using System;
using UnityEngine.AI;

namespace Game.Scripts.Runtime.Navigation
{
    /// <summary>
    /// Lightweight cache around NavMesh availability checks so gameplay code
    /// can gracefully degrade when a bake is not present.
    /// </summary>
    public static class NavMeshRuntimeUtility
    {
        private static bool? _cachedHasNavMesh;

        /// <summary>
        /// Returns true if there is any baked NavMesh data loaded at runtime.
        /// Result is cached until <see cref="InvalidateCache"/> is called.
        /// </summary>
        public static bool HasNavMeshData()
        {
            if (_cachedHasNavMesh.HasValue)
            {
                return _cachedHasNavMesh.Value;
            }

            try
            {
                var triangulation = NavMesh.CalculateTriangulation();
                var hasData = triangulation.vertices != null && triangulation.vertices.Length > 0;
                _cachedHasNavMesh = hasData;
                return hasData;
            }
            catch (Exception)
            {
                _cachedHasNavMesh = false;
                return false;
            }
        }

        /// <summary>
        /// Clears the cached NavMesh availability state. Call this after baking at runtime.
        /// </summary>
        public static void InvalidateCache()
        {
            _cachedHasNavMesh = null;
        }
    }
}