/*
** $Id: lbaselib.c,v 1.276.1.1 2013/04/12 18:48:47 roberto Exp $
** Basic library
** See Copyright Notice in lua.h
*/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define lbaselib_c
#define LUA_LIB

#include "lua.h"

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

static int luaB_print(lua_State *L)
{
	int n = lua_gettop(L); /* number of arguments */
	int i;
	lua_getglobal(L, "tostring");
	for (i = 1; i <= n; i++)
	{
		const char *s;
		size_t l;
		lua_pushvalue(L, -1); /* function to be called */
		lua_pushvalue(L, i);  /* value to print */
		lua_call(L, 1, 1);
		s = lua_tolstring(L, -1, &l); /* get result */
		if (s == NULL)
			return luaL_error(L,
							  LUA_QL("tostring") " must return a string to " LUA_QL("print"));
		if (i > 1) luai_writestring("\t", 1);
		luai_writestring(s, l);
		lua_pop(L, 1); /* pop result */
	}
	luai_writeline();
	return 0;
}

#define SPACECHARS " \f\n\r\t\v"

static int luaB_tonumber(lua_State *L)
{
	if (lua_isnoneornil(L, 2))
	{ /* standard conversion */
		int isnum;
		lua_Number n = lua_tonumberx(L, 1, &isnum);
		if (isnum)
		{
			lua_pushnumber(L, n);
			return 1;
		} /* else not a number; must be something */
		luaL_checkany(L, 1);
	}
	else
	{
		size_t l;
		const char *s = luaL_checklstring(L, 1, &l);
		const char *e = s + l; /* end point for 's' */
		int base = luaL_checkint(L, 2);
		int neg = 0;
		luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
		s += strspn(s, SPACECHARS); /* skip initial spaces */
		if (*s == '-')
		{
			s++;
			neg = 1;
		} /* handle signal */
		else if (*s == '+')
			s++;
		if (isalnum((unsigned char)*s))
		{
			lua_Number n = 0;
			do
			{
				int digit = (isdigit((unsigned char)*s)) ? *s - '0'
														 : toupper((unsigned char)*s) - 'A' + 10;
				if (digit >= base) break; /* invalid numeral; force a fail */
				n = n * (lua_Number)base + (lua_Number)digit;
				s++;
			} while (isalnum((unsigned char)*s));
			s += strspn(s, SPACECHARS); /* skip trailing spaces */
			if (s == e)
			{ /* no invalid trailing characters? */
				lua_pushnumber(L, (neg) ? -n : n);
				return 1;
			} /* else not a number */
		}     /* else not a number */
	}
	lua_pushnil(L); /* not a number */
	return 1;
}

static int luaB_error(lua_State *L)
{
	int level = luaL_optint(L, 2, 1);
	lua_settop(L, 1);
	if (lua_isstring(L, 1) && level > 0)
	{ /* add extra information? */
		luaL_where(L, level);
		lua_pushvalue(L, 1);
		lua_concat(L, 2);
	}
	return lua_error(L);
}

static int luaB_getmetatable(lua_State *L)
{
	luaL_checkany(L, 1);
	if (!lua_getmetatable(L, 1))
	{
		lua_pushnil(L);
		return 1; /* no metatable */
	}
	luaL_getmetafield(L, 1, "__metatable");
	return 1; /* returns either __metatable field (if present) or metatable */
}

static int luaB_setmetatable(lua_State *L)
{
	int t = lua_type(L, 2);
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
				  "nil or table expected");
	if (luaL_getmetafield(L, 1, "__metatable"))
		return luaL_error(L, "cannot change a protected metatable");
	lua_settop(L, 2);
	lua_setmetatable(L, 1);
	return 1;
}

static int luaB_rawequal(lua_State *L)
{
	luaL_checkany(L, 1);
	luaL_checkany(L, 2);
	lua_pushboolean(L, lua_rawequal(L, 1, 2));
	return 1;
}

static int luaB_rawlen(lua_State *L)
{
	int t = lua_type(L, 1);
	luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
				  "table or string expected");
	lua_pushinteger(L, lua_rawlen(L, 1));
	return 1;
}

static int luaB_rawget(lua_State *L)
{
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_checkany(L, 2);
	lua_settop(L, 2);
	lua_rawget(L, 1);
	return 1;
}

static int luaB_rawset(lua_State *L)
{
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_checkany(L, 2);
	luaL_checkany(L, 3);
	lua_settop(L, 3);
	lua_rawset(L, 1);
	return 1;
}

