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

namespace Glass.Testbed.TestCases.Controls
{
    /// <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 with art a test case can set.
        /// </summary>
        private class ArtPanel : ResizablePanel
        {
            public new Material Material
            {
                get => base.Material;
                set => SetMaterial(value);
            }
        }

        /// <summary>
        /// A ResizablePanel whose drag handle is its title strip child.
        /// </summary>
        private sealed class TitledPanel : ArtPanel
        {
            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 ArtPanel resizable;
        private Label sizeReadout;
        private TitledPanel movable;
        private Label titleLabel;


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

            sizeReadout = new Label(Widgets.FieldTextStyle, "")
            {
                DebugName = "size readout",
                Bounds = Rect.FromPositionAndSize(Vector.Zero, new Vector(160, 40)),
            };
            resizable.CanvasChildren.Add(sizeReadout);

            movable = NewChild<TitledPanel>("movable");
            movable.Material = UiPacksheetMaterials.GreenFlatPanel;
            movable.MinSize = MinSize;
            movable.ResizeCursors = ResizeCursorMaterials.ByZone;
            movable.MoveCursor = CursorExtraMaterials.Move;
            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 = new Label(Widgets.SmallCaptionStyle, "Drag here to move") { DebugName = "title label" };
            titleStrip.CanvasChildren.Add(titleLabel);

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

            UpdateSizeReadout();
            LayOutTitleStrip();
        }

        private void UpdateSizeReadout()
        {
            sizeReadout.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;
        }
    }
}