using System.IO;
using System.Reflection;
using System.Linq;
using System;
using System.Collections.Generic;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.ApiExplorer;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.Extensions.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.OpenApi.Models;
using Microsoft.Extensions.Options;
using Swashbuckle.AspNetCore.SwaggerGen;

using AyaNova.Models;
using AyaNova.Util;
using AyaNova.Generator;
using AyaNova.Biz;


using NLog.Web;
using NLog.Targets;
using NLog.Config;
using NLog.Extensions.Logging;

namespace AyaNova
{
    public class Startup
    {
        /////////////////////////////////////////////////////////////
        //
        public Startup( Microsoft.AspNetCore.Hosting.IWebHostEnvironment hostingEnvironment)
        {//ILogger<Startup> logger, ILoggerFactory logFactory,

                // Get the factory for ILogger instances.
    var nlogLoggerProvider = new NLogLoggerProvider();

    // Create an ILogger.
    _newLog = nlogLoggerProvider.CreateLogger(typeof(Startup).FullName);

            //x_log = logger;
            _hostingEnvironment = hostingEnvironment;
            //AyaNova.Util.ApplicationLogging.LoggerFactory = logFactory;
            //AyaNova.Util.ApplicationLogging.theLogger = _newLog;
            AyaNova.Util.ApplicationLogging.LoggerProvider=nlogLoggerProvider;

            //this must be set here
            ServerBootConfig.AYANOVA_CONTENT_ROOT_PATH = hostingEnvironment.ContentRootPath;

        }

        private readonly ILogger _newLog;

       // private readonly ILogger<Startup>x_log;
        private string _connectionString = "";
        private readonly Microsoft.AspNetCore.Hosting.IWebHostEnvironment _hostingEnvironment;

        ////////////////////////////////////////////////////////////
        // This method gets called by the runtime. Use this method to add services to the container.
        //
        public void ConfigureServices(IServiceCollection services)
        {
            _newLog.LogDebug("BOOT: initializing services...");



            //Server state service for shutting people out of api
            _newLog.LogDebug("BOOT: init ApiServerState service");
            services.AddSingleton(new AyaNova.Api.ControllerHelpers.ApiServerState());

            //Init controllers
            _newLog.LogDebug("BOOT: init controllers");
            var MvcBuilder = services.AddControllers(config =>
                          {
                             // config.Filters.Add(new AyaNova.Api.ControllerHelpers.ApiCustomExceptionFilter(AyaNova.Util.ApplicationLogging.LoggerFactory));
                              config.Filters.Add(new AyaNova.Api.ControllerHelpers.ApiCustomExceptionFilter(_newLog));
                          });

            //Prevent default model binding automatic 400 page so we can consistently show *our* error to our specs
            //https://docs.microsoft.com/en-us/aspnet/core/web-api/index?view=aspnetcore-3.1#automatic-http-400-responses
            MvcBuilder.ConfigureApiBehaviorOptions(options =>
                    {
                        options.SuppressModelStateInvalidFilter = true;
                    });

            _newLog.LogDebug("BOOT: init JSON");
            MvcBuilder.AddNewtonsoftJson(options =>
                {
                    options.SerializerSettings.DateTimeZoneHandling = Newtonsoft.Json.DateTimeZoneHandling.Utc;
                });




            //2019-10-17 METRICS will not work just yet with .netcore 3.1 see here https://github.com/AppMetrics/AppMetrics/issues/480
            //awaiting a new release from them
            _newLog.LogDebug("BOOT: init Metrics service");
            services.AddMetrics();





            _newLog.LogDebug("BOOT: ensuring user and backup folders exist and are separate locations...");
            FileUtil.EnsureUserAndUtilityFoldersExistAndAreNotIdentical(_hostingEnvironment.ContentRootPath);

            #region DATABASE
            _connectionString = ServerBootConfig.AYANOVA_DB_CONNECTION;

            //Check DB server exists and can be connected to
            _newLog.LogDebug("BOOT: Testing database server connection...");

            //parse the connection string properly
            DbUtil.ParseConnectionString(_newLog, _connectionString);

            //Probe for database server
            //Will retry every 10 seconds for up to 5 minutes before bailing
            if (!DbUtil.DatabaseServerExists(_newLog, "BOOT: waiting for db server "))
            {
                var err = $"BOOT: E1000 - AyaNova can't connect to the database server after trying for 5 minutes (connection string is:\"{DbUtil.DisplayableConnectionString}\")";
                _newLog.LogCritical(err);
                throw new System.ApplicationException(err);
            }



