using UnityEngine;

namespace DestroyIt
{
    [RequireComponent(typeof (CharacterController))]
    [RequireComponent(typeof (AudioSource))]
    public class FirstPersonController : MonoBehaviour
    {
        [SerializeField] private bool m_IsWalking = false;
        [SerializeField] private float m_WalkSpeed = 0f;
        [SerializeField] private float m_RunSpeed = 0f;
        [SerializeField] [Range(0f, 1f)] private float m_RunstepLenghten = 0f;
        [SerializeField] private float m_JumpSpeed = 0f;
        [SerializeField] private float m_StickToGroundForce = 0f;
        [SerializeField] private float m_GravityMultiplier = 0f;
        [SerializeField] private MouseLook m_MouseLook = new MouseLook();
        [SerializeField] private float m_StepInterval = 0f;

        private Camera m_Camera;
        private bool m_Jump;
        private float m_YRotation;
        private Vector2 m_Input;
        private Vector3 m_MoveDir = Vector3.zero;
        private CharacterController m_CharacterController;
        private CollisionFlags m_CollisionFlags;
        private bool m_PreviouslyGrounded;
        private float m_StepCycle;
        private float m_NextStep;
        private bool m_Jumping;

        // Use this for initialization
        private void Start()
        {
            m_CharacterController = GetComponent<CharacterController>();
            m_Camera = Camera.main;
            m_StepCycle = 0f;
            m_NextStep = m_StepCycle/2f;
            m_Jumping = false;
			m_MouseLook.Init(transform , m_Camera.transform);
        }


        // Update is called once per frame
        private void Update()
        {
            RotateView();
            // the jump state needs to read here to make sure it is not missed
            if (!m_Jump)
                m_Jump = CrossPlatformInputManager.GetButtonDown("Jump");

            if (!m_PreviouslyGrounded && m_CharacterController.isGrounded)
            {
                m_MoveDir.y = 0f;
                m_Jumping = false;
            }
            if (!m_CharacterController.isGrounded && !m_Jumping && m_PreviouslyGrounded)
                m_MoveDir.y = 0f;

            m_PreviouslyGrounded = m_CharacterController.isGrounded;
        }

        private void FixedUpdate()
        {
            float speed;
            GetInput(out speed);
            // always move along the camera forward as it is the direction that it being aimed at
            Vector3 desiredMove = transform.forward*m_Input.y + transform.right*m_Input.x;

            // get a normal for the surface that is being touched to move along it
            RaycastHit hitInfo;
            Physics.SphereCast(transform.position, m_CharacterController.radius, Vector3.down, out hitInfo,
                               m_CharacterController.height/2f, Physics.AllLayers, QueryTriggerInteraction.Ignore);
            desiredMove = Vector3.ProjectOnPlane(desiredMove, hitInfo.normal).normalized;

            m_MoveDir.x = desiredMove.x*speed;
            m_MoveDir.z = desiredMove.z*speed;


            if (m_CharacterController.isGrounded)
            {
                m_MoveDir.y = -m_StickToGroundForce;

                if (m_Jump)
                {
                    m_MoveDir.y = m_JumpSpeed;
                    m_Jump = false;
                    m_Jumping = true;
                }
            }
            else
            {
                m_MoveDir += Physics.gravity*m_GravityMultiplier*Time.fixedDeltaTime;
            }
            m_CollisionFlags = m_CharacterController.Move(m_MoveDir*Time.fixedDeltaTime);

            ProgressStepCycle(speed);

            m_MouseLook.UpdateCursorLock();
        }

        private void ProgressStepCycle(float speed)
        {
            if (m_CharacterController.velocity.sqrMagnitude > 0 && (m_Input.x != 0 || m_Input.y != 0))
            {
                m_StepCycle += (m_CharacterController.velocity.magnitude + (speed*(m_IsWalking ? 1f : m_RunstepLenghten)))*
                             Time.fixedDeltaTime;
            }

            if (!(m_StepCycle > m_NextStep)) return;

            m_NextStep = m_StepCycle + m_StepInterval;
        }

        private void GetInput(out float speed)
        {
            // Read input
            float horizontal = CrossPlatformInputManager.GetAxis("Horizontal");
            float vertical = CrossPlatformInputManager.GetAxis("Vertical");

#if !MOBILE_INPUT
            // On standalone builds, walk/run speed is modified by a key press.
            // keep track of whether or not the character is walking or running
            m_IsWalking = !Input.GetKey(KeyCode.LeftShift);
#endif
            // set the desired speed to be walking or running
            speed = m_IsWalking ? m_WalkSpeed : m_RunSpeed;
            m_Input = new Vector2(horizontal, vertical);

            // normalize input if it exceeds 1 in combined length:
            if (m_Input.sqrMagnitude > 1)
                m_Input.Normalize();
        }


        private void RotateView()
        {
            m_MouseLook.LookRotation (transform, m_Camera.transform);
        }


        private void OnControllerColliderHit(ControllerColliderHit hit)
        {
            Rigidbody body = hit.collider.attachedRigidbody;
            //dont move the rigidbody if the character is on top of it
            if (m_CollisionFlags == CollisionFlags.Below) return;

            if (body == null || body.isKinematic) return;

            body.AddForceAtPosition(m_CharacterController.velocity*0.1f, hit.point, ForceMode.Impulse);
        }
    }
}