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

namespace Glass.Testbed.TestCases.Rendering
{
    /// <summary>
    /// Switches who draws the mouse cursor, so the three answers can be compared against each other live.
    /// </summary>
    public class CursorTestCase : TestCase
    {
        private readonly World world;
        private readonly Dictionary<CursorMode, Button> buttons = new Dictionary<CursorMode, Button>();

        public CursorTestCase(World world)
        {
            this.world = world;
        }

        /// <summary>
        /// Stands in for a radio group: the chosen mode wears yellow.
        /// </summary>
        private void ShowChoice()
        {
            foreach (KeyValuePair<CursorMode, Button> button in buttons)
            {
                button.Value.ButtonMaterial = button.Key == world.CursorMode
                    ? UiPacksheetMaterials.YellowButton
                    : UiPacksheetMaterials.Button;
            }
        }

        // The row is consumed a column at a time, so it has to be the caller's rect rather than a copy of it.
        private void AddChoice(ref Rect row, CursorMode mode, string label, Vector buttonSize)
        {
            CursorMode chooseMe = mode;

            Button choice = new Label(Widgets.ButtonLabelStyle, label).FillParent(new Button(ButtonBehavior.Default)
            {
                DebugName = $"{mode} cursor",
                ButtonMaterial = UiPacksheetMaterials.Button,
                Bounds = row.NewCol(buttonSize.X, margin: Gutter),
            });

            choice.OnActivate += delegate (ButtonBase _, in KeyboardSnapshot __, KeyboardManager ___)
            {
                world.CursorMode = chooseMe;
                ShowChoice();
            };

            Add(choice);
            buttons[mode] = choice;
        }

        protected override void Populate()
        {
            AddCaption("System leaves the pointer alone; hardware hands the art to the OS; software draws it here");
            AddCaption("Software lands last in the frame, so nothing can cover it, but it trails by a tick");

            // Every button shares the widest label's size, so switching modes never reflows the row.
            Vector buttonSize = Vector.Max(
                Widgets.ButtonLabel("System").PreferredSize(Constraints.Unbounded),
                Widgets.ButtonLabel("Hardware").PreferredSize(Constraints.Unbounded),
                Widgets.ButtonLabel("Software").PreferredSize(Constraints.Unbounded));

            Rect row = ContentAggregator.NewRow(buttonSize.Y);

            AddChoice(ref row, CursorMode.System, "System", buttonSize);
            AddChoice(ref row, CursorMode.Hardware, "Hardware", buttonSize);
            AddChoice(ref row, CursorMode.Software, "Software", buttonSize);
        }

        /// <summary>
        /// The mode outlives the case being hidden, so the buttons are re-marked rather than reset.
        /// </summary>
        protected override void Setup()
        {
            ShowChoice();
        }
    }
}