/* Copyright (c) 2010, Vsevolod Stakhov
 * 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 ''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 AUTHOR 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.
 */

#include "kvstorage_config.h"
#include "main.h"
#include "cfg_xml.h"
#ifdef WITH_DB
#include "kvstorage_bdb.h"
#endif
#ifdef WITH_SQLITE
#include "kvstorage_sqlite.h"
#endif
#include "kvstorage_file.h"

#define FILE_STORAGE_LEVELS 3


/* Global hash of storages indexed by id */
GHashTable *storages = NULL;
/* Last used id for explicit numbering */
gint last_id = 0;

struct kvstorage_config_parser {
	enum {
		KVSTORAGE_STATE_INIT,
		KVSTORAGE_STATE_PARAM,
		KVSTORAGE_STATE_BACKEND,
		KVSTORAGE_STATE_EXPIRE,
		KVSTORAGE_STATE_ID,
		KVSTORAGE_STATE_NAME,
		KVSTORAGE_STATE_CACHE_TYPE,
		KVSTORAGE_STATE_CACHE_MAX_ELTS,
		KVSTORAGE_STATE_CACHE_MAX_MEM,
		KVSTORAGE_STATE_CACHE_NO_OVERWRITE,
		KVSTORAGE_STATE_BACKEND_TYPE,
		KVSTORAGE_STATE_BACKEND_FILENAME,
		KVSTORAGE_STATE_BACKEND_SYNC_OPS,
		KVSTORAGE_STATE_BACKEND_DO_FSYNC,
		KVSTORAGE_STATE_BACKEND_DO_REF,
		KVSTORAGE_STATE_EXPIRE_TYPE,
		KVSTORAGE_STATE_ERROR
	} state;
	struct kvstorage_config *current_storage;
	memory_pool_t *pool;
	gchar *cur_elt;
};

static void
kvstorage_config_destroy (gpointer k)
{
	struct kvstorage_config				*kconf = k;

	if (kconf->name) {
		g_free (kconf->name);
	}

	if (kconf->storage) {
		rspamd_kv_storage_destroy (kconf->storage);
	}

	g_free (kconf);
}

/* Init kvstorage */
static void
kvstorage_init_callback (const gpointer key, const gpointer value, gpointer unused)
{
	struct kvstorage_config				*kconf = value;
	struct rspamd_kv_cache				*cache;
	struct rspamd_kv_backend			*backend = NULL;
	struct rspamd_kv_expire				*expire = NULL;

	switch (kconf->cache.type) {
	case KVSTORAGE_TYPE_CACHE_HASH:
		cache = rspamd_kv_hash_new ();
		break;
	case KVSTORAGE_TYPE_CACHE_RADIX:
		cache = rspamd_kv_radix_new ();
		break;
#ifdef WITH_JUDY
	case KVSTORAGE_TYPE_CACHE_JUDY:
		cache = rspamd_kv_judy_new ();
		break;
#endif
	default:
		msg_err ("unknown cache type, internal error");
		return;
	}

	switch (kconf->backend.type) {
	case KVSTORAGE_TYPE_BACKEND_NULL:
	case KVSTORAGE_TYPE_BACKEND_MAX:
		backend = NULL;
		break;
	case KVSTORAGE_TYPE_BACKEND_FILE:
		backend = rspamd_kv_file_new (kconf->backend.filename, kconf->backend.sync_ops,
				FILE_STORAGE_LEVELS, kconf->backend.do_fsync, kconf->backend.do_ref);
		break;
#ifdef WITH_DB
	case KVSTORAGE_TYPE_BACKEND_BDB:
		backend = rspamd_kv_bdb_new (kconf->backend.filename, kconf->backend.sync_ops);
		break;
#endif
#ifdef WITH_SQLITE
	case KVSTORAGE_TYPE_BACKEND_SQLITE:
		backend = rspamd_kv_sqlite_new (kconf->backend.filename, kconf->backend.sync_ops);
		break;
#endif
	}

	switch (kconf->expire.type) {
	case KVSTORAGE_TYPE_EXPIRE_LRU:
		expire = rspamd_lru_expire_new ();
		break;
	}

	kconf->storage = rspamd_kv_storage_new (kconf->id, kconf->name, cache, backend, expire,
			kconf->cache.max_elements, kconf->cache.max_memory, kconf->cache.no_overwrite);
}

