using BTCPayServer.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.AspNetCore.Hosting;
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.AspNetCore.Http;
using NBitpayClient;
using NBitcoin;
using BTCPayServer.Data;
using Microsoft.EntityFrameworkCore;
using System.IO;
using Microsoft.Data.Sqlite;
using NBXplorer;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.Hosting;
using BTCPayServer.Services;
using BTCPayServer.Services.Invoices;
using BTCPayServer.Services.Rates;
using BTCPayServer.Services.Stores;
using BTCPayServer.Services.Fees;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Rewrite;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Options;
using Microsoft.AspNetCore.Authorization;
using BTCPayServer.Controllers;
using BTCPayServer.Services.Mails;
using Microsoft.AspNetCore.Identity;
using BTCPayServer.Models;
using System.Threading.Tasks;
using System.Threading;
using BTCPayServer.Services.Wallets;
using BTCPayServer.Authentication;
using Microsoft.Extensions.Caching.Memory;
using BTCPayServer.Logging;

namespace BTCPayServer.Hosting
{
    public static class BTCPayServerServices
    {
        public class OwnStoreAuthorizationRequirement : IAuthorizationRequirement
        {
            public OwnStoreAuthorizationRequirement()
            {
            }

            public OwnStoreAuthorizationRequirement(string role)
            {
                Role = role;
            }

            public string Role
            {
                get; set;
            }
        }

        public class OwnStoreHandler : AuthorizationHandler<OwnStoreAuthorizationRequirement>
        {
            StoreRepository _StoreRepository;
            UserManager<ApplicationUser> _UserManager;
            public OwnStoreHandler(StoreRepository storeRepository, UserManager<ApplicationUser> userManager)
            {
                _StoreRepository = storeRepository;
                _UserManager = userManager;
            }
            protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, OwnStoreAuthorizationRequirement requirement)
            {
                object storeId = null;
                if (!((Microsoft.AspNetCore.Mvc.ActionContext)context.Resource).RouteData.Values.TryGetValue("storeId", out storeId))
                    context.Succeed(requirement);
                else if (storeId != null)
                {
                    var user = _UserManager.GetUserId(((Microsoft.AspNetCore.Mvc.ActionContext)context.Resource).HttpContext.User);
                    if (user != null)
                    {
                        var store = await _StoreRepository.FindStore((string)storeId, user);
                        if (store != null)
                            if (requirement.Role == null || requirement.Role == store.Role)
                                context.Succeed(requirement);
                    }
                }
            }
        }
        public static IServiceCollection AddBTCPayServer(this IServiceCollection services)
        {
            services.AddDbContext<ApplicationDbContext>((provider, o) =>
            {
                var factory = provider.GetRequiredService<ApplicationDbContextFactory>();
                factory.ConfigureBuilder(o);
            });
            services.TryAddSingleton<SettingsRepository>();
            services.TryAddSingleton<InvoicePaymentNotification>();
            services.TryAddSingleton<BTCPayServerOptions>(o => o.GetRequiredService<IOptions<BTCPayServerOptions>>().Value);
            services.TryAddSingleton<InvoiceRepository>(o =>
            {
                var opts = o.GetRequiredService<BTCPayServerOptions>();
                var dbContext = o.GetRequiredService<ApplicationDbContextFactory>();
                var dbpath = Path.Combine(opts.DataDir, "InvoiceDB");
                if (!Directory.Exists(dbpath))
                    Directory.CreateDirectory(dbpath);
                return new InvoiceRepository(dbContext, dbpath, opts.Network);
            });
            services.AddSingleton<BTCPayServerEnvironment>();
            services.TryAddSingleton<TokenRepository>();
            services.TryAddSingleton<EventAggregator>();
            services.TryAddSingleton<ApplicationDbContextFactory>(o => 
            {
                var opts = o.GetRequiredService<BTCPayServerOptions>();
                ApplicationDbContextFactory dbContext = null;
                if (opts.PostgresConnectionString == null)
                {
                    var connStr = "Data Source=" + Path.Combine(opts.DataDir, "sqllite.db");
                    Logs.Configuration.LogInformation($"SQLite DB used ({connStr})");
                    dbContext = new ApplicationDbContextFactory(DatabaseType.Sqlite, connStr);
                }
                else
                {
                    Logs.Configuration.LogInformation($"Postgres DB used ({opts.PostgresConnectionString})");
                    dbContext = new ApplicationDbContextFactory(DatabaseType.Postgres, opts.PostgresConnectionString);
                }
                return dbContext;
            });

