using System.Collections;
using System.Collections.Generic;

namespace System.Windows.Forms
{
    public partial class Control
    {
        public class ControlCollection : CollectionBase
        {
            private Control owner;

            public Control this[int index] => (Control)List[index];

            public int Add(Control control)
            {
                int index = IndexOf(control);
                if (index != -1)
                    return index;
                
                if (control.Parent != null)
                    control.Parent = null;

                var result = List.Add(control);
                owner.AddChild(control);
                control.SetParent(owner);
                if (control.Dock != DockStyle.None)
                    owner.UpdateLayout();
                owner.DoControlAdded(control);
                return result;
            }

            public void AddRange(Control[] controls)
            {
                foreach (Control c in controls)
                    Add(c);
            }

            public void Remove(Control control)
            {
                List.Remove(control);
                owner.RemoveChild(control);
                control.SetParent(null);
                if (control.Dock != DockStyle.None)
                    owner.UpdateLayout();
                owner.DoControlRemoved(control);
            }

            public new void RemoveAt(int index) => Remove(this[index]);

            public new void Clear()
            {
                while (Count > 0)
                    Remove(this[0]);
            }

            public int IndexOf(Control control) => List.IndexOf(control);

            public bool Contains(Control control) => List.Contains(control);

            public void SetChildIndex(Control control, int index)
            {
                List.Remove(control);
                List.Insert(index, control);
                owner.RemoveChild(control);
                owner.SetChildIndex(control, index);
                control.SetParent(owner);
                if (control.Dock != DockStyle.None)
                    owner.UpdateLayout();
            }

            public void Insert(int index, Control control)
            {
                Add(control);
                SetChildIndex(control, index);
            }

            private void Find(string name, bool searchChildren, List<Control> result)
            {
                foreach (Control c in List)
                {
                    if (c.Name == name)
                        result.Add(c);
                    if (searchChildren)
                        c.Controls.Find(name, searchChildren, result);
                }
            }

            public Control[] Find(string name, bool searchChildren)
            {
                List<Control> result = new List<Control>();
                Find(name, searchChildren, result);
                return result.ToArray();
            }

            public ControlCollection(Control owner)
            {
                this.owner = owner;
            }
        }

    }
}