text: /**
   * @file text_history.c
   * @author CuBeatSystems
   * @author Shinichiro Nakamura
   * @copyright
   * ===============================================================
   * Natural Tiny Shell (NT-Shell) Version 0.3.1
   * ===============================================================
   * Copyright (c) 2010-2016 Shinichiro Nakamura
   *
   * Permission is hereby granted, free of charge, to any person
   * obtaining a copy of this software and associated documentation
   * files (the "Software"), to deal in the Software without
   * restriction, including without limitation the rights to use,
   * copy, modify, merge, publish, distribute, sublicense, and/or
   * sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following
   * conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
   * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
   * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include "mbed.h"
  #include "text_history.h"
  #include "ntlibc.h"
  
  /**
   * @brief Initialize this module.
   *
   * @param p A pointer to the handler.
   */
  void text_history_init(text_history_t *p)
  {
      int i;
      p->rp = 0;
      p->wp = 0;
      for (i = 0; i < (int)sizeof(p->history); i++) {
          p->history[i] = 0;
      }
  }
  
  /**
   * @brief Write to the history.
   *
   * @param p A pointer to the handler.
   * @param buf A pointer to the buffer.
   */
  int text_history_write(text_history_t *p, char *buf)
  {
      char *sp = p->history + (TEXTHISTORY_MAXLEN * p->wp);
      if (buf[0] == '\0') {
          return 0;
      }
      while (*buf) {
          *sp = *buf;
          sp++;
          buf++;
      }
      *sp = '\0';
      p->wp = (p->wp + 1) % TEXTHISTORY_DEPTH;
      p->rp = p->wp;
      return 1;
  }
  
  /**
   * @brief Read from the history.
   *
   * @param p A pointer to the handler.
   * @param buf A pointer to the buffer.
   * @param siz A size of the buffer.
   */
  int text_history_read(text_history_t *p, char *buf, const int siz)
  {
      char *sp = p->history + (TEXTHISTORY_MAXLEN * p->rp);
      int n = 0;
      while (*sp) {
          *buf = *sp;
          buf++;
          sp++;
          n++;
          if (siz - 1 <= n) {
              break;
          }
      }
      *buf = '\0';
      return n;
  }
  
  /**
   * @brief Change the pointing location to the next.
   *
   * @param p A pointer to the handler.
   */
  int text_history_read_point_next(text_history_t *p)
  {
      int n = (p->rp + 1) % TEXTHISTORY_DEPTH;
      if (n != p->wp) {
          p->rp = n;
          return 1;
      }
      return 0;
  }
  
  /**
   * @brief Change the pointing location to the previous.
   *
   * @param p A pointer to the handler.
   */
  int text_history_read_point_prev(text_history_t *p)
  {
      int n = (p->rp == 0) ? (TEXTHISTORY_DEPTH - 1) : (p->rp - 1);
      if (n != p->wp) {
          char *sp = p->history + (TEXTHISTORY_MAXLEN * n);
          if (*sp != '\0') {
              p->rp = n;
              return 1;
          }
      }
      return 0;
  }
  
  /**
   * @brief Find the given text string from the text history.
   *
   * @param p A pointer to the handler.
   * @param index An index number of the history.
   * @param text The target text string.
   * @param buf A pointer to the buffer.
   * @param siz A size of the buffer.
   *
   * @retval 0 Success.
   * @retval !0 Failure.
   */
  int text_history_find(text_history_t *p,
          const int index, const char *text,
          char *buf, const int siz)
  {
      const int text_len = ntlibc_strlen((const char *)text);
      int found = 0;
      int i;
      for (i = 0; i < TEXTHISTORY_DEPTH; i++) {
          int target = (p->rp + i) % TEXTHISTORY_DEPTH;
          char *txtp = p->history + (TEXTHISTORY_MAXLEN * target);
          const int target_len = ntlibc_strlen((const char *)txtp);
          int comp_len = (target_len < text_len) ? target_len : text_len;
          if ((ntlibc_strncmp(
                      (const char *)txtp,
                      (const char *)text, comp_len) == 0) && (comp_len > 0)) {
              if (found == index) {
                  if (siz <= ntlibc_strlen(txtp)) {
                      return -1;
                  }
                  ntlibc_strcpy((char *)buf, (char *)txtp);
                  return 0;
              }
              found++;
          }
      }
      return -1;
  }
  
  