/* XML parse callbacks */
/* Called for open tags <foo bar="baz"> */
void kvstorage_xml_start_element (GMarkupParseContext	*context,
								const gchar         *element_name,
								const gchar        **attribute_names,
								const gchar        **attribute_values,
								gpointer             user_data,
								GError             **error)
{
	struct kvstorage_config_parser 	*kv_parser = user_data;

	switch (kv_parser->state) {
	case KVSTORAGE_STATE_INIT:
		/* XXX: never get this state */
		break;
	case KVSTORAGE_STATE_PARAM:
		if (kv_parser->current_storage == NULL) {
			/* Make temporary pool */
			if (kv_parser->pool != NULL) {
				memory_pool_delete (kv_parser->pool);
			}
			kv_parser->pool = memory_pool_new (memory_pool_get_size ());

			/* Create new kvstorage_config */
			kv_parser->current_storage = g_malloc0 (sizeof (struct kvstorage_config));
			kv_parser->current_storage->id = last_id++;
		}
		if (g_ascii_strcasecmp (element_name, "type") == 0) {
			kv_parser->state = KVSTORAGE_STATE_CACHE_TYPE;
			kv_parser->cur_elt = "type";
		}
		else if (g_ascii_strcasecmp (element_name, "max_elements") == 0) {
			kv_parser->state = KVSTORAGE_STATE_CACHE_MAX_ELTS;
			kv_parser->cur_elt = "max_elements";
		}
		else if (g_ascii_strcasecmp (element_name, "max_memory") == 0) {
			kv_parser->state = KVSTORAGE_STATE_CACHE_MAX_MEM;
			kv_parser->cur_elt = "max_memory";
		}
		else if (g_ascii_strcasecmp (element_name, "no_overwrite") == 0) {
			kv_parser->state = KVSTORAGE_STATE_CACHE_NO_OVERWRITE;
			kv_parser->cur_elt = "no_overwrite";
		}
		else if (g_ascii_strcasecmp (element_name, "id") == 0) {
			kv_parser->state = KVSTORAGE_STATE_ID;
			kv_parser->cur_elt = "id";
		}
		else if (g_ascii_strcasecmp (element_name, "name") == 0) {
			kv_parser->state = KVSTORAGE_STATE_NAME;
			kv_parser->cur_elt = "name";
		}
		else if (g_ascii_strcasecmp (element_name, "backend") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND;
			kv_parser->cur_elt = "backend";
		}
		else if (g_ascii_strcasecmp (element_name, "expire") == 0) {
			kv_parser->state = KVSTORAGE_STATE_EXPIRE;
			kv_parser->cur_elt = "expire";
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected",
						element_name);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	case KVSTORAGE_STATE_BACKEND:
		if (g_ascii_strcasecmp (element_name, "type") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND_TYPE;
			kv_parser->cur_elt = "type";
		}
		else if (g_ascii_strcasecmp (element_name, "filename") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND_FILENAME;
			kv_parser->cur_elt = "filename";
		}
		else if (g_ascii_strcasecmp (element_name, "sync_ops") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND_SYNC_OPS;
			kv_parser->cur_elt = "sync_ops";
		}
		else if (g_ascii_strcasecmp (element_name, "fsync") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND_DO_FSYNC;
			kv_parser->cur_elt = "fsync";
		}
		else if (g_ascii_strcasecmp (element_name, "ref") == 0) {
			kv_parser->state = KVSTORAGE_STATE_BACKEND_DO_REF;
			kv_parser->cur_elt = "ref";
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected in backend definition",
						element_name);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	case KVSTORAGE_STATE_EXPIRE:
		if (g_ascii_strcasecmp (element_name, "type") == 0) {
			kv_parser->state = KVSTORAGE_STATE_EXPIRE_TYPE;
			kv_parser->cur_elt = "type";
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected in expire definition",
						element_name);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	default:
		/* Do nothing at other states */
		break;
	}

}

#define CHECK_TAG(s)																													\
do {																																	\
if (g_ascii_strcasecmp (element_name, kv_parser->cur_elt) == 0) {																		\
	kv_parser->state = (s);																												\
}																																		\
else {																																	\
	if (*error == NULL) *error = g_error_new (xml_error_quark (), XML_UNMATCHED_TAG, "element %s is unexpected in this state, expected %s", element_name, kv_parser->cur_elt);	\
	kv_parser->state = KVSTORAGE_STATE_ERROR;																							\
}																																		\
} while (0)

