using UnityEngine;
using System.Collections;

public class CarController : MonoBehaviour {

public WheelCollider[] WColForward;
public WheelCollider[] WColBack;

public Transform[] wheelsF; //1
public Transform[] wheelsB; //1

public float wheelOffset = 0.1f; //2
public float wheelRadius = 0.13f; //2

public float maxSteer = 30;
public float maxAccel = 25;
public float maxBrake = 50;

public Transform COM;

public class WheelData{ //3
public Transform wheelTransform; //4
public WheelCollider col; //5
public Vector3 wheelStartPos; //6
public float rotation = 0.0f; //7
}

protected WheelData[] wheels; //8

// Use this for initialization

void Start () {
rigidbody.centerOfMass = COM.localPosition;

wheels = new WheelData[WColForward.Length+WColBack.Length]; //8

for (int i = 0; i<WColForward.Length; i++){ //9
wheels[i] = SetupWheels(wheelsF[i],WColForward[i]); //9
}

for (int i = 0; i<WColBack.Length; i++){ //9
wheels[i+WColForward.Length] = SetupWheels(wheelsB[i],WColBack[i]); //9
}

}

private WheelData SetupWheels(Transform wheel, WheelCollider col){ //10
WheelData result = new WheelData();

result.wheelTransform = wheel; //10
result.col = col; //10
result.wheelStartPos = wheel.transform.localPosition; //10

return result; //10

}

void FixedUpdate () {

float accel = 0;
float steer = 0;

accel = Input.GetAxis("Vertical");
steer = Input.GetAxis("Horizontal");

CarMove(accel,steer);
UpdateWheels(); //11
}

private void UpdateWheels(){ //11
float delta = Time.fixedDeltaTime; //12

foreach (WheelData w in wheels){ //13
WheelHit hit; //14

Vector3 lp = w.wheelTransform.localPosition; //15
if(w.col.GetGroundHit(out hit)){ //16
lp.y -= Vector3.Dot(w.wheelTransform.position - hit.point, transform.up) - wheelRadius; //17
}else{ //18

lp.y = w.wheelStartPos.y - wheelOffset; //18
}
w.wheelTransform.localPosition = lp; //19

w.rotation = Mathf.Repeat(w.rotation + delta * w.col.rpm * 360.0f / 60.0f, 360.0f); //20
w.wheelTransform.localRotation = Quaternion.Euler(w.rotation, w.col.steerAngle, 90.0f); //21
}

}

private void CarMove(float accel,float steer){

foreach(WheelCollider col in WColForward){
col.steerAngle = steer*maxSteer;
}

if(accel == 0){
foreach(WheelCollider col in WColBack){
col.brakeTorque = maxBrake;
}

}else{

foreach(WheelCollider col in WColBack){
col.brakeTorque = 0;
col.motorTorque    = accel*maxAccel;
}

}

}

}