/*

** $Id: lbaselib.c $

** Basic library

** See Copyright Notice in lua.h

*/

#define lbaselib_c

#define LUA_LIB

#include "lprefix.h"

#include <ctype.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#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;

  for (i = 1; i <= n; i++) {  /* for each argument */

    size_t l;

    const char *s = luaL_tolstring(L, i, &l);  /* convert it to string */

    if (i > 1)  /* not the first element? */

      lua_writestring("\t", 1);  /* add a tab before it */

    lua_writestring(s, l);  /* print it */

    lua_pop(L, 1);  /* pop result */

  }

  lua_writeline();

  return 0;

}

/*

** Creates a warning with all given arguments.

** Check first for errors; otherwise an error may interrupt

** the composition of a warning, leaving it unfinished.

*/

static int luaB_warn (lua_State *L) {

  int n = lua_gettop(L);  /* number of arguments */

  int i;

  luaL_checkstring(L, 1);  /* at least one argument */

  for (i = 2; i <= n; i++)

    luaL_checkstring(L, i);  /* make sure all arguments are strings */

  for (i = 1; i < n; i++)  /* compose warning */

    lua_warning(L, lua_tostring(L, i), 1);

  lua_warning(L, lua_tostring(L, n), 0);  /* close warning */

  return 0;

}

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

static const char *b_str2int (const char *s, int base, lua_Integer *pn) {

  lua_Unsigned n = 0;

  int neg = 0;

  s += strspn(s, SPACECHARS);  /* skip initial spaces */

  if (*s == '-') { s++; neg = 1; }  /* handle sign */

  else if (*s == '+') s++;

  if (!isalnum((unsigned char)*s))  /* no digit? */

    return NULL;

  do {

    int digit = (isdigit((unsigned char)*s)) ? *s - '0'

                   : (toupper((unsigned char)*s) - 'A') + 10;

    if (digit >= base) return NULL;  /* invalid numeral */

    n = n * base + digit;

    s++;

  } while (isalnum((unsigned char)*s));

  s += strspn(s, SPACECHARS);  /* skip trailing spaces */

  *pn = (lua_Integer)((neg) ? (0u - n) : n);

  return s;

}

static int luaB_tonumber (lua_State *L) {

  if (lua_isnoneornil(L, 2)) {  /* standard conversion? */

    if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */

      lua_settop(L, 1);  /* yes; return it */

      return 1;

    }

    else {

      size_t l;

      const char *s = lua_tolstring(L, 1, &l);

      if (s != NULL && lua_stringtonumber(L, s) == l + 1)

        return 1;  /* successful conversion to number */

      /* else not a number */

      luaL_checkany(L, 1);  /* (but there must be some parameter) */

    }

  }

  else {

    size_t l;

    const char *s;

    lua_Integer n = 0;  /* to avoid warnings */

    lua_Integer base = luaL_checkinteger(L, 2);

    luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */

    s = lua_tolstring(L, 1, &l);

    luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");

    if (b_str2int(s, (int)base, &n) == s + l) {

      lua_pushinteger(L, n);

      return 1;

    }  /* else not a number */

  }  /* else not a number */

  luaL_pushfail(L);  /* not a number */

  return 1;

}

static int luaB_error (lua_State *L) {

  int level = (int)luaL_optinteger(L, 2, 1);

  lua_settop(L, 1);

  if (lua_type(L, 1) == LUA_TSTRING && level > 0) {

    luaL_where(L, level);   /* add extra information */

    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_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");

  if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL))

    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_argexpected(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,

                      "table or string");

  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 pushmode (lua_State *L, int oldmode) {

  if (oldmode == -1)

    luaL_pushfail(L);  /* invalid call to 'lua_gc' */

  else

    lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"

                                             : "generational");

  return 1;

}

/*

** check whether call to 'lua_gc' was valid (not inside a finalizer)

*/

#define checkvalres(res) { if (res == -1) break; }

static int luaB_collectgarbage (lua_State *L) {

  static const char *const opts[] = {"stop", "restart", "collect",

    "count", "step", "setpause", "setstepmul",

    "isrunning", "generational", "incremental", NULL};

  static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,

    LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,

    LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};

  int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];

  switch (o) {

    case LUA_GCCOUNT: {

      int k = lua_gc(L, o);

      int b = lua_gc(L, LUA_GCCOUNTB);

      checkvalres(k);

      lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));

      return 1;

    }

    case LUA_GCSTEP: {

      int step = (int)luaL_optinteger(L, 2, 0);

      int res = lua_gc(L, o, step);

      checkvalres(res);

      lua_pushboolean(L, res);

      return 1;

    }

    case LUA_GCSETPAUSE:

    case LUA_GCSETSTEPMUL: {

      int p = (int)luaL_optinteger(L, 2, 0);

      int previous = lua_gc(L, o, p);

      checkvalres(previous);

      lua_pushinteger(L, previous);

      return 1;

    }

    case LUA_GCISRUNNING: {

      int res = lua_gc(L, o);

      checkvalres(res);

      lua_pushboolean(L, res);

      return 1;

    }

    case LUA_GCGEN: {

      int minormul = (int)luaL_optinteger(L, 2, 0);

      int majormul = (int)luaL_optinteger(L, 3, 0);

      return pushmode(L, lua_gc(L, o, minormul, majormul));

