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

namespace StellaOps.Provcache;

/// <summary>
/// Extension methods for registering Provcache services.
/// </summary>
public static partial class ProvcacheServiceCollectionExtensions
{
    /// <summary>
    /// Adds Provcache services to the service collection.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configuration">The configuration section.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddProvcache(
        this IServiceCollection services,
        IConfiguration configuration)
    {
        ArgumentNullException.ThrowIfNull(services);
        ArgumentNullException.ThrowIfNull(configuration);

        var section = configuration.GetSection(ProvcacheOptions.SectionName);

        // Register options
        services.AddOptions<ProvcacheOptions>()
            .Bind(section)
            .ValidateDataAnnotations()
            .ValidateOnStart();

        services.AddOptions<LazyFetchHttpOptions>()
            .Bind(section.GetSection(LazyFetchHttpOptions.SectionName))
            .ValidateDataAnnotations()
            .ValidateOnStart();

        // Register core services
        services.AddSingleton<IProvcacheService, ProvcacheService>();

        // Register write-behind queue as hosted service
        services.AddSingleton<IWriteBehindQueue, WriteBehindQueue>();
        services.AddHostedService<WriteBehindQueueHostedService>();
        services.AddHttpClient(HttpChunkFetcher.HttpClientName);
        services.AddProvcacheInvalidators();

        return services;
    }

    /// <summary>
    /// Adds Provcache services with custom options.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configure">Action to configure options.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddProvcache(
        this IServiceCollection services,
        Action<ProvcacheOptions> configure)
    {
        ArgumentNullException.ThrowIfNull(services);
        ArgumentNullException.ThrowIfNull(configure);

        // Register options
        services.AddOptions<ProvcacheOptions>()
            .Configure(configure)
            .ValidateDataAnnotations()
            .ValidateOnStart();

        services.AddOptions<LazyFetchHttpOptions>()
            .ValidateDataAnnotations()
            .ValidateOnStart();

        // Register core services
        services.AddSingleton<IProvcacheService, ProvcacheService>();

        // Register write-behind queue as hosted service
        services.AddSingleton<IWriteBehindQueue, WriteBehindQueue>();
        services.AddHostedService<WriteBehindQueueHostedService>();
        services.AddHttpClient(HttpChunkFetcher.HttpClientName);
        services.AddProvcacheInvalidators();

        return services;
    }

}