/****************************************************************************
 * apps/nshlib/nsh_envcmds.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <libgen.h>
#include <errno.h>

#include "nsh.h"
#include "nsh_console.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define CHAR_ESCAPE(s, c) \
          case (c):       \
            *(s)++ = (c); \
            break

/****************************************************************************
 * Private Data
 ****************************************************************************/

#ifndef CONFIG_DISABLE_ENVIRON
static const char g_pwd[]    = "PWD";
#  ifndef CONFIG_NSH_DISABLE_CD
static const char g_oldpwd[] = "OLDPWD";
#  endif
#endif

#if !defined(CONFIG_NSH_DISABLE_CD) || !defined(CONFIG_DISABLE_ENVIRON)
static const char g_home[]   = CONFIG_LIBC_HOMEDIR;
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_ECHO
static void str_escape(FAR char *s)
{
  FAR char *q;
  int l;
  int c;

  for (q = s; *q; q++)
    {
      if (*q != '\\')
        {
          *s++ = *q;
          continue;
        }

      switch (*++q)
        {
          case '0':
            for (c = 0, l = 3; l && q[1] >= '0' && q[1] <= '8'; l--, q++)
              {
                c = 8 * c + (q[1] - '0');
              }

            *s++ = c;
            break;

          case 'x':
            for (c = 0, l = 2; l && isxdigit(q[1]); l--, q++)
              {
                if (isdigit(q[1]))
                  {
                    c = 16 * c + (q[1] - '0');
                  }
                else
                  {
                    c = 16 * c + (tolower(q[1]) - 'a' + 10);
                  }
              }

            *s++ = c;
            break;

          case '\0':
            *s++ = '\\';
            *s++ = '\0';
            return;

          default:
            *s++ = '\\';
            *s++ = *q;
            break;

          CHAR_ESCAPE(s, '\a');
          CHAR_ESCAPE(s, '\b');
          CHAR_ESCAPE(s, '\f');
          CHAR_ESCAPE(s, '\n');
          CHAR_ESCAPE(s, '\r');
          CHAR_ESCAPE(s, '\v');
          CHAR_ESCAPE(s, '\\');
        }
    }

  *s = '\0';
}
#endif

/****************************************************************************
 * Name: nsh_getwd
 ****************************************************************************/

#ifndef CONFIG_DISABLE_ENVIRON
static inline FAR const char *nsh_getwd(FAR const char *wd)
{
  FAR const char *val;

  /* If no working directory is defined, then default to the home directory */

  val = getenv(wd);
  if (val == NULL)
    {
      val = g_home;
    }

  return val;
}
#endif

/****************************************************************************
 * Name: nsh_dumpvar
 ****************************************************************************/

#if defined(CONFIG_NSH_VARS) && !defined(CONFIG_NSH_DISABLE_SET)
static int nsh_dumpvar(FAR struct nsh_vtbl_s *vtbl, FAR void *arg,
                       FAR const char *pair)
{
  UNUSED(arg);

  nsh_output(vtbl, "%s\n", pair);
  return OK;
}
#endif

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nsh_getwd
 ****************************************************************************/

FAR const char *nsh_getcwd(FAR struct nsh_vtbl_s *vtbl)
{
#ifndef CONFIG_DISABLE_ENVIRON
  return nsh_getwd(g_pwd);
#else
  return vtbl->cwd;
#endif
}

/****************************************************************************
 * Name: nsh_getfullpath
 ****************************************************************************/

#ifndef CONFIG_DISABLE_ENVIRON
FAR char *nsh_getfullpath(FAR struct nsh_vtbl_s *vtbl,
                          FAR const char *relpath)
{
  FAR const char *wd;

  /* Handle some special cases */

  if (!relpath || relpath[0] == '\0')
    {
      /* No relative path provided */

      return strdup(g_home);
    }
  else if (relpath[0] == '/')
    {
      return strdup(relpath);
    }

  /* Get the path to the current working directory */

  wd = nsh_getcwd(vtbl);

  /* Fake the '.' directory */

  if (strcmp(relpath, ".") == 0)
    {
      return strdup(wd);
    }

  /* Return the full path */

  return nsh_getdirpath(vtbl, wd, relpath);
}

/****************************************************************************
 * Name: nsh_freefullpath
 ****************************************************************************/

void nsh_freefullpath(FAR char *fullpath)
{
  if (fullpath)
    {
      free(fullpath);
    }
}
#endif /* CONFIG_DISABLE_ENVIRON */

/****************************************************************************
 * Name: cmd_cd
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_CD
int cmd_cd(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  FAR const char *path = argv[1];
  FAR char *alloc = NULL;
  FAR char *fullpath = NULL;
  int ret = OK;

