using JdeScoping.Core.ViewModels;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Logging;

namespace JdeScoping.Api.Hubs;

/// <summary>
/// SignalR hub for real-time status updates
/// </summary>
public class StatusHub : Hub
{
    private const string StatusCacheKey = "StatusHub_CachedStatus";

    private readonly IMemoryCache _cache;
    private readonly ILogger<StatusHub> _logger;
    private readonly TimeProvider _timeProvider;

    /// <summary>
    /// Initializes a new instance of the <see cref="StatusHub"/> class.
    /// </summary>
    /// <param name="cache">The memory cache for caching status updates.</param>
    /// <param name="logger">The logger instance.</param>
    /// <param name="timeProvider">The time provider for getting current UTC time.</param>
    public StatusHub(IMemoryCache cache, ILogger<StatusHub> logger, TimeProvider timeProvider)
    {
        _cache = cache;
        _logger = logger;
        _timeProvider = timeProvider;
    }

    /// <summary>
    /// Called by worker service to update status.
    /// Caches the update and broadcasts to all clients.
    /// </summary>
    /// <param name="statusUpdate">Status update to broadcast</param>
    public async Task SetStatus(StatusUpdateViewModel statusUpdate)
    {
        _cache.Set(StatusCacheKey, statusUpdate);
        await Clients.All.SendAsync("statusUpdate", statusUpdate);
        _logger.LogDebug("Status updated: {Message}", statusUpdate.Message);
    }

    /// <summary>
    /// Called by clients to get initial cached status on connection.
    /// </summary>
    /// <returns>The most recent status update</returns>
    public StatusUpdateViewModel GetCachedStatus()
    {
        return _cache.GetOrCreate(StatusCacheKey, _ => new StatusUpdateViewModel
        {
            Message = "Unknown",
            Timestamp = _timeProvider.GetUtcNow().DateTime
        })!;
    }

    /// <summary>
    /// Called by controllers/services to broadcast search updates.
    /// </summary>
    /// <param name="searchUpdate">Search update to broadcast</param>
    public async Task PublishSearchUpdate(SearchUpdateViewModel searchUpdate)
    {
        await Clients.All.SendAsync("searchUpdate", searchUpdate);
        _logger.LogDebug("Search update published: ID={Id}, Status={Status}", searchUpdate.Id, searchUpdate.Status);
    }

    /// <inheritdoc />
    public override Task OnConnectedAsync()
    {
        _logger.LogInformation("Client {ConnectionId} connected to StatusHub", Context.ConnectionId);
        return base.OnConnectedAsync();
    }

    /// <inheritdoc />
    public override Task OnDisconnectedAsync(Exception? exception)
    {
        _logger.LogInformation("Client {ConnectionId} disconnected from StatusHub", Context.ConnectionId);
        return base.OnDisconnectedAsync(exception);
    }
}