using System.Collections.Concurrent;
using Json.Schema;

namespace NeonSprawl.Server;

/// <summary>
/// Thread-safe registration for <see cref="SchemaRegistry.Global"/> (JsonSchema.Net registry is not concurrent).
/// Used by content catalog loaders when parallel integration tests spin up multiple hosts.
/// </summary>
internal static class CatalogSchemaRegistry
{
    private static readonly Lock RegisterLock = new();
    private static readonly ConcurrentDictionary<string, JsonSchema> SchemasByPath =
        new(StringComparer.Ordinal);

    /// <summary>Parses <paramref name="schemaFilePath"/> once per process and registers it under a global lock.</summary>
    public static JsonSchema GetOrRegisterFromFile(string schemaFilePath)
    {
        var fullPath = Path.GetFullPath(schemaFilePath);
        if (SchemasByPath.TryGetValue(fullPath, out var cached))
            return cached;

        lock (RegisterLock)
        {
            if (SchemasByPath.TryGetValue(fullPath, out cached))
                return cached;

            var schema = JsonSchema.FromText(File.ReadAllText(fullPath));
            SchemaRegistry.Global.Register(schema);
            SchemasByPath[fullPath] = schema;
            return schema;
        }
    }
}