/*	
 * This Script Controls the car!
 */
using System.Collections;
using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class LPPV_CarController : MonoBehaviour {


	public enum WheelType
	{
		FrontLeft, FrontRight, RearLeft, RearRight
	}
	public enum SpeedUnit
	{
		Imperial, Metric
	}
	[Serializable]
	class Wheel
	{
		public WheelCollider collider;
		public GameObject mesh;
		public WheelType wheelType;
	}

	[SerializeField] private Wheel[] wheels = new Wheel[4];
	[SerializeField] private float maxTorque = 2000f, maxBrakeTorque = 500f, maxSteerAngle = 30f; //max Torque of Wheels, max Brake Torque and Maximum Steer Angle of steerable wheels
	[SerializeField] private static int NoOfGears = 5;
	[SerializeField] private float downForce = 100f; // The Force to apply downwards so that car stays on track!
	[SerializeField] private SpeedUnit speedUnit;	//Speed Unit - Imperial - Miles Per Hour, Metric - Kilometers Per Hour
	[SerializeField] private float topSpeed = 140;
	[SerializeField] private Transform centerOfMass;
	[SerializeField] private Text speedText;

	#if UNITY_ANDROID || UNITY_IOS
	[SerializeField] private LPPV_VButton accelerateButton, brakeButton, handBrakeButton;
	#endif

	[HideInInspector] public bool Accelerating = false, Deccelerating = false, HandBrake = false;
	private Rigidbody _rgbd;
	public float CurrentSpeed{
		get 
		{  
			float speed = _rgbd.velocity.magnitude;
			if (speedUnit == SpeedUnit.Imperial)
				speed *= 2.23693629f;
			else
				speed *= 3.6f; 
			return speed;
		}
	}

	private void VisualizeWheel(Wheel wheel)
	{
		//This method copies the position and rotation of the wheel collider and pastes it to the corresponding mesh!
		if (wheel.mesh == null || wheel.collider == null)
			return;

		Vector3 position;
		Quaternion rotation;
		wheel.collider.GetWorldPose(out position, out rotation);	//Fetch the position and Rotation from the WheelCollider into temporary variables

		wheel.mesh.transform.position = position;
		wheel.mesh.transform.rotation = rotation;
	}

	private void Start () 
	{
		_rgbd = GetComponent<Rigidbody> ();
		if (centerOfMass != null && _rgbd != null)
			_rgbd.centerOfMass = centerOfMass.localPosition;
		for (int i = 0; i < wheels.Length; ++i)
			VisualizeWheel (wheels [i]);
	}

	private void Move(float motorInput, float steerInput, bool handBrake)
	{
		HandBrake = handBrake;
		motorInput = Mathf.Clamp (motorInput, -1f, 1f);
		if (motorInput > 0f) 
		{
			//Accelerate vehicle!
			Accelerating = true;
			Deccelerating = false;
		} else if(motorInput < 0f)
		{
			//Brake Vehicle!
			Accelerating = false;
			Deccelerating = true;
		}

		steerInput = Mathf.Clamp (steerInput, -1f, 1f);
		float steer = steerInput * maxSteerAngle;

		for (int i = 0; i < wheels.Length; ++i) 
		{
			if (wheels [i].collider == null)
				break;
			if (wheels [i].wheelType == WheelType.FrontLeft || wheels [i].wheelType == WheelType.FrontRight) 
			{
				wheels [i].collider.steerAngle = steer;

			}
			if (!handBrake) 
			{
				wheels [i].collider.brakeTorque = 0f;
				if (Accelerating)
					wheels [i].collider.motorTorque = motorInput * maxTorque / 4f;
				else if (Deccelerating)
					wheels [i].collider.motorTorque = motorInput * maxBrakeTorque / 4f;
			} else 
			{
				if (wheels [i].wheelType == WheelType.RearLeft || wheels [i].wheelType == WheelType.RearRight) 
					wheels [i].collider.brakeTorque = maxBrakeTorque * 20f;
				wheels [i].collider.motorTorque = 0f;
			}
			if(wheels[i].mesh != null)
				VisualizeWheel (wheels [i]);
		}

		StickToTheGround ();
		ManageSpeed ();
	}

	//This Method Applies down force so that car grips the ground strongly
	private void StickToTheGround()
	{
		if (wheels [0].collider == null)
			return;
		wheels [0].collider.attachedRigidbody.AddForce (-transform.up * downForce * wheels [0].collider.attachedRigidbody.velocity.magnitude);
	}


	//used to keep speed withing Minimum and maximum Speed Limits
	private void ManageSpeed()
	{
		float speed = _rgbd.velocity.magnitude;
		switch (speedUnit)
		{
		case SpeedUnit.Imperial:
			speed *= 2.23693629f;
			if (speed > topSpeed)
				_rgbd.velocity = (topSpeed/2.23693629f) * _rgbd.velocity.normalized;
			break;

		case SpeedUnit.Metric:
			speed *= 3.6f;
			if (speed > topSpeed)
				_rgbd.velocity = (topSpeed/3.6f) * _rgbd.velocity.normalized;
			break;
		}
	}

	private string imp = " MPH", met = " KPH";
	private void Update()
	{
		if (speedText != null)
		{
			if(speedUnit == SpeedUnit.Imperial)
				speedText.text = ((int)CurrentSpeed).ToString () + imp;
			else
				speedText.text = ((int)CurrentSpeed).ToString () + met;
		}
	}
	private void FixedUpdate()
	{
		float motor = 0f, steering = 0f;
		bool handBrakeInput = false;
		#if UNITY_STANDALONE || UNITY_WEBGL
			motor = Input.GetAxis("Vertical");
			steering = Input.GetAxis("Horizontal");
			handBrakeInput = Input.GetButton ("Jump");
		#endif

		#if UNITY_ANDROID || UNITY_IOS
		steering = Input.acceleration.x;
		if(accelerateButton != null)
		{
			if(accelerateButton.value)
				motor = 1f;
		}
		if(brakeButton != null)
		{
			if(brakeButton.value)
				motor = -1f;
		}
		if(handBrakeButton != null)
		{
			handBrakeInput = handBrakeButton.value;
			if(handBrakeButton.value)
			{
				motor = 0f;
			}
		}
		#endif
		Move (motor, steering, handBrakeInput);
	}

}