/*

 * POSIX library for Lua 5.1, 5.2 & 5.3.

 * (c) Gary V. Vaughan <gary@vaughan.pe>, 2013-2015

 * (c) Reuben Thomas <rrt@sc3d.org> 2010-2013

 * (c) Natanael Copa <natanael.copa@gmail.com> 2008-2010

 * Clean up and bug fixes by Leo Razoumov <slonik.az@gmail.com> 2006-10-11

 * Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br> 07 Apr 2006 23:17:49

 * Based on original by Claudio Terra for Lua 3.x.

 * With contributions by Roberto Ierusalimschy.

 * With documentation from Steve Donovan 2012

 */

/***

 Command Line Argument Processing.

@module posix.getopt

*/

#include <config.h>

#include <getopt.h>

#include "_helpers.c"

/* getopt_long */

/* N.B. We don't need the symbolic constants no_argument,

   required_argument and optional_argument, since their values are

   defined as 0, 1 and 2 respectively. */

static const char *const arg_types[] =

{

	"none", "required", "optional", NULL

};

static int

iter_getopt_long(lua_State *L)

{

	int longindex = 0, ret, argc = lua_tointeger(L, lua_upvalueindex(1));

	char **argv = (char **)lua_touserdata(L, lua_upvalueindex(3));

	struct option *longopts = (struct option *)lua_touserdata(L, lua_upvalueindex(3 + argc + 1));

	if (argv == NULL) /* If we have already completed, return now. */

		return 0;

	/* Fetch upvalues to pass to getopt_long. */

	ret = getopt_long(argc, argv,

			  lua_tostring(L, lua_upvalueindex(2)),

			  longopts,

			  &longindex);

	if (ret == -1)

		return 0;

	else

	{

		char c = ret;

		lua_pushlstring(L, &c, 1);

		lua_pushstring(L, optarg);

		lua_pushinteger(L, optind);

		lua_pushinteger(L, longindex);

		return 4;

	}

}

/***

Parse command-line options.

@function getopt

@param arg command line arguments

@string shortopts short option specifier

@tparam[opt] table longopts long options table

@int[opt=0] opterr index of the option with an error

@int[opt=1] optind index of the next unprocessed option

@return option iterator, returning 4 values

@see getopt(3)

@see getopt_long(3)

@usage

local longopts = {

  {"help", "none", 1},

  {"version", "none", 3},

}

for r, longindex, err, i in P.getopt (arg, "ho:v", longopts, err, i) do

  process (arg, err, i)

end

@see getopt.lua

*/

static int

Pgetopt(lua_State *L)

{

	int argc, i, n = 0;

	const char *shortopts;

	char **argv;

	struct option *longopts;

	checknargs(L, 5);

	checktype(L, 1, LUA_TTABLE, "list");

	shortopts = luaL_checkstring(L, 2);

	if (!lua_isnoneornil(L, 3))

		checktype(L, 3, LUA_TTABLE, "table or nil");

	opterr = optint(L, 4, 0);

	optind = optint(L, 5, 1);

	argc = (int)lua_objlen(L, 1) + 1;

	lua_pushinteger(L, argc);

	lua_pushstring(L, shortopts);

	argv = lua_newuserdata(L, (argc + 1) * sizeof(char *));

	argv[argc] = NULL;

	for (i = 0; i < argc; i++)

	{

		lua_pushinteger(L, i);

		lua_gettable(L, 1);

		argv[i] = (char *)luaL_checkstring(L, -1);

	}

	if (lua_type(L, 3) == LUA_TTABLE)

	{

		n = (int)lua_objlen(L, 3);

	}

	longopts = lua_newuserdata(L, (n + 1) * sizeof(struct option));

	longopts[n].name = NULL;

	longopts[n].has_arg = 0;

	longopts[n].flag = NULL;

	longopts[n].val = 0;

	for (i = 1; i <= n; i++)

	{

		const char *name, *val;

		int has_arg;

		lua_pushinteger(L, i);

		lua_gettable(L, 3);

		luaL_checktype(L, -1, LUA_TTABLE);

		lua_pushinteger(L, 1);

		lua_gettable(L, -2);

		name = luaL_checkstring(L, -1);

		lua_pushinteger(L, 2);

		lua_gettable(L, -3);

		has_arg = luaL_checkoption(L, -1, NULL, arg_types);

		lua_pop(L, 1);

		lua_pushinteger(L, 3);

		lua_gettable(L, -3);

		val = luaL_checkstring(L, -1);

		lua_pop(L, 1);

		longopts[i - 1].name = name;

		longopts[i - 1].has_arg = has_arg;

		longopts[i - 1].flag = NULL;

		longopts[i - 1].val = val[0];

		lua_pop(L, 1);

	}

	/* Push remaining upvalues, and make and push closure. */

	lua_pushcclosure(L, iter_getopt_long, 4 + argc + n);

	return 1;

}

static const luaL_Reg posix_getopt_fns[] =

{

	LPOSIX_FUNC( Pgetopt		),

	{NULL, NULL}

};

LUALIB_API int

luaopen_posix_getopt(lua_State *L)

{

	luaL_register(L, "posix.getopt", posix_getopt_fns);

	lua_pushliteral(L, "posix.getopt for " LUA_VERSION " / " PACKAGE_STRING);

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

	return 1;

}