  /* Check for special arguments */

  if (argc < 2 || strcmp(path, "~") == 0)
    {
      path = g_home;
    }
#ifndef CONFIG_DISABLE_ENVIRON
  else if (strcmp(path, "-") == 0)
    {
      alloc = strdup(nsh_getwd(g_oldpwd));
      path  = alloc;
    }
#endif
  else if (strcmp(path, "..") == 0)
    {
      alloc = strdup(nsh_getcwd(vtbl));
      path  = dirname(alloc);
    }
  else
    {
      fullpath = nsh_getfullpath(vtbl, path);
      path     = fullpath;
    }

  /* Set the new working directory */

  ret = chdir(path);
  if (ret != 0)
    {
      nsh_error(vtbl, g_fmtcmdfailed, argv[0], "chdir", NSH_ERRNO);
      ret = ERROR;
    }
#ifdef CONFIG_DISABLE_ENVIRON
  else
    {
      strlcpy(vtbl->cwd, path, sizeof(vtbl->cwd));
    }
#endif

  /* Free any memory that was allocated */

  if (alloc)
    {
      free(alloc);
    }

  if (fullpath)
    {
      nsh_freefullpath(fullpath);
    }

  return ret;
}
#endif

/****************************************************************************
 * Name: cmd_echo
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_ECHO
int cmd_echo(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  int newline = 1;
  int escape = 0;

  --argc;
  ++argv;

  while (argc > 0 && argv[0][0] == '-')
    {
      FAR char const *temp = argv[0] + 1;
      size_t i;

      for (i = 0; temp[i]; i++)
        {
          switch (temp[i])
            {
              case 'e':
              case 'E':
              case 'n':
                break;
              default:
                goto do_echo;
            }
        }

      if (i == 0)
        {
          goto do_echo;
        }

      while (*temp)
        {
          switch (*temp++)
            {
              case 'e':
                escape = 1;
                break;

              case 'E':
                escape = 0;
                break;

              case 'n':
                newline = 0;
                break;
            }
        }

      --argc;
      ++argv;
    }

do_echo:
  while (argc > 0)
    {
      if (escape)
        {
          str_escape(argv[0]);
        }

      nsh_output(vtbl, "%s", argv[0]);

      --argc;
      ++argv;
      if (argc > 0)
        {
          nsh_output(vtbl, " ");
        }
    }

  if (newline)
    {
      nsh_output(vtbl, "\n");
    }

  return OK;
}
#endif

/****************************************************************************
 * Name: cmd_env
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_ENV
int cmd_env(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  UNUSED(argc);

  return nsh_catfile(vtbl, argv[0],
                     CONFIG_NSH_PROC_MOUNTPOINT "/self/group/env");
}
#endif

/****************************************************************************
 * Name: cmd_pwd
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_PWD
int cmd_pwd(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  UNUSED(argc);
  UNUSED(argv);

  nsh_output(vtbl, "%s\n", nsh_getcwd(vtbl));
  return OK;
}
#endif

/****************************************************************************
 * Name: cmd_set
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_SET
int cmd_set(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  FAR char *value;
  int ret = OK;
#ifdef NSH_HAVE_VARS
  int ndx = 1;
#endif

#ifndef CONFIG_NSH_DISABLESCRIPT
  FAR char *popt;
  const char opts[] = NSH_NP_SET_OPTIONS;
  int op;

#ifdef CONFIG_NSH_VARS
  /* Set with no arguments will show all of the NSH variables */

  if (argc == 1)
    {
      ret = nsh_foreach_var(vtbl, nsh_dumpvar, NULL);
      nsh_output(vtbl, "\n");
      return ret < 0 ? ERROR : OK;
    }
  else
#endif
#ifdef NSH_HAVE_VARS
  /* Support set [{+|-}{e|x|xe|ex}] [<name> <value>] */

  if (argc == 2 || argc == 4)
#else
  /* Support set [{+|-}{e|x|xe|ex}] */

#endif
    {
      if (strlen(argv[1]) < 2)
        {
          ret = -EINVAL;
          nsh_error(vtbl, g_fmtargrequired, argv[0], "set", NSH_ERRNO);
        }
      else
        {
          op = argv[1][0];
          if (op != '-' && op != '+')
            {
              ret = -EINVAL;
              nsh_error(vtbl, g_fmtarginvalid, argv[0], "set", NSH_ERRNO);
            }
          else
            {
              value = &argv[1][1];
              while (*value && *value != ' ')
                {
                  popt = strchr(opts, *value++);
                  if (popt == NULL)
                    {
                      nsh_error(vtbl, g_fmtarginvalid,
                                argv[0], "set", NSH_ERRNO);
                      ret = -EINVAL;
                      break;
                    }

                  if (op == '+')
                    {
                      vtbl->np.np_flags |= 1 << (popt - opts);
                    }
                  else
                    {
                      vtbl->np.np_flags &= ~(1 << (popt - opts));
                    }
                }

