/****************************************************************************
 * apps/nshlib/nsh_session.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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <termios.h>

#ifdef CONFIG_NSH_CLE
#  include "system/cle.h"
#else
#  include "system/readline.h"
#endif

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

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

/****************************************************************************
 * Name: nsh_session
 *
 * Description:
 *   This is the common session login on any NSH session.  This function
 *   returns when an error reading from the input stream occurs, presumably
 *   signaling the end of the session.
 *
 *   This function:
 *   - Performs the login sequence if so configured
 *   - Executes the NSH login script
 *   - Presents a greeting
 *   - Then provides a prompt then gets and processes the command line.
 *   - This continues until an error occurs, then the session returns.
 *
 * Input Parameters:
 *   pstate - Abstracts the underlying session.
 *
 * Returned Values:
 *   EXIT_SUCCESS or EXIT_FAILURE is returned.
 *
 ****************************************************************************/

int nsh_session(FAR struct console_stdio_s *pstate,
                int login, int argc, FAR char *argv[])
{
  FAR struct nsh_vtbl_s *vtbl;
  int ret = EXIT_FAILURE;

  DEBUGASSERT(pstate);
  vtbl = &pstate->cn_vtbl;

#ifdef CONFIG_NSH_CONSOLE_LOGIN
  if (login == NSH_LOGIN_LOCAL)
    {
      /* Login User and Password Check */

      if (nsh_login(pstate) != OK)
        {
          nsh_exit(vtbl, 1);
          return -1; /* nsh_exit does not return */
        }
    }
  else
#endif /* CONFIG_NSH_CONSOLE_LOGIN */
#ifdef CONFIG_NSH_TELNET_LOGIN
  if (login == NSH_LOGIN_TELNET)
    {
      /* Login User and Password Check */

      if (nsh_telnetlogin(pstate) != OK)
        {
          nsh_exit(vtbl, 1);
          return -1; /* nsh_exit does not return */
        }
    }
#endif /* CONFIG_NSH_TELNET_LOGIN */

  if (login != NSH_LOGIN_NONE)
    {
      /* Present a greeting and possibly a Message of the Day (MOTD) */

      write(OUTFD(pstate), g_nshgreeting, strlen(g_nshgreeting));

#ifdef CONFIG_NSH_MOTD
#  ifdef CONFIG_NSH_PLATFORM_MOTD
      /* Output the platform message of the day */

      platform_motd(vtbl->iobuffer, IOBUFFERSIZE);
      dprintf(OUTFD(pstate), "%s\n", vtbl->iobuffer);
#  else
      /* Output the fixed message of the day */

      dprintf(OUTFD(pstate), "%s\n", g_nshmotd);
#  endif
#endif

      /* Execute the login script */

#ifdef CONFIG_NSH_ROMFSRC
      nsh_loginscript(vtbl);
#endif
    }

  /* Process the command line option */

  if (argc > 1)
    {
      if (strcmp(argv[1], "-h") == 0)
        {
          nsh_output(vtbl, "Usage: %s [<script-path>|-c <command>]\n",
                     argv[0]);
          return EXIT_SUCCESS;
        }
      else if (strcmp(argv[1], "-c") == 0)
        {
          /* Process the inline command */

          if (argc > 2)
            {
              return nsh_parse(vtbl, argv[2]);
            }
          else
            {
              nsh_error(vtbl, g_fmtargrequired, argv[0]);
              return EXIT_FAILURE;
            }
        }
      else if (argv[1][0] == '-')
        {
          /* Unknown option */

          nsh_error(vtbl, g_fmtsyntax, argv[0]);
          return EXIT_FAILURE;
        }
      else
        {
#ifndef CONFIG_NSH_DISABLESCRIPT
          /* Execute the shell script */

          return nsh_script(vtbl, argv[0], argv[1], true);
#else
          return EXIT_FAILURE;
#endif
        }
    }

#ifdef CONFIG_NSH_DISABLE_ECHOBACK
  /* Disable echoback */

  if (isatty(INFD(pstate)))
    {
      struct termios cfg;

      if (tcgetattr(INFD(pstate), &cfg) == 0)
        {
          cfg.c_lflag &= ~ECHO;
          tcsetattr(INFD(pstate), TCSANOW, &cfg);
        }
    }
#endif

  /* Then enter the command line parsing loop */

  for (; ; )
    {
      /* For the case of debugging the USB console...
       * dump collected USB trace data
       */

#ifdef CONFIG_NSH_USBDEV_TRACE
      nsh_usbtrace();
#endif

      /* Get the next line of input. readline() returns EOF
       * on end-of-file or any read failure.
       */

#ifdef CONFIG_NSH_CLE
      /* cle() normally returns the number of characters read, but will
       * return a negated errno value on end of file or if an error
       * occurs. Either  will cause the session to terminate.
       */

      ret = cle_fd(pstate->cn_line, nsh_prompt(), LINE_MAX,
                   INFD(pstate), OUTFD(pstate));
      if (ret < 0)
        {
          dprintf(ERRFD(pstate), g_fmtcmdfailed, "nsh_session",
                  "cle", NSH_ERRNO_OF(-ret));
          continue;
        }
#else
      /* Display the prompt string */

      write(OUTFD(pstate), nsh_prompt(), strlen(nsh_prompt()));

      /* readline() normally returns the number of characters read, but
       * will return EOF on end of file or if an error occurs.  EOF
       * will cause the session to terminate.
       */

      ret = readline_fd(pstate->cn_line, LINE_MAX,
                        INFD(pstate), OUTFD(pstate));
      if (ret == EOF)
        {
          /* NOTE: readline() does not set the errno variable, but
           * perhaps we will be lucky and it will still be valid.
           */

          dprintf(ERRFD(pstate), g_fmtcmdfailed, "nsh_session",
                  "readline", NSH_ERRNO);
          ret = EXIT_SUCCESS;
          break;
        }
#endif

      /* Parse process the command */

      nsh_parse(vtbl, pstate->cn_line);
      nsh_update_prompt();
    }

  return ret;
}