using UnityEngine;

namespace Passer.CreatureControl {

    public class Creature : MonoBehaviour {
        /// <summary>The target bones rig</summary>
        /// The target bones rig contain the target pose of the creature
        /// The creature movements will try to move the creature such that the target pose is reached
        /// as closely as possible
        public TargetRig targetRig;
        public Transform creatureRig;

        public Vector3 targetToRootTranslation;
        public Quaternion targetToRootRotation;

        /// <summary>
        /// Ensure a target rig is available
        /// </summary>
        /// <param name="targetRigResourceName">The name of the target rig resource</param>
        /// <returns>True when the creature rig has been updated</returns>
        /// The parameter is used to instantiate a new target rig when none has been found.
        public bool CheckTargetRig(string targetRigResourceName) {
            if (this.targetRig == null) {
                // See if there is a target rig, but we just haven't found it
                this.targetRig = this.GetComponentInChildren<TargetRig>();
                if (this.targetRig == null) {
                    GameObject targetsRigPrefab = Resources.Load<GameObject>(targetRigResourceName);
                    GameObject targetRig = Instantiate(targetsRigPrefab);
                    targetRig.name = "Target Rig";

                    targetRig.transform.SetPositionAndRotation(this.transform.position, this.transform.rotation);
                    targetRig.transform.SetParent(this.transform);
                    this.targetRig = targetRig.GetComponent<TargetRig>();
                }
                return true;
            }
            else
                return false;
        }

        /// <summary>
        /// Ensure that the creature rig is available
        /// </summary>
        /// <returns>True when the creature rig has been updated</returns>
        public bool CheckCreatureRig() {
            if (this.creatureRig == null) {
                SkinnedMeshRenderer[] skinnedMeshRenderers = this.GetComponentsInChildren<SkinnedMeshRenderer>();
                foreach (SkinnedMeshRenderer skinnedMeshRenderer in skinnedMeshRenderers) {
                    Transform rendererParent = skinnedMeshRenderer.transform.parent;
                    if (this.creatureRig == null || this.creatureRig == rendererParent)
                        this.creatureRig = rendererParent;
                    else
                        Debug.LogWarning("Unclear avatar root");
                }
                return this.creatureRig != null;
            }
            else
                return false;
        }

        public virtual void UpdateBones() {
            Vector3 newPosition = this.targetRig.transform.position + targetToRootTranslation;
            Quaternion newOrientation = this.targetRig.transform.rotation * targetToRootRotation;
            this.transform.SetPositionAndRotation(newPosition, newOrientation);
        }
    }

}