// Copyright (c) Jan Škoruba. All Rights Reserved.
// Licensed under the Apache License, Version 2.0.

using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Serilog;
using Skoruba.Duende.IdentityServer.Admin.EntityFramework.Configuration.Configuration;
using LiteCharmsSecurity.Admin.EntityFramework.Shared.DbContexts;
using LiteCharmsSecurity.Admin.EntityFramework.Shared.Entities.Identity;
using LiteCharmsSecurity.Admin.EntityFramework.