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

namespace Glass.Testbed
{
    /// <summary>
    /// A guided tour whose spotlight the user can move or dismiss, so it needs a Setup to put itself back.
    /// </summary>
    public class SpotlightTestCase : TestCase
    {
        /// <summary>
        /// Sits below whatever it is a child of, which under a Spotlight is the highlighted control.
        /// </summary>
        private class CoachMark : Panel
        {
            public Vector Offset { get; set; }

            public override void Update(TimeSpan elapsed, UpdateState state)
            {
                base.Update(elapsed, state);

                Bounds = Rect.FromPositionAndSize(
                    new Vector(0, state.ParentClientRect.Height) + Offset, Bounds.Size);
            }
        }

        private static readonly Vector ButtonSize = new Vector(190, 56);
        private static readonly Vector CoachButtonSize = new Vector(140, 44);

        private readonly List<Button> targets = new List<Button>();
        private readonly Spotlight spotlight;
        private readonly TextMaterial coachLabel;
        private int step;

        public SpotlightTestCase(string name) : base(name)
        {
            spotlight = new Spotlight(new SolidColorMaterial
            {
                Color = System.Drawing.Color.FromArgb(170, 0, 0, 0),
            })
            {
                DebugName = "spotlight",
            };

            coachLabel = Widgets.ButtonLabel("Click");
        }

        /// <summary>
        /// Re-parenting is the whole move: nothing else tells the spotlight where its new target sits.
        /// </summary>
        private void MoveSpotlightTo(int target)
        {
            targets[step].ChildControls.Remove(spotlight);
            step = target;
            targets[step].ChildControls.Add(spotlight);
            coachLabel.Text = $"Click {targets[step].DebugName}";
        }

        private void BuildTargets()
        {
            Rect buttonRow = ContentAggregator.NewRow(ButtonSize.Y);

            foreach (string name in new[] { "Build", "Attack", "Harvest" })
            {
                string buttonName = name;
                int clicks = 0;
                TextMaterial label = Widgets.ButtonLabel($"{buttonName}: 0");

                Button target = new Panel { Material = label }.FillParent(new Button
                {
                    DebugName = buttonName,
                    ButtonMaterial = UiPacksheetMaterials.Button,
                    Bounds = buttonRow.NewCol(ButtonSize.X, margin: Gutter),
                });

                target.OnClick += delegate (in MouseState _, MouseButtonFlags __)
                {
                    ++clicks;
                    label.Text = $"{buttonName}: {clicks}";
                };

                Add(target);
                targets.Add(target);
            }
        }

        private void BuildCoachMark()
        {
            Panel coachText = coachLabel.BuildControl(Constraints.Unbounded);

            // Laid out before the mark exists, so the mark can be sized to what it ends up holding rather than to a
            // guess that has to stay in step with it.  The button row sets the width, and the label centres across it.
            var content = new RectAggregator(
                Rect.FromPositionAndSize(Vector.Zero, new Vector(2 * CoachButtonSize.X + Gutter, 0)),
                new Vector(0, Gutter));

            coachText.Bounds = content.NewRow(coachText.Bounds.Height);
            Rect coachButtonRow = content.NewRow(CoachButtonSize.Y);

            Button next = new Panel { Material = Widgets.ButtonLabel("Next") }.FillParent(new Button
            {
                DebugName = "next step",
                ButtonMaterial = UiPacksheetMaterials.Button,
                Bounds = coachButtonRow.NewCol(CoachButtonSize.X, margin: Gutter),
            });

            Button done = new Panel { Material = Widgets.ButtonLabel("Done") }.FillParent(new Button
            {
                DebugName = "done",
                ButtonMaterial = UiPacksheetMaterials.Button,
                Bounds = coachButtonRow.NewCol(CoachButtonSize.X),
            });

            var coachMark = new CoachMark
            {
                DebugName = "coach mark",
                Material = UiPacksheetMaterials.YellowPanel,
                Bounds = Rect.FromPositionAndSize(
                    Vector.Zero, UiPacksheetMaterials.YellowPanel.BoundsFor(content.Rect).Size),
                Offset = new Vector(0, Gutter),
            };
            spotlight.ChildControls.Add(coachMark);

            coachMark.ChildControls.Add(coachText);
            coachMark.ChildControls.Add(next);
            coachMark.ChildControls.Add(done);

            next.OnClick += delegate (in MouseState _, MouseButtonFlags __)
            {
                MoveSpotlightTo((step + 1) % targets.Count);
            };

            done.OnClick += delegate (in MouseState _, MouseButtonFlags __)
            {
                targets[step].ChildControls.Remove(spotlight);
            };
        }

        protected override void Populate()
        {
            AddCaption("Everything dims but the highlighted button, which still takes its clicks");
            AddCaption("Modal means the tab strip is blocked too — Done releases it");

            BuildTargets();
            BuildCoachMark();
        }

        /// <summary>
        /// Cases are built once, so a tour the user left part way through or dismissed restarts here.
        /// </summary>
        protected override void Setup()
        {
            MoveSpotlightTo(0);
        }
    }
}