using System;
using Goo;
using Sandbox.UI;
using static Sandbox.BeatPadTokens;

namespace Sandbox;

// Pure presenter for one mode button. Flood (0..1) crossfades paper->hot for the
// Active state; PressOffset collapses the shadow on press (same feel as a pad).
internal static class ModeButtonBlob
{
    public readonly record struct Props(
        int Index,
        string Label,
        float Flood,
        float PressOffset,
        bool Hovered,
        Action<MousePanelEvent> OnDown,
        Action<MousePanelEvent> OnUp);

    public static Container Build(Props p)
    {
        float off = p.PressOffset;
        Color face = Color.Lerp(Paper, Hot, p.Flood);
        Color shadowColor = p.Hovered ? Hot : Ink;
        Color text = Color.Lerp(Ink, Paper, p.Flood);

        return new Container
        {
            Key = $"mode-{p.Index}",
            Width = ModeW,
            Height = ModeH,
            Position = PositionMode.Relative,
            OnMouseDown = p.OnDown,
            OnMouseUp = p.OnUp,
            Children =
            {
                new Container
                {
                    Key = "shadow",
                    Position = PositionMode.Absolute,
                    Left = ModeShadow, Top = ModeShadow,
                    Width = Length.Percent(100), Height = Length.Percent(100),
                    BackgroundColor = shadowColor,
                    BorderRadius = ModeRadius,
                    PointerEvents = PointerEvents.None,
                },
                new Container
                {
                    Key = "face",
                    Position = PositionMode.Absolute,
                    Left = 0, Top = 0,
                    Width = Length.Percent(100), Height = Length.Percent(100),
                    BackgroundColor = face,
                    BorderColor = Ink,
                    BorderWidth = OutlineWidth,
                    BorderRadius = ModeRadius,
                    JustifyContent = Justify.Center,
                    AlignItems = Align.Center,
                    Transform = Goo.PanelTransform.Translate(off, off),
                    PointerEvents = PointerEvents.None,
                    Children =
                    {
                        new Text(p.Label)
                        {
                            FontSize = 12f,
                            FontColor = text,
                            FontFamily = FontLabel,
                            FontWeight = 600,
                            TextTransform = TextTransform.Uppercase,
                            LetterSpacing = 2f,
                            TextAlign = TextAlign.Center,
                        },
                    },
                },
            },
        };
    }
}