#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include "finalize.h"
#include "str.h"

enum
{
    MIN_CAPACITY = 8
};

void
releaseStr(const struct Str *str)
{
    free((char *)(uintptr_t)str->cstr);
}

void
clearStr(struct Str *str)
{
    if (str->capacity == 0) {
        str->end = str->cstr = malloc(MIN_CAPACITY);
        if (!str->cstr) {
            fprintf(stderr, "clearStr: out of memory\n");
            finalizeExit(1);
        }
        str->capacity = MIN_CAPACITY;
    }
    *(str->end = str->cstr) = 0;
}

void
appendCharToStr(struct Str *str, char c)
{
    size_t len = str->end - str->cstr; // length without terminating 0

    // check if another character and 0 byte fits into string
    if (len + 2 > str->capacity) {
        str->capacity = len + 2;
        if (str->capacity < MIN_CAPACITY) {
            str->capacity = MIN_CAPACITY;
        } else {
            str->capacity *= 2;
        }
        str->cstr = realloc(str->cstr, str->capacity);
        if (!str->cstr) {
            fprintf(stderr, "appendCharToStr: out of memory\n");
            finalizeExit(1);
        }
        str->end = str->cstr + len;
    }

    *str->end++ = c;
    *str->end = 0;
}