using System.Drawing;

namespace System.Windows.Forms
{
    public partial class ContainerControl : Control
    {
        protected System.Windows.Controls.ScrollViewer scrollViewer { get; private set; }

        protected System.Windows.Controls.Panel container { get; private set; }

        public AutoScaleMode AutoScaleMode { get; set; }

        public SizeF AutoScaleDimensions { get; set; }

        public bool AutoScroll
        {
            get => scrollViewer.HorizontalScrollBarVisibility == Windows.Controls.ScrollBarVisibility.Auto;
            set
            {
                scrollViewer.HorizontalScrollBarVisibility = scrollViewer.VerticalScrollBarVisibility = value ? Windows.Controls.ScrollBarVisibility.Auto : Windows.Controls.ScrollBarVisibility.Disabled;
                if (value)
                {
                    scrollViewer.Content = container;
                    (control as System.Windows.Controls.ContentControl).Content = scrollViewer;
                    scrollViewer.ScrollChanged += (s, e) => OnScroll(new ScrollEventArgs(ScrollEventType.EndScroll, 0));
                }
            }
        }

        // do not set WPF Padding for container controls. It has different behaviour compared to WinForms
        private Padding padding;
        public override Padding Padding 
        {
            get => padding;
            set
            {
                padding = value;
                UpdateLayout();
            }
        }

        public event ScrollEventHandler Scroll;

        protected override void ScaleCore(float dx, float dy)
        {
            base.ScaleCore(dx, dy);
            ScaleInternals(dx, dy);
        }

        internal void ScaleInternals(float dx, float dy)
        {
            AutoScaleDimensions = new Drawing.SizeF(AutoScaleDimensions.Width * dx, AutoScaleDimensions.Height * dy);
            Padding = new Padding((int)(Padding.Left * dx), (int)(Padding.Top * dy), (int)(Padding.Right * dx), (int)(Padding.Bottom * dy));
            DefaultPadding = new Padding((int)(DefaultPadding.Left * dx), (int)(DefaultPadding.Top * dy), (int)(DefaultPadding.Right * dx), (int)(DefaultPadding.Bottom * dy));
        }

        protected virtual void OnScroll(ScrollEventArgs e) => Scroll?.Invoke(this, e);

        internal override void AddChild(Control child)
        {
            // mimic winforms behavior: add actually inserts a child at the beginning of the list
            container.Children.Insert(0, child.control);
        }

        internal override void RemoveChild(Control child)
        {
            container.Children.Remove(child.control);
        }

        internal override void SetChildIndex(Control child, int index)
        {
            container.Children.Insert(container.Children.Count - index, child.control);
        }

        protected void SetContentControl(System.Windows.Controls.ContentControl control) => SetContentControl(control, control);
        protected void SetContentControl(System.Windows.Controls.Control control, System.Windows.Controls.ContentControl contentControl) => 
            SetContentControl(control, contentControl, new System.Windows.Controls.Grid());
        protected void SetContentControl(System.Windows.Controls.Control control, System.Windows.Controls.ContentControl contentControl, System.Windows.Controls.Panel container)
        {
            this.container = container;
            container.FlowDirection = FlowDirection.LeftToRight;
            scrollViewer = new();
            scrollViewer.FocusVisualStyle = null;
            contentControl.Content = container;
            SetControl(control);
            container.Tag = this;
        }

        internal override void AfterDpiChange(float rescale)
        {
            ScaleInternals(rescale, rescale);
            base.AfterDpiChange(rescale);
        }

        public ContainerControl()
        {
            SetContentControl(new OwnerDrawControl(this));
        }
    }
}