// Copyright Epic Games, Inc. All Rights Reserved.

#include <stdarg.h>
#include <zencore/memory.h>
#include <zencore/stream.h>
#include <zencore/testing.h>

#include <algorithm>
#include <stdexcept>

namespace zen {

MemoryInStream::MemoryInStream(const void* buffer, size_t size)
: m_Buffer(reinterpret_cast<const uint8_t*>(buffer), reinterpret_cast<const uint8_t*>(buffer) + size)
{
}

void
MemoryInStream::Read(void* buffer, size_t byteCount, uint64_t offset)
{
	RwLock::ExclusiveLockScope _(m_Lock);

	const size_t needEnd = offset + byteCount;

	if (needEnd > m_Buffer.size())
		throw std::runtime_error("read past end of file!");	 // TODO: better exception

	memcpy(buffer, m_Buffer.data() + offset, byteCount);
}

void
MemoryOutStream::Write(const void* data, size_t byteCount, uint64_t offset)
{
	RwLock::ExclusiveLockScope _(m_Lock);

	const size_t needEnd = offset + byteCount;

	if (needEnd > m_Buffer.size())
		m_Buffer.resize(needEnd);

	memcpy(m_Buffer.data() + offset, data, byteCount);
}

void
MemoryOutStream::Flush()
{
	// No-op
}

//////////////////////////////////////////////////////////////////////////
//
// Testing related code follows...
//

#if ZEN_WITH_TESTS

void
stream_forcelink()
{
}

#endif

}  // namespace zen