using System;
using System.Numerics;
using Raylib_cs;

namespace PhysicsEngine
{
    public static class DrawHelper
    {
        public static Color GetDarkerColor(Color color, float factor = 0.5f)
        {
            return new Color(
                (byte)(color.R * factor),
                (byte)(color.G * factor),
                (byte)(color.B * factor),
                color.A
            );
        }

        public static void DrawRotatedBox(Vector2 position, Vector2 size, float rotationRadians, Color fillColor, float pixelsPerMeter = 100.0f, float outlineThickness = 3.0f)
        {
            Vector2 sizePixels = size * pixelsPerMeter;
            Vector2 positionPixels = position * pixelsPerMeter;
            float rotationDegrees = rotationRadians * (180.0f / MathF.PI);

            Color outlineColor = GetDarkerColor(fillColor);

            // 1. Draw the outer outline rectangle (exact original size, outline colour)
            Vector2 outerSizePixels = sizePixels;
            Vector2 outerOrigin = outerSizePixels * 0.5f;
            Rectangle outerRec = new Rectangle(positionPixels.X, positionPixels.Y, outerSizePixels.X, outerSizePixels.Y);
            Raylib.DrawRectanglePro(outerRec, outerOrigin, rotationDegrees, outlineColor);

            // 2. Draw the inner fill rectangle, reduced by outlineThickness on all sides
            Vector2 innerSizePixels = new Vector2(
                MathF.Max(0, sizePixels.X - outlineThickness),
                MathF.Max(0, sizePixels.Y - outlineThickness)
            );
            Vector2 innerOrigin = innerSizePixels * 0.5f;
            Rectangle innerRec = new Rectangle(positionPixels.X, positionPixels.Y, innerSizePixels.X, innerSizePixels.Y);
            Raylib.DrawRectanglePro(innerRec, innerOrigin, rotationDegrees, fillColor);
        }

        public static void DrawCircleBody(Vector2 position, float radius, float rotationRadians, Color fillColor, float pixelsPerMeter = 100.0f, float outlineThickness = 3.0f)
        {
            Vector2 positionPixels = position * pixelsPerMeter;
            float radiusPixels = radius * pixelsPerMeter;
            Color outlineColor = GetDarkerColor(fillColor);

            // 1. Draw outer circle (outline colour, exact radius)
            Raylib.DrawCircleV(positionPixels, radiusPixels, outlineColor);

            // 2. Draw inner circle (fill colour, radius reduced by outlineThickness)
            float innerRadius = MathF.Max(0, radiusPixels - outlineThickness);
            Raylib.DrawCircleV(positionPixels, innerRadius, fillColor);

            // Draw rotation indicator line inside the fill (same as before, but from centre to inner edge)
            float cos = MathF.Cos(rotationRadians);
            float sin = MathF.Sin(rotationRadians);
            Vector2 edge = positionPixels + new Vector2(cos, sin) * innerRadius;
            Raylib.DrawLineEx(positionPixels, edge, 2.0f, outlineColor);
        }
    }
}