using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;

namespace ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests;

/// <summary>
/// DeploymentManagerOptions must be resolvable via the
/// Options pattern and bindable to the "ScadaBridge:DeploymentManager"
/// configuration section. The component itself does not depend on
/// IConfiguration (enforced by Host's OptionsTests) — the Host binds the
/// section; AddDeploymentManager only guarantees IOptions resolvability.
/// </summary>
public class ServiceCollectionExtensionsTests
{
    /// <summary>Verifies that AddDeploymentManager registers resolvable options with default values.</summary>
    [Fact]
    public void AddDeploymentManager_RegistersResolvableOptions_WithDefaults()
    {
        var services = new ServiceCollection();
        services.AddDeploymentManager();

        using var provider = services.BuildServiceProvider();
        var options = provider.GetRequiredService<IOptions<DeploymentManagerOptions>>().Value;

        // No section bound -> the option-class defaults are retained.
        Assert.Equal(TimeSpan.FromSeconds(5), options.OperationLockTimeout);
    }

    /// <summary>Verifies that the options bind to the configuration section the way the host wires them.</summary>
    [Fact]
    public void AddDeploymentManager_OptionsBindToConfigurationSection_AsTheHostWires()
    {
        // Mirrors the Host wiring: the Host calls Configure<DeploymentManagerOptions>
        // against OptionsSection, then AddDeploymentManager().
        var configuration = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                ["ScadaBridge:DeploymentManager:OperationLockTimeout"] = "00:00:09",
                ["ScadaBridge:DeploymentManager:ArtifactDeploymentTimeoutPerSite"] = "00:03:00"
            })
            .Build();

        var services = new ServiceCollection();
        services.Configure<DeploymentManagerOptions>(
            configuration.GetSection(ServiceCollectionExtensions.OptionsSection));
        services.AddDeploymentManager();

        using var provider = services.BuildServiceProvider();
        var options = provider.GetRequiredService<IOptions<DeploymentManagerOptions>>().Value;

        Assert.Equal(TimeSpan.FromSeconds(9), options.OperationLockTimeout);
        Assert.Equal(TimeSpan.FromMinutes(3), options.ArtifactDeploymentTimeoutPerSite);
    }

    /// <summary>Verifies that the options section name matches the conventional component section path.</summary>
    [Fact]
    public void OptionsSection_MatchesTheConventionalComponentSectionPath()
    {
        Assert.Equal("ScadaBridge:DeploymentManager", ServiceCollectionExtensions.OptionsSection);
    }

    // The deployment-status notifier must be a singleton so the
    // scoped DeploymentService and the Central UI's scoped Blazor page share
    // one instance — without that, a push notification raised by the service
    // would never reach the page's subscription.
    /// <summary>Verifies that AddDeploymentManager registers the deployment status notifier as a singleton.</summary>
    [Fact]
    public void AddDeploymentManager_RegistersDeploymentStatusNotifier_AsSingleton()
    {
        var services = new ServiceCollection();
        services.AddLogging();
        services.AddDeploymentManager();

        using var provider = services.BuildServiceProvider();

        var fromRoot = provider.GetRequiredService<IDeploymentStatusNotifier>();
        using var scope = provider.CreateScope();
        var fromScope = scope.ServiceProvider.GetRequiredService<IDeploymentStatusNotifier>();

        Assert.IsType<DeploymentStatusNotifier>(fromRoot);
        Assert.Same(fromRoot, fromScope);
    }
}