#include <assert.h>

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

#include "vector.h"
#include "util.h"

#define VECTOR_START_SIZE	8
#define VECTOR_GROW_FACTOR	2
#define ITEMSZ sizeof(int)

void
vector_init(ivector *v)
{
	assert(v);

	v->n = 0;
	v->maxsz = VECTOR_START_SIZE;
	v->data = xmalloc(ITEMSZ * VECTOR_START_SIZE);
}

void
vector_initdata(ivector *v, int *arr, size_t arrsz)
{
	assert(v && arrsz);
	v->n = arrsz;
	v->maxsz = (arrsz > VECTOR_START_SIZE) ? arrsz : VECTOR_START_SIZE;
	v->data = xmalloc(ITEMSZ * v->maxsz);
	memcpy(v->data, arr, arrsz * ITEMSZ);
}

void
vector_free(ivector *v)
{
	assert(v);

	v->n = 0;
	v->maxsz = 0;
	xfree(v->data);
	v->data = NULL;
}

size_t
vector_len(const ivector *v)
{
	assert(v);
	return v->n;
}

int *
vector_data(const ivector *v)
{
	assert(v);
	return v->data;
}

void
vector_resize(ivector *v, int n)
{
	assert(v);
	if (n <= v->maxsz) {
		if (n > v->n) {
			memset(v->data + v->n, 0, (n - v->n) * ITEMSZ);
		}
		v->n = n;
	} else {
		size_t new_max = v->maxsz;
		while (new_max < n) {
			new_max *= VECTOR_GROW_FACTOR;
		}
		v->data = xrealloc(v->data, new_max * ITEMSZ);
		if (n > v->n) {
			memset(v->data + v->n, 0, (n - v->n) * ITEMSZ);
		}
		v->n = n;
		v->maxsz = new_max;
	}
}

void
vector_set(ivector *v, size_t idx, int val)
{
	assert(v && idx < v->n);
	v->data[idx] = val;
}

int
vector_get(const ivector *v, size_t idx)
{
	assert(v && idx < v->n);
	return v->data[idx];
}

void
vector_push(ivector *v, int val)
{
	assert(v);
	if (v->n == v->maxsz) {
		vector_resize(v, v->n + 1);
		v->data[v->n - 1] = val;
	} else {
		v->data[v->n++] = val;
	}
}

void
vector_pop(ivector *v)
{
	assert(v);
	if (v->n > 0){
		v->n--;
	}
}

void
vector_insert(ivector *v, size_t idx, int val)
{
	assert(v && v->n >= idx);
	if (v->n == v->maxsz) {
		size_t new_max = v->maxsz * VECTOR_GROW_FACTOR;
		v->data = xrealloc(v->data, new_max * ITEMSZ);
		v->maxsz = new_max;
	}
	memmove(v->data + idx + 1, v->data + idx, (v->n - idx) * ITEMSZ);
	v->data[idx] = val;
	v->n++;
}

void
vector_del(ivector *v, size_t idx)
{
	assert(v && idx < v->n);
	memmove(v->data + idx, v->data + idx + 1, (v->n - idx - 1) * ITEMSZ);
	v->n--;
}

void
vector_clear(ivector *v)
{
	vector_resize(v, 0);
}