            services.TryAddSingleton<BTCPayNetworkProvider>(o => 
            {
                var opts = o.GetRequiredService<BTCPayServerOptions>();
                return new BTCPayNetworkProvider(opts.Network);
            });

            services.TryAddSingleton<StoreRepository>();
            services.TryAddSingleton<BTCPayWallet>();
            services.TryAddSingleton<CurrencyNameTable>();
            services.TryAddSingleton<IFeeProviderFactory>(o => new NBXplorerFeeProviderFactory(o.GetRequiredService<ExplorerClient>())
            {
                Fallback = new FeeRate(100, 1),
                BlockTarget = 20
            });

            services.TryAddSingleton<NBXplorerWaiterAccessor>();
            services.AddSingleton<IHostedService, NBXplorerWaiter>();
            services.TryAddSingleton<ExplorerClient>(o =>
            {
                var opts = o.GetRequiredService<BTCPayServerOptions>();
                var explorer = new ExplorerClient(opts.Network, opts.Explorer);
                if (!explorer.SetCookieAuth(opts.CookieFile))
                    explorer.SetNoAuth();
                return explorer;
            });
            services.TryAddSingleton<Bitpay>(o =>
            {
                if (o.GetRequiredService<BTCPayServerOptions>().Network == Network.Main)
                    return new Bitpay(new Key(), new Uri("https://bitpay.com/"));
                else
                    return new Bitpay(new Key(), new Uri("https://test.bitpay.com/"));
            });
            services.TryAddSingleton<IRateProvider>(o =>
            {
                var coinaverage = new CoinAverageRateProvider();
                var bitpay = new BitpayRateProvider(new Bitpay(new Key(), new Uri("https://bitpay.com/")));
                return new CachedRateProvider(new FallbackRateProvider(new IRateProvider[] { coinaverage, bitpay }), o.GetRequiredService<IMemoryCache>()) { CacheSpan = TimeSpan.FromMinutes(1.0) };
            });
            
            services.AddSingleton<IHostedService, InvoiceNotificationManager>();

            services.TryAddSingleton<InvoiceWatcherAccessor>();
            services.AddSingleton<IHostedService, InvoiceWatcher>();
            services.TryAddScoped<IHttpContextAccessor, HttpContextAccessor>();
            services.TryAddSingleton<IAuthorizationHandler, OwnStoreHandler>();
            services.AddTransient<AccessTokenController>();
            services.AddTransient<InvoiceController>();
            // Add application services.
            services.AddTransient<IEmailSender, EmailSender>();

            services.AddAuthorization(o =>
            {
                o.AddPolicy("CanAccessStore", builder =>
                {
                    builder.AddRequirements(new OwnStoreAuthorizationRequirement());
                });

                o.AddPolicy("OwnStore", builder =>
                {
                    builder.AddRequirements(new OwnStoreAuthorizationRequirement("Owner"));
                });
            });

            return services;
        }

        public static IApplicationBuilder UsePayServer(this IApplicationBuilder app)
        {
            using (var scope = app.ApplicationServices.GetService<IServiceScopeFactory>().CreateScope())
            {
                //Wait the DB is ready
                Retry(() =>
                {
                    scope.ServiceProvider.GetRequiredService<ApplicationDbContext>().Database.Migrate();
                });
            }

            app.UseMiddleware<BTCPayMiddleware>();
            return app;
        }

        static void Retry(Action act)
        {
            CancellationTokenSource cts = new CancellationTokenSource(10000);
            while (true)
            {
                try
                {
                    act();
                    return;
                }
                catch
                {
                    if (cts.IsCancellationRequested)
                        throw;
                    Thread.Sleep(1000);
                }
            }
        }
    }


}