using UnityEngine;
using System;

namespace Obi
{
	public abstract class ObiExternalForce : MonoBehaviour
	{

		public float intensity = 0;
		public float turbulence = 0;
		public float turbulenceFrequency = 1;
		public float turbulenceSeed = 0;
		public ObiSolver[] affectedSolvers;

		public void OnEnable()
		{
            foreach (ObiSolver solver in affectedSolvers)
            {
                if (solver != null)
                    solver.OnBeginStep += Solver_OnStepBegin;
            }
		}

		public void OnDisable()
		{
            foreach (ObiSolver solver in affectedSolvers)
            {
                if (solver != null)
                    solver.OnBeginStep -= Solver_OnStepBegin;
            }
		}

        void Solver_OnStepBegin(ObiSolver solver, float stepTime)
        {
            foreach (ObiActor actor in solver.actors)
            {
                if (actor != null)
                    ApplyForcesToActor(actor);
            }
        }

		protected float GetTurbulence(float turbulenceIntensity){
			return Mathf.PerlinNoise(Time.fixedTime * turbulenceFrequency,turbulenceSeed) * turbulenceIntensity;
		}

		public abstract void ApplyForcesToActor(ObiActor actor);	
		
	}
}