#include "vector.h"

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

struct vector *vector_init(size_t n)
{
    struct vector *res = malloc(sizeof(struct vector));
    if (res == NULL)
    {
        return NULL;
    }

    res->size = 0;
    res->capacity = n;
    res->data = malloc(n * sizeof(int));
    if (res->data == NULL)
    {
        return NULL;
    }
    return res;
}

void vector_destroy(struct vector *v)
{
    if (v)
    {
        free(v->data);
        free(v);
    }
}

struct vector *vector_resize(struct vector *v, size_t n)
{
    if (!v)
    {
        return NULL;
    }
    if (n == v->capacity)
    {
        return v;
    }
    if (v)
    {
        int *tmp = realloc(v->data, n * sizeof(int));
        if (tmp == NULL)
        {
            return NULL;
        }
        v->data = tmp;

        if (n < v->size)
        {
            v->size = n;
        }
        v->capacity = n;
        return v;
    }
    return NULL;
}

struct vector *vector_append(struct vector *v, int elt)
{
    if (v == NULL)
    {
        return NULL;
    }

    if (v->size == v->capacity)
    {
        if (vector_resize(v, v->capacity * 2) == NULL)
        {
            return NULL;
        }
    }
    v->data[v->size] = elt;
    v->size++;
    return v;
}

void vector_print(const struct vector *v)
{
    if (v == NULL || v->size == 0)
    {
        printf("\n");
        return;
    }
    for (size_t i = 0; i < v->size - 1; i++)
    {
        printf("%d,", v->data[i]);
    }
    printf("%d\n", v->data[v->size - 1]);
}

struct vector *vector_reset(struct vector *v, size_t n)
{
    if (vector_resize(v, n) == NULL)
    {
        return NULL;
    }

    v->size = 0;
    return v;
}

struct vector *vector_insert(struct vector *v, size_t i, int elt)
{
    if (v == NULL || i > v->size)
        return NULL;
    if (i == v->size)
    {
        return vector_append(v, elt);
    }
    if (v->size == v->capacity)
    {
        if (vector_resize(v, v->capacity * 2) == NULL)
        {
            return NULL;
        }
    }
    for (size_t j = v->size; j > i; j--)
    {
        v->data[j] = v->data[j - 1];
    }
    v->size++;

    v->data[i] = elt;
    return v;
}

struct vector *vector_remove(struct vector *v, size_t i)
{
    if (v == NULL || v->size == 0 || i >= v->size)
    {
        return NULL;
    }
    for (size_t j = i; j < v->size - 1; j++)
    {
        v->data[j] = v->data[j + 1];
    }

    v->size--;

    if (v->size < v->capacity / 2)
    {
        if (vector_resize(v, v->capacity / 2) == NULL)
        {
            return NULL;
        }
    }
    return v;
}