using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(OVRSceneAnchor))]
public class VolumeAndPlaneSwitcher : MonoBehaviour
{
    public OVRSceneAnchor planePrefab;
    public OVRSceneAnchor volumePrefab;

    public enum GeometryType
    {
        Plane,
        Volume,
    }

    [System.Serializable]
    public struct LabelGeometryPair
    {
        public string label;
        public GeometryType desiredGeometryType;
    }

    public List<LabelGeometryPair> desiredSwitches;

    private void ReplaceAnchor(OVRSceneAnchor prefab, Vector3 position, Quaternion rotation, Vector3 localScale)
    {
        var anchor = Instantiate(prefab, transform.parent);
        anchor.enabled = false; // disable so it won't update transform
        anchor.InitializeFrom(GetComponent<OVRSceneAnchor>());

        anchor.transform.SetPositionAndRotation(position, rotation);
        foreach (Transform child in anchor.transform)
        {
            child.localScale = localScale;
        }

        Destroy(gameObject);
    }

    void Start()
    {
        var classification = GetComponent<OVRSemanticClassification>();
        if (!classification) return;

        foreach (LabelGeometryPair pair in desiredSwitches)
        {
            if (classification.Contains(pair.label))
            {
                Vector3 position = Vector3.zero;
                Quaternion rotation = Quaternion.identity;
                Vector3 localScale = Vector3.zero;
                switch (pair.desiredGeometryType)
                {
                    case GeometryType.Plane:
                    {
                        var volume = GetComponent<OVRSceneVolume>();
                        if (!volume)
                        {
                            Debug.LogWarning(
                                $"Ignoring desired volume to plane switch for {pair.label} because it is not a volume.");
                            continue;
                        }

                        Debug.Log($"IN Volume Position {transform.position}, Dimensions: {volume.Dimensions}");
                        // This object is a volume, but we want a plane instead.
                        GetTopPlaneFromVolume(
                            transform,
                            volume.Dimensions,
                            out position,
                            out rotation,
                            out localScale);
                        Debug.Log($"OUT Plane Position {position}, Dimensions: {localScale}");
                        ReplaceAnchor(planePrefab, position, rotation, localScale);
                        break;
                    }
                    case GeometryType.Volume:
                    {
                        var plane = GetComponent<OVRScenePlane>();
                        if (!plane)
                        {
                            Debug.LogWarning(
                                $"Ignoring desired plane to volume switch for {pair.label} because it is not a plane.");
                            continue;
                        }

                        Debug.Log($"IN Plane Position {transform.position}, Dimensions: {plane.Dimensions}");
                        // This object is a plane, but we want a volume instead.
                        GetVolumeFromTopPlane(
                            transform,
                            plane.Dimensions,
                            transform.position.y,
                            out position,
                            out rotation,
                            out localScale);
                        Debug.Log($"OUT Volume Position {position}, Dimensions: {localScale}");
                        ReplaceAnchor(volumePrefab, position, rotation, localScale);
                        break;
                    }
                }
            }
        }

        // IF we arrived here, no conversion was needed. Let's remove this component
        Destroy(this);
    }

    private void GetVolumeFromTopPlane(
        Transform plane,
        Vector2 dimensions,
        float height,
        out Vector3 position,
        out Quaternion rotation,
        out Vector3 localScale)
    {
        position = plane.position;
        rotation = plane.rotation;
        localScale = new Vector3(dimensions.x, dimensions.y, height);
    }

    private void GetTopPlaneFromVolume(
        Transform volume,
        Vector3 dimensions,
        out Vector3 position,
        out Quaternion rotation,
        out Vector3 localScale)
    {
        float halfHeight = dimensions.y / 2.0f;
        position = volume.position + Vector3.up * halfHeight;
        rotation = Quaternion.LookRotation(Vector3.up, -volume.forward);
        localScale = new Vector3(dimensions.x, dimensions.z, dimensions.y);
    }
}