using UnityEngine;
using KinematicCharacterController;

namespace Code.Gameplay.Character.Controller
{
    public class GroundMovementSystem
    {
        private readonly float _maxStableMoveSpeed;
        private readonly float _sprintMoveSpeed;
        private readonly float _stableMovementSharpness;

        public GroundMovementSystem(float maxStableMoveSpeed, float sprintMoveSpeed, float stableMovementSharpness)
        {
            _maxStableMoveSpeed = maxStableMoveSpeed;
            _sprintMoveSpeed = sprintMoveSpeed;
            _stableMovementSharpness = stableMovementSharpness;
        }
        
        public void UpdateVelocity(
            ref Vector3 currentVelocity,
            CharacterInputHandler inputHandler,
            KinematicCharacterMotor motor,
            float deltaTime)
        {
            var currentVelocityMagnitude = currentVelocity.magnitude;

            var effectiveGroundNormal = motor.GroundingStatus.GroundNormal;

            currentVelocity = motor.GetDirectionTangentToSurface(currentVelocity, effectiveGroundNormal) *
                              currentVelocityMagnitude;

            var inputRight = Vector3.Cross(inputHandler.MoveInputVector, motor.CharacterUp);
            var reorientedInput = Vector3.Cross(effectiveGroundNormal, inputRight).normalized *
                                  inputHandler.MoveInputVector.magnitude;

            var targetSpeed = inputHandler.IsSprinting ? _sprintMoveSpeed : _maxStableMoveSpeed;
            var targetMovementVelocity = reorientedInput * targetSpeed;

            currentVelocity = Vector3.Lerp(
                currentVelocity,
                targetMovementVelocity,
                1f - Mathf.Exp(-_stableMovementSharpness * deltaTime)
            );
        }
    }
}