using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Serilog.Context;
using ZB.MOM.WW.CBDDC.Network;

namespace ZB.MOM.WW.CBDDC.Hosting.HostedServices;

/// <summary>
/// Hosted service that manages the lifecycle of the discovery service.
/// </summary>
public class DiscoveryServiceHostedService : IHostedService
{
    private readonly IDiscoveryService _discoveryService;
    private readonly ILogger<DiscoveryServiceHostedService> _logger;

    /// <summary>
    /// Initializes a new instance of the <see cref="DiscoveryServiceHostedService"/> class.
    /// </summary>
    /// <param name="discoveryService">The discovery service to manage.</param>
    /// <param name="logger">The logger used for service lifecycle events.</param>
    public DiscoveryServiceHostedService(
        IDiscoveryService discoveryService,
        ILogger<DiscoveryServiceHostedService> logger)
    {
        _discoveryService = discoveryService;
        _logger = logger;
    }

    /// <summary>
    /// Starts the discovery service.
    /// </summary>
    /// <param name="cancellationToken">A token used to cancel the startup operation.</param>
    /// <returns>A task that represents the asynchronous start operation.</returns>
    public async Task StartAsync(CancellationToken cancellationToken)
    {
        using var serviceContext = LogContext.PushProperty("Service", nameof(DiscoveryServiceHostedService));
        using var operationContext = LogContext.PushProperty("OperationId", Guid.NewGuid().ToString("N"));
        using var actionContext = LogContext.PushProperty("Action", "Start");

        _logger.LogInformation("Starting Discovery Service...");
        await _discoveryService.Start();
        _logger.LogInformation("Discovery Service started");
    }

    /// <summary>
    /// Stops the discovery service.
    /// </summary>
    /// <param name="cancellationToken">A token used to cancel the shutdown operation.</param>
    /// <returns>A task that represents the asynchronous stop operation.</returns>
    public async Task StopAsync(CancellationToken cancellationToken)
    {
        using var serviceContext = LogContext.PushProperty("Service", nameof(DiscoveryServiceHostedService));
        using var operationContext = LogContext.PushProperty("OperationId", Guid.NewGuid().ToString("N"));
        using var actionContext = LogContext.PushProperty("Action", "Stop");

        _logger.LogInformation("Stopping Discovery Service...");
        await _discoveryService.Stop();
        _logger.LogInformation("Discovery Service stopped");
    }
}