using System.Text.Json.Nodes;

namespace w4c_workflows.Services.Nodes.Executors;

/// <summary>
/// Resolves an item field by name, with optional dot notation for nested
/// objects (<c>user.name</c> → <c>{ "user": { "name": … } }</c>). Missing paths
/// return null, never throw, so sort/dedup/aggregate treat them as empty.
/// </summary>
internal static class NodeJsonPath
{
    public static JsonNode? Read(JsonObject json, string? path, bool dotNotation)
    {
        if (string.IsNullOrEmpty(path))
            return null;

        if (!dotNotation || !path.Contains('.'))
            return json.TryGetPropertyValue(path, out var direct) ? direct : null;

        JsonNode? current = json;
        foreach (var segment in path.Split('.'))
        {
            if (current is not JsonObject obj || !obj.TryGetPropertyValue(segment, out current))
                return null;
        }

        return current;
    }
}