/* Copyright (c) 2010-2012, 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 "config.h"
#include "util.h"
#include "main.h"
#include "protocol.h"
#include "upstream.h"
#include "cfg_file.h"
#include "cfg_xml.h"
#include "url.h"
#include "message.h"
#include "map.h"
#include "dns.h"

#include "lua/lua_common.h"

#ifdef WITH_GPERF_TOOLS
#   include <glib/gprintf.h>
#endif

/* 60 seconds for worker's IO */
#define DEFAULT_WORKER_IO_TIMEOUT 60000

gpointer init_lua_worker (void);
void start_lua_worker (struct rspamd_worker *worker);

worker_t lua_worker = {
	"lua",					/* Name */
	init_lua_worker,		/* Init function */
	start_lua_worker,		/* Start function */
	TRUE,					/* Has socket */
	FALSE,					/* Non unique */
	FALSE,					/* Non threaded */
	TRUE					/* Killable */
};

/*
 * Worker's context
 */
struct rspamd_lua_worker_ctx {
	/* DNS resolver */
	struct rspamd_dns_resolver     *resolver;
	/* Events base */
	struct event_base              *ev_base;
	/* Other params */
	GHashTable					   *params;
	/* Lua script to load */
	gchar						   *file;
	/* Lua state */
	lua_State					   *L;
	/* Callback for accept */
	gint							cbref_accept;
	/* Callback for finishing */
	gint							cbref_fin;
	/* Config file */
	struct config_file 			   *cfg;
};

/* Lua bindings */
LUA_FUNCTION_DEF (worker, get_ev_base);
LUA_FUNCTION_DEF (worker, register_accept_callback);
LUA_FUNCTION_DEF (worker, register_exit_callback);
LUA_FUNCTION_DEF (worker, get_option);
LUA_FUNCTION_DEF (worker, get_resolver);
LUA_FUNCTION_DEF (worker, get_cfg);

static const struct luaL_reg    lua_workerlib_m[] = {
	LUA_INTERFACE_DEF (worker, get_ev_base),
	LUA_INTERFACE_DEF (worker, register_accept_callback),
	LUA_INTERFACE_DEF (worker, register_exit_callback),
	LUA_INTERFACE_DEF (worker, get_option),
	LUA_INTERFACE_DEF (worker, get_resolver),
	LUA_INTERFACE_DEF (worker, get_cfg),
	{"__tostring", lua_class_tostring},
	{NULL, NULL}
};

static sig_atomic_t             wanna_die = 0;

/* Basic functions of LUA API for worker object */
static gint
luaopen_lua_worker (lua_State * L)
{
	lua_newclass (L, "rspamd{worker}", lua_workerlib_m);
	luaL_openlib (L, "rspamd_worker", null_reg, 0);

	lua_pop (L, 1);                      /* remove metatable from stack */

	return 1;
}

struct rspamd_lua_worker_ctx      *
lua_check_lua_worker (lua_State * L)
{
	void								*ud = luaL_checkudata (L, 1, "rspamd{worker}");
	luaL_argcheck (L, ud != NULL, 1, "'worker' expected");
	return ud ? *((struct rspamd_lua_worker_ctx **)ud) : NULL;
}

static int
lua_worker_get_ev_base (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);
	struct event_base								**pbase;

	if (ctx) {
		pbase = lua_newuserdata (L, sizeof (struct event_base *));
		lua_setclass (L, "rspamd{ev_base}", -1);
		*pbase = ctx->ev_base;
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_worker_register_accept_callback (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);

	if (ctx) {
		if (!lua_isfunction (L, 2)) {
			msg_err ("invalid callback passed");
			lua_pushnil (L);
		}
		else {
			lua_pushvalue (L, 2);
			ctx->cbref_accept = luaL_ref (L, LUA_REGISTRYINDEX);
			return 0;
		}
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_worker_register_exit_callback (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);

	if (ctx) {
		if (!lua_isfunction (L, 2)) {
			msg_err ("invalid callback passed");
			lua_pushnil (L);
		}
		else {
			lua_pushvalue (L, 2);
			ctx->cbref_fin = luaL_ref (L, LUA_REGISTRYINDEX);
			return 0;
		}
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_worker_get_option (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);
	GList											*val;
	gint											 i;
	const gchar										*name;

	if (ctx) {
		name = luaL_checkstring (L, 2);
		if (name == NULL) {
			msg_err ("no name specified");
			lua_pushnil (L);
		}
		else {
			val = g_hash_table_lookup (ctx->params, name);
			if (val == NULL) {
				lua_pushnil (L);
			}
			else {
				/* Push the array */
				i = 1;
				lua_newtable (L);
				while (val) {
					lua_pushstring (L, val->data);
					lua_rawseti (L, -2, i++);
					val = g_list_next (val);
				}
			}
		}
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_worker_get_resolver (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);
	struct rspamd_dns_resolver						**presolver;

