using UnityEngine;
using UnityEngine.UIElements;
using System.Collections.Generic;

namespace Hallucinate.UI.Components
{
    /// <summary>
    /// An adjustable Vector Element that you can "sketch" and tweak directly in UI Builder (UXML).
    /// Supports Parametric shapes (Pill, Polygon, Star) and Custom Paths.
    /// </summary>
    public class VectorShapeElement : VisualElement
    {
        public enum ShapeType { Pill, Polygon, Star, CustomPath }

        public new class UxmlFactory : UxmlFactory<VectorShapeElement, UxmlTraits> { }

        public new class UxmlTraits : VisualElement.UxmlTraits
        {
            UxmlEnumAttributeDescription<ShapeType> m_ShapeType = new UxmlEnumAttributeDescription<ShapeType> { name = "shape-type", defaultValue = ShapeType.Pill };
            UxmlColorAttributeDescription m_FillColor = new UxmlColorAttributeDescription { name = "fill-color", defaultValue = Color.white };
            UxmlColorAttributeDescription m_StrokeColor = new UxmlColorAttributeDescription { name = "stroke-color", defaultValue = Color.black };
            UxmlFloatAttributeDescription m_StrokeWidth = new UxmlFloatAttributeDescription { name = "stroke-width", defaultValue = 2f };
            UxmlFloatAttributeDescription m_CornerRadius = new UxmlFloatAttributeDescription { name = "corner-radius", defaultValue = 10f };
            UxmlIntAttributeDescription m_Sides = new UxmlIntAttributeDescription { name = "sides", defaultValue = 5 };
            UxmlFloatAttributeDescription m_Inwardness = new UxmlFloatAttributeDescription { name = "star-inwardness", defaultValue = 0.5f };
            UxmlStringAttributeDescription m_PathData = new UxmlStringAttributeDescription { name = "path-data", defaultValue = "" };

            public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
            {
                base.Init(ve, bag, cc);
                var ate = ve as VectorShapeElement;

                ate.shapeType = m_ShapeType.GetValueFromBag(bag, cc);
                ate.fillColor = m_FillColor.GetValueFromBag(bag, cc);
                ate.strokeColor = m_StrokeColor.GetValueFromBag(bag, cc);
                ate.strokeWidth = m_StrokeWidth.GetValueFromBag(bag, cc);
                ate.cornerRadius = m_CornerRadius.GetValueFromBag(bag, cc);
                ate.sides = Mathf.Max(3, m_Sides.GetValueFromBag(bag, cc));
                ate.inwardness = Mathf.Clamp01(m_Inwardness.GetValueFromBag(bag, cc));
                ate.pathData = m_PathData.GetValueFromBag(bag, cc);
                
                ate.MarkDirtyRepaint();
            }
        }

        public ShapeType shapeType { get; set; }
        public Color fillColor { get; set; }
        public Color strokeColor { get; set; }
        public float strokeWidth { get; set; }
        public float cornerRadius { get; set; }
        public int sides { get; set; }
        public float inwardness { get; set; }
        public string pathData { get; set; }

        public VectorShapeElement()
        {
            generateVisualContent += OnGenerateVisualContent;
        }

        private void OnGenerateVisualContent(MeshGenerationContext mgc)
        {
            var paint = mgc.painter2D;
            var rect = contentRect;

            if (rect.width <= 0 || rect.height <= 0) return;

            paint.BeginPath();
            paint.fillColor = fillColor;
            paint.strokeColor = strokeColor;
            paint.lineWidth = strokeWidth;

            switch (shapeType)
            {
                case ShapeType.Pill: DrawPill(paint, rect); break;
                case ShapeType.Polygon: DrawPolygon(paint, rect, false); break;
                case ShapeType.Star: DrawPolygon(paint, rect, true); break;
                case ShapeType.CustomPath: DrawCustomPath(paint); break;
            }

            paint.ClosePath();
            paint.Fill();
            if (strokeWidth > 0) paint.Stroke();
        }

        private void DrawPill(Painter2D paint, Rect rect)
        {
            float r = Mathf.Min(cornerRadius, rect.width / 2f, rect.height / 2f);
            paint.MoveTo(new Vector2(r, 0));
            paint.LineTo(new Vector2(rect.width - r, 0));
            paint.ArcTo(new Vector2(rect.width, 0), new Vector2(rect.width, r), r);
            paint.LineTo(new Vector2(rect.width, rect.height - r));
            paint.ArcTo(new Vector2(rect.width, rect.height), new Vector2(rect.width - r, rect.height), r);
            paint.LineTo(new Vector2(r, rect.height));
            paint.ArcTo(new Vector2(0, rect.height), new Vector2(0, rect.height - r), r);
            paint.LineTo(new Vector2(0, r));
            paint.ArcTo(new Vector2(0, 0), new Vector2(r, 0), r);
        }

        private void DrawPolygon(Painter2D paint, Rect rect, bool isStar)
        {
            Vector2 center = rect.center;
            float radius = Mathf.Min(rect.width, rect.height) / 2f;
            int totalPoints = isStar ? sides * 2 : sides;
            float angleStep = 360f / totalPoints;

            for (int i = 0; i < totalPoints; i++)
            {
                float angle = (i * angleStep - 90f) * Mathf.Deg2Rad;
                float r = radius;
                if (isStar && i % 2 != 0) r *= inwardness;

                Vector2 pos = center + new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * r;
                if (i == 0) paint.MoveTo(pos);
                else paint.LineTo(pos);
            }
        }

        private void DrawCustomPath(Painter2D paint)
        {
            if (string.IsNullOrEmpty(pathData)) return;
            string[] pairs = pathData.Split(' ');
            for (int i = 0; i < pairs.Length; i++)
            {
                string[] coords = pairs[i].Split(',');
                if (coords.Length == 2 && float.TryParse(coords[0], out float x) && float.TryParse(coords[1], out float y))
                {
                    if (i == 0) paint.MoveTo(new Vector2(x, y));
                    else paint.LineTo(new Vector2(x, y));
                }
            }
        }
    }
}