/*
 * 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.
 */

#include "config.h"
#include "url.h"
#include "main.h"
#include "message.h"
#include "lua-rspamd.h"
#include "cfg_file.h"

#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

/* Lua module init function */
#define MODULE_INIT_FUNC "module_init"

/* Interface definitions */
#define LUA_FUNCTION_DEF(class, name) static int lua_##class##_##name(lua_State *L)
#define LUA_INTERFACE_DEF(class, name) { #name, lua_##class##_##name }

#define LUA_GMIME_BRIDGE_GET(class, name, mime_class)									\
static int																				\
lua_##class##_##name(lua_State *L)														\
{																						\
	GMime##mime_class *obj = lua_check_##class(L);										\
	if (obj != NULL) {																	\
		lua_pushstring (L, g_mime_##class##_##name(obj));								\
	}																					\
	else {																				\
		lua_pushnil (L);																\
	}																					\
	return 1;																			\
}																			

#define LUA_GMIME_BRIDGE_SET(class, name, mime_class)									\
static int																				\
lua_##class##_##name(lua_State *L)														\
{																						\
	const char *str;																	\
	GMime##mime_class *obj = lua_check_##class(L);										\
	if (obj != NULL) {																	\
		str = luaL_checkstring (L, 2);													\
		g_mime_##class##_##name(obj, str);												\
	}																					\
	else {																				\
		lua_pushnil (L);																\
	}																					\
	return 1;																			\
}																			

lua_State *L = NULL;

/* Task methods */
LUA_FUNCTION_DEF(task, get_message);
LUA_FUNCTION_DEF(task, insert_result);
LUA_FUNCTION_DEF(task, get_urls);

static const struct luaL_reg tasklib_m[] = {
	LUA_INTERFACE_DEF(task, get_message),
	LUA_INTERFACE_DEF(task, insert_result),
	LUA_INTERFACE_DEF(task, get_urls),
	{NULL, NULL},
};

/*  Message methods */
LUA_FUNCTION_DEF(message, get_subject);
LUA_FUNCTION_DEF(message, set_subject);
LUA_FUNCTION_DEF(message, get_message_id);
LUA_FUNCTION_DEF(message, set_message_id);
LUA_FUNCTION_DEF(message, get_sender);
LUA_FUNCTION_DEF(message, set_sender);
LUA_FUNCTION_DEF(message, get_reply_to);
LUA_FUNCTION_DEF(message, set_reply_to);
LUA_FUNCTION_DEF(message, get_header);
LUA_FUNCTION_DEF(message, set_header);

static const struct luaL_reg msglib_m[] = {
	LUA_INTERFACE_DEF(message, get_subject),
	LUA_INTERFACE_DEF(message, set_subject),
	LUA_INTERFACE_DEF(message, get_message_id),
	LUA_INTERFACE_DEF(message, set_message_id),
	LUA_INTERFACE_DEF(message, get_sender),
	LUA_INTERFACE_DEF(message, set_sender),
	LUA_INTERFACE_DEF(message, get_reply_to),
	LUA_INTERFACE_DEF(message, set_reply_to),
	LUA_INTERFACE_DEF(message, get_header),
	LUA_INTERFACE_DEF(message, set_header),
	{NULL, NULL}
};

void 
lua_newclass (lua_State *L, const char *classname, const struct luaL_reg *func) 
{
	luaL_newmetatable (L, classname); /* mt */
	/* create __index table to place methods */
	lua_pushstring (L, "__index");    /* mt,"__index" */
	lua_newtable (L);                 /* mt,"__index",it */
	/* put class name into class metatable */
	lua_pushstring (L, "class");      /* mt,"__index",it,"class" */
	lua_pushstring (L, classname);    /* mt,"__index",it,"class",classname */
	lua_rawset (L, -3);               /* mt,"__index",it */
	/* pass all methods that start with _ to the metatable, and all others
	 * to the index table */
	for (; func->name; func++) {     /* mt,"__index",it */
		lua_pushstring (L, func->name);
		lua_pushcfunction (L, func->func);
		lua_rawset (L, func->name[0] == '_' ? -5: -3);
	}
	lua_rawset (L, -3);               /* mt */
	lua_pop (L, 1);
}

void lua_setclass (lua_State *L, const char *classname, int objidx) 
{
	luaL_getmetatable (L, classname);
	if (objidx < 0) {
		objidx--;
	}
	lua_setmetatable (L, objidx);
}

static struct worker_task *
lua_check_task (lua_State *L) 
{
	void *ud = luaL_checkudata (L, 1, "Rspamd.task");
	luaL_argcheck (L, ud != NULL, 1, "'task' expected");
	return (struct worker_task *)ud;
}