	if (ctx) {
		presolver = lua_newuserdata (L, sizeof (gpointer));
		lua_setclass (L, "rspamd{resolver}", -1);
		*presolver = ctx->resolver;
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

static int
lua_worker_get_cfg (lua_State *L)
{
	struct rspamd_lua_worker_ctx					*ctx = lua_check_lua_worker (L);
	struct config_file								**pcfg;

	if (ctx) {
		pcfg = lua_newuserdata (L, sizeof (gpointer));
		lua_setclass (L, "rspamd{config}", -1);
		*pcfg = ctx->cfg;
	}
	else {
		lua_pushnil (L);
	}

	return 1;
}

/* End of lua API */
/* Signal handlers */

#ifndef HAVE_SA_SIGINFO
static void
sig_handler (gint signo)
#else
static void
sig_handler (gint signo, siginfo_t * info, void *unused)
#endif
{
	struct timeval                  tv;

	switch (signo) {
	case SIGINT:
	case SIGTERM:
		if (!wanna_die) {
			wanna_die = 1;
			tv.tv_sec = 0;
			tv.tv_usec = 0;
			event_loopexit (&tv);

#ifdef WITH_GPERF_TOOLS
			ProfilerStop ();
#endif
		}
		break;
	}
}

/*
 * Config reload is designed by sending sigusr2 to active workers and pending shutdown of them
 */
static void
sigusr2_handler (gint fd, short what, void *arg)
{
	struct rspamd_worker           *worker = (struct rspamd_worker *) arg;
	/* Do not accept new connections, preparing to end worker's process */
	struct timeval                  tv;

	if (!wanna_die) {
		tv.tv_sec = SOFT_SHUTDOWN_TIME;
		tv.tv_usec = 0;
		event_del (&worker->sig_ev_usr1);
		event_del (&worker->sig_ev_usr2);
		event_del (&worker->bind_ev);
		msg_info ("worker's shutdown is pending in %d sec", SOFT_SHUTDOWN_TIME);
		event_loopexit (&tv);
	}
	return;
}

/*
 * Reopen log is designed by sending sigusr1 to active workers and pending shutdown of them
 */
static void
sigusr1_handler (gint fd, short what, void *arg)
{
	struct rspamd_worker           *worker = (struct rspamd_worker *) arg;

	reopen_log (worker->srv->logger);

	return;
}

static gboolean
handle_lua_param (struct config_file *cfg, struct rspamd_xml_userdata *unused, GHashTable *attrs, gchar *data, gpointer user_data, gpointer dest_struct, gint offset)
{
	struct rspamd_lua_worker_ctx       *ctx = dest_struct;
	GList							   *val;
	gchar							   *tag = user_data;

	val = g_hash_table_lookup (ctx->params, tag);
	if (val == NULL) {
		g_hash_table_insert (ctx->params, g_strdup (tag), g_list_prepend (NULL, data));
	}
	else {
		val = g_list_append (val, data);
	}

	return TRUE;
}


/*
 * Accept new connection and construct task
 */
static void
lua_accept_socket (gint fd, short what, void *arg)
{
	struct rspamd_worker           *worker = (struct rspamd_worker *) arg;
	struct rspamd_lua_worker_ctx   *ctx, **pctx;
	union sa_union                  su;
	socklen_t                       addrlen = sizeof (su.ss);
	gint                            nfd;
	struct in_addr				    addr;
	gchar						   *addr_str = NULL;
	lua_State					   *L;

	ctx = worker->ctx;
	L = ctx->L;

	if ((nfd =
			accept_from_socket (fd, (struct sockaddr *) &su.ss, &addrlen)) == -1) {
		msg_warn ("accept failed: %s", strerror (errno));
		return;
	}
	/* Check for EAGAIN */
	if (nfd == 0){
		return;
	}

	if (su.ss.ss_family == AF_UNIX) {
		msg_info ("accepted connection from unix socket");
		addr.s_addr = INADDR_NONE;
		addr_str = "127.0.0.1";
	}
	else if (su.ss.ss_family == AF_INET) {
		msg_info ("accepted connection from %s port %d",
				inet_ntoa (su.s4.sin_addr), ntohs (su.s4.sin_port));
		memcpy (&addr, &su.s4.sin_addr,
				sizeof (struct in_addr));
		addr_str = g_strdup (inet_ntoa (su.s4.sin_addr));
	}

