// SPDX-License-Identifier: GPL-2.0-or-later

// SPDX-FileCopyrightText: © 2012 Jan Luebbe <j.luebbe@pengutronix.de>

/* Partially based on code from BusyBox. */

#include <common.h>

#include <command.h>

#include <environment.h>

#include <errno.h>

#include <init.h>

#include <malloc.h>

#include <xfuncs.h>

#include <math.h>

static void setvar(const char *name, const char *val)

{

  setenv(name, val); /* return value is always 0 */

}

static arith_t run_arith(const char *s)

{

  arith_state_t math_state;

  arith_t result;

  math_state.lookupvar = getenv;

  math_state.setvar    = setvar;

  math_state.endofname = arith_endofname;

  result = arith(&math_state, s);

  if (math_state.errmsg)

    printf("let: %s\n", math_state.errmsg);

  return result;

}

static int do_let(int argc, char *argv[])

{

  arith_t i;

  argv++;

  if (!*argv) {

    printf("let: expression expected\n");

    return COMMAND_ERROR_USAGE;

  }

  do {

    i = run_arith(*argv);

  } while (*++argv);

  return !i;

}

BAREBOX_CMD_HELP_START(let)

BAREBOX_CMD_HELP_TEXT ("Supported operations are in order of decreasing precedence:")

BAREBOX_CMD_HELP_TEXT ("  X++, X--")

BAREBOX_CMD_HELP_TEXT ("  ++X, --X")

BAREBOX_CMD_HELP_TEXT ("  +X, -X")

BAREBOX_CMD_HELP_TEXT ("  !X, ~X")

BAREBOX_CMD_HELP_TEXT ("  X**Y")

BAREBOX_CMD_HELP_TEXT ("  X*Y, X/Y, X%Y")

BAREBOX_CMD_HELP_TEXT ("  X+Y, X-Y")

BAREBOX_CMD_HELP_TEXT ("  X<<Y, X>>Y")

BAREBOX_CMD_HELP_TEXT ("  X<Y, X<=Y, X>=Y, X>Y")

BAREBOX_CMD_HELP_TEXT ("  X==Y, X!=Y")

BAREBOX_CMD_HELP_TEXT ("  X&Y")

BAREBOX_CMD_HELP_TEXT ("  X^Y")

BAREBOX_CMD_HELP_TEXT ("  X|Y")

BAREBOX_CMD_HELP_TEXT ("  X&&Y")

BAREBOX_CMD_HELP_TEXT ("  X||Y")

BAREBOX_CMD_HELP_TEXT ("  X?Y:Z")

BAREBOX_CMD_HELP_TEXT ("  X*=Y, X/=Y, X%=Y")

BAREBOX_CMD_HELP_TEXT ("  X=Y, X&=Y, X|=Y, X^=Y, X+=Y, X-=Y, X<<=Y, X>>=Y")

BAREBOX_CMD_HELP_END

BAREBOX_CMD_START(let)

  .cmd            = do_let,

  BAREBOX_CMD_DESC("evaluate arithmetic expressions")

  BAREBOX_CMD_OPTS("EXPR [EXPR ...]")

  BAREBOX_CMD_GROUP(CMD_GRP_SCRIPT)

  BAREBOX_CMD_HELP(cmd_let_help)

BAREBOX_CMD_END