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

namespace Glass.Testbed
{
    /// <summary>
    /// ProgressBars filling from each edge, driven together by a NumberField, each with a label split across the edge
    /// of the fill.  A slow sweep shows how a fill edge that falls between pixels looks.
    /// </summary>
    public class ProgressBarTestCase : TestCase
    {
        private static readonly Color DarkText = Color.FromArgb(24, 28, 34);

        private static readonly ProgressBarMaterial BarMaterial = new ProgressBarMaterial
        {
            Background = new SolidColorMaterial
            {
                Color = DarkText,
                BorderSize = new Rect.BorderSize { Top = 2, Bottom = 2, Left = 2, Right = 2 },
            },
            Empty = new SolidColorMaterial { Color = Color.FromArgb(190, 196, 206) },
            Fill = new SolidColorMaterial { Color = Color.FromArgb(40, 110, 200) },
        };

        private static readonly Material GoalMarker = new SolidColorMaterial { Color = Color.Orange };

        private static readonly NumberFieldMaterial FieldMaterial = new NumberFieldMaterial
        {
            Background = UiPacksheetMaterials.TextField,
            Label = Widgets.FieldText("") with { VerticalAlignment = Alignment.Vertical.Center },
            IncrementButton = UiPacksheetMaterials.ScrollBarUpArrow,
            DecrementButton = UiPacksheetMaterials.ScrollBarDownArrow,
        };

        private static readonly Vector HorizontalSize = new Vector(320, 32);
        private static readonly Vector VerticalSize = new Vector(72, 200);

        // Slow enough that the sweep's fill edge sits between pixels on most frames.
        private const double SweepPerSecond = 0.02;

        private readonly List<(ProgressBar Bar, TextMaterial EmptyLabel, TextMaterial FilledLabel)> drivenBars =
            new List<(ProgressBar Bar, TextMaterial EmptyLabel, TextMaterial FilledLabel)>();

        private NumberField field;
        private ProgressBar sweepBar;
        private double sweepProgress;

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

        private static TextMaterial Label(StringView text, Color color)
        {
            return Widgets.SmallCaption(text) with
            {
                TintColor = color,
                HorizontalAlignment = Alignment.Horizontal.Center,
                VerticalAlignment = Alignment.Vertical.Center,
            };
        }

        /// <summary>
        /// A bar with the same label in both parts: dark over the empty part, light over the fill.
        /// </summary>
        private static (ProgressBar Bar, TextMaterial EmptyLabel, TextMaterial FilledLabel) BuildBar(
            string debugName, Anchor fillFrom, Rect bounds, StringView text)
        {
            var bar = new ProgressBar
            {
                DebugName = debugName,
                ProgressBarMaterial = BarMaterial,
                FillFrom = fillFrom,
                Bounds = bounds,
            };

            TextMaterial emptyLabel = Label(text, DarkText);
            TextMaterial filledLabel = Label(text, Color.White);
            bar.EmptyContent.CanvasChildren.Add(
                new Panel { DebugName = "empty label", Material = emptyLabel, Bounds = bar.CanvasRect });
            bar.FilledContent.CanvasChildren.Add(
                new Panel { DebugName = "filled label", Material = filledLabel, Bounds = bar.CanvasRect });

            return (bar, emptyLabel, filledLabel);
        }

        private void AddDrivenBar(string debugName, Anchor fillFrom, Rect bounds)
        {
            var driven = BuildBar(debugName, fillFrom, bounds, "");
            drivenBars.Add(driven);
            Add(driven.Bar);
        }

        private void ApplyFieldValue()
        {
            Scalar progress = (double)(field.Value / 100);

            foreach (var driven in drivenBars)
            {
                driven.Bar.Progress = progress;
                driven.EmptyLabel.Text = field.DisplayText;
                driven.FilledLabel.Text = field.DisplayText;
            }
        }

        protected override void Populate()
        {
            AddCaption("Step or scrub the number to drive the bars.");
            AddCaption("Each label is two copies, one clipped to each part,");
            AddCaption("so it changes colour where the fill ends.");
            AddCaption("The orange mark is on the top bar itself, over both parts.");

            field = new NumberField(new NumberFieldBehavior(), new NumberField.Data
            {
                Grid = new NumberGrid { Max = 100, Resolution = 0.1m, Step = 1 },
                Value = 40,
                Format = (value, culture) => value.ToString("F1", culture) + "%",
            })
            {
                DebugName = "progress",
                NumberFieldMaterial = FieldMaterial,
            };
            Vector fieldSize = field.PreferredBoundsSize;
            Rect fieldRow = ContentAggregator.NewRow(fieldSize.Y);
            field.Bounds = fieldRow.NewCol(fieldSize.X);
            Add(field);

            Rect leftRow = ContentAggregator.NewRow(HorizontalSize.Y);
            AddDrivenBar("from left", Anchor.Left, leftRow.NewCol(HorizontalSize.X));

            Rect rightRow = ContentAggregator.NewRow(HorizontalSize.Y);
            AddDrivenBar("from right", Anchor.Right, rightRow.NewCol(HorizontalSize.X));

            Rect verticalRow = ContentAggregator.NewRow(VerticalSize.Y);
            AddDrivenBar("from top", Anchor.Top, verticalRow.NewCol(VerticalSize.X, margin: Gutter));
            AddDrivenBar("from bottom", Anchor.Bottom, verticalRow.NewCol(VerticalSize.X));

            ProgressBar markedBar = drivenBars[0].Bar;
            Rect track = markedBar.CanvasRect;
            markedBar.CanvasChildren.Add(new Panel
            {
                DebugName = "goal marker",
                Material = GoalMarker,
                Bounds = Rect.FromPositionAndSize(new Vector(track.Width * 0.75 - 1, 0), new Vector(2, track.Height)),
            });

            field.OnValueChanged += (_, __, ___) => ApplyFieldValue();
            ApplyFieldValue();

            AddCaption("A slow sweep, for a fill edge that falls between pixels");
            Rect sweepRow = ContentAggregator.NewRow(HorizontalSize.Y);
            sweepBar = BuildBar("sweep", Anchor.Left, sweepRow.NewCol(HorizontalSize.X), "Sub-pixel sweep").Bar;
            Add(sweepBar);
        }

        protected override void Setup()
        {
            sweepProgress = 0;
        }

        public override void Update(TimeSpan elapsed)
        {
            sweepProgress = (sweepProgress + elapsed.TotalSeconds * SweepPerSecond) % 1;
            sweepBar.Progress = sweepProgress;
        }
    }
}