#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>

#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

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

#define SBCONN_META "sircbot-connection"
#ifndef VERSION
#define VERSION "unknown"
#endif

static int *Lsbconn_checkarg(lua_State *L, int index)
{
	int *fdp;
	luaL_checktype(L, index, LUA_TUSERDATA);
	fdp = (int *) luaL_checkudata(L, index, SBCONN_META);
	if (fdp == NULL)
		luaL_typerror(L, index, SBCONN_META);
	return fdp;
}

static int Lsbconn_new(lua_State *L)
{
	int *fdp;
	const char *channel_name = luaL_checklstring(L, 1, NULL);
	struct sockaddr_un sun;
	fdp = (int *) lua_newuserdata(L, sizeof(int *));
	luaL_getmetatable(L, SBCONN_META);
	lua_setmetatable(L, -2);

	*fdp = socket(PF_UNIX, SOCK_STREAM, 0);
	if (*fdp < 0)
		luaL_error(L, "Failed to create socket for '%s'", channel_name);

	sun.sun_family = AF_UNIX;
	snprintf(sun.sun_path, sizeof(sun.sun_path), "/var/run/sircbot/%s",
		channel_name);
	if (connect(*fdp, (struct sockaddr *) &sun, sizeof(sun)) < 0)
		luaL_error(L, "%s", sun.sun_path);

	return 1;
}

static int Lsbconn_destroy(lua_State *L)
{
	int *fdp = Lsbconn_checkarg(L, 1);
	close(*fdp);
	return 1;
}

static int Lsbconn_send(lua_State *L)
{
	int *fdp;
	const char *msg;
	int r;

	fdp = Lsbconn_checkarg(L, 1);
	msg = luaL_checklstring(L, 2, NULL);
	r = write(*fdp, msg, strlen(msg));
	lua_pushinteger(L, r);
	return 1;
}

static const luaL_reg sbconn_meta_methods[] = {
	{ "__gc",	Lsbconn_destroy },
	{ NULL,		NULL }
};

static const luaL_reg sircbot_methods[] = {
	{ "connect",	Lsbconn_new },
	{ "send",	Lsbconn_send },
	{ NULL,		NULL }
};

LUALIB_API int luaopen_sircbot(lua_State *L)
{
	/* register sircbot library */
	luaL_register(L, "sircbot", sircbot_methods);

	/* version */
	lua_pushliteral(L, "version");
	lua_pushliteral(L, VERSION);
	lua_settable(L, -3);

	/* register metatable for it */
	luaL_newmetatable(L, SBCONN_META);
	luaL_register(L, NULL, sbconn_meta_methods);
	lua_pushliteral(L, "__index");
	lua_pushvalue(L, -3);
	lua_rawset(L, -3);
	lua_pushliteral(L, "__metatable");
	lua_pushvalue(L, -3);
	lua_rawset(L, -3);
	lua_pop(L, 1);

	return 1;
}