using System;
using UnityEngine;
using UnityEngine.InputSystem;

[RequireComponent(typeof(Rigidbody2D))]
public class CarLogic : MonoBehaviour
{
    public InputAction steeringAction;
    public InputAction accelerationAction;
    public InputAction brakeAction;

    public float accelerationAmount = 10;
    [Tooltip("In degrees")]
    public float steeringAnglePerSecond = 10;

    public float maxAcceleration = 100;
    
    private Rigidbody2D _rigidbody;
    private Transform _transform;
    private float _currentAcceleration;

    private void Awake()
    {
        _rigidbody = GetComponent<Rigidbody2D>();
        _transform = transform;
    }

    private void Start()
    {
        steeringAction.Enable();
        accelerationAction.Enable();
        brakeAction.Enable();
    }

    private void Update()
    {
        var steeringValue = steeringAction.ReadValue<float>();
        var accelerationValue = accelerationAction.ReadValue<float>();
        // TODO: The what that I changed this too I like a lot better, however I do want to eventually figure out what was wrong with this verbose approach.
        // Vector2 velocityDir = _transform.up;
        // var currentAngleRad = Mathf.Acos(Vector3.Dot(velocityDir, Vector3.up));
        // var deltaAngleRad = steeringValue * steeringAnglePerSecond * Time.deltaTime * Mathf.Deg2Rad;
        // var angleRad = deltaAngleRad + currentAngleRad;
        //
        // var angleCos = Mathf.Cos(angleRad);
        // var angleSin = Mathf.Sin(angleRad);
        // Vector2 nextVelocityDir;
        // nextVelocityDir.x = angleCos * velocityDir.x -
        //                     angleSin * velocityDir.y;
        // nextVelocityDir.y = angleSin * velocityDir.x +
        //                     angleCos * velocityDir.y;
        //
        // nextVelocityDir *= accelerationAmount * accelerationValue * Time.deltaTime;

        // TODO: probably not correct... ODE or some other formula.
        if (accelerationValue <= 0)
        {
            _currentAcceleration -= _rigidbody.drag * Time.deltaTime;
        }

        _currentAcceleration += accelerationValue * accelerationAmount * Time.deltaTime;
        
        var newAngle = steeringValue * steeringAnglePerSecond * Time.deltaTime;
        
        if (_currentAcceleration > 0.01)
        {
            _transform.Rotate(Vector3.forward, newAngle, Space.World);
        }

        // TODO: reverse logic.
        if (_currentAcceleration < 0)
        {
            _currentAcceleration = 0;
        }

        if (_currentAcceleration > maxAcceleration)
        {
            _currentAcceleration = maxAcceleration;
        }

        Debug.Log(_currentAcceleration);
        _rigidbody.velocity = _transform.up * _currentAcceleration;
    }
}