using System.Collections.Generic;
using UnityEngine;
using CSharpESP.Drawing;

namespace CSharpESP.Renderers
{
    public class BoneRenderer
    {
        // Humanoid bone joint pairs
        private static readonly (HumanBodyBones, HumanBodyBones)[] s_BonePairs = new (HumanBodyBones, HumanBodyBones)[]
        {
            // Head and Spine
            (HumanBodyBones.Head, HumanBodyBones.Neck),
            (HumanBodyBones.Neck, HumanBodyBones.Chest),
            (HumanBodyBones.Chest, HumanBodyBones.Spine),
            (HumanBodyBones.Spine, HumanBodyBones.Hips),

            // Left Arm
            (HumanBodyBones.Neck, HumanBodyBones.LeftShoulder),
            (HumanBodyBones.LeftShoulder, HumanBodyBones.LeftUpperArm),
            (HumanBodyBones.LeftUpperArm, HumanBodyBones.LeftLowerArm),
            (HumanBodyBones.LeftLowerArm, HumanBodyBones.LeftHand),

            // Right Arm
            (HumanBodyBones.Neck, HumanBodyBones.RightShoulder),
            (HumanBodyBones.RightShoulder, HumanBodyBones.RightUpperArm),
            (HumanBodyBones.RightUpperArm, HumanBodyBones.RightLowerArm),
            (HumanBodyBones.RightLowerArm, HumanBodyBones.RightHand),

            // Left Leg
            (HumanBodyBones.Hips, HumanBodyBones.LeftUpperLeg),
            (HumanBodyBones.LeftUpperLeg, HumanBodyBones.LeftLowerLeg),
            (HumanBodyBones.LeftLowerLeg, HumanBodyBones.LeftFoot),

            // Right Leg
            (HumanBodyBones.Hips, HumanBodyBones.RightUpperLeg),
            (HumanBodyBones.RightUpperLeg, HumanBodyBones.RightLowerLeg),
            (HumanBodyBones.RightLowerLeg, HumanBodyBones.RightFoot)
        };

        public static void Render(Camera camera, Animator animator, Color color, float thickness = 1.2f)
        {
            if (animator == null || !animator.isHuman) return;

            // Cache bone screen positions to avoid duplicate projections
            Dictionary<HumanBodyBones, Vector2> boneScreenMap = new Dictionary<HumanBodyBones, Vector2>();

            foreach (var pair in s_BonePairs)
            {
                if (!TryGetBoneScreenPos(camera, animator, pair.Item1, boneScreenMap, out Vector2 posA))
                    continue;

                if (!TryGetBoneScreenPos(camera, animator, pair.Item2, boneScreenMap, out Vector2 posB))
                    continue;

                RenderHelper.DrawLine(posA, posB, color, thickness);
            }

            // Draw Head marker
            if (TryGetBoneScreenPos(camera, animator, HumanBodyBones.Head, boneScreenMap, out Vector2 headScreen))
            {
                float headRadius = 4f;
                Rect headRect = new Rect(headScreen.x - headRadius, headScreen.y - headRadius, headRadius * 2f, headRadius * 2f);
                RenderHelper.DrawBox(headRect, color, 1f);
            }
        }

        private static bool TryGetBoneScreenPos(
            Camera camera,
            Animator animator,
            HumanBodyBones bone,
            Dictionary<HumanBodyBones, Vector2> cache,
            out Vector2 screenPos)
        {
            if (cache.TryGetValue(bone, out screenPos))
            {
                return true;
            }

            Transform t = animator.GetBoneTransform(bone);
            if (t == null)
            {
                screenPos = Vector2.zero;
                return false;
            }

            if (MathUtils.WorldToScreen(camera, t.position, out screenPos))
            {
                cache[bone] = screenPos;
                return true;
            }

            return false;
        }
    }
}