// 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 wpStreamAtEnd(const WpStream *stream) {
	return stream->position >= stream->count;
}

b8 _streamHasCount(const WpStream *stream, u64 count) {
	return stream->position + count <= stream->count;
}

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

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

	return NULL;
}

void *_streamConsumeCount(WpStream *stream, u64 count, u64 item_size) {
	_streamValidate(stream, item_size);

	if (_streamHasCount(stream, count)) {
		u64 index = stream->position * stream->item_size;
		stream->position += count;
		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");
}