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

#include "libstring.h"

struct string *string_create(char *s)
{
    if (!s)
    {
        struct string *r = calloc(1, sizeof(struct string));
        char *data = calloc((BASE_STRING_SIZE + 1), sizeof(char));
        if (!r || !data)
        {
            fprintf(stderr, "string_create: calloc failed.\n");
            return NULL;
        }
        r->data = data;
        r->capacity = BASE_STRING_SIZE;
        return r;
    }

    struct string *str = malloc(1 * sizeof(struct string));
    if (!str)
    {
        fprintf(stderr, "string_create: malloc failed.\n");
        return NULL;
    }

    // Align the capacity on the string base size
    size_t l = strlen(s);
    size_t m = (l + 1) % BASE_STRING_SIZE;
    str->length = l;
    str->capacity = (l + 1) + (BASE_STRING_SIZE - m);
    str->data = calloc(str->capacity, sizeof(char));
    if (!str->data)
    {
        fprintf(stderr, "string_create: malloc failed.\n");
        return NULL;
    }
    memcpy(str->data, s, l);

    return str;
}

void string_free(struct string *str)
{
    if (str)
    {
        free(str->data);
        free(str);
    }
}

static bool _resize_string(struct string *str, int p)
{
    char *new_data = realloc(
        str->data, ((p >= 0) ? str->capacity * 2 : str->capacity / 2) + 1);
    if (!new_data)
    {
        fprintf(stderr, "_resize_string: realloc failed.\n");
        return false;
    }

    str->data = new_data;
    str->capacity = ((p >= 0) ? str->capacity * 2 : str->capacity / 2);
    return true;
}

bool string_pushc(struct string *str, char c)
{
    if (str->length == str->capacity)
    {
        if (!_resize_string(str, 1))
        {
            return false;
        }
    }
    str->data[str->length] = c;
    str->length++;
    str->data[str->length] = 0;
    return true;
}

bool string_pushstr(struct string *str, char *s)
{
    if (!s || !s[0])
    {
        return true;
    }
    size_t l = strlen(s);
    while (str->length + l >= str->capacity)
    {
        if (!_resize_string(str, 1))
        {
            return false;
        }
    }

    memcpy(str->data + str->length, s, l);
    str->length += l;
    str->data[str->length] = 0;
    return true;
}

bool string_catenate(struct string *dst, struct string *src)
{
    if (!src)
    {
        return true;
    }

    if (!dst || !string_pushstr(dst, src->data))
    {
        return false;
    }

    string_free(src);
    return true;
}

struct string *string_deepcopy(struct string *str)
{
    return string_create(str->data);
}