#ifndef BUFFER_H
#define BUFFER_H

struct buffer {
	DA_DEF_STRUCT_ITEM(char, data);
	size_t cur;
};

struct buffer buffer_create(void);
void buffer_destroy(struct buffer buf);

struct buffer buffer_mv_cur_letf(struct buffer buf);
struct buffer buffer_mv_cur_right(struct buffer buf);
struct buffer buffer_mv_cur_up(struct buffer buf);
struct buffer buffer_mv_cur_down(struct buffer buf);

struct buffer buffer_insert_char(struct buffer buf, size_t index, char c);
struct buffer buffer_remove_char_mv_cur(struct buffer buf, size_t index);
struct buffer buffer_remove_char(struct buffer buf, size_t index);
struct buffer buffer_remove_between(struct buffer buf,
				    size_t start, size_t end);

size_t buffer_index_bw_word(struct buffer buf);

#if defined(BUFFER_IMP) || defined(IMP)

#include "da.h"

struct buffer
buffer_create(void)
{
	struct buffer buf = {0};
	DA_CREATE(buf.data, sizeof(char));

	return buf;
}

void
buffer_destroy(struct buffer buf)
{
	free(buf.data.items);
}


struct buffer
buffer_mv_cur_letf(struct buffer buf)
{
	if ( buf.cur == 0 ) {
		return buf;
	}
	--buf.cur;
	return buf;
}

struct buffer
buffer_mv_cur_right(struct buffer buf)
{
	if ( buf.cur == buf.data.size ) {
		return buf;
	}
	++buf.cur;
	return buf;
}

struct buffer
buffer_mv_cur_up(struct buffer buf)
{
	return buf;
}

struct buffer
buffer_mv_cur_down(struct buffer buf)
{
	return buf;
}


struct buffer
buffer_insert_char(struct buffer buf, size_t index, char c)
{
	if ( index > buf.data.size ) {
		DA_APPEND(buf.data, c);
		++buf.cur;
		return buf;
	}

	DA_INSERT(buf.data, c, index);
	++buf.cur;
	return buf;

}

struct buffer
buffer_remove_char_mv_cur(struct buffer buf, size_t index)
{
	if ( buf.data.size == 0 ) {
		return buf;
	}

	if ( index > buf.data.size ) {
		return buf;
	}

	if ( buf.data.size == index ) {
		buf.data.items[--buf.data.size] = 0;
		--buf.cur;
		return buf;
	}

	DA_DELETE(buf.data, index);
	--buf.cur;

	return buf;
}

struct buffer
buffer_remove_char(struct buffer buf, size_t index)
{
	if ( buf.data.size == 0 ) {
		return buf;
	}

	if ( index > buf.data.size ) {
		return buf;
	}

	if ( buf.data.size == index ) {
		buf.data.items[--buf.data.size] = 0;
		return buf;
	}

	DA_DELETE(buf.data, index);

	return buf;
}

struct buffer
buffer_remove_between(struct buffer buf, size_t start, size_t end)
{
	if ( buf.data.size == 0 ) {
		return buf;
	}

	if ( start == end ) {
		return buffer_remove_char(buf, start);
	}

	if ( start > end ) {
		return buf;
	}

	DA_DEF_STRUCT_ITEM(char, da);
	DA_ASSIGN(da, buf.data);

	/* There is no need to check start > buf.data.size, because */
	/* we know that start < end */
	if ( end > da.size ) {
		return buf;
	}

	size_t nrm = end - start;
	printf("%ld\n", nrm);
	memmove(da.items+start, da.items+end, da.size - nrm);
	da.size -= nrm;
	buf.cur -= nrm;

	return buf;
}

#include <ctype.h>

size_t
buffer_index_bw_word(struct buffer buf)
{
	if ( buf.data.size == 0 ) {
		return 0;
	}

	bool found_letter = false;
	size_t i = buf.cur;
	for ( ; i > 0; --i) {
		char c = buf.data.items[i];
		if ( isalpha(c) ) {
			found_letter = true;
		} else if ( found_letter ) {
			return i+1;
		}
	}
	if ( i == 0 ) {
		char c = buf.data.items[i];
		if ( isalpha(c) ) {
			found_letter = true;
		} else if ( found_letter ) {
			return i+1;
		}
	}

	return i;
}

#endif /* defined(BUFFER_IMP) || defined(IMP) */

#endif