using System;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using StellaOps.Signals.Models;

namespace StellaOps.Signals.Services;

/// <summary>
/// Placeholder events publisher; replace with real bus integration when contracts are finalized.
/// </summary>
internal sealed class InMemoryEventsPublisher : IEventsPublisher
{
    private readonly ILogger<InMemoryEventsPublisher> logger;
    private readonly ReachabilityFactEventBuilder eventBuilder;
    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web)
    {
        WriteIndented = false,
        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull
    };

    public InMemoryEventsPublisher(ILogger<InMemoryEventsPublisher> logger, ReachabilityFactEventBuilder eventBuilder)
    {
        this.logger = logger;
        this.eventBuilder = eventBuilder ?? throw new ArgumentNullException(nameof(eventBuilder));
    }

    public Task PublishFactUpdatedAsync(ReachabilityFactDocument fact, CancellationToken cancellationToken)
    {
        ArgumentNullException.ThrowIfNull(fact);

        var envelope = eventBuilder.Build(fact);
        var json = JsonSerializer.Serialize(envelope, SerializerOptions);

        logger.LogInformation(json);
        return Task.CompletedTask;
    }
}