	/* Call finalizer function */
	lua_rawgeti (L, LUA_REGISTRYINDEX, ctx->cbref_accept);
	pctx = lua_newuserdata (L, sizeof (gpointer));
	lua_setclass (L, "rspamd{worker}", -1);
	*pctx = ctx;
	lua_pushinteger (L, nfd);
	lua_pushstring (L, addr_str);
	lua_pushinteger (L, addr.s_addr);


	if (lua_pcall (L, 4, 0, 0) != 0) {
		msg_info ("call to worker accept failed: %s", lua_tostring (L, -1));
	}

	if (addr_str) {
		g_free (addr_str);
	}
}

gpointer
init_lua_worker (void)
{
	struct rspamd_lua_worker_ctx       *ctx;
	GQuark								type;

	type = g_quark_try_string ("lua");

	ctx = g_malloc0 (sizeof (struct rspamd_lua_worker_ctx));
	ctx->params = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify)g_list_free);


	register_worker_opt (type, "file", xml_handle_string, ctx, G_STRUCT_OFFSET (struct rspamd_lua_worker_ctx, file));
	register_worker_opt (type, "*", handle_lua_param, ctx, 0);

	return ctx;
}

/*
 * Start worker process
 */
void
start_lua_worker (struct rspamd_worker *worker)
{
	struct sigaction                signals;
	struct rspamd_lua_worker_ctx   *ctx = worker->ctx, **pctx;
	lua_State					   *L;

#ifdef WITH_PROFILER
	extern void                     _start (void), etext (void);
	monstartup ((u_long) & _start, (u_long) & etext);
#endif

	gperf_profiler_init (worker->srv->cfg, "lua_worker");

	worker->srv->pid = getpid ();

	ctx->ev_base = event_init ();

	L = worker->srv->cfg->lua_state;
	ctx->L = L;
	ctx->cfg = worker->srv->cfg;

	init_signals (&signals, sig_handler);
	sigprocmask (SIG_UNBLOCK, &signals.sa_mask, NULL);

	/* SIGUSR2 handler */
	signal_set (&worker->sig_ev_usr2, SIGUSR2, sigusr2_handler, (void *) worker);
	event_base_set (ctx->ev_base, &worker->sig_ev_usr2);
	signal_add (&worker->sig_ev_usr2, NULL);

	/* SIGUSR1 handler */
	signal_set (&worker->sig_ev_usr1, SIGUSR1, sigusr1_handler, (void *) worker);
	event_base_set (ctx->ev_base, &worker->sig_ev_usr1);
	signal_add (&worker->sig_ev_usr1, NULL);

	/* Accept event */
	event_set (&worker->bind_ev, worker->cf->listen_sock, EV_READ | EV_PERSIST,
			lua_accept_socket, (void *) worker);
	event_base_set (ctx->ev_base, &worker->bind_ev);
	event_add (&worker->bind_ev, NULL);

	ctx->resolver = dns_resolver_init (ctx->ev_base, worker->srv->cfg);

	/* Open worker's lib */
	luaopen_lua_worker (L);

	if (ctx->file == NULL) {
		msg_err ("No lua script defined, so no reason to exist");
		exit (EXIT_SUCCESS);
	}
	if (access (ctx->file, R_OK) == -1) {
		msg_err ("Error reading lua script %s: %s", ctx->file, strerror (errno));
		exit (EXIT_SUCCESS);
	}

	pctx = lua_newuserdata (L, sizeof (gpointer));
	lua_setclass (L, "rspamd{worker}", -1);
	lua_setglobal (L, "rspamd_worker");
	*pctx = ctx;

	if (luaL_dofile (L, ctx->file) != 0) {
		msg_err ("Error executing lua script %s: %s", ctx->file, lua_tostring (L, -1));
		exit (EXIT_SUCCESS);
	}

	if (ctx->cbref_accept == 0) {
		msg_err ("No accept function defined, so no reason to exist");
		exit (EXIT_SUCCESS);
	}

	/* Maps events */
	start_map_watch (worker->srv->cfg, ctx->ev_base);

	event_base_loop (ctx->ev_base, 0);
	luaL_unref (L, LUA_REGISTRYINDEX, ctx->cbref_accept);
	if (ctx->cbref_fin != 0) {
		/* Call finalizer function */
		lua_rawgeti (L, LUA_REGISTRYINDEX, ctx->cbref_fin);
		pctx = lua_newuserdata (L, sizeof (gpointer));
		lua_setclass (L, "rspamd{worker}", -1);
		*pctx = ctx;
		if (lua_pcall (L, 1, 0, 0) != 0) {
			msg_info ("call to worker finalizer failed: %s", lua_tostring (L, -1));
		}
		/* Free resources */
		luaL_unref (L, LUA_REGISTRYINDEX, ctx->cbref_fin);
	}

	close_log (rspamd_main->logger);
	exit (EXIT_SUCCESS);
}

/*
 * vi:ts=4
 */