using System;
using System.Collections.Generic;
using System.Linq;
using CppSharp;
using CppSharp.AST;
using CppSharp.AST.Extensions;
using CppSharp.Passes;

namespace Test.Passes
{
    /// <summary>
    /// All nested classses set unnested.
    /// </summary>
    public class SetNestedClassesNotNested : TranslationUnitPass
    {
        private List<Class> nestedClassesToMove;

        public SetNestedClassesNotNested()
            => VisitOptions.ResetFlags(VisitFlags.ClassProperties);


        public override bool VisitClassDecl(Class @class)
        {
            if (!(@class.Namespace is Namespace))
                nestedClassesToMove.Add(@class);

            return base.VisitClassDecl(@class);
        }


        public override bool VisitTranslationUnit(TranslationUnit unit)
        {
            nestedClassesToMove = new List<Class>();
            if (!base.VisitTranslationUnit(unit)) return false;

            foreach (var @class in nestedClassesToMove)
            {
                Diagnostics.Message($"Nested class moved to base location. {@class.GetType().Name}, {@class.TranslationUnit?.FileName}, {@class.QualifiedOriginalName}.");

                var parent = @class.Namespace;
                @class.Namespace = GetNamespace(@class);
                @class.Namespace.Declarations.Add(@class);
                parent.Declarations.Remove(@class);
            }
            return true;
        }

        private Namespace GetNamespace(Declaration declaration)
        {
            var @namespace = declaration.Namespace;

            while (!(@namespace is Namespace))
            {
                @namespace = @namespace.Namespace;
                if (@namespace == null) return null;
            }
            return (Namespace)@namespace;
        }

    }
}