            _newLog.LogInformation("BOOT: Connected to database server - {0}", DbUtil.DisplayableConnectionString);


            //ensure database is ready and present
            DbUtil.EnsureDatabaseExists(_newLog);

            bool LOG_SENSITIVE_DATA = false;

#if (DEBUG)
            // LOG_SENSITIVE_DATA = true;

#endif

            _newLog.LogDebug("BOOT: init EF service");

            services.AddEntityFrameworkNpgsql().AddDbContext<AyContext>(
                options => options.UseNpgsql(_connectionString
                //,opt => opt.EnableRetryOnFailure()//REMOVED THIS BECAUSE IT WAS INTEFERING WITH TRANSACTIONS BUT THEN DIDN'T USE THE TRANSACTION BUT IT SEEMS FASTER WITHOUT IT AS WELL SO...??
                )//http://www.npgsql.org/efcore/misc.html?q=execution%20strategy#execution-strategy
                            .ConfigureWarnings(warnings => //https://livebook.manning.com/#!/book/entity-framework-core-in-action/chapter-12/v-10/85
                                    warnings.Throw( //Throw an exception on client eval, not necessarily an error but a smell
                                                    // Microsoft.EntityFrameworkCore.Diagnostics.RelationalEventId.QueryClientEvaluationWarning
                                    ))
                            .EnableSensitiveDataLogging(LOG_SENSITIVE_DATA)
                );




            #endregion


            // Add service and create Policy with options
            _newLog.LogDebug("BOOT: init CORS service");
            services.AddCors(options =>
            {
                options.AddPolicy("CorsPolicy",
                    builder => builder.AllowAnyOrigin()
                    .AllowAnyMethod()
                    .AllowAnyHeader()
                    //.AllowCredentials()
                    );
            });




            #region Swagger

            services
                 .AddApiVersioning(options =>
                 {
                     options.AssumeDefaultVersionWhenUnspecified = true;
                     options.DefaultApiVersion = Microsoft.AspNetCore.Mvc.ApiVersion.Parse("8.0");
                     options.ReportApiVersions = true;
                 });
            services.AddVersionedApiExplorer(options => options.GroupNameFormat = "'v'VVV");
            services.AddTransient<IConfigureOptions<SwaggerGenOptions>, ConfigureSwaggerOptions>();
            services.AddSwaggerGen(
                c =>
                {
                    // integrate xml comments
                    c.IncludeXmlComments(XmlCommentsFilePath);

                    //https://stackoverflow.com/questions/56234504/migrating-to-swashbuckle-aspnetcore-version-5
                    //First we define the security scheme
                    c.AddSecurityDefinition("Bearer", //Name the security scheme
                        new OpenApiSecurityScheme
                        {
                            Description = "JWT Authorization header using the Bearer scheme.",
                            Type = SecuritySchemeType.Http, //We set the scheme type to http since we're using bearer authentication
                            Scheme = "bearer" //The name of the HTTP Authorization scheme to be used in the Authorization header. In this case "bearer".
                        });

                    c.AddSecurityRequirement(new OpenApiSecurityRequirement{
                                    {
                                        new OpenApiSecurityScheme{
                                            Reference = new OpenApiReference{
                                                Id = "Bearer", //The name of the previously defined security scheme.
                                                Type = ReferenceType.SecurityScheme
                                            }
                                        },new List<string>()
                                    }
                                });
                }
            );


            #endregion

            #region JWT AUTHENTICATION
            //get the key if specified
            var secretKey = ServerBootConfig.AYANOVA_JWT_SECRET;

            //If no key specified make a unique one
            //This means the jwt creds won't survive a server reboot
            //so in that case users need to specify an AyaNova_JWT_SECRET environment variable
            if (string.IsNullOrWhiteSpace(secretKey))
            {
                secretKey = Util.Hasher.GenerateSalt();
            }
            //WAS "UNLICENSED5G*QQJ8#bQ7$Xr_@sXfHq4"


            //If secretKey is less than 32 characters, pad it
            if (secretKey.Length < 32)
            {
                secretKey = secretKey.PadRight(32, '-');
            }

            ServerBootConfig.AYANOVA_JWT_SECRET = secretKey;
            var signingKey = new SymmetricSecurityKey(System.Text.Encoding.ASCII.GetBytes(ServerBootConfig.AYANOVA_JWT_SECRET));