static GMimeMessage *
lua_check_message (lua_State *L)
{
	void *ud = luaL_checkudata (L, 1, "Rspamd.message");
	luaL_argcheck (L, ud != NULL, 1, "'message' expected");
	return (GMimeMessage *)ud;
}
/*** Task interface	***/
static int
lua_task_get_message (lua_State *L)
{
	GMimeMessage **pmsg;
	struct worker_task *task = lua_check_task (L);

	if (task != NULL) {
		/* XXX write handler for message object */
		pmsg = lua_newuserdata (L, sizeof (GMimeMessage *));
		lua_setclass (L, "Rspamd.message", -1);
		*pmsg = task->message;
	}
	return 1;
}

static int 
lua_task_insert_result (lua_State *L)
{
	struct worker_task *task = lua_check_task (L);
	const char *metric_name, *symbol_name;
	double flag;

	if (task != NULL) {
		metric_name = luaL_checkstring (L, 2);
		symbol_name = luaL_checkstring (L, 3);
		flag = luaL_checknumber (L, 4);
		insert_result (task, metric_name, symbol_name, flag, NULL);
	}
	return 1;
}

static int 
lua_task_get_urls (lua_State *L)
{
	struct worker_task *task = lua_check_task (L);
	struct uri *url;

	if (task != NULL) {
		TAILQ_FOREACH (url, &task->urls, next) {	
			lua_pushstring (L, struri (url));	
		}
	}
	return 1;
}

/*** Message interface	***/

LUA_GMIME_BRIDGE_GET(message, get_subject, Message)
LUA_GMIME_BRIDGE_SET(message, set_subject, Message)
LUA_GMIME_BRIDGE_GET(message, get_message_id, Message)
LUA_GMIME_BRIDGE_SET(message, set_message_id, Message)
LUA_GMIME_BRIDGE_GET(message, get_sender, Message)
LUA_GMIME_BRIDGE_SET(message, set_sender, Message)
LUA_GMIME_BRIDGE_GET(message, get_reply_to, Message)
LUA_GMIME_BRIDGE_SET(message, set_reply_to, Message)

static int
lua_message_get_header (lua_State *L)
{
	const char *headern;
	GMimeMessage *obj = lua_check_message (L);
	GList *res = NULL, *cur;

	if (obj != NULL) {
		headern = luaL_checkstring (L, 2);
		if (headern) {
			res = message_get_header (NULL, obj, headern);
			if (res) {
				cur = res;
				while (cur) {
					lua_pushstring (L, (const char *)cur->data);
					g_free (cur->data);
					cur = g_list_next (cur);
				}
				g_free (res);
			}
			else {
				lua_pushnil (L);
			}
		}
		else {
			lua_pushnil (L);
		}
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_message_set_header (lua_State *L)
{
	const char *headern, *headerv;
	GMimeMessage *obj = lua_check_message (L);

	if (obj != NULL) {
		headern = luaL_checkstring (L, 2);
		headerv = luaL_checkstring (L, 3);
		if (headern && headerv) {
			message_set_header (obj, headern, headerv);
		}
		else {
			lua_pushnil (L);
		}
	}
	else {
		lua_pushnil (L);
	}
	
	return 1;
}

/*** Init functions ***/
static int
luaopen_task (lua_State *L)
{
	lua_newclass (L, "Rspamd.task", tasklib_m);
    
	luaL_openlib (L, "task", tasklib_m, 0);
    
	return 1;
}

static int
luaopen_message (lua_State *L)
{
	lua_newclass (L, "Rspamd.message", msglib_m);
    
	luaL_openlib (L, "message", msglib_m, 0);
    
	return 1;
}

static void
init_lua ()
{
	if (L == NULL) {
		L = lua_open ();
		luaL_openlibs (L);

		luaopen_task (L);
		luaopen_message (L);
	}
}

void
init_lua_filters (struct config_file *cfg)
{
	struct perl_module *module;
	char *init_func;
	size_t funclen;
	struct config_file **pcfg;
	
	init_lua ();
	LIST_FOREACH (module, &cfg->perl_modules, next) {
		if (module->path) {
			luaL_loadfile (L, module->path);

