using UnityEngine;

namespace Passer.CreatureControl {

    /// <summary>
    /// A target rig for a creature
    /// </summary>
    public class TargetRig : MonoBehaviour {

        public Animator animator;

        public virtual void PoseLimbs() {
        }

        public void MatchTo(Creature creature) {
            bool anythingChangedDummy = false;
            MatchTo(creature, ref anythingChangedDummy);
        }

        public virtual void MatchTo(Creature creature, ref bool anythingChanged) {
            Vector3 targetToModelTranslation = creature.model.position - this.transform.position;
            bool changed = targetToModelTranslation != creature.targetToModelTranslation;
            if (changed) {
                anythingChanged = true;
                creature.targetToModelTranslation = targetToModelTranslation;
            }

            Quaternion targetToModelRotation = Quaternion.Inverse(this.transform.rotation) * creature.model.rotation;
            changed = targetToModelRotation != creature.targetToModelRotation;
            if (changed) {
                anythingChanged = true;
                creature.targetToModelRotation = targetToModelRotation;
            }
        }

        public static Quaternion TargetToBoneRotation(Transform bone, Transform nextBone) {
            if (bone == null || nextBone == null)
                return Quaternion.identity;

            Vector3 direction = nextBone.position - bone.position;
            Quaternion targetRotation = Quaternion.LookRotation(direction, Vector3.up);
            Quaternion toBoneRotation = Quaternion.Inverse(targetRotation) * bone.rotation;
            return toBoneRotation;
        }

        public static Quaternion TargetToBoneRotation(Transform target, Transform nextTarget, Transform bone) {
            Vector3 direction = nextTarget.position - bone.position;
            Quaternion targetRotation = Quaternion.LookRotation(direction, Vector3.up);
            Quaternion toBoneRotation = Quaternion.Inverse(targetRotation) * bone.rotation;
            return toBoneRotation;
        }

        public static Quaternion TargetToBoneRotation_Debug(Transform target, Transform nextTarget, Transform bone) {
            Vector3 direction = nextTarget.position - target.position;
            Quaternion targetRotation = Quaternion.LookRotation(direction, Vector3.up);
            Debug.DrawRay(bone.position, targetRotation * Vector3.forward, Color.blue);
            Debug.DrawRay(bone.position, targetRotation * Vector3.up, Color.green);

            Quaternion toBoneRotation = Quaternion.Inverse(targetRotation) * bone.rotation;
            Debug.Log($"{targetRotation.eulerAngles} {bone.rotation.eulerAngles} -> {toBoneRotation.eulerAngles}");
            return toBoneRotation;
        }
    }

}