            _newLog.LogDebug("BOOT: init Authorization service");
            services.AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            }).AddJwtBearer(options =>
                {
                    // options.AutomaticAuthenticate = true;
                    // options.AutomaticChallenge = true;
                    options.TokenValidationParameters = new TokenValidationParameters
                    {
                        // Token signature will be verified using a private key.
                        ValidateIssuerSigningKey = true,
                        RequireSignedTokens = true,
                        IssuerSigningKey = signingKey,
                        ValidateIssuer = true,
                        ValidIssuer = "ayanova.com",
                        ValidateAudience = false,
                        //ValidAudience = "http://localhost:7575/"

                        // Token will only be valid if not expired yet, with 5 minutes clock skew.
                        ValidateLifetime = true,
                        RequireExpirationTime = true,
                        ClockSkew = new TimeSpan(0, 5, 0),
                    };
                });



            #endregion

            _newLog.LogDebug("BOOT: init Generator service");
            services.AddSingleton<IHostedService, GeneratorService>();

        }



        ////////////////////////////////////////////////////////////
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        //
        public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.IWebHostEnvironment env,
        AyContext dbContext, IApiVersionDescriptionProvider provider, AyaNova.Api.ControllerHelpers.ApiServerState apiServerState, IServiceProvider serviceProvider)
        {
            _newLog.LogDebug("BOOT: configuring request pipeline...");

            //this *may* be useful in the event of an issue so uncomment if necessary but errors during dev are handled equally by the logging, I think
            // if (env.IsDevelopment())
            // {
            //     app.UseDeveloperExceptionPage();
            // }


            //Store a reference to the dependency injection service for static classes 
            ServiceProviderProvider.Provider = app.ApplicationServices;

            //Enable ability to handle reverse proxy
            app.UseForwardedHeaders(new ForwardedHeadersOptions
            {
                ForwardedHeaders = Microsoft.AspNetCore.HttpOverrides.ForwardedHeaders.XForwardedFor | Microsoft.AspNetCore.HttpOverrides.ForwardedHeaders.XForwardedProto
            });

            #region STATIC FILES
            _newLog.LogDebug("BOOT: pipeline - static files");
            app.UseDefaultFiles();
            app.UseStaticFiles();
            //Might need the following if the page doesn't update in the client properly
            //however the vue build process will automatically uniquify each build file names so maybe not required
            // app.UseStaticFiles(new StaticFileOptions
            // {
            //     OnPrepareResponse = context =>
            //     {
            //         if (context.File.Name == "index.html")
            //         {
            //             context.Context.Response.Headers.Add("Cache-Control", "no-cache, no-store");
            //             context.Context.Response.Headers.Add("Expires", "-1");
            //         }
            //     }
            // });
            #endregion

            _newLog.LogDebug("BOOT: pipeline - ROUTING");
            app.UseRouting();//this wasn't here for 2.2 but added for 3.0, needs to come before the stuff after 

            _newLog.LogDebug("BOOT: pipeline - CORS");
            app.UseCors("CorsPolicy");


            #region AUTH / ROLES
            _newLog.LogDebug("BOOT: pipeline - authentication");
            //Use authentication middleware
            app.UseAuthentication();

            _newLog.LogDebug("BOOT: pipeline - authorization");
            app.UseAuthorization();


            //Custom middleware to get user roles and put them into the request so 
            //they can be authorized in routes.
            app.Use(async (context, next) =>
            {
                if (!context.User.Identity.IsAuthenticated)
                {
                    context.Request.HttpContext.Items["AY_ROLES"] = 0;
                }
                else
                {
                    //Get user ID from claims
                    long userId = Convert.ToInt64(context.User.FindFirst(c => c.Type == "id").Value);

                    //Get the database context
                    var ct = context.RequestServices.GetService<AyContext>();

                    //get the user record
                    var u = ct.User.AsNoTracking().Where(a => a.Id == userId).Select(m => new { roles = m.Roles, name = m.Name, id = m.Id, localeId = m.LocaleId }).First();
                    context.Request.HttpContext.Items["AY_ROLES"] = u.roles;
                    context.Request.HttpContext.Items["AY_USERNAME"] = u.name;
                    context.Request.HttpContext.Items["AY_USER_ID"] = u.id;
                    context.Request.HttpContext.Items["AY_LOCALE_ID"] = u.localeId;
                }
                await next.Invoke();
            });

            #endregion

            _newLog.LogDebug("BOOT: pipeline - ENDPOINTS");
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });

