// VexTrustGateServiceCollectionExtensions - DI registration
// Part of SPRINT_1227_0004_0003: VexTrustGate Policy Integration

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using StellaOps.Policy.Engine.Confidence;
using StellaOps.Policy.Engine.Gates;

namespace StellaOps.Policy.Engine.DependencyInjection;

/// <summary>
/// Extension methods for registering VEX trust gate services.
/// </summary>
public static class VexTrustGateServiceCollectionExtensions
{
    /// <summary>
    /// Add VEX trust gate services to the DI container.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configuration">The configuration root.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddVexTrustGate(
        this IServiceCollection services,
        IConfiguration configuration)
    {
        ArgumentNullException.ThrowIfNull(services);
        ArgumentNullException.ThrowIfNull(configuration);

        // Bind options
        services.Configure<VexTrustGateOptions>(
            configuration.GetSection(VexTrustGateOptions.SectionKey));

        // Register gate
        services.TryAddSingleton<IVexTrustGate, VexTrustGate>();

        // Register metrics
        services.TryAddSingleton<VexTrustGateMetrics>();

        // Register confidence factor provider
        services.TryAddSingleton<IConfidenceFactorProvider, VexTrustConfidenceFactorProvider>();

        return services;
    }

    /// <summary>
    /// Add VEX trust gate with custom options.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configureOptions">Action to configure options.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddVexTrustGate(
        this IServiceCollection services,
        Action<VexTrustGateOptions> configureOptions)
    {
        ArgumentNullException.ThrowIfNull(services);
        ArgumentNullException.ThrowIfNull(configureOptions);

        services.Configure(configureOptions);

        services.TryAddSingleton<IVexTrustGate, VexTrustGate>();
        services.TryAddSingleton<VexTrustGateMetrics>();
        services.TryAddSingleton<IConfidenceFactorProvider, VexTrustConfidenceFactorProvider>();

        return services;
    }
}