using System.Collections.Generic;

using System.Diagnostics.Contracts;

using System.Linq;

using ReClassNET.Extensions;

using ReClassNET.Util;

namespace ReClassNET.Nodes

{

public class ClassUtil

{

internal static IEnumerable<ClassNode> Classes;

public static bool IsCycleFree(ClassNode parent, ClassNode check)

{

Contract.Requires(parent != null);

Contract.Requires(check != null);

if (Classes == null)

{

return true;

}

return IsCycleFree(parent, check, Classes);

}

public static bool IsCycleFree(ClassNode parent, ClassNode check, IEnumerable<ClassNode> classes)

{

Contract.Requires(parent != null);

Contract.Requires(check != null);

Contract.Requires(classes != null);

Contract.Requires(Contract.ForAll(classes, c => c != null));

var toCheck = new HashSet<ClassNode>(

check.Yield()

.Traverse(

c => c.Nodes

.Where(n => n is ClassInstanceNode || n is ClassInstanceArrayNode)

.Select(n => ((BaseReferenceNode)n).InnerNode)

)

);

return IsCycleFree(parent, toCheck, classes);

}

private static bool IsCycleFree(ClassNode root, HashSet<ClassNode> seen, IEnumerable<ClassNode> classes)

{

Contract.Requires(root != null);

Contract.Requires(seen != null);

Contract.Requires(Contract.ForAll(seen, c => c != null));

Contract.Requires(Contract.ForAll(classes, c => c != null));

if (!seen.Add(root))

{

return false;

}

var classNodes = classes as IList<ClassNode> ?? classes.ToList();

foreach (var cls in classNodes/*.Except(seen)*/)

{

if (cls.Nodes

.OfType<BaseReferenceNode>()

.Where(n => n is ClassInstanceNode || n is ClassInstanceArrayNode)

.Any(n => n.InnerNode == root))

{

if (!IsCycleFree(cls, seen, classNodes))

{

return false;

}

}

}

return true;

}

}

}