/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    shell.c
 * @brief   Simple CLI shell code.
 *
 * @addtogroup SHELL
 * @{
 */

#include <string.h>

#include "ch.h"
#include "hal.h"
#include "shell.h"
#include "chprintf.h"

/**
 * @brief   Shell termination event source.
 */
EventSource shell_terminated;

static char *_strtok(char *str, const char *delim, char **saveptr) {
  char *token;
  if (str)
    *saveptr = str;
  token = *saveptr;

  if (!token)
    return NULL;

  token += strspn(token, delim);
  *saveptr = strpbrk(token, delim);
  if (*saveptr)
    *(*saveptr)++ = '\0';

  return *token ? token : NULL;
}

static void usage(BaseSequentialStream *chp, char *p) {

  chprintf(chp, "Usage: %s\r\n", p);
}

static void list_commands(BaseSequentialStream *chp, const ShellCommand *scp) {

  while (scp->sc_name != NULL) {
    chprintf(chp, "%s ", scp->sc_name);
    scp++;
  }
}

static void cmd_info(BaseSequentialStream *chp, int argc, char *argv[]) {

  (void)argv;
  if (argc > 0) {
    usage(chp, "info");
    return;
  }

  chprintf(chp, "Kernel:       %s\r\n", CH_KERNEL_VERSION);
#ifdef CH_COMPILER_NAME
  chprintf(chp, "Compiler:     %s\r\n", CH_COMPILER_NAME);
#endif
  chprintf(chp, "Architecture: %s\r\n", CH_ARCHITECTURE_NAME);
#ifdef CH_CORE_VARIANT_NAME
  chprintf(chp, "Core Variant: %s\r\n", CH_CORE_VARIANT_NAME);
#endif
#ifdef CH_PORT_INFO
  chprintf(chp, "Port Info:    %s\r\n", CH_PORT_INFO);
#endif
#ifdef PLATFORM_NAME
  chprintf(chp, "Platform:     %s\r\n", PLATFORM_NAME);
#endif
#ifdef BOARD_NAME
  chprintf(chp, "Board:        %s\r\n", BOARD_NAME);
#endif
#ifdef __DATE__
#ifdef __TIME__
  chprintf(chp, "Build time:   %s%s%s\r\n", __DATE__, " - ", __TIME__);
#endif
#endif
}

static void cmd_systime(BaseSequentialStream *chp, int argc, char *argv[]) {

  (void)argv;
  if (argc > 0) {
    usage(chp, "systime");
    return;
  }
  chprintf(chp, "%lu\r\n", (unsigned long)chTimeNow());
}

/**
 * @brief   Array of the default commands.
 */
static ShellCommand local_commands[] = {
  {"info", cmd_info},
  {"systime", cmd_systime},
  {NULL, NULL}
};

static bool_t cmdexec(const ShellCommand *scp, BaseSequentialStream *chp,
                      char *name, int argc, char *argv[]) {

  while (scp->sc_name != NULL) {
    if (strcasecmp(scp->sc_name, name) == 0) {
      scp->sc_function(chp, argc, argv);
      return FALSE;
    }
    scp++;
  }
  return TRUE;
}

/**
 * @brief   Shell thread function.
 *
 * @param[in] p         pointer to a @p BaseSequentialStream object
 * @return              Termination reason.
 * @retval RDY_OK       terminated by command.
 * @retval RDY_RESET    terminated by reset condition on the I/O channel.
 */
static msg_t shell_thread(void *p) {
  int n;
  msg_t msg = RDY_OK;
  BaseSequentialStream *chp = ((ShellConfig *)p)->sc_channel;
  const ShellCommand *scp = ((ShellConfig *)p)->sc_commands;
  char *lp, *cmd, *tokp, line[SHELL_MAX_LINE_LENGTH];
  char *args[SHELL_MAX_ARGUMENTS + 1];