    }

    case LUA_GCINC: {

      int pause = (int)luaL_optinteger(L, 2, 0);

      int stepmul = (int)luaL_optinteger(L, 3, 0);

      int stepsize = (int)luaL_optinteger(L, 4, 0);

      return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize));

    }

    default: {

      int res = lua_gc(L, o);

      checkvalres(res);

      lua_pushinteger(L, res);

      return 1;

    }

  }

  luaL_pushfail(L);  /* invalid call (inside a finalizer) */

  return 1;

}

static int luaB_type (lua_State *L) {

  int t = lua_type(L, 1);

  luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");

  lua_pushstring(L, lua_typename(L, t));

  return 1;

}

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 pairscont (lua_State *L, int status, lua_KContext k) {

  (void)L; (void)status; (void)k;  /* unused */

  return 3;

}

static int luaB_pairs (lua_State *L) {

  luaL_checkany(L, 1);

  if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) {  /* no metamethod? */

    lua_pushcfunction(L, luaB_next);  /* will return generator, */

    lua_pushvalue(L, 1);  /* state, */

    lua_pushnil(L);  /* and initial value */

  }

  else {

    lua_pushvalue(L, 1);  /* argument 'self' to metamethod */

    lua_callk(L, 1, 3, 0, pairscont);  /* get 3 values from metamethod */

  }

  return 3;

}

/*

** Traversal function for 'ipairs'

*/

static int ipairsaux (lua_State *L) {

  lua_Integer i = luaL_checkinteger(L, 2);

  i = luaL_intop(+, i, 1);

  lua_pushinteger(L, i);

  return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;

}

/*

** 'ipairs' function. Returns 'ipairsaux', given "table", 0.

** (The given "table" may not be a table.)

*/

static int luaB_ipairs (lua_State *L) {

  luaL_checkany(L, 1);

  lua_pushcfunction(L, ipairsaux);  /* iteration function */

  lua_pushvalue(L, 1);  /* state */

  lua_pushinteger(L, 0);  /* initial value */

  return 3;

}

static int load_aux (lua_State *L, int status, int envidx) {

  if (l_likely(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) */

    luaL_pushfail(L);

    lua_insert(L, -2);  /* put before error message */

    return 2;  /* return fail 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 (l_unlikely(!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, int d1, lua_KContext d2) {

  (void)d1;  (void)d2;  /* only to match 'lua_Kfunction' prototype */

  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 (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))

    return lua_error(L);

  lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);

  return dofilecont(L, 0, 0);

}

static int luaB_assert (lua_State *L) {

  if (l_likely(lua_toboolean(L, 1)))  /* condition is true? */

    return lua_gettop(L);  /* return all arguments */

  else {  /* error */

    luaL_checkany(L, 1);  /* there must be a condition */

    lua_remove(L, 1);  /* remove it */

    lua_pushliteral(L, "assertion failed!");  /* default message */

    lua_settop(L, 1);  /* leave only message (default if no other one) */

    return luaB_error(L);  /* call 'error' */

  }

}

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 {

    lua_Integer i = luaL_checkinteger(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 - (int)i;

  }

}

/*

** Continuation function for 'pcall' and 'xpcall'. Both functions

** already pushed a 'true' before doing the call, so in case of success

** 'finishpcall' only has to return everything in the stack minus

** 'extra' values (where 'extra' is exactly the number of items to be

** ignored).

*/

static int finishpcall (lua_State *L, int status, lua_KContext extra) {

  if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) {  /* error? */

    lua_pushboolean(L, 0);  /* first result (false) */

    lua_pushvalue(L, -2);  /* error message */

    return 2;  /* return false, msg */

  }

  else

    return lua_gettop(L) - (int)extra;  /* return all results */

}

static int luaB_pcall (lua_State *L) {

  int status;

  luaL_checkany(L, 1);

  lua_pushboolean(L, 1);  /* first result if no errors */

  lua_insert(L, 1);  /* put it in place */

  status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);

  return finishpcall(L, status, 0);

}

/*

** Do a protected call with error handling. After 'lua_rotate', the

** stack will have <f, err, true, f, [args...]>; so, the function passes

** 2 to 'finishpcall' to skip the 2 first values when returning results.

*/

static int luaB_xpcall (lua_State *L) {

  int status;

  int n = lua_gettop(L);

  luaL_checktype(L, 2, LUA_TFUNCTION);  /* check error function */

  lua_pushboolean(L, 1);  /* first result */

  lua_pushvalue(L, 1);  /* function */

  lua_rotate(L, 3, 2);  /* move them below function's arguments */

  status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);

  return finishpcall(L, status, 2);

}

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},

  {"next", luaB_next},

  {"pairs", luaB_pairs},

  {"pcall", luaB_pcall},

  {"print", luaB_print},

  {"warn", luaB_warn},

  {"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},

  /* placeholders */

  {LUA_GNAME, NULL},

  {"_VERSION", NULL},

  {NULL, NULL}

};

LUAMOD_API int luaopen_base (lua_State *L) {

  /* open lib into global table */

  lua_pushglobaltable(L);

  luaL_setfuncs(L, base_funcs, 0);

  /* set global _G */

  lua_pushvalue(L, -1);

  lua_setfield(L, -2, LUA_GNAME);

  /* set global _VERSION */

  lua_pushliteral(L, LUA_VERSION);

  lua_setfield(L, -2, "_VERSION");

  return 1;

}