using Core.Blueprint.Mongo;
using Core.Blueprint.Mongo.Configuration;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using MongoDB.Driver;

namespace Core.Blueprint.DAL.Mongo.Configuration
{
    /// <summary>
    /// The <see cref="RegisterBlueprint"/> class contains extension methods for registering the MongoDB context and configuration settings 
    /// to the <see cref="IServiceCollection"/> in the dependency injection container.
    /// </summary>
    public static class RegisterBlueprint
    {
        /// <summary>
        /// Adds the MongoDB layer services to the <see cref="IServiceCollection"/>.
        /// Registers the MongoDB context and configuration settings for MongoDB connection, database name, and audience.
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection"/> to which the services will be added.</param>
        /// <param name="configuration">The <see cref="IConfiguration"/> used to load MongoDB settings.</param>
        /// <returns>The updated <see cref="IServiceCollection"/> with MongoDB services registered.</returns>
        public static IServiceCollection AddMongoLayer(this IServiceCollection services, IConfiguration configuration)
        {
            var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? string.Empty;

            services.AddSingleton<IMongoContext, MongoContext>();

            var ConnectionString = configuration.GetSection("ConnectionStrings:MongoDB").Value ?? string.Empty;
            var Databasename = configuration.GetSection("MongoDb:DatabaseName").Value ?? string.Empty;
            var Audience = (environment == "Local")
                ? configuration.GetSection("MongoDb:LocalAudience").Value
                : configuration.GetSection("MongoDb:Audience").Value;

            if (string.IsNullOrEmpty(ConnectionString) || string.IsNullOrEmpty(Databasename) || string.IsNullOrEmpty(Audience))
                throw new InvalidOperationException("Mongo connection is not configured correctly.");

            services.Configure<MongoDbSettings>(options =>
            {
                options.ConnectionString = ConnectionString;
                options.Databasename = Databasename;
                options.Audience = Audience;
            });

            services.AddSingleton<IMongoClient>(serviceProvider =>
            {
                var settings = serviceProvider.GetRequiredService<IOptions<MongoDbSettings>>().Value;
                var mongoClientSettings = MongoClientSettings.FromConnectionString(settings.ConnectionString);
                mongoClientSettings.Credential = MongoCredential.CreateOidcCredential(new AzureIdentityProvider(settings.Audience));
                return new MongoClient(mongoClientSettings);
            });

            services.AddSingleton<IMongoDatabase>(serviceProvider =>
            {
                var settings = serviceProvider.GetRequiredService<IOptions<MongoDbSettings>>().Value;
                var client = serviceProvider.GetRequiredService<IMongoClient>();
                return client.GetDatabase(settings.Databasename);
            });

            services.AddSingleton<IMongoDbSettings>(serviceProvider => serviceProvider.GetRequiredService<IOptions<MongoDbSettings>>().Value);

            return services;
        }
    }
}