using System;

using System.Collections.Generic;

using System.Text;

namespace UnityDataTools.FileSystem;

// An archive node is a file in an archive.

public struct ArchiveNode

{

public string Path;

public long Size;

public ArchiveNodeFlags Flags;

}

// Class used to open a Unity archive file (such as an AssetBundle).

public class UnityArchive : IDisposable

{

internal UnityArchiveHandle m_Handle;

Lazy<List<ArchiveNode>> m_Nodes;

public IReadOnlyList<ArchiveNode> Nodes => m_Nodes.Value.AsReadOnly();

internal UnityArchive()

{

m_Nodes = new Lazy<List<ArchiveNode>>(() => GetArchiveNodes());

}

List<ArchiveNode> GetArchiveNodes()

{

var r = DllWrapper.GetArchiveNodeCount(m_Handle, out var count);

UnityFileSystem.HandleErrors(r);

if (count == 0)

return null;

var nodes = new List<ArchiveNode>(count);

var path = new StringBuilder(512);

for (var i = 0; i < count; ++i)

{

DllWrapper.GetArchiveNode(m_Handle, i, path, path.Capacity, out var size, out var flags);

UnityFileSystem.HandleErrors(r);

nodes.Add(new ArchiveNode() { Path = path.ToString(), Size = size, Flags = flags });

}

return nodes;

}

public void Dispose()

{

if (m_Handle != null && !m_Handle.IsInvalid)

{

m_Handle.Dispose();

m_Nodes = new Lazy<List<ArchiveNode>>(() => GetArchiveNodes());

}

}

}