using System;
using System.Globalization;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Net.Mime;
using System.Text;
using Jellyfin.MediaEncoding.Hls.Extensions;
using Jellyfin.Networking.Configuration;
using Jellyfin.Server.Extensions;
using Jellyfin.Server.HealthChecks;
using Jellyfin.Server.Implementations;
using Jellyfin.Server.Implementations.Extensions;
using Jellyfin.Server.Infrastructure;
using Jellyfin.Server.Middleware;
using MediaBrowser.Common.Net;
using MediaBrowser.Controller;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Extensions;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Infrastructure;
using Microsoft.AspNetCore.StaticFiles;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Hosting;
using Prometheus;

namespace Jellyfin.Server
{
    /// <summary>
    /// Startup configuration for the Kestrel webhost.
    /// </summary>
    public class Startup
    {
        private readonly IServerConfigurationManager _serverConfigurationManager;
        private readonly IServerApplicationHost _serverApplicationHost;

        /// <summary>
        /// Initializes a new instance of the <see cref="Startup" /> class.
        /// </summary>
        /// <param name="serverConfigurationManager">The server configuration manager.</param>
        /// <param name="serverApplicationHost">The server application host.</param>
        public Startup(
            IServerConfigurationManager serverConfigurationManager,
            IServerApplicationHost serverApplicationHost)
        {
            _serverConfigurationManager = serverConfigurationManager;
            _serverApplicationHost = serverApplicationHost;
        }

        /// <summary>
        /// Configures the service collection for the webhost.
        /// </summary>
        /// <param name="services">The service collection.</param>
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddResponseCompression();
            services.AddHttpContextAccessor();
            services.AddHttpsRedirection(options =>
            {
                options.HttpsPort = _serverApplicationHost.HttpsPort;
            });

            // TODO remove once this is fixed upstream https://github.com/dotnet/aspnetcore/issues/34371
            services.AddSingleton<IActionResultExecutor<PhysicalFileResult>, SymlinkFollowingPhysicalFileResultExecutor>();
            services.AddJellyfinApi(_serverApplicationHost.GetApiPluginAssemblies(), _serverConfigurationManager.GetNetworkConfiguration());
            services.AddJellyfinDbContext();
            services.AddJellyfinApiSwagger();

            // configure custom legacy authentication
            services.AddCustomAuthentication();

            services.AddJellyfinApiAuthorization();

            var productHeader = new ProductInfoHeaderValue(
                _serverApplicationHost.Name.Replace(' ', '-'),
                _serverApplicationHost.ApplicationVersionString);
            var acceptJsonHeader = new MediaTypeWithQualityHeaderValue(MediaTypeNames.Application.Json, 1.0);
            var acceptXmlHeader = new MediaTypeWithQualityHeaderValue(MediaTypeNames.Application.Xml, 0.9);
            var acceptAnyHeader = new MediaTypeWithQualityHeaderValue("*/*", 0.8);
            Func<IServiceProvider, HttpMessageHandler> defaultHttpClientHandlerDelegate = (_) => new SocketsHttpHandler()
            {
                AutomaticDecompression = DecompressionMethods.All,
                RequestHeaderEncodingSelector = (_, _) => Encoding.UTF8
            };

            services
                .AddHttpClient(NamedClient.Default, c =>
                {
                    c.DefaultRequestHeaders.UserAgent.Add(productHeader);
                    c.DefaultRequestHeaders.Accept.Add(acceptJsonHeader);
                    c.DefaultRequestHeaders.Accept.Add(acceptXmlHeader);
                    c.DefaultRequestHeaders.Accept.Add(acceptAnyHeader);
                })
                .ConfigurePrimaryHttpMessageHandler(defaultHttpClientHandlerDelegate);

            services.AddHttpClient(NamedClient.MusicBrainz, c =>
                {
                    c.DefaultRequestHeaders.UserAgent.Add(productHeader);
                    c.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue($"({_serverApplicationHost.ApplicationUserAgentAddress})"));
                    c.DefaultRequestHeaders.Accept.Add(acceptXmlHeader);
                    c.DefaultRequestHeaders.Accept.Add(acceptAnyHeader);
                })
                .ConfigurePrimaryHttpMessageHandler(defaultHttpClientHandlerDelegate);

