using System;
using System.Security.Claims;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;
using Bit.Api.Utilities;
using Bit.Core;
using Bit.Core.Identity;
using System.Linq;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.Net.Http.Headers;
using Newtonsoft.Json.Serialization;
using AspNetCoreRateLimit;
using Serilog.Events;
using Stripe;
using Bit.Core.Utilities;
using IdentityModel;
using IdentityServer4.AccessTokenValidation;
using jsreport.AspNetCore;
using Bit.Core.IdentityServer;

namespace Bit.Api
{
    public class Startup
    {
        public Startup(IHostingEnvironment env, IConfiguration configuration)
        {
            Configuration = configuration;
            Environment = env;
        }

        public IConfiguration Configuration { get; private set; }
        public IHostingEnvironment Environment { get; set; }

        public void ConfigureServices(IServiceCollection services)
        {
            var provider = services.BuildServiceProvider();

            // Options
            services.AddOptions();

            // Settings
            var globalSettings = services.AddGlobalSettingsServices(Configuration);
            services.Configure<ApiSettings>(Configuration.GetSection("apiSettings"));
            if(!globalSettings.SelfHosted)
            {
                services.Configure<IpRateLimitOptions>(Configuration.GetSection("IpRateLimitOptions"));
                services.Configure<IpRateLimitPolicies>(Configuration.GetSection("IpRateLimitPolicies"));
            }

            // Data Protection
            services.AddCustomDataProtectionServices(Environment, globalSettings);

            // Stripe Billing
            StripeConfiguration.SetApiKey(globalSettings.StripeApiKey);

            // Repositories
            services.AddSqlServerRepositories(globalSettings);

            // Context
            services.AddScoped<CurrentContext>();

            // Caching
            services.AddMemoryCache();

            if(!globalSettings.SelfHosted)
            {
                // Rate limiting
                services.AddSingleton<IIpPolicyStore, MemoryCacheIpPolicyStore>();
                services.AddSingleton<IRateLimitCounterStore, MemoryCacheRateLimitCounterStore>();
            }

            // Identity
            services.AddCustomIdentityServices(globalSettings);

            services
                .AddAuthentication(IdentityServerAuthenticationDefaults.AuthenticationScheme)
                .AddIdentityServerAuthentication(options =>
                {
                    options.Authority = globalSettings.BaseServiceUri.InternalIdentity;
                    options.RequireHttpsMetadata = !Environment.IsDevelopment() &&
                        globalSettings.BaseServiceUri.InternalIdentity.StartsWith("https");
                    options.NameClaimType = ClaimTypes.Email;
                    options.TokenRetriever = TokenRetrieval.FromAuthorizationHeaderOrQueryString(
                        new string[] { "Bearer", "Bearer3" });
                    options.SupportedTokens = SupportedTokens.Jwt;
                });

            services.AddAuthorization(config =>
            {
                config.AddPolicy("Application", policy =>
                {
                    policy.RequireAuthenticatedUser();
                    policy.RequireClaim(JwtClaimTypes.AuthenticationMethod, "Application");
                    policy.RequireClaim(JwtClaimTypes.Scope, "api");
                });
                config.AddPolicy("Web", policy =>
                {
                    policy.RequireAuthenticatedUser();
                    policy.RequireClaim(JwtClaimTypes.AuthenticationMethod, "Application");
                    policy.RequireClaim(JwtClaimTypes.Scope, "api");
                    policy.RequireClaim(JwtClaimTypes.ClientId, "web");
                });
                config.AddPolicy("Push", policy =>
                {
                    policy.RequireAuthenticatedUser();
                    policy.RequireClaim(JwtClaimTypes.Scope, "api.push");
                });
                config.AddPolicy("Licensing", policy =>
                {
                    policy.RequireAuthenticatedUser();
                    policy.RequireClaim(JwtClaimTypes.Scope, "api.licensing");
                });
            });

            services.AddScoped<AuthenticatorTokenProvider>();

            // Services
            services.AddBaseServices();
            services.AddDefaultServices(globalSettings);

            // Cors
            services.AddCors(config =>
            {
                config.AddPolicy("All", policy =>
                    policy.AllowAnyHeader().AllowAnyMethod().AllowAnyOrigin().SetPreflightMaxAge(TimeSpan.FromDays(1)));
            });

            // MVC
            services.AddMvc(config =>
            {
                config.Filters.Add(new ExceptionHandlerFilterAttribute());
                config.Filters.Add(new ModelStateValidationFilterAttribute());

                // Allow JSON of content type "text/plain" to avoid cors preflight
                var textPlainMediaType = MediaTypeHeaderValue.Parse("text/plain");
                foreach(var jsonFormatter in config.InputFormatters.OfType<JsonInputFormatter>())
                {
                    jsonFormatter.SupportedMediaTypes.Add(textPlainMediaType);
                }
            }).AddJsonOptions(options => options.SerializerSettings.ContractResolver = new DefaultContractResolver());

            // PDF generation
            if(!globalSettings.SelfHosted)
            {
                services.AddJsReport(new jsreport.Local.LocalReporting()
                    .UseBinary(jsreport.Binary.JsReportBinary.GetBinary())
                    .AsUtility()
                    .Create());
            }
        }

        public void Configure(
            IApplicationBuilder app,
            IHostingEnvironment env,
            ILoggerFactory loggerFactory,
            IApplicationLifetime appLifetime,
            GlobalSettings globalSettings)
        {
            loggerFactory.AddSerilog(env, appLifetime, globalSettings, (e) =>
            {
                var context = e.Properties["SourceContext"].ToString();
                if(e.Exception != null && (e.Exception.GetType() == typeof(SecurityTokenValidationException) ||
                    e.Exception.Message == "Bad security stamp."))
                {
                    return false;
                }

                if(context.Contains(typeof(IpRateLimitMiddleware).FullName) && e.Level == LogEventLevel.Information)
                {
                    return true;
                }

                if(context.Contains("IdentityServer4.Validation.TokenValidator") ||
                    context.Contains("IdentityServer4.Validation.TokenRequestValidator"))
                {
                    return e.Level > LogEventLevel.Error;
                }

                return e.Level >= LogEventLevel.Error;
            });

            // Default Middleware
            app.UseDefaultMiddleware(env);

            if(!globalSettings.SelfHosted)
            {
                // Rate limiting
                app.UseMiddleware<CustomIpRateLimitMiddleware>();
            }

            // Add static files to the request pipeline.
            app.UseStaticFiles();

            // Add Cors
            app.UseCors("All");

            // Add authentication to the request pipeline.
            app.UseAuthentication();

            // Add current context
            app.UseMiddleware<CurrentContextMiddleware>();

            // Add MVC to the request pipeline.
            app.UseMvc();
        }
    }
}