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

namespace DigitalData.Core.Abstractions;

/// <summary>
/// Extension methods for <see cref="IServiceProvider"/> to retrieve configuration options.
/// </summary>
public static class ServiceProviderExtensions
{
    /// <summary>
    /// Retrieves an instance of <typeparamref name="TOptions"/> from the <see cref="IServiceProvider"/>.
    /// If the options are not registered, returns null.
    /// </summary>
    /// <typeparam name="TOptions">The type of the options to retrieve.</typeparam>
    /// <param name="service">The service provider instance.</param>
    /// <returns>An instance of <typeparamref name="TOptions"/> or null if not found.</returns>
    public static TOptions? GetOptions<TOptions>(this IServiceProvider service) where TOptions : class
        => service.GetService<IOptions<TOptions>>()?.Value;

    /// <summary>
    /// Retrieves an instance of <typeparamref name="TOptions"/> from the <see cref="IServiceProvider"/>.
    /// Throws an exception if the options are not registered.
    /// </summary>
    /// <typeparam name="TOptions">The type of the options to retrieve.</typeparam>
    /// <param name="service">The service provider instance.</param>
    /// <returns>An instance of <typeparamref name="TOptions"/>.</returns>
    /// <exception cref="InvalidOperationException">Thrown when the options are not registered.</exception>
    public static TOptions GetRequiredOptions<TOptions>(this IServiceProvider service) where TOptions : class
        => service.GetRequiredService<IOptions<TOptions>>().Value;
}