/*
** $Id: loslib.c,v 1.19.1.3 2008年01月18日 16:38:18 roberto Exp $
** Standard Operating System library
** See Copyright Notice in lua.h
*/


#include <errno.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define loslib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


static int os_pushresult (lua_State *L, int i, const char *filename) {
 int en = errno; /* calls to Lua API may change this value */
 if (i) {
 lua_pushboolean(L, 1);
 return 1;
 }
 else {
 lua_pushnil(L);
 lua_pushfstring(L, "%s: %s", filename, strerror(en));
 lua_pushinteger(L, en);
 return 3;
 }
}


static int os_execute (lua_State *L) {
 lua_pushinteger(L, system(luaL_optstring(L, 1, NULL)));
 return 1;
}


static int os_remove (lua_State *L) {
 const char *filename = luaL_checkstring(L, 1);
 return os_pushresult(L, remove(filename) == 0, filename);
}


static int os_rename (lua_State *L) {
 const char *fromname = luaL_checkstring(L, 1);
 const char *toname = luaL_checkstring(L, 2);
 return os_pushresult(L, rename(fromname, toname) == 0, fromname);
}


static int os_tmpname (lua_State *L) {
 char buff[LUA_TMPNAMBUFSIZE];
 int err;
 lua_tmpnam(buff, err);
 if (err)
 return luaL_error(L, "unable to generate a unique filename");
 lua_pushstring(L, buff);
 return 1;
}


static int os_getenv (lua_State *L) {
 lua_pushstring(L, getenv(luaL_checkstring(L, 1))); /* if NULL push nil */
 return 1;
}


static int os_clock (lua_State *L) {
 lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC);
 return 1;
}


/*
** {======================================================
** Time/Date operations
** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S,
** wday=%w+1, yday=%j, isdst=? }
** =======================================================
*/

static void setfield (lua_State *L, const char *key, int value) {
 lua_pushinteger(L, value);
 lua_setfield(L, -2, key);
}

static void setboolfield (lua_State *L, const char *key, int value) {
 if (value < 0) /* undefined? */
 return; /* does not set field */
 lua_pushboolean(L, value);
 lua_setfield(L, -2, key);
}

static int getboolfield (lua_State *L, const char *key) {
 int res;
 lua_getfield(L, -1, key);
 res = lua_isnil(L, -1) ? -1 : lua_toboolean(L, -1);
 lua_pop(L, 1);
 return res;
}


static int getfield (lua_State *L, const char *key, int d) {
 int res;
 lua_getfield(L, -1, key);
 if (lua_isnumber(L, -1))
 res = (int)lua_tointeger(L, -1);
 else {
 if (d < 0)
 return luaL_error(L, "field " LUA_QS " missing in date table", key);
 res = d;
 }
 lua_pop(L, 1);
 return res;
}


static int os_date (lua_State *L) {
 const char *s = luaL_optstring(L, 1, "%c");
 time_t t = luaL_opt(L, (time_t)luaL_checknumber, 2, time(NULL));
 struct tm *stm;
 if (*s == '!') { /* UTC? */
 stm = gmtime(&t);
 s++; /* skip `!' */
 }
 else
 stm = localtime(&t);
 if (stm == NULL) /* invalid date? */
 lua_pushnil(L);
 else if (strcmp(s, "*t") == 0) {
 lua_createtable(L, 0, 9); /* 9 = number of fields */
 setfield(L, "sec", stm->tm_sec);
 setfield(L, "min", stm->tm_min);
 setfield(L, "hour", stm->tm_hour);
 setfield(L, "day", stm->tm_mday);
 setfield(L, "month", stm->tm_mon+1);
 setfield(L, "year", stm->tm_year+1900);
 setfield(L, "wday", stm->tm_wday+1);
 setfield(L, "yday", stm->tm_yday+1);
 setboolfield(L, "isdst", stm->tm_isdst);
 }
 else {
 char cc[3];
 luaL_Buffer b;
 cc[0] = '%'; cc[2] = '0円';
 luaL_buffinit(L, &b);
 for (; *s; s++) {
 if (*s != '%' || *(s + 1) == '0円') /* no conversion specifier? */
 luaL_addchar(&b, *s);
 else {
 size_t reslen;
 char buff[200]; /* should be big enough for any conversion result */
 cc[1] = *(++s);
 reslen = strftime(buff, sizeof(buff), cc, stm);
 luaL_addlstring(&b, buff, reslen);
 }
 }
 luaL_pushresult(&b);
 }
 return 1;
}


static int os_time (lua_State *L) {
 time_t t;
 if (lua_isnoneornil(L, 1)) /* called without args? */
 t = time(NULL); /* get current time */
 else {
 struct tm ts;
 luaL_checktype(L, 1, LUA_TTABLE);
 lua_settop(L, 1); /* make sure table is at the top */
 ts.tm_sec = getfield(L, "sec", 0);
 ts.tm_min = getfield(L, "min", 0);
 ts.tm_hour = getfield(L, "hour", 12);
 ts.tm_mday = getfield(L, "day", -1);
 ts.tm_mon = getfield(L, "month", -1) - 1;
 ts.tm_year = getfield(L, "year", -1) - 1900;
 ts.tm_isdst = getboolfield(L, "isdst");
 t = mktime(&ts);
 }
 if (t == (time_t)(-1))
 lua_pushnil(L);
 else
 lua_pushnumber(L, (lua_Number)t);
 return 1;
}


static int os_difftime (lua_State *L) {
 lua_pushnumber(L, difftime((time_t)(luaL_checknumber(L, 1)),
 (time_t)(luaL_optnumber(L, 2, 0))));
 return 1;
}

/* }====================================================== */


static int os_setlocale (lua_State *L) {
 static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,
 LC_NUMERIC, LC_TIME};
 static const char *const catnames[] = {"all", "collate", "ctype", "monetary",
 "numeric", "time", NULL};
 const char *l = luaL_optstring(L, 1, NULL);
 int op = luaL_checkoption(L, 2, "all", catnames);
 lua_pushstring(L, setlocale(cat[op], l));
 return 1;
}


static int os_exit (lua_State *L) {
 exit(luaL_optint(L, 1, EXIT_SUCCESS));
}

static const luaL_Reg syslib[] = {
 {"clock", os_clock},
 {"date", os_date},
 {"difftime", os_difftime},
 {"execute", os_execute},
 {"exit", os_exit},
 {"getenv", os_getenv},
 {"remove", os_remove},
 {"rename", os_rename},
 {"setlocale", os_setlocale},
 {"time", os_time},
 {"tmpname", os_tmpname},
 {NULL, NULL}
};

/* }====================================================== */



LUALIB_API int luaopen_os (lua_State *L) {
 luaL_register(L, LUA_OSLIBNAME, syslib);
 return 1;
}