using System.Collections.Generic;
using Unity.Properties;

namespace Uigenx.Binding
{
    /// <summary>
    /// Caches parsed <see cref="PropertyPath"/> values. Parsing allocates one substring per segment,
    /// so anything that resolves a path more than once should go through here.
    /// </summary>
    public static class UgxPropertyPaths
    {
        /// <summary>
        /// Upper bound on cached paths. Paths come from generated code and from the studio, so the
        /// working set is small; the cap only stops a misbehaving peer from growing the cache.
        /// </summary>
        public const int MaxCached = 512;

        static readonly Dictionary<string, PropertyPath> Cache = new Dictionary<string, PropertyPath>(64);

        public static PropertyPath Get(string path)
        {
            if (string.IsNullOrEmpty(path)) return default;
            if (Cache.TryGetValue(path, out var cached)) return cached;

            var parsed = new PropertyPath(path);
            if (Cache.Count < MaxCached) Cache[path] = parsed;
            return parsed;
        }

        public static void ClearCache() => Cache.Clear();
    }
}