///-----------------------------------------------------------------
/// Namespace: <Cozmo>
/// Class: <CozmoMovement>
/// Description: <Defines the possible movement of the virtual cozmo.>
/// Author: <Tobias Hassel> Date: <29.07.2019>
/// Notes: <>
///-----------------------------------------------------------------
/// 


using UnityEngine;

namespace Cozmo
{
    public class CozmoMovement : MonoBehaviour
    {
        private const string MOVEMENT_AXIS_NAME = "Vertical";   // name of the movement input axis
        private const string TURN_AXIS_NAME = "Horizontal";     // name of the rotation input axis

        [Tooltip("Determines how fast the robot is moving forward and backwards.")]
        public float m_Speed = 12f;
        [Tooltip("Determines how fast the robot is turning in degrees per second.")]
        public float m_TurnSpeed = 180f;

        private Rigidbody cozmoRigidbody;           // Reference to cozmos rigidbody
        private float m_MovementInputValue;         // current input value for movement
        private float m_TurnInputValue;             // current input value for rotation


        private void Awake()
        {
            cozmoRigidbody = GetComponent<Rigidbody>();
        }


        private void OnEnable()
        {
            // When the cozmo is turned on, make sure it's not kinematic.
            cozmoRigidbody.isKinematic = false;

            // reset movement and rotation values
            m_MovementInputValue = 0f;
            m_TurnInputValue = 0f;
        }


        private void OnDisable()
        {
            // When the cozmo is turned off, set it to kinematic so it stops moving.
            cozmoRigidbody.isKinematic = true;
        }


        private void Update()
        {
            // Store the value of both input axes.
            m_MovementInputValue = Input.GetAxis(MOVEMENT_AXIS_NAME);
            m_TurnInputValue = Input.GetAxis(TURN_AXIS_NAME);
        }


        private void FixedUpdate()
        {
            // Adjust position and rotation 
            Move();
            Turn();
        }

        /// <summary>
        /// Move the cozmo forward (0 < directionValue <= 1) or backwards (0 > directionvalue >= -1)
        /// </summary>
        /// <param name="directionValue"></param>
        public void Move(float directionValue)
        {
            // clamp directionValue to make sure its between -1 and 1
            Mathf.Clamp(directionValue, -1, 1);

            Vector3 movement = directionValue * transform.forward * m_Speed * Time.deltaTime;

            // Apply this movement to the rigidbody's position.
            cozmoRigidbody.MovePosition(cozmoRigidbody.position + movement);
        }

        /// <summary>
        /// Move cozmo based on the input value
        /// </summary>
        public void Move()
        {
            Move(m_MovementInputValue);
        }


        /// <summary>
        /// Rotate cozmo based on the input value
        /// </summary>
        public void Turn()
        {
            Turn(m_TurnInputValue);
        }

        /// <summary>
        /// Rotate cozmo 
        /// </summary>
        /// <param name="turnValue"></param>
        public void Turn(float turnValue)
        {
            // clamp turnValue to make sure its between -1 and 1
            Mathf.Clamp(turnValue, -1, 1);

            float turn = turnValue * m_TurnSpeed * Time.deltaTime;

            // Make this into a rotation in the y axis.
            Quaternion turnRotation = Quaternion.Euler(0f, turn, 0f);

            // Apply this rotation to the rigidbody's rotation.
            cozmoRigidbody.MoveRotation(cozmoRigidbody.rotation * turnRotation);
        }

    }
}