using UnityEngine;
using UnityEngine.UIElements;

namespace ProjectM.Client
{
    /// <summary>
    /// UI Toolkit factories for the in-game HUD — a thin extension of <see cref="MenuUi"/>'s Aether palette so the
    /// HUD reads in the same visual language as the menu / pause / settings screens. Bars are a dark rounded track
    /// + a percent-width fill; labels use the shared text weights/colours. Every element is built
    /// <c>pickingMode = Ignore</c> by default so the HUD never eats clicks meant for the game world (only the
    /// interactive build-palette buttons opt back into picking).
    /// </summary>
    public static class HudUi
    {
        public static readonly Color Track = new(0f, 0f, 0f, 0.55f);

        /// <summary>A dark rounded bar track with a percent-width fill child (returned via <paramref name="fill"/>).</summary>
        public static VisualElement Bar(float width, float height, Color fillColor, out VisualElement fill)
        {
            var track = new VisualElement();
            track.style.width = width;
            track.style.height = height;
            track.style.backgroundColor = Track;
            track.style.paddingLeft = 2; track.style.paddingRight = 2;
            track.style.paddingTop = 2; track.style.paddingBottom = 2;
            track.style.flexDirection = FlexDirection.Row;
            track.pickingMode = PickingMode.Ignore;
            MenuUi.Round(track, 4);

            fill = new VisualElement();
            fill.style.height = Length.Percent(100);
            fill.style.width = Length.Percent(100);
            fill.style.backgroundColor = fillColor;
            fill.pickingMode = PickingMode.Ignore;
            MenuUi.Round(fill, 3);
            track.Add(fill);
            return track;
        }

        /// <summary>A bold HUD label (non-interactive).</summary>
        public static Label Text(string text, int size, Color color, TextAnchor align)
        {
            var l = new Label(text);
            l.style.fontSize = size;
            l.style.color = color;
            l.style.unityTextAlign = align;
            l.style.unityFontStyleAndWeight = FontStyle.Bold;
            l.pickingMode = PickingMode.Ignore;
            return l;
        }

        /// <summary>Set a fill's width to a 0..1 fraction of its track.</summary>
        public static void SetFill(VisualElement fill, float frac)
        {
            if (fill != null) fill.style.width = Length.Percent(Mathf.Clamp01(frac) * 100f);
        }

        /// <summary>A semi-transparent rounded panel for grouping a cluster of HUD elements.</summary>
        public static VisualElement Group(Align items = Align.FlexStart)
        {
            var g = new VisualElement();
            g.style.alignItems = items;
            g.pickingMode = PickingMode.Ignore;
            return g;
        }

    }
}