			/* Call module init function */
			funclen = strlen (module->path) + sizeof (":") + sizeof (MODULE_INIT_FUNC) - 1;
			init_func = g_malloc (funclen);
			snprintf (init_func, funclen, "%s:%s", module->path, MODULE_INIT_FUNC);
			lua_getglobal (L, init_func);
			pcfg = lua_newuserdata (L, sizeof (struct config_file *));
			lua_setclass (L, "Rspamd.config", -1);
			*pcfg = cfg;
			/* do the call (1 arguments, 1 result) */
			if (lua_pcall (L, 1, 1, 0) != 0) {
				msg_info ("lua_init_filters: call to %s failed", init_func);
			}
		}
	}
}


int
lua_call_header_filter (const char *function, struct worker_task *task)
{
	int result;
	struct worker_task **ptask;

	lua_getglobal (L, function);
	ptask = lua_newuserdata (L, sizeof (struct worker_task *));
	lua_setclass (L, "Rspamd.task", -1);
	*ptask = task;
	
	if (lua_pcall (L, 1, 1, 0) != 0) {
		msg_info ("lua_init_filters: call to %s failed", function);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_call_header_filter: function %s must return a number", function);
	}
	result = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	return result;
}

int
lua_call_mime_filter (const char *function, struct worker_task *task)
{
	int result;
	struct worker_task **ptask;

	lua_getglobal (L, function);
	ptask = lua_newuserdata (L, sizeof (struct worker_task *));
	lua_setclass (L, "Rspamd.task", -1);
	*ptask = task;
	
	if (lua_pcall (L, 1, 1, 0) != 0) {
		msg_info ("lua_init_filters: call to %s failed", function);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_call_header_filter: function %s must return a number", function);
	}
	result = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	return result;
}

int
lua_call_message_filter (const char *function, struct worker_task *task)
{
	int result;
	struct worker_task **ptask;

	lua_getglobal (L, function);
	ptask = lua_newuserdata (L, sizeof (struct worker_task *));
	lua_setclass (L, "Rspamd.task", -1);
	*ptask = task;
	
	if (lua_pcall (L, 1, 1, 0) != 0) {
		msg_info ("lua_init_filters: call to %s failed", function);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_call_header_filter: function %s must return a number", function);
	}
	result = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	return result;
}

int
lua_call_url_filter (const char *function, struct worker_task *task)
{
	int result;
	struct worker_task **ptask;

	lua_getglobal (L, function);
	ptask = lua_newuserdata (L, sizeof (struct worker_task *));
	lua_setclass (L, "Rspamd.task", -1);
	*ptask = task;
	
	if (lua_pcall (L, 1, 1, 0) != 0) {
		msg_info ("lua_init_filters: call to %s failed", function);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_call_header_filter: function %s must return a number", function);
	}
	result = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	return result;
}

int
lua_call_chain_filter (const char *function, struct worker_task *task, int *marks, unsigned int number)
{
	int result, i;

	lua_getglobal (L, function);

	for (i = 0; i < number; i ++) {
		lua_pushnumber (L, marks[i]);
	}
	if (lua_pcall (L, number, 1, 0) != 0) {
		msg_info ("lua_init_filters: call to %s failed", function);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_call_header_filter: function %s must return a number", function);
	}
	result = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	return result;
}

/*
 * LUA custom consolidation function
 */
struct consolidation_callback_data {
	struct worker_task *task;
	double score;
	const char *func;
};

static void
lua_consolidation_callback (gpointer key, gpointer value, gpointer arg)
{
	double res;
	struct symbol *s = (struct symbol *)value;
	struct consolidation_callback_data *data = (struct consolidation_callback_data *)arg;

	lua_getglobal (L, data->func);

	lua_pushstring (L, (const char *)key);
	lua_pushnumber (L, s->score);
	if (lua_pcall (L, 2, 1, 0) != 0) {
		msg_info ("lua_consolidation_callback: call to %s failed", data->func);
	}

	/* retrieve result */
	if (!lua_isnumber (L, -1)) {
		msg_info ("lua_consolidation_callback: function %s must return a number", data->func);
	}
	res = lua_tonumber (L, -1);
	lua_pop (L, 1);  /* pop returned value */
	data->score += res;
}

double
lua_consolidation_func (struct worker_task *task, const char *metric_name, const char *function_name)
{
	struct metric_result *metric_res;
	double res = 0.;
	struct consolidation_callback_data data = { task, 0, function_name };

	if (function_name == NULL) {
		return 0;
	}

	metric_res = g_hash_table_lookup (task->results, metric_name);
	if (metric_res == NULL) {
		return res;
	}

	g_hash_table_foreach (metric_res->symbols, lua_consolidation_callback, &data);

	return data.score;
}

void
add_luabuf (const char *line)
{
	int error;
	init_lua ();

	error = luaL_loadbuffer(L, line, strlen(line), "config")  ||
			lua_pcall(L, 0, 0, 0);
	if (error) {
		yyerror ("lua error: %s", lua_tostring(L, -1));
		lua_pop(L, 1);  /* pop error message from the stack */
	}
}