// vim:fileencoding=utf-8:foldmethod=marker

#include "stream.h"
#include "../../common/aliases/aliases.h"
#include "../../common/assert/assert.h"

void _streamValidate(const WpStream *stream, u64 item_size);

b8 _streamAtEnd(const WpStream *stream, u64 item_size) {
	_streamValidate(stream, item_size);
	return stream->position >= stream->count;
}

b8 _streamHasNext(const WpStream *stream, u64 item_size) {
	_streamValidate(stream, item_size);
	return stream->position + 1 < stream->count;
}

void *_streamPeek(const WpStream *stream, u64 item_size) {
	if (_streamHasNext(stream, item_size)) {
		u64 index = (stream->position + 1) * stream->item_size;
		return (void *)(&((u8 *)(stream->data))[index]);
	}

	return NULL;
}

void *_streamConsume(WpStream *stream, u64 item_size) {
	if (!_streamAtEnd(stream, item_size)) {
		u64 index = stream->position++ * stream->item_size;
		return (void *)(&((u8 *)(stream->data))[index]);
	}

	return NULL;
}

void _streamValidate(const WpStream *stream, u64 item_size) {
	wpDebugAssert(stream != NULL, "`stream` should not be NULL");
	wpRuntimeAssert(stream->item_size == item_size, "Invalid item type provided");
}