namespace OECS;

/// <summary>
/// Describes a component type discovered at compile time by the source generator.
/// Used by <see cref="WorldSerializer"/> to save/load components without reflection.
/// </summary>
public sealed class ComponentDescriptor
{
    /// <summary>
    /// The assembly-qualified name of the component type, for stable serialization
    /// across assemblies.
    /// </summary>
    public string TypeName { get; }

    /// <summary>
    /// The <see cref="System.Type"/> of the component.
    /// </summary>
    public Type Type { get; }

    /// <summary>
    /// Serializes a boxed component instance to a MessagePack byte array.
    /// </summary>
    public Func<object, byte[]> Serialize { get; }

    /// <summary>
    /// Deserializes a MessagePack byte array and adds the component to the entity
    /// via the typed <see cref="World.AddComponent{T}"/> method. No reflection.
    /// </summary>
    public Action<World, Entity, byte[]> DeserializeAndAdd { get; }

    /// <summary>
    /// Deserializes a MessagePack byte array to a boxed component object.
    /// Used by <see cref="WorldSerializer"/> for relationship fixup before adding.
    /// </summary>
    public Func<byte[], object> Deserialize { get; }

    public ComponentDescriptor(
        string typeName,
        Type type,
        Func<object, byte[]> serialize,
        Action<World, Entity, byte[]> deserializeAndAdd,
        Func<byte[], object> deserialize)
    {
        TypeName = typeName;
        Type = type;
        Serialize = serialize;
        DeserializeAndAdd = deserializeAndAdd;
        Deserialize = deserialize;
    }
}