using DigitalData.Core.Abstractions.Security;
using DigitalData.Core.Security.Config;
using DigitalData.Core.Security.Cryptographer;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using System.Security.Claims;

namespace DigitalData.Core.Security
{
    public static class DIExtensions
    {
        private static IServiceCollection AddParamsConfigureOptions<TParams>(this IServiceCollection services) where TParams : RSAFactoryParams
            => services.AddSingleton<IConfigureOptions<TParams>, ParamsConfigureOptions<TParams>>();

        private static IServiceCollection AddAsymCryptService(this IServiceCollection services) => services
            .AddParamsConfigureOptions<AsymCryptParams>()
            .AddAutoMapper(typeof(MappingProfile).Assembly)
            .AddSingleton<IAsymCryptHandler, AsymCryptHandler>();

        /// <summary>
        /// Registers a custom asym crypt service with specified parameters from the given configuration section.
        /// </summary>
        /// <param name="services"></param>
        /// <param name="section"></param>
        /// <returns>The updated <see cref="IServiceCollection"/> with the RSA Factory registered.</returns>
        public static IServiceCollection AddAsymCryptService(this IServiceCollection services, IConfigurationSection section) => services
            .Configure<AsymCryptParams>(section)
            .AddAsymCryptService();

        /// <summary>
        /// Registers an asym crypt service with the specified parameters from the given instance.
        /// </summary>
        /// <param name="services"></param>
        /// <returns>The updated <see cref="IServiceCollection"/> with the RSA Factory registered.</returns>
        public static IServiceCollection AddAsymCryptService(this IServiceCollection services, AsymCryptParams? asymCryptParams = null) => services
            .AddSingleton(Options.Create(asymCryptParams ?? new()))
            .AddAsymCryptService();

        /// <summary>
        /// Registers a custom RSA Factory with specified parameters from the given configuration section.
        /// </summary>
        /// <param name="services"></param>
        /// <param name="section"></param>
        /// <returns>The updated <see cref="IServiceCollection"/> with the RSA Factory registered.</returns>
        public static IServiceCollection AddRSAFactory(this IServiceCollection services, IConfigurationSection section) => services
            .AddParamsConfigureOptions<RSAFactoryParams>()
            .Configure<RSAFactoryParams>(section)
            .AddSingleton<IRSAFactory, RSAFactory<RSAFactoryParams>>();

        private static IServiceCollection AddClaimDescriptor<TPrincipal>(this IServiceCollection services,
            Func<TPrincipal, IDictionary<string, object>>? claimsMapper = null,
            Func<TPrincipal, ClaimsIdentity>? subjectMapper = null)
        {
            var descriptor = new ClaimDescriptor<TPrincipal>
            {
                CreateClaims = claimsMapper,
                CreateSubject = subjectMapper
            };

            return services.AddSingleton(sp => Options.Create(descriptor));
        }

        public static IServiceCollection AddTokenDescriptions(this IServiceCollection services, IConfiguration configuration)
            => services.Configure<IEnumerable<TokenDescription>>(configuration);

        public static IServiceCollection AddTokenDescriptions(this IServiceCollection services, params TokenDescription[] tokenDescriptions)
            => services.AddSingleton<IOptions<IEnumerable<TokenDescription>>>(Options.Create(tokenDescriptions));

        public static IServiceCollection AddJwtSignatureHandler<TPrincipal>(this IServiceCollection services, Func<TPrincipal, IDictionary<string, object>>? claimsMapper = null, Func<TPrincipal, ClaimsIdentity>? subjectMapper = null, IConfiguration? tokenDescriptionconfig = null, params TokenDescription[]? tokenDescriptions)
        {
            if (tokenDescriptionconfig is not null)
                services.AddTokenDescriptions(tokenDescriptionconfig);

            if (tokenDescriptions is not null)
                services.AddTokenDescriptions(tokenDescriptions);

            return services
                .AddClaimDescriptor(claimsMapper: claimsMapper, subjectMapper: subjectMapper)
                .AddSingleton<IJwtSignatureHandler<TPrincipal>, JwtSignatureHandler<TPrincipal>>();
        }
    }
}