#ifdef NSH_HAVE_VARS
              if (ret == OK)
                {
                  ndx = 2;
                }
#endif
            }
        }
    }

#ifdef NSH_HAVE_VARS
  if (ret == OK && (argc == 3 || argc == 4))
#endif
#endif /* CONFIG_NSH_DISABLESCRIPT */
#ifdef NSH_HAVE_VARS
    {
#if defined(CONFIG_NSH_VARS) && !defined(CONFIG_DISABLE_ENVIRON)
      FAR char *oldvalue;
#endif

      /* Trim whitespace from the value */

      value = nsh_trimspaces(argv[ndx + 1]);

#ifdef CONFIG_NSH_VARS
#ifndef CONFIG_DISABLE_ENVIRON
      /* Check if the NSH variable has already been promoted to an group-
       * wide environment variable.
       *
       * REVISIT:  Is this the correct behavior?  Bash would create/modify
       * a local variable that shadows the environment variable.
       */

      oldvalue = getenv(argv[ndx]);
      if (oldvalue == NULL)
#endif
        {
          /* Set the NSH variable */

          ret = nsh_setvar(vtbl, argv[ndx], value);
          if (ret < 0)
            {
              nsh_error(vtbl, g_fmtcmdfailed, argv[0], "nsh_setvar",
                         NSH_ERRNO_OF(-ret));
            }
        }
#endif /* CONFIG_NSH_VARS */

#if !defined(CONFIG_DISABLE_ENVIRON)
#ifdef CONFIG_NSH_VARS
      else
#endif
        {
          /* Set the environment variable */

          ret = setenv(argv[ndx], value, TRUE);
          if (ret < 0)
            {
              nsh_error(vtbl, g_fmtcmdfailed, argv[0], "setenv",
                               NSH_ERRNO);
            }
        }
#endif /* !CONFIG_DISABLE_ENVIRON */
    }
#endif /* NSH_HAVE_VARS */

  return ret;
}
#endif /* CONFIG_NSH_DISABLE_SET */

/****************************************************************************
 * Name: cmd_unset
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_UNSET
int cmd_unset(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  UNUSED(argc);

#if defined(CONFIG_NSH_VARS) || !defined(CONFIG_DISABLE_ENVIRON)
  int status;
#endif
  int ret = OK;

#if defined(CONFIG_NSH_VARS)
  /* Unset NSH variable */

  status = nsh_unsetvar(vtbl, argv[1]);
  if (status < 0 && status != -ENOENT)
    {
      nsh_error(vtbl, g_fmtcmdfailed, argv[0], "nsh_unsetvar",
                NSH_ERRNO_OF(-status));
      ret = ERROR;
    }
#endif

#if !defined(CONFIG_DISABLE_ENVIRON)
  /* Unset environment variable */

  status = unsetenv(argv[1]);
  if (status < 0)
    {
      nsh_error(vtbl, g_fmtcmdfailed, argv[0], "unsetenv", NSH_ERRNO);
      ret = ERROR;
    }
#endif

  return ret;
}
#endif

/****************************************************************************
 * Name: cmd_export
 ****************************************************************************/

#ifndef CONFIG_NSH_DISABLE_EXPORT
int cmd_export(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
{
  FAR const char *value = "";
  int status;
  int ret = OK;

  /* Get the value from the command line if provided.  argc may be either 2
   * or 3
   */

  if (argc == 3)
    {
      value = argv[2];
    }
  else
    {
      FAR const char *tmp;

      /* Try to get the value from the NSH variable */

      tmp = nsh_getvar(vtbl, argv[1]);
      if (tmp != NULL)
        {
          value = tmp;
        }
    }

  /* Set the environment variable to the selected value */

  status = setenv(argv[1], value, TRUE);
  if (status < 0)
    {
      nsh_error(vtbl, g_fmtcmdfailed, argv[0], "unsetenv", NSH_ERRNO);
      ret = ERROR;
    }
  else
    {
      /* Unset NSH variable.
       *
       * REVISIT:  Is this the correct behavior?  Bash would retain
       * a local variable that shadows the environment variable.
       */

      status = nsh_unsetvar(vtbl, argv[1]);
      if (status < 0 && status != -ENOENT)
        {
          nsh_error(vtbl, g_fmtcmdfailed, argv[0], "nsh_unsetvar",
                     NSH_ERRNO_OF(-status));
          ret = ERROR;
        }
    }

  return ret;
}
#endif