using UnityEngine;

namespace Controller.Bicycle
{
    public class RbBicycleController : BicycleControllerBaseBehaviour, IBicycleController
    {
        private void Awake()
        {
            rbTransform = rigidBody.transform;
            rigidBody.freezeRotation = true;
            rigidBody.centerOfMass = centerOfMass.position;
        }

        private void Start()
        {
            speedBooster = BikeSpeedBooster.Instance;
        }

        private void FixedUpdate()
        {
            //rigidBody.isKinematic = currentSpeed <= THRESHOLD_STANDING;

            ApplyVelocity();
            ApplySteerAngleAndRotation();
        }

        private void OnGUI()
        {
            GUI.TextField(new Rect(200, 100, 400, 50), $"Boost = {speedBooster.Boost}");
        }

        //TODO: maybe add some kind of rolling physics after downhill
        private void ApplyVelocity()
        {
            var targetVelocity = CalculateTargetVelocity();

            var velocityChange = targetVelocity - rigidBody.velocity;
            velocityChange.y = 0;
            rigidBody.AddForce(velocityChange, ForceMode.VelocityChange);
        }

        private Vector3 CalculateTargetVelocity()
        {
            if (adjustSpeedToSlope)
            {
                previousSoeedAdjusted = currentSpeedAdjusted;
                var boost = speedBooster.Boost;
                float nextSpeedAdjusted;
                if (boost > 1 && CurrentSpeedSensed < 5.55f) //5.55 m/s = 20 km/h
                    nextSpeedAdjusted = 5.55f * boost;
                else
                    nextSpeedAdjusted = CurrentSpeedSensed * speedBooster.Boost;

                currentSpeedAdjusted = Mathf.Max(Mathf.Max(0,
                    previousSoeedAdjusted - Time.deltaTime * MAX_DIF_SPEED_ADJUSTED_PER_SECOND), nextSpeedAdjusted);
            }
            else
            {
                currentSpeedAdjusted = CurrentSpeedSensed;
            }

            var tv = new Vector3(0, 0, currentSpeedAdjusted);
            tv = rbTransform.TransformDirection(tv);
            return tv;
        }

        private void ApplySteerAngleAndRotation()
        {
            //don't lean and rotate when veeeeeery sloooow/standing. Otherwise bike will rotate already
            if (CurrentSpeed < 0.3f) //ca 1 km/h
            {
                CurrentSteerAngle = 0;
                CurrentLeaningAngle = 0;
            }

            var sumMode = controllerMode.weightLeaning + controllerMode.weightSteering;
            var calculatedSteerAngle = (controllerMode.weightSteering * CurrentSteerAngle +
                                        controllerMode.weightLeaning + currentLeaningAngle) /
                                       sumMode; //TODO: maybe define what leaning angle means as steering angle;

            var r = rbTransform.localRotation.eulerAngles;

            float rectifiedZ;
            if (r.z > 180f)
                rectifiedZ = -360 + r.z;
            else if (r.z < -180f)
                rectifiedZ = 360 + r.z;
            else
                rectifiedZ = r.z;

            var leanDif = -CurrentLeaningAngle - rectifiedZ;
            rbTransform.localRotation =
                Quaternion.Euler(r + new Vector3(0, calculatedSteerAngle, leanDif) * Time.fixedDeltaTime);
        }

        #region Variables

        private Transform rbTransform;
        private float currentSteerAngle;
        private float currentLeaningAngle;
        private float currentSpeedAdjusted;
        private float previousSoeedAdjusted;
        private const float MAX_DIF_SPEED_ADJUSTED_PER_SECOND = 10f;
        private BikeSpeedBooster speedBooster;

        [Tooltip("Needs a RbBicycleSlopeSpeedManager to be attached to this GameObject")]
        public bool adjustSpeedToSlope = true;

        public Vector3 Forward => rbTransform.forward;

        public Vector3 Right => -rbTransform.right;

        public Vector3 Up => rbTransform.up;

        public BicycleControllerMode ControllerMode
        {
            get => controllerMode;
            set => controllerMode = value;
        }

        public float CurrentSpeedSensed { private set; get; }

        public float CurrentSpeed
        {
            get => adjustSpeedToSlope ? currentSpeedAdjusted : CurrentSpeedSensed;
            set => CurrentSpeedSensed = Mathf.Clamp(value, 0, maxSpeed);
        }

        public float CurrentSpeedKph => CurrentSpeed * 3.6f;

        public float CurrentSteerAngle
        {
            get => currentSteerAngle;
            set => currentSteerAngle = Mathf.Clamp(value, -maxSteeringAngle, maxSteeringAngle);
        }

        public float CurrentLeaningAngle
        {
            get => currentLeaningAngle;
            set
            {
                //don't lean while standing / walking to bike
                if (rigidBody.velocity.magnitude < .5f) return;
                currentLeaningAngle = Mathf.Clamp(value, -maxLeaningAngle, maxLeaningAngle);
            }
        }

        public Vector3 RigidBodyVelocity => rigidBody.velocity;

        #endregion
    }
}