static int luaB_collectgarbage(lua_State *L)
{
	static const char *const opts[] = {"stop", "restart", "collect",
									   "count", "step", "setpause", "setstepmul",
									   "setmajorinc", "isrunning", "generational", "incremental", NULL};
	static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
								  LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
								  LUA_GCSETMAJORINC, LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
	int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
	int ex = luaL_optint(L, 2, 0);
	int res = lua_gc(L, o, ex);
	switch (o)
	{
		case LUA_GCCOUNT:
		{
			int b = lua_gc(L, LUA_GCCOUNTB, 0);
			lua_pushnumber(L, res + ((lua_Number)b / 1024));
			lua_pushinteger(L, b);
			return 2;
		}
		case LUA_GCSTEP:
		case LUA_GCISRUNNING:
		{
			lua_pushboolean(L, res);
			return 1;
		}
		default:
		{
			lua_pushinteger(L, res);
			return 1;
		}
	}
}

static int luaB_type(lua_State *L)
{
	luaL_checkany(L, 1);
	lua_pushstring(L, luaL_typename(L, 1));
	return 1;
}

static int pairsmeta(lua_State *L, const char *method, int iszero,
					 lua_CFunction iter)
{
	if (!luaL_getmetafield(L, 1, method))
	{                                     /* no metamethod? */
		luaL_checktype(L, 1, LUA_TTABLE); /* argument must be a table */
		lua_pushcfunction(L, iter);       /* will return generator, */
		lua_pushvalue(L, 1);              /* state, */
		if (iszero)
			lua_pushinteger(L, 0); /* and initial value */
		else
			lua_pushnil(L);
	}
	else
	{
		lua_pushvalue(L, 1); /* argument 'self' to metamethod */
		lua_call(L, 1, 3);   /* get 3 values from metamethod */
	}
	return 3;
}

static int luaB_next(lua_State *L)
{
	luaL_checktype(L, 1, LUA_TTABLE);
	lua_settop(L, 2); /* create a 2nd argument if there isn't one */
	if (lua_next(L, 1))
		return 2;
	else
	{
		lua_pushnil(L);
		return 1;
	}
}

static int luaB_pairs(lua_State *L)
{
	return pairsmeta(L, "__pairs", 0, luaB_next);
}

static int ipairsaux(lua_State *L)
{
	int i = luaL_checkint(L, 2);
	luaL_checktype(L, 1, LUA_TTABLE);
	i++; /* next value */
	lua_pushinteger(L, i);
	lua_rawgeti(L, 1, i);
	return (lua_isnil(L, -1)) ? 1 : 2;
}

static int luaB_ipairs(lua_State *L)
{
	return pairsmeta(L, "__ipairs", 1, ipairsaux);
}

static int load_aux(lua_State *L, int status, int envidx)
{
	if (status == LUA_OK)
	{
		if (envidx != 0)
		{                                  /* 'env' parameter? */
			lua_pushvalue(L, envidx);      /* environment for loaded function */
			if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
				lua_pop(L, 1);             /* remove 'env' if not used by previous call */
		}
		return 1;
	}
	else
	{ /* error (message is on top of the stack) */
		lua_pushnil(L);
		lua_insert(L, -2); /* put before error message */
		return 2;          /* return nil plus error message */
	}
}

static int luaB_loadfile(lua_State *L)
{
	const char *fname = luaL_optstring(L, 1, NULL);
	const char *mode = luaL_optstring(L, 2, NULL);
	int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
	int status = luaL_loadfilex(L, fname, mode);
	return load_aux(L, status, env);
}

/*
** {======================================================
** Generic Read function
** =======================================================
*/

/*
** reserved slot, above all arguments, to hold a copy of the returned
** string to avoid it being collected while parsed. 'load' has four
** optional arguments (chunk, source name, mode, and environment).
*/
#define RESERVEDSLOT 5

/*
** Reader for generic `load' function: `lua_load' uses the
** stack for internal stuff, so the reader cannot change the
** stack top. Instead, it keeps its resulting string in a
** reserved slot inside the stack.
*/
static const char *generic_reader(lua_State *L, void *ud, size_t *size)
{
	(void)(ud); /* not used */
	luaL_checkstack(L, 2, "too many nested functions");
	lua_pushvalue(L, 1); /* get function */
	lua_call(L, 0, 1);   /* call it */
	if (lua_isnil(L, -1))
	{
		lua_pop(L, 1); /* pop result */
		*size = 0;
		return NULL;
	}
	else if (!lua_isstring(L, -1))
		luaL_error(L, "reader function must return a string");
	lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
	return lua_tolstring(L, RESERVEDSLOT, size);
}

static int luaB_load(lua_State *L)
{
	int status;
	size_t l;
	const char *s = lua_tolstring(L, 1, &l);
	const char *mode = luaL_optstring(L, 3, "bt");
	int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
	if (s != NULL)
	{ /* loading a string? */
		const char *chunkname = luaL_optstring(L, 2, s);
		status = luaL_loadbufferx(L, s, l, chunkname, mode);
	}
	else
	{ /* loading from a reader function */
		const char *chunkname = luaL_optstring(L, 2, "=(load)");
		luaL_checktype(L, 1, LUA_TFUNCTION);
		lua_settop(L, RESERVEDSLOT); /* create reserved slot */
		status = lua_load(L, generic_reader, NULL, chunkname, mode);
	}
	return load_aux(L, status, env);
}

