using UnityEngine;

namespace CreatureControl {

    /// <summary>
    /// A leg of a creature
    /// </summary>
    [System.Serializable]
    public class Leg {
        /// <summary>
        /// The upper leg or thigh bone
        /// </summary>
        public Transform femur;
        /// <summary>
        /// The lower leg or shank bone
        /// </summary>
        public Transform tibia;
        /// <summary>
        /// The foot bone
        /// </summary>
        public Transform tarsus;

        [SerializeField]
        private float _femurLength;
        public float femurLength {
            get {
                if (_femurLength <= 0 && this.femur != null && this.tibia != null)
                    _femurLength = Vector3.Distance(this.femur.position, this.tibia.position);
                return _femurLength;
            }
        }
        // A bit inefficient is this is used a lot...
        //public float tibiaLength => Vector3.Distance(this.tibia.position, this.tarsus.position);
        private float _tibiaLength;
        public float tibiaLength {
            get {
                if (_tibiaLength <= 0 && this.tibia != null && this.tarsus != null)
                    _tibiaLength = Vector3.Distance(this.tibia.position, this.tarsus.position);
                return _tibiaLength;
            }
        }
        public float length => femurLength + tibiaLength;

        public void ResetLengths() {
            _femurLength = 0;
            _tibiaLength = 0;            
        }

        /// <summary>
        /// Check if all bones of the legs have been configured
        /// </summary>
        /// <returns>True when all bones are configured</returns>
        public bool isConfigured => femur != null && tibia != null && tarsus != null;
    }

}