using System.Collections.Generic;
using InfiniteWorld.VoxelWorld;
using InfiniteWorld.VoxelWorld.Contracts;
using UnityEngine;

namespace VoxelWorldScene
{
    /// <summary>
    /// Combines the world generator's current stream target with scene spawn anchors into one interest feed for nav coverage.
    /// </summary>
    public sealed class SceneWorldInterestReader : IWorldInterestReader
    {
        private readonly VoxelWorldGenerator worldGenerator;
        private VoxelWorldSpawnAnchor[] spawnAnchors;
        private int lastAnchorRefreshFrame = -1;

        public SceneWorldInterestReader(VoxelWorldGenerator worldGenerator)
        {
            this.worldGenerator = worldGenerator;
        }

        /// <summary>
        /// Mirrors the generator's interest version so downstream systems can invalidate cached plans when scene interest changes.
        /// </summary>
        public int InterestVersion => worldGenerator != null ? worldGenerator.InterestVersion : 0;

        /// <summary>
        /// Appends both dynamic actor interest and static spawn-anchor interest into the supplied list.
        /// </summary>
        public void GetInterestPoints(List<WorldInterestPoint> results)
        {
            if (results == null)
            {
                return;
            }

            worldGenerator?.GetInterestPoints(results);
            RefreshSpawnAnchors();

            if (spawnAnchors == null)
            {
                return;
            }

            for (int i = 0; i < spawnAnchors.Length; i++)
            {
                VoxelWorldSpawnAnchor anchor = spawnAnchors[i];
                if (anchor == null || !anchor.isActiveAndEnabled)
                {
                    continue;
                }

                results.Add(new WorldInterestPoint(anchor.transform.position, anchor.Priority, WorldInterestKind.SpawnAnchor));
            }
        }

        private void RefreshSpawnAnchors()
        {
            if (lastAnchorRefreshFrame == Time.frameCount)
            {
                return;
            }

            lastAnchorRefreshFrame = Time.frameCount;
            spawnAnchors = Object.FindObjectsByType<VoxelWorldSpawnAnchor>(FindObjectsInactive.Exclude, FindObjectsSortMode.None);
        }
    }
}