using Annulus;
using Azimuth;
using System;
using System.Collections.Generic;

namespace Glass.Testbed
{
    /// <summary>
    /// A ResizablePanel anyone can drag by its edges or corners, with a live readout of its current size, next to one
    /// that can also be moved by dragging its title strip.
    /// </summary>
    public class ResizablePanelTestCase : TestCase
    {
        /// <summary>
        /// A ResizablePanel whose drag handle is its title strip child.
        /// </summary>
        private sealed class TitledPanel : ResizablePanel
        {
            public Control TitleStrip { get; set; }

            public override bool IsDragHandle(Vector position)
            {
                return TitleStrip != null && TitleStrip.Bounds.ContainsPoint(position - CanvasOrigin);
            }
        }

        private const int StageHeight = 320;
        private const int TitleHeight = 28;
        private static readonly Vector InitialOffset = new Vector(40, 40);
        private static readonly Vector InitialSize = new Vector(200, 150);
        private static readonly Vector MovableOffset = new Vector(300, 40);
        private static readonly Vector MinSize = new Vector(80, 60);

        private ResizablePanel resizable;
        private TextMaterial sizeReadoutMaterial;
        private TitledPanel movable;
        private Panel titleLabel;

        public ResizablePanelTestCase(string name) : base(name) { }

        protected override void Populate()
        {
            AddCaption("Drag the edges or corners to resize; MinSize keeps it from collapsing to nothing");
            AddCaption("Drag the blue title strip to move the right-hand panel; a click brings a panel to the front");

            Rect stage = ContentAggregator.NewRow(StageHeight);

            resizable = NewChild<ResizablePanel>("resizable");
            resizable.Material = UiPacksheetMaterials.GreenFlatPanel;
            resizable.MinSize = MinSize;
            resizable.ResizeCursors = ResizeCursorMaterials.ByZone;
            resizable.MoveToFrontOnClick = true;
            resizable.Bounds = Rect.FromPositionAndSize(stage.TopLeft + InitialOffset, InitialSize);

            sizeReadoutMaterial = Widgets.FieldText("");
            var sizeReadout = resizable.CanvasChildren.NewChild<Panel>("size readout");
            sizeReadout.Material = sizeReadoutMaterial;
            sizeReadout.Bounds = Rect.FromPositionAndSize(Vector.Zero, new Vector(160, 40));

            movable = NewChild<TitledPanel>("movable");
            movable.Material = UiPacksheetMaterials.GreenFlatPanel;
            movable.MinSize = MinSize;
            movable.ResizeCursors = ResizeCursorMaterials.ByZone;
            movable.MoveToFrontOnClick = true;
            movable.Bounds = Rect.FromPositionAndSize(stage.TopLeft + MovableOffset, InitialSize);

            var titleStrip = movable.CanvasChildren.NewChild<Panel>("title strip");
            titleStrip.Material = UiPacksheetMaterials.BlueFlatPanel;
            movable.TitleStrip = titleStrip;

            titleLabel = titleStrip.CanvasChildren.NewChild<Panel>("title label");
            titleLabel.Material = Widgets.SmallCaption("Drag here to move");

            resizable.OnResized += _ => UpdateSizeReadout();
            movable.OnResized += _ => LayOutTitleStrip();

            UpdateSizeReadout();
            LayOutTitleStrip();
        }

        private void UpdateSizeReadout()
        {
            sizeReadoutMaterial.Text = $"{resizable.Bounds.Size.X:F0} x {resizable.Bounds.Size.Y:F0}";
        }

        private void LayOutTitleStrip()
        {
            movable.TitleStrip.Bounds = Rect.FromPositionAndSize(
                Vector.Zero, new Vector(movable.CanvasLayout.CanvasRect.Width, TitleHeight));
            titleLabel.Bounds = movable.TitleStrip.CanvasLayout.CanvasRect;
        }
    }
}