/* Called for close tags </foo> */
void kvstorage_xml_end_element (GMarkupParseContext	*context,
								const gchar         *element_name,
								gpointer             user_data,
								GError             **error)
{
	struct kvstorage_config_parser 	*kv_parser = user_data;

	switch (kv_parser->state) {
	case KVSTORAGE_STATE_INIT:
	case KVSTORAGE_STATE_PARAM:
		if (g_ascii_strcasecmp (element_name, "keystorage") == 0) {
			/* XXX: Init actual storage */
			return;
		}
		if (*error == NULL) {
			*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "end element %s is unexpected, expected start element",
					element_name);
		}
		kv_parser->state = KVSTORAGE_STATE_ERROR;
		break;
	case KVSTORAGE_STATE_ID:
	case KVSTORAGE_STATE_NAME:
	case KVSTORAGE_STATE_CACHE_TYPE:
	case KVSTORAGE_STATE_CACHE_MAX_ELTS:
	case KVSTORAGE_STATE_CACHE_MAX_MEM:
	case KVSTORAGE_STATE_CACHE_NO_OVERWRITE:
		CHECK_TAG (KVSTORAGE_STATE_PARAM);
		break;
	case KVSTORAGE_STATE_BACKEND_TYPE:
	case KVSTORAGE_STATE_BACKEND_FILENAME:
	case KVSTORAGE_STATE_BACKEND_SYNC_OPS:
	case KVSTORAGE_STATE_BACKEND_DO_FSYNC:
	case KVSTORAGE_STATE_BACKEND_DO_REF:
		CHECK_TAG (KVSTORAGE_STATE_BACKEND);
		break;
	case KVSTORAGE_STATE_EXPIRE_TYPE:
		CHECK_TAG (KVSTORAGE_STATE_EXPIRE);
		break;
	case KVSTORAGE_STATE_BACKEND:
		if (g_ascii_strcasecmp (element_name, "backend") == 0) {
			kv_parser->state = KVSTORAGE_STATE_PARAM;
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected",
						element_name);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	case KVSTORAGE_STATE_EXPIRE:
		if (g_ascii_strcasecmp (element_name, "expire") == 0) {
			kv_parser->state = KVSTORAGE_STATE_PARAM;
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "element %s is unexpected",
						element_name);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	default:
		/* Do nothing at other states */
		break;
	}
}
#undef CHECK_TAG

/* text is not nul-terminated */
void kvstorage_xml_text       (GMarkupParseContext		*context,
								const gchar         *text,
								gsize                text_len,
								gpointer             user_data,
								GError             **error)
{
	struct kvstorage_config_parser 	*kv_parser = user_data;
	gchar                           *err_str;

	/* Strip space symbols */
	while (*text && g_ascii_isspace (*text)) {
		text ++;
	}
	if (*text == '\0') {
		/* Skip empty text */
		return;
	}

	switch (kv_parser->state) {
	case KVSTORAGE_STATE_INIT:
	case KVSTORAGE_STATE_PARAM:
		if (*error == NULL) {
			*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "text is unexpected, expected start element");
		}
		kv_parser->state = KVSTORAGE_STATE_ERROR;
		break;
	case KVSTORAGE_STATE_ID:
		kv_parser->current_storage->id = strtoul (text, &err_str, 10);
		if ((gsize)(err_str - text) != text_len) {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "invalid number: %*s", (int)text_len, text);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		else {
			last_id ++;
			last_id = MAX (kv_parser->current_storage->id, last_id);
		}
		break;
	case KVSTORAGE_STATE_NAME:
		kv_parser->current_storage->name = g_malloc (text_len + 1);
		rspamd_strlcpy (kv_parser->current_storage->name, text, text_len + 1);
		break;
	case KVSTORAGE_STATE_CACHE_MAX_ELTS:
		kv_parser->current_storage->cache.max_elements = parse_limit (text, text_len);
		break;
	case KVSTORAGE_STATE_CACHE_MAX_MEM:
		kv_parser->current_storage->cache.max_memory = parse_limit (text, text_len);
		break;
	case KVSTORAGE_STATE_CACHE_NO_OVERWRITE:
		kv_parser->current_storage->cache.no_overwrite = parse_flag (text);
		break;
	case KVSTORAGE_STATE_CACHE_TYPE:
		if (g_ascii_strncasecmp (text, "hash", MIN (text_len, sizeof ("hash") - 1)) == 0) {
			kv_parser->current_storage->cache.type = KVSTORAGE_TYPE_CACHE_HASH;
		}
		else if (g_ascii_strncasecmp (text, "radix", MIN (text_len, sizeof ("radix") - 1)) == 0) {
			kv_parser->current_storage->cache.type = KVSTORAGE_TYPE_CACHE_RADIX;
		}
#ifdef WITH_JUDY
		else if (g_ascii_strncasecmp (text, "judy", MIN (text_len, sizeof ("judy") - 1)) == 0) {
			kv_parser->current_storage->cache.type = KVSTORAGE_TYPE_CACHE_JUDY;
		}
#endif
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "invalid cache type: %*s", (int)text_len, text);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	case KVSTORAGE_STATE_BACKEND_TYPE:
		if (g_ascii_strncasecmp (text, "null", MIN (text_len, sizeof ("null") - 1)) == 0) {
			kv_parser->current_storage->backend.type = KVSTORAGE_TYPE_BACKEND_NULL;
		}
		else if (g_ascii_strncasecmp (text, "file", MIN (text_len, sizeof ("file") - 1)) == 0) {
			kv_parser->current_storage->backend.type = KVSTORAGE_TYPE_BACKEND_FILE;
		}
#ifdef WITH_DB
		else if (g_ascii_strncasecmp (text, "bdb", MIN (text_len, sizeof ("bdb") - 1)) == 0) {
			kv_parser->current_storage->backend.type = KVSTORAGE_TYPE_BACKEND_BDB;
		}
#endif
#ifdef WITH_SQLITE
		else if (g_ascii_strncasecmp (text, "sqlite", MIN (text_len, sizeof ("sqlite") - 1)) == 0) {
			kv_parser->current_storage->backend.type = KVSTORAGE_TYPE_BACKEND_SQLITE;
		}
#endif
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "invalid backend type: %*s", (int)text_len, text);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	case KVSTORAGE_STATE_BACKEND_FILENAME:
		kv_parser->current_storage->backend.filename = g_malloc (text_len + 1);
		rspamd_strlcpy (kv_parser->current_storage->backend.filename, text, text_len + 1);
		break;
	case KVSTORAGE_STATE_BACKEND_SYNC_OPS:
		kv_parser->current_storage->backend.sync_ops = parse_limit (text, text_len);
		break;
	case KVSTORAGE_STATE_BACKEND_DO_FSYNC:
		kv_parser->current_storage->backend.do_fsync = parse_flag (text);
		break;
	case KVSTORAGE_STATE_BACKEND_DO_REF:
		kv_parser->current_storage->backend.do_ref = parse_flag (text);
		break;
	case KVSTORAGE_STATE_EXPIRE_TYPE:
		if (g_ascii_strncasecmp (text, "lru", MIN (text_len, sizeof ("lru") - 1)) == 0) {
			kv_parser->current_storage->expire.type = KVSTORAGE_TYPE_EXPIRE_LRU;
		}
		else {
			if (*error == NULL) {
				*error = g_error_new (xml_error_quark (), XML_EXTRA_ELEMENT, "invalid expire type: %*s", (int)text_len, text);
			}
			kv_parser->state = KVSTORAGE_STATE_ERROR;
		}
		break;
	default:
		/* Do nothing at other states */
		break;
	}

