using System;
using RebootKit.Engine.Extensions;
using UnityEngine;

namespace RebootKit.Engine.Services.Simulation {
    public class PhysicsObjectDragger : MonoBehaviour {
        [field: SerializeField]
        public float DampingFactor { get; private set; } = 1.0f;

        [field: SerializeField]
        public float AngularSlowdown { get; private set; } = 90.0f;

        [field: SerializeField]
        public float DragForce { get; private set; } = 10.0f;

        public Rigidbody Current { get; private set; }

        [field: SerializeField]
        public Vector3 TargetWorldPosition { get; set; }

        public bool IsDragging => Current != null;

        public void FixedUpdate() {
            if (Current.OrNull() == null) {
                return;
            }

            Vector3 direction = (TargetWorldPosition - Current.position).normalized;
            float distance = Vector3.Distance(TargetWorldPosition, Current.position);

            Vector3 damping = Current.linearVelocity * DampingFactor;

            Vector3 force = direction * Mathf.Clamp(distance * DragForce, 0, DragForce) - damping;
            Current.AddForce(force, ForceMode.Force);

            Current.angularVelocity = Vector3.MoveTowards(Current.angularVelocity, Vector3.zero, Time.fixedDeltaTime * AngularSlowdown);
        }

        void OnDrawGizmosSelected() {
            Gizmos.color = Color.green;
            Gizmos.DrawSphere(TargetWorldPosition, 0.1f);
        }

        public void Grab(Rigidbody physicsObject) {
            Drop();

            Current = physicsObject;
            Current.linearDamping = 5.0f;
        }

        public void Drop() {
            if (Current == null) {
                return;
            }

            Current.linearDamping = 0.0f;
            Current = null;
        }
    }
}