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

static int dofilecont(lua_State *L)
{
	return lua_gettop(L) - 1;
}

static int luaB_dofile(lua_State *L)
{
	const char *fname = luaL_optstring(L, 1, NULL);
	lua_settop(L, 1);
	if (luaL_loadfile(L, fname) != LUA_OK)
		return lua_error(L);
	lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
	return dofilecont(L);
}

static int luaB_assert(lua_State *L)
{
	if (!lua_toboolean(L, 1))
		return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
	return lua_gettop(L);
}

static int luaB_select(lua_State *L)
{
	int n = lua_gettop(L);
	if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#')
	{
		lua_pushinteger(L, n - 1);
		return 1;
	}
	else
	{
		int i = luaL_checkint(L, 1);
		if (i < 0)
			i = n + i;
		else if (i > n)
			i = n;
		luaL_argcheck(L, 1 <= i, 1, "index out of range");
		return n - i;
	}
}

static int finishpcall(lua_State *L, int status)
{
	if (!lua_checkstack(L, 1))
	{                     /* no space for extra boolean? */
		lua_settop(L, 0); /* create space for return values */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "stack overflow");
		return 2; /* return false, msg */
	}
	lua_pushboolean(L, status); /* first result (status) */
	lua_replace(L, 1);          /* put first result in first slot */
	return lua_gettop(L);
}

static int pcallcont(lua_State *L)
{
	int status = lua_getctx(L, NULL);
	return finishpcall(L, (status == LUA_YIELD));
}

static int luaB_pcall(lua_State *L)
{
	int status;
	luaL_checkany(L, 1);
	lua_pushnil(L);
	lua_insert(L, 1); /* create space for status result */
	status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, pcallcont);
	return finishpcall(L, (status == LUA_OK));
}

static int luaB_xpcall(lua_State *L)
{
	int status;
	int n = lua_gettop(L);
	luaL_argcheck(L, n >= 2, 2, "value expected");
	lua_pushvalue(L, 1); /* exchange function... */
	lua_copy(L, 2, 1);   /* ...and error handler */
	lua_replace(L, 2);
	status = lua_pcallk(L, n - 2, LUA_MULTRET, 1, 0, pcallcont);
	return finishpcall(L, (status == LUA_OK));
}

static int luaB_tostring(lua_State *L)
{
	luaL_checkany(L, 1);
	luaL_tolstring(L, 1, NULL);
	return 1;
}

static const luaL_Reg base_funcs[] = {
	{"assert", luaB_assert},
	{"collectgarbage", luaB_collectgarbage},
	{"dofile", luaB_dofile},
	{"error", luaB_error},
	{"getmetatable", luaB_getmetatable},
	{"ipairs", luaB_ipairs},
	{"loadfile", luaB_loadfile},
	{"load", luaB_load},
#if defined(LUA_COMPAT_LOADSTRING)
	{"loadstring", luaB_load},
#endif
	{"next", luaB_next},
	{"pairs", luaB_pairs},
	{"pcall", luaB_pcall},
	{"print", luaB_print},
	{"rawequal", luaB_rawequal},
	{"rawlen", luaB_rawlen},
	{"rawget", luaB_rawget},
	{"rawset", luaB_rawset},
	{"select", luaB_select},
	{"setmetatable", luaB_setmetatable},
	{"tonumber", luaB_tonumber},
	{"tostring", luaB_tostring},
	{"type", luaB_type},
	{"xpcall", luaB_xpcall},
	{NULL, NULL}};

LUAMOD_API int luaopen_base(lua_State *L)
{
	/* set global _G */
	lua_pushglobaltable(L);
	lua_pushglobaltable(L);
	lua_setfield(L, -2, "_G");
	/* open lib into global table */
	luaL_setfuncs(L, base_funcs, 0);
	lua_pushliteral(L, LUA_VERSION);
	lua_setfield(L, -2, "_VERSION"); /* set global _VERSION */
	return 1;
}
