using System.Security.Cryptography;
using System.Text;
using System.Text.Encodings.Web;
using System.Text.Json;
using System.Text.Json.Serialization;
using static StellaOps.Localization.T;

namespace StellaOps.Canonicalization.Json;

/// <summary>
/// Produces canonical JSON output with deterministic ordering.
/// Implements RFC 8785 principles for stable output.
/// </summary>
public static class CanonicalJsonSerializer
{
    private static readonly JsonSerializerOptions _options = new()
    {
        WriteIndented = false,
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        DictionaryKeyPolicy = JsonNamingPolicy.CamelCase,
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
        NumberHandling = JsonNumberHandling.Strict,
        Converters =
        {
            new StableDictionaryConverterFactory(),
            new Iso8601DateTimeConverter()
        }
    };

    public static string Serialize<T>(T value)
        => JsonSerializer.Serialize(value, _options);

    public static (string Json, string Digest) SerializeWithDigest<T>(T value)
    {
        var json = Serialize(value);
        var hash = SHA256.HashData(Encoding.UTF8.GetBytes(json));
        var digest = Convert.ToHexString(hash).ToLowerInvariant();
        return (json, digest);
    }

    public static T Deserialize<T>(string json)
    {
        return JsonSerializer.Deserialize<T>(json, _options)
            ?? throw new InvalidOperationException(_t("common.canonicalization.deserialize_failed", typeof(T).Name));
    }
}