#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include "str.h"
#include "util.h"

#define INIT_SZ 20

//Внутренняя функция,
//позволяет убедиться что строка может вместить как минимум newsz символов
void
_str_ensure(str *s, int newsz)
{
	int tmp;
	newsz += 1; // добавляем единичку чтобы влез нулевой байт
	if (newsz < s->capacity)
		return;

	tmp = s->capacity * 2;
	if (tmp > newsz) {
		newsz = tmp;
	}
	s->ptr = xrealloc(s->ptr, newsz);
	s->capacity = newsz;
}

void
str_init(str *s)
{
	assert(s);
<<<<<<< HEAD
	// <YOURCODE>
=======
	s->len = 0;
	s->capacity = INIT_SZ;
	s->ptr = malloc(INIT_SZ);
	s->ptr[0] = '\0';
>>>>>>> f115cdc (all tasks done)
}

void
str_deinit(str *s)
{
	if (s->ptr)
		free(s->ptr);
	s->ptr = NULL;
}

void
str_init_data(str *s, const char *initial)
{
	assert(s && initial);
<<<<<<< HEAD
	// <YOURCODE>
=======
	int len = strlen(initial);
	s->len = len;
	s->capacity = len + 1;
	s->ptr = malloc(s->capacity);
	strcpy(s->ptr, initial);
>>>>>>> f115cdc (all tasks done)
}

char *
str_data(str *s)
{
	assert(s);
<<<<<<< HEAD
	// <YOURCODE>
	return NULL;
=======
	return s->ptr;
>>>>>>> f115cdc (all tasks done)
}

void
str_set(str *s, char *cstr)
{
	assert(s && cstr);
<<<<<<< HEAD
	// <YOURCODE>
=======
	int len = strlen(cstr);
	_str_ensure(s, len);
	strcpy(s->ptr, cstr);
	s->len = len;
>>>>>>> f115cdc (all tasks done)
}

str
str_copy(str *s)
{
	assert(s);
<<<<<<< HEAD
	// <YOURCODE>
=======
	str s2;
	str_init(&s2);
	_str_ensure(&s2, s->len);
	strcpy(s2.ptr, s->ptr);
	s2.len = s->len;
	return s2;
>>>>>>> f115cdc (all tasks done)
}

int
str_count(str *s, char ch)
{
	assert(s);
<<<<<<< HEAD
	// <YOURCODE>
	return 0;
=======
	int count = 0;
	for (int i = 0; i < s->len; i++) {
		if (s->ptr[i] == ch)
			count++;
	}
	return count;
>>>>>>> f115cdc (all tasks done)
}

void
str_append(str *s, char *cstr)
{
	assert(s && cstr);
<<<<<<< HEAD
	// <YOURCODE>
=======
	int len = strlen(cstr);
	_str_ensure(s, s->len + len);
	strcpy(s->ptr + s->len, cstr);
	s->len += len;
>>>>>>> f115cdc (all tasks done)
}

void
str_append_n(str *s, char *cstr, int len)
{
	assert(s && cstr);
<<<<<<< HEAD
	// <YOURCODE>
=======
	_str_ensure(s, s->len + len);
	memcpy(s->ptr + s->len, cstr, len);
	s->len += len;
	s->ptr[s->len] = '\0';
>>>>>>> f115cdc (all tasks done)
}

void
str_shrink(str *s, int len)
{
	assert(s && len >= 0);
<<<<<<< HEAD
	// <YOURCODE>
=======
	if (len < s->len) {
		s->len= len;
		s->ptr[len] = '\0';
	}
>>>>>>> f115cdc (all tasks done)
}

int
str_find(str *s, char *substr)
{
	assert(s && substr);
	char *p = strstr(s->ptr, substr);
	if (p == NULL)
		return -1;
	return p - s->ptr;
}

str
str_sub(str *s, int start_idx, int length)
{
	assert(s && start_idx >= 0 && length >= 0);

	str s2;
	str_init(&s2);
<<<<<<< HEAD
	// <YOURCODE>
=======
	
	if (start_idx >= s-> len) {
		return s2;
	}

	int actual_len = length;
	if (start_idx + length > s->len) {
		actual_len = s->len - start_idx;
	}

	_str_ensure(&s2, actual_len);
	memcpy(s2.ptr, s->ptr + start_idx, actual_len);
	s2.ptr[actual_len] = '\0';
	s2.len = actual_len;

>>>>>>> f115cdc (all tasks done)
	return s2;
}

// Hint: you can create temporary string object!
int
str_replace(str *s, char *substr, char *replacement)
{
	assert(s && substr && replacement);
<<<<<<< HEAD
	// <YOURCODE>
	return 0;
=======
	
	int count = 0;
	int substr_len = strlen(substr);
	int repl_len = strlen(replacement);

	str tmp;
	str_init(&tmp);

	int i = 0;
	while (i < s->len) {
		int pos = str_find(s, substr);
		if (pos == -1) {
			str_append_n(&tmp, s->ptr + i, s->len - i);
			break;
		}

		if (pos > 0) {
			str_append_n(&tmp, s->ptr, pos);
		}

		str_append(&tmp, replacement);
		count++;

		int skip = pos + substr_len;
		memmove(s->ptr, s->ptr + skip, s->len - skip + 1);
		s->len -= skip;
		i = 0;
	}

	str_set(s, tmp.ptr);
	str_deinit(&tmp);

	return count;
>>>>>>> f115cdc (all tasks done)
}