#include "vector.h"
#include <stdio.h>
#include <stddef.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#define DEFAULT_INITIAL_ALLOCATION 10

void VectorNew(vector *v, int elemSize, VectorFreeFunction freefn, int initialAllocation) {
	assert(v!=NULL);
	assert(elemSize > 0);
	if(initialAllocation <= 0 )
		initialAllocation = DEFAULT_INITIAL_ALLOCATION;
	v->buffer = malloc(elemSize * initialAllocation);
	if(v->buffer == NULL) {
		fprintf(stderr, "malloc failed for vector");
		exit(EXIT_FAILURE);
	}
	v->capacity = initialAllocation;
	v->count = 0;
	v->freefn = freefn;
	v->elemSize = elemSize;
}

//TODO make this work
void VectorDispose(vector *v) {
	/*begin Vector sanity check*/
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/*end vector sanity check */
	if(v->freefn != NULL) {
		int i;
		for(i=0 ; i<v->count ; i++) {
			(*v->freefn)(VectorNth(v, i));
		}
	}
	printf("Made it through the loop\n");
	v->count = -1;
	v->elemSize = -1;
	v->capacity = -1;
	v->freefn = NULL;
	free(v->buffer);
}

int VectorLength(const vector *v) {
	/*begin Vector sanity check*/
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/*end vector sanity check */
	return v->count;
}

void *VectorNth(const vector *v, int position) {
	/*begin vector sanity check*/
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/*end vector sanity check */
	assert(position >= 0 && position < v->count);
	void *retval = (void *)(((unsigned char *)v->buffer) + position * v->elemSize);
	return retval;
}

void VectorInsert(vector *v, const void *elemAddr, int position){
	/*begin vector sanity check*/
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/*end vector sanity check */
	assert(position > 0 && position <= v->count);
	assert(elemAddr != NULL);
	if(position == v->count) {
		VectorAppend(v, elemAddr);
		return;
	}
	if(v->count == v->capacity) {
		v->capacity *= 2;
		v->buffer = realloc(v->buffer, v->capacity * v->elemSize);
		if(v->buffer == NULL) {
			fprintf(stderr, "realloc failed for vector\n");
			exit(EXIT_FAILURE);
		}
	}
	void *insertPos = (void *)(((unsigned char *)v->buffer) + position * v->elemSize);
	memmove((void *)(((unsigned char *)insertPos) + v->elemSize), insertPos, v->elemSize * (v->count - position));
	memcpy(insertPos, elemAddr, v->elemSize);
	v->count++;
	
}

void VectorAppend(vector *v, const void *elemAddr){
	/*begin Vector sanity check*/
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/*end vector sanity check */
	assert(elemAddr != NULL);
	if(v->count == v->capacity) {
		//gotta resize the vector first
		v->capacity*=2;
		printf("Preparing to realloc\n");
		v->buffer = realloc(v->buffer, v->elemSize * v->capacity );
		if(v->buffer == NULL) {
			fprintf(stderr, "malloc failed for vector");
			exit(EXIT_FAILURE);
		}
	}
	void *insertPos = (void *)(((unsigned char *)v->buffer) + v->count * v->elemSize);
	memcpy(insertPos, elemAddr, v->elemSize);
	v->count++;
}

void VectorReplace(vector *v, const void *elemAddr, int position) {
	/* begin vector sanity check */
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/* end vector sanity check */
	assert(position >=0);
	assert(position <= v->count);
	assert(elemAddr != NULL);
	void *insertPos = (void *)(((unsigned char *)v->buffer) + position * v->elemSize);
	memcpy(insertPos, elemAddr, v->elemSize);
}

void VectorDelete(vector *v, int position) {
	/* begin vector sanity check */
	assert(v != NULL);
	assert(v->count >= 0);
	assert(v->elemSize > 0);
	assert(v->buffer != NULL);
	assert(v->capacity > 0);
	assert(v->count <= v->capacity);
	/* end vector sanity check */
	assert(position > 0 && position <= v->count);
	void *removalPos = VectorNth(v, position);
	if(v->freefn != NULL) {
		(*v->freefn)(removalPos);
	}
	memmove(removalPos, (void *)(((unsigned char *)removalPos)+v->elemSize), (--v->count - position) * v->elemSize );
}


int main(int argc, char **argv) {
	vector v;
	VectorNew(&v, sizeof(int), NULL, 0);
	int nums[50], i = 0;
	for(;i<50;i++) {
		nums[i] = i * 4;
		VectorAppend(&v, &nums[i]);
	}
	int replacement = 99;
	int rep2 = 456;
	VectorReplace(&v, &replacement, 6);
	
	for(i=0 ; i<VectorLength(&v); i++) {
		printf("%d:%d, ", i, *((int *)VectorNth(&v, i)) );
	}
	printf("\n");
	VectorInsert(&v, &rep2, 2);
	for(i=0 ; i<VectorLength(&v); i++) {
		printf("%d:%d, ", i, *((int *)VectorNth(&v, i)) );
	}
	printf("\n");
	VectorDelete(&v, 10);
	for(i=0 ; i<VectorLength(&v); i++) {
		printf("%d:%d, ", i, *((int *)VectorNth(&v, i)) );
	}	
	VectorDispose(&v);
	
	return EXIT_SUCCESS;
}