AssetRipper.Primitives/VersionUtilities/UnityVersion.cs

namespace AssetRipper.VersionUtilities;

/// <summary>
/// A value type for holding Unity versions
/// </summary>
public readonly partial struct UnityVersion
{
	private const int majorOffset = 48;
	private const int minorOffset = 32;
	private const int buildOffset = 16;
	private const int typeOffset = 8;

	private const ulong byteMask = 0xFFUL;
	private const ulong ushortMask = 0xFFFFUL;

	private readonly ulong m_data;

	/// <summary>
	/// The first number in a Unity version string
	/// </summary>
	public ushort Major => unchecked((ushort)((m_data >> majorOffset) & ushortMask));

	/// <summary>
	/// The second number in a Unity version string
	/// </summary>
	public ushort Minor => unchecked((ushort)((m_data >> minorOffset) & ushortMask));

	/// <summary>
	/// The third number in a Unity version string
	/// </summary>
	public ushort Build => unchecked((ushort)((m_data >> buildOffset) & ushortMask));

	/// <summary>
	/// The letter in a Unity version string
	/// </summary>
	public UnityVersionType Type => (UnityVersionType)unchecked((byte)((m_data >> typeOffset) & byteMask));

	/// <summary>
	/// The last number in a Unity version string
	/// </summary>
	public byte TypeNumber => unchecked((byte)(m_data & byteMask));

	/// <summary>
	/// The minimum value this type can have
	/// </summary>
	public static UnityVersion MinVersion { get; } = new UnityVersion(0UL);

	/// <summary>
	/// The maximum value this type can have
	/// </summary>
	public static UnityVersion MaxVersion { get; } = new UnityVersion(ulong.MaxValue);

	/// <summary>
	/// Construct a new Unity version
	/// </summary>
	public UnityVersion(ushort major)
	{
		m_data = (ulong)major << majorOffset;
	}

	/// <summary>
	/// Construct a new Unity version
	/// </summary>
	public UnityVersion(ushort major, ushort minor)
	{
		m_data = ((ulong)major << majorOffset) | ((ulong)minor << minorOffset);
	}

	/// <summary>
	/// Construct a new Unity version
	/// </summary>
	public UnityVersion(ushort major, ushort minor, ushort build)
	{
		m_data = ((ulong)major << majorOffset) | ((ulong)minor << minorOffset) | ((ulong)build << buildOffset);
	}

	/// <summary>
	/// Construct a new Unity version
	/// </summary>
	public UnityVersion(ushort major, ushort minor, ushort build, UnityVersionType type)
	{
		m_data = ((ulong)major << majorOffset) | ((ulong)minor << minorOffset) | ((ulong)build << buildOffset)
			| ((ulong)type << typeOffset);
	}

	/// <summary>
	/// Construct a new Unity version
	/// </summary>
	public UnityVersion(ushort major, ushort minor, ushort build, UnityVersionType type, byte typeNumber)
	{
		m_data = ((ulong)major << majorOffset) | ((ulong)minor << minorOffset) | ((ulong)build << buildOffset)
			| ((ulong)type << typeOffset) | typeNumber;
	}

	private UnityVersion(ulong data)
	{
		m_data = data;
	}

	/// <summary>
	/// Converts this to its binary representation
	/// </summary>
	/// <returns>An unsigned long integer having the same bits as this</returns>
	public ulong GetBits() => m_data;

	/// <summary>
	/// Converts a binary representation into its respective version
	/// </summary>
	/// <param name="bits">An unsigned long integer having the relevant bits</param>
	/// <returns>A new Unity version with the cooresponding bits</returns>
	public static UnityVersion FromBits(ulong bits) => new UnityVersion(bits);
}