  chRegSetThreadName("shell");
  chprintf(chp, "\r\nChibiOS/RT Shell\r\n");
  while (TRUE) {
    chprintf(chp, "ch> ");
    if (shellGetLine(chp, line, sizeof(line))) {
      chprintf(chp, "\r\nlogout");
      break;
    }
    lp = _strtok(line, " \t", &tokp);
    cmd = lp;
    n = 0;
    while ((lp = _strtok(NULL, " \t", &tokp)) != NULL) {
      if (n >= SHELL_MAX_ARGUMENTS) {
        chprintf(chp, "too many arguments\r\n");
        cmd = NULL;
        break;
      }
      args[n++] = lp;
    }
    args[n] = NULL;
    if (cmd != NULL) {
      if (strcasecmp(cmd, "exit") == 0) {
        if (n > 0) {
          usage(chp, "exit");
          continue;
        }
        break;
      }
      else if (strcasecmp(cmd, "help") == 0) {
        if (n > 0) {
          usage(chp, "help");
          continue;
        }
        chprintf(chp, "Commands: help exit ");
        list_commands(chp, local_commands);
        if (scp != NULL)
          list_commands(chp, scp);
        chprintf(chp, "\r\n");
      }
      else if (cmdexec(local_commands, chp, cmd, n, args) &&
          ((scp == NULL) || cmdexec(scp, chp, cmd, n, args))) {
        chprintf(chp, "%s", cmd);
        chprintf(chp, " ?\r\n");
      }
    }
  }
  /* Atomically broadcasting the event source and terminating the thread,
     there is not a chSysUnlock() because the thread terminates upon return.*/
  chSysLock();
  chEvtBroadcastI(&shell_terminated);
  chThdExitS(msg);
  return 0; /* Never executed.*/
}

/**
 * @brief   Shell manager initialization.
 */
void shellInit(void) {

  chEvtInit(&shell_terminated);
}

/**
 * @brief   Spawns a new shell.
 * @pre     @p CH_USE_MALLOC_HEAP and @p CH_USE_DYNAMIC must be enabled.
 *
 * @param[in] scp       pointer to a @p ShellConfig object
 * @param[in] size      size of the shell working area to be allocated
 * @param[in] prio      priority level for the new shell
 * @return              A pointer to the shell thread.
 * @retval NULL         thread creation failed because memory allocation.
 */
#if CH_USE_HEAP && CH_USE_DYNAMIC
Thread *shellCreate(const ShellConfig *scp, size_t size, tprio_t prio) {

  return chThdCreateFromHeap(NULL, size, prio, shell_thread, (void *)scp);
}
#endif

/**
 * @brief   Create statically allocated shell thread.
 *
 * @param[in] scp       pointer to a @p ShellConfig object
 * @param[in] wsp       pointer to a working area dedicated to the shell thread stack
 * @param[in] size      size of the shell working area
 * @param[in] prio      priority level for the new shell
 * @return              A pointer to the shell thread.
 */
Thread *shellCreateStatic(const ShellConfig *scp, void *wsp,
                          size_t size, tprio_t prio) {

  return chThdCreateStatic(wsp, size, prio, shell_thread, (void *)scp);
}

/**
 * @brief   Reads a whole line from the input channel.
 *
 * @param[in] chp       pointer to a @p BaseSequentialStream object
 * @param[in] line      pointer to the line buffer
 * @param[in] size      buffer maximum length
 * @return              The operation status.
 * @retval TRUE         the channel was reset or CTRL-D pressed.
 * @retval FALSE        operation successful.
 */
bool_t shellGetLine(BaseSequentialStream *chp, char *line, unsigned size) {
  char *p = line;

  while (TRUE) {
    char c;

    if (chSequentialStreamRead(chp, (uint8_t *)&c, 1) == 0)
      return TRUE;
    if (c == 4) {
      chprintf(chp, "^D");
      return TRUE;
    }
    if (c == 8) {
      if (p != line) {
        chSequentialStreamPut(chp, c);
        chSequentialStreamPut(chp, 0x20);
        chSequentialStreamPut(chp, c);
        p--;
      }
      continue;
    }
    if (c == '\r') {
      chprintf(chp, "\r\n");
      *p = 0;
      return FALSE;
    }
    if (c < 0x20)
      continue;
    if (p < line + size - 1) {
      chSequentialStreamPut(chp, c);
      *p++ = (char)c;
    }
  }
}

/** @} */