/**
 * @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 <string.h>
#include "text_history.h"
#include "core/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 = 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 = 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 <= strlen(txtp)) {
					return -1;
				}
				strcpy((char *)buf, (char *)txtp);
				return 0;
			}
			found++;
		}
	}
	return -1;
}