            #region SWAGGER

            _newLog.LogDebug("BOOT: pipeline - api explorer");
            // Enable middleware to serve generated Swagger as a JSON endpoint.          
            app.UseSwagger();
            app.UseSwaggerUI(
                   options =>
                   {
                       foreach (var description in provider.ApiVersionDescriptions)
                       {
                           options.SwaggerEndpoint(
                               $"/swagger/{description.GroupName}/swagger.json",
                               description.GroupName.ToUpperInvariant());
                       }
                       options.DefaultModelsExpandDepth(-1);//This is meant to hide the Models section that would appear at the bottom of the swagger ui showing *all* models from the api
                       options.DocumentTitle = "AyaNova API explorer";
                       options.RoutePrefix = "api-docs";
                   });


            #endregion swagger


            // ******************************************************************
            // ******************** TESTING WIPE DB *****************************
            //
            //Set this to true to wipe the db and reinstall a trial license and re-seed the data
            var TESTING_REFRESH_DB = true;//#######################################################################################

#if (DEBUG)
            //TESTING
            if (TESTING_REFRESH_DB)
                ServerBootConfig.AYANOVA_PERMANENTLY_ERASE_DATABASE = TESTING_REFRESH_DB;
            //TESTING
#endif


            if (ServerBootConfig.AYANOVA_PERMANENTLY_ERASE_DATABASE)
            {
                _newLog.LogWarning("BOOT: AYANOVA_PERMANENTLY_ERASE_DATABASE is true, dropping and recreating database");
                Util.DbUtil.DropAndRecreateDb(_newLog);
                AySchema.CheckAndUpdate(dbContext, _newLog);
            }

            //Check schema
            _newLog.LogDebug("BOOT: db schema check");
            AySchema.CheckAndUpdate(dbContext, _newLog);

            //Check database integrity
            _newLog.LogDebug("BOOT: db integrity check");
            DbUtil.CheckFingerPrint(AySchema.EXPECTED_COLUMN_COUNT, AySchema.EXPECTED_INDEX_COUNT, _newLog);

            //Initialize license
            AyaNova.Core.License.Initialize(apiServerState, dbContext, _newLog);

            //Ensure locales are present, not missing any keys and that there is a server default locale that exists          
            LocaleBiz lb = new LocaleBiz(dbContext, 1, ServerBootConfig.AYANOVA_DEFAULT_LANGUAGE_ID, AuthorizationRoles.OpsAdminFull);
            lb.ValidateLocales();



#if (DEBUG)
            //TESTING
            if (TESTING_REFRESH_DB)
            {
                AyaNova.Core.License.Fetch(apiServerState, dbContext, _newLog);
                Util.Seeder.SeedDatabase(Util.Seeder.SeedLevel.SmallOneManShopTrialDataSet, -7);//#############################################################################################
            }
            //TESTING
#endif


            //AUTOID VALUES INITIALIZATION 
            ServerBootConfig.SetMostRecentAutoIdValuesFromDatabase(dbContext);

            //SPA FALLBACK ROUTE                 
            app.Use(async (context, next) =>
            {
                //to support html5 pushstate routing in spa
                //this ensures that a refresh at the client will not 404 but rather force back to the index.html app page and then handled internally by the client 
                await next();
                if (!context.Response.HasStarted && context.Request.Path.Value != "/docs" && context.Response.StatusCode == 404 && !Path.HasExtension(context.Request.Path.Value))
                {
                    context.Request.Path = "/index.html";
                    context.Response.StatusCode = 200;
                    context.Response.ContentType = "text/html";
                    await context.Response.SendFileAsync(Path.Combine(env.WebRootPath, "index.html"));
                }
            });


            //Log the active user count so it's in the log record
            _newLog.LogInformation($"BOOT: Active techs - {UserBiz.ActiveCount}");

            //Log the license info so it's on the record
            _newLog.LogInformation($"BOOT: License -\r\n=-=-=-=-=-=-=-=-=-=-\r\n{AyaNova.Core.License.LicenseInfo}=-=-=-=-=-=-=-=-=-=-");



            //Open up the server for visitors
            apiServerState.SetOpen();

            //final startup log
            _newLog.LogInformation("BOOT: COMPLETED - SERVER IS NOW OPEN");

        }


        #region Swagger and API Versioning utilities

        static string XmlCommentsFilePath
        {
            get
            {
                var basePath = AppContext.BaseDirectory;
                var fileName = typeof(Startup).GetTypeInfo().Assembly.GetName().Name + ".xml";
                return Path.Combine(basePath, fileName);
            }
        }


        #endregion
    }
}