            services.AddHttpClient(NamedClient.Dlna, c =>
                {
                    c.DefaultRequestHeaders.UserAgent.ParseAdd(
                        string.Format(
                            CultureInfo.InvariantCulture,
                            "{0}/{1} UPnP/1.0 {2}/{3}",
                            MediaBrowser.Common.System.OperatingSystem.Name,
                            Environment.OSVersion,
                            _serverApplicationHost.Name,
                            _serverApplicationHost.ApplicationVersionString));

                    c.DefaultRequestHeaders.Add("CPFN.UPNP.ORG", _serverApplicationHost.FriendlyName); // Required for UPnP DeviceArchitecture v2.0
                    c.DefaultRequestHeaders.Add("FriendlyName.DLNA.ORG", _serverApplicationHost.FriendlyName); // REVIEW: where does this come from?
                })
                .ConfigurePrimaryHttpMessageHandler(defaultHttpClientHandlerDelegate);

            services.AddHealthChecks()
                .AddCheck<DbContextFactoryHealthCheck<JellyfinDb>>(nameof(JellyfinDb));

            services.AddHlsPlaylistGenerator();
        }

        /// <summary>
        /// Configures the app builder for the webhost.
        /// </summary>
        /// <param name="app">The application builder.</param>
        /// <param name="env">The webhost environment.</param>
        /// <param name="appConfig">The application config.</param>
        public void Configure(
            IApplicationBuilder app,
            IWebHostEnvironment env,
            IConfiguration appConfig)
        {
            app.UseBaseUrlRedirection();

            // Wrap rest of configuration so everything only listens on BaseUrl.
            var config = _serverConfigurationManager.GetNetworkConfiguration();
            app.Map(config.BaseUrl, mainApp =>
            {
                if (env.IsDevelopment())
                {
                    mainApp.UseDeveloperExceptionPage();
                }

                mainApp.UseForwardedHeaders();
                mainApp.UseMiddleware<ExceptionMiddleware>();

                mainApp.UseMiddleware<ResponseTimeMiddleware>();

                mainApp.UseWebSockets();

                mainApp.UseResponseCompression();

                mainApp.UseCors();

                if (config.RequireHttps && _serverApplicationHost.ListenWithHttps)
                {
                    mainApp.UseHttpsRedirection();
                }

                // This must be injected before any path related middleware.
                mainApp.UsePathTrim();
                mainApp.UseStaticFiles();
                if (appConfig.HostWebClient())
                {
                    var extensionProvider = new FileExtensionContentTypeProvider();

                    // subtitles octopus requires .data, .mem files.
                    extensionProvider.Mappings.Add(".data", MediaTypeNames.Application.Octet);
                    extensionProvider.Mappings.Add(".mem", MediaTypeNames.Application.Octet);
                    mainApp.UseStaticFiles(new StaticFileOptions
                    {
                        FileProvider = new PhysicalFileProvider(_serverConfigurationManager.ApplicationPaths.WebPath),
                        RequestPath = "/web",
                        ContentTypeProvider = extensionProvider
                    });

                    mainApp.UseRobotsRedirection();
                }

                mainApp.UseAuthentication();
                mainApp.UseJellyfinApiSwagger(_serverConfigurationManager);
                mainApp.UseQueryStringDecoding();
                mainApp.UseRouting();
                mainApp.UseAuthorization();

                mainApp.UseLanFiltering();
                mainApp.UseIpBasedAccessValidation();
                mainApp.UseWebSocketHandler();
                mainApp.UseServerStartupMessage();

                if (_serverConfigurationManager.Configuration.EnableMetrics)
                {
                    // Must be registered after any middleware that could change HTTP response codes or the data will be bad
                    mainApp.UseHttpMetrics();
                }

                mainApp.UseEndpoints(endpoints =>
                {
                    endpoints.MapControllers();
                    if (_serverConfigurationManager.Configuration.EnableMetrics)
                    {
                        endpoints.MapMetrics("/metrics");
                    }

                    endpoints.MapHealthChecks("/health");
                });
            });
        }
    }
}