using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;

   namespace Console472
{
    class Program
    {
        static void Main(string[] args)
        {
            var treeData = new GroupedTreeBranches()
            {
                DiscountGroup = new List<DiscountGroup>()
                {
                    new DiscountGroup
                    {
                        Name = "DG1",
                        ID = 1
                    },
                    new DiscountGroup
                    {
                        Name = "DG2",
                        ID = 2
                    },
                    new DiscountGroup
                    {
                        Name = "DG3",
                        ID = 3
                    }
                },
                SubGroup = new List<SubGroup>()
                {
                    new SubGroup
                    {
                        Name = "SG 1",
                        ID = 200,
                        Parent = new DiscountGroup(){ID = 1, Name = "DG1"}
                    },
                    new SubGroup
                    {
                        Name = "SG 2",
                        ID = 201,
                        Parent = new DiscountGroup(){ID = 1, Name = "DG1"}
                    },
                    new SubGroup
                    {
                        Name = "SG 3",
                        ID = 202,
                        Parent = new DiscountGroup(){ID = 2, Name = "DG2"}
                    },
                    new SubGroup
                    {
                        Name = "SG 4",
                        ID = 203,
                        Parent = new DiscountGroup(){ID = 2, Name = "DG2"}
                    }
                },
                PriceIntervals = new List<PriceIntervals>()
                {
                    new PriceIntervals
                    {
                        Name = "Price 1",
                        ID = 100,
                        Parent = new DiscountGroup { ID = 1, Name = "DG1"}
                    },
                    new PriceIntervals
                    {
                        Name = "Price 2",
                        Parent = new DiscountGroup { ID = 1, Name = "DG1"}
                    },
                    new PriceIntervals
                    {
                        Name = "Price 2",
                        ID = 101,
                        Parent = new DiscountGroup { ID = 2, Name = "DG2"}
                    },
                },
                Rotation = new List<Rotation>()
                {
                    new Rotation
                    {
                        Name = "Rot 1",
                        ID = 20,
                        Parent = new DiscountGroup(){ID = 200,  Name = "SG 1"},
                    },
                    new Rotation
                    {
                        Name = "Rot 2",
                        ID = 21,
                        Parent = new SubGroup(){ID = 200,  Name = "SG 1"},
                    },
                    new Rotation
                    {
                        Name = "Rot 3",
                        ID = 22,
                        Parent = new SubGroup(){ID = 201,  Name = "SG 2"},
                    },
                    new Rotation
                    {
                        Name = "Rot 4",
                        ID = 23,
                        Parent = new SubGroup(){ID = 201,  Name = "SG 2"},
                    },
                }
            };

            var tn = new TreeNode();

            foreach (var item in treeData.DiscountGroup)
            {
                tn.AddChild(item);

                var sg = treeData.SubGroup.Where(w => w.Parent.Name == item.Name);
                Each(sg, a => item.AddChild(a));

                var pi = treeData.PriceIntervals.Where(w => w.Parent.Name == item.Name);
                Each(pi, a => item.AddChild(a));

                foreach (var item2 in item.Children.Where(w => w.GetType() == typeof(SubGroup)))
                {
                    var rot = treeData.Rotation.Where(w => w.Parent.GetType() == typeof(SubGroup) && w.Parent.Name == item2.Name);
                    Each(rot, a => item2.AddChild(a));
                }

                if(item.Name == "SG 1")
                {
                    var last = treeData.Rotation.Where(w => w.Name == "Rot 1").SingleOrDefault();
                    item.AddChild(last);
                }
            }


            Console.ReadKey();
        }

        private static void Each<T>(IEnumerable<T> items, Action<T> action)
        {
            foreach (var item in items)
            {
                action(item);
            }
        }
    }

    public class TreeNode : ITreeNode
    {
        public ObservableCollection<ITreeNode> Children { get; set; }
        public string Name { get; set; }
        public ITreeNode Parent { get; set; }

        public TreeNode()
        {
            Children = new ObservableCollection<ITreeNode>();
        }

        public void AddChild(ITreeNode child)
        {
            Children.Add(child);
        }

        public void RemoveChild(ITreeNode child)
        {
            Children.Remove(child);
        }
    }

    public class DiscountGroup : TreeNode
    {
        public int ID { get; set; }
    }

    public class Rotation : TreeNode
    {
        public int ID { get; set; }
    }

    public class PriceIntervals : TreeNode
    {
        public int ID { get; set; }
    }

    public class SubGroup : TreeNode
    {
        public int ID { get; set; }
    }

    public class GroupedTreeBranches
    {
        public IEnumerable<DiscountGroup> DiscountGroup { get; set; }
        public IEnumerable<Rotation> Rotation { get; set; }
        public IEnumerable<PriceIntervals> PriceIntervals { get; set; }
        public IEnumerable<SubGroup> SubGroup { get; set; }
    }

    public interface ITreeNode
    {
        ObservableCollection<ITreeNode> Children { get; set; }
        string Name { get; set; }
        ITreeNode Parent { get; set; }
        void AddChild(ITreeNode child);
        void RemoveChild(ITreeNode child);
    }
}