_destruct_func)free_task_soft, task);

	if (*saved == 0) {
		session->state = STATE_REPLY;
		r = rspamd_snprintf (out_buf, sizeof (out_buf), "no hashes written" CRLF "END" CRLF);
		if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
			return;
		}
	}
}

static void
fuzzy_controller_handler (gchar **args, struct controller_session *session, gint cmd)
{
	gchar                           *arg, out_buf[BUFSIZ], *err_str;
	guint32                         size;
	gint                            r, value = 1, flag = 0, *sargs;

	/* Process size */
	arg = args[0];
	if (!arg || *arg == '\0') {
		msg_info ("empty content length");
		r = rspamd_snprintf (out_buf, sizeof (out_buf), "fuzzy command requires length as argument" CRLF "END" CRLF);
		if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
			return;
		}
		session->state = STATE_REPLY;
		return;
	}
	errno = 0;
	size = strtoul (arg, &err_str, 10);
	if (errno != 0 || (err_str && *err_str != '\0')) {
		r = rspamd_snprintf (out_buf, sizeof (out_buf), "learn size is invalid" CRLF);
		if (! rspamd_dispatcher_write (session->dispatcher, out_buf, r, FALSE, FALSE)) {
			return;
		}
		session->state = STATE_REPLY;
		return;
	}
	/* Process value */
	arg = args[1];
	if (arg && *arg != '\0') {
		errno = 0;
		value = strtol (arg, &err_str, 10);
		if (errno != 0 || *err_str != '\0') {
			msg_info ("error converting numeric argument %s", arg);
			value = 0;
		}
	}
	/* Process flag */
	arg = args[2];
	if (arg && *arg != '\0') {
		errno = 0;
		flag = strtol (arg, &err_str, 10);
		if (errno != 0 || *err_str != '\0') {
			msg_info ("error converting numeric argument %s", arg);
			flag = 0;
		}
	}

	session->state = STATE_OTHER;
	rspamd_set_dispatcher_policy (session->dispatcher, BUFFER_CHARACTER, size);
	session->other_handler = fuzzy_process_handler;
	/* Prepare args */
	sargs = memory_pool_alloc (session->session_pool, sizeof (gint) * 3);
	sargs[0] = cmd;
	sargs[1] = value;
	sargs[2] = flag;
	session->other_data = sargs;
}

static void
fuzzy_add_handler (gchar **args, struct controller_session *session)
{
	fuzzy_controller_handler (args, session, FUZZY_WRITE);
}

static void
fuzzy_delete_handler (gchar **args, struct controller_session *session)
{
	fuzzy_controller_handler (args, session, FUZZY_DEL);
}

static gint
fuzzy_mime_filter (struct worker_task *task)
{
	/* XXX: remove this */
	return 0;
}