}

/* Called on error, including one set by other
* methods in the vtable. The GError should not be freed.
*/
void
kvstorage_xml_error	(GMarkupParseContext		*context,
								GError              *error,
								gpointer             user_data)
{
	msg_err ("kvstorage xml parser error: %s", error->message);
}

/*
 * Cleanup kvstorage after end tag was read
 */
static void
kvstorage_cleanup (gpointer ud)
{
	struct kvstorage_config_parser 	*kv_parser = ud;

	g_hash_table_insert (storages, &kv_parser->current_storage->id, kv_parser->current_storage);
	kv_parser->state = KVSTORAGE_STATE_INIT;
	g_hash_table_foreach (storages, kvstorage_init_callback, NULL);
	kv_parser->current_storage = NULL;
}

/** Public API */

/* Init subparser of kvstorage config */
void
init_kvstorage_config (void)
{
	GMarkupParser					*parser;
	struct kvstorage_config_parser 	*kv_parser;

	if (storages == NULL) {
		storages = g_hash_table_new_full (g_int_hash, g_int_equal, NULL, kvstorage_config_destroy);
	}
	else {
		/* Create new global table */
		g_hash_table_destroy (storages);
		storages = g_hash_table_new_full (g_int_hash, g_int_equal, NULL, kvstorage_config_destroy);
	}

	/* Create and register subparser */
	parser = g_malloc0 (sizeof (GMarkupParser));
	parser->start_element = kvstorage_xml_start_element;
	parser->end_element = kvstorage_xml_end_element;
	parser->error = kvstorage_xml_error;
	parser->text = kvstorage_xml_text;

	kv_parser = g_malloc0 (sizeof (struct kvstorage_config_parser));
	kv_parser->state = KVSTORAGE_STATE_PARAM;
	kv_parser->pool = memory_pool_new (memory_pool_get_size ());

	register_subparser ("keystorage", 0, parser, kvstorage_cleanup, kv_parser);
}

/* Get configuration for kvstorage with specified ID */
struct kvstorage_config*
get_kvstorage_config (gint id)
{
	if (storages == NULL) {
		return NULL;
	}
	return g_hash_table_lookup (storages, &id);
}

void
destroy_kvstorage_config (void)
{
	if (storages != NULL) {
		g_hash_table_destroy (storages);
		storages = NULL;
	}
}