/*
 * dynamic-arr.c
 *
 *  Created on: Sep 3, 2011
 *      Author: Tiberiu
 */

#include <stdlib.h>
#include <memory.h>
#include <array.h>

void DynamicArrayCreate (uint32 ElemSize, DynamicArray* arr)
{
	// Create a simple array. Allocate 16 elems for start
	arr->ElemSize = ElemSize;
	arr->Size = 0;
	arr->Allocated = 0x10;
	arr->Data = kmalloc(0x10 * ElemSize);
}

void DynamicArrayPush (void* item, DynamicArray* arr)
{
	// Make sure we have enough space
	if (arr->Allocated <= arr->Size)
	{
		arr->Allocated += 0x10;
		arr->Data = kmrealloc(arr->Data, arr->Allocated * arr->ElemSize);
	}

	// Calculate the address of next item
	uint32 addr = (uint32)arr->Data + arr->Size * arr->ElemSize;

	// Copy data
	memcpy((void*)addr, item, arr->ElemSize);
	++arr->Size;
}

void DynamicArrayPop (DynamicArray* arr)
{
	// Decrease size
	--arr->Size;
}

void DynamicArrayInsert (void* item, uint32 index, DynamicArray* arr)
{
	// Make sure we have enough space
	if (arr->Allocated <= arr->Size)
	{
		arr->Allocated += 0x10;
		arr->Data = kmrealloc(arr->Data, arr->Allocated * arr->ElemSize);
	}

	// Move the data out of the way
	uint8* buffer = (uint8*) arr->Data;
	uint32 start = index * arr->ElemSize;
	uint32 end = arr->Size * arr->ElemSize;

	for (--end; end >= start; end--)
		buffer[end + arr->ElemSize] = buffer[end];

	// Insert item
	memcpy((void*)((uint32)arr->Data + start), item, arr->ElemSize);
	++ arr->Size;
}

void DynamicArrayRemove (uint32 index, DynamicArray* arr)
{
	uint8* buffer = (uint8*) arr->Data;
	uint32 start = index * arr->ElemSize;
	uint32 end = (arr->Size-1) * arr->ElemSize;

	for (; start < end; start++)
		buffer[start] = buffer[start + arr->ElemSize];

	-- arr->Size;
}

void DynamicArraySwap (uint32 a, uint32 b, DynamicArray* arr)
{
	uint8 temp, *buffer = (uint8*) arr->Data;
	uint32 addra = a * arr->ElemSize;
	uint32 addrb = b * arr->ElemSize;
	uint32 i;

	for (i = 0; i < arr->ElemSize; i++)
	{
		// Swap byte i from elem A with byte i from elem B
		temp = buffer[addra + i];
		buffer[addra + i] = buffer[addrb + i];
		buffer[addrb + i] = temp;
	}
}

void DynamicArrayDispose (DynamicArray* arr)
{
	// Free used data
	kfree(arr->Data);

	// Set everything to 0 so we don't attempt to add more items and stuff
	arr->Allocated = 0;
	arr->Size = 0;
	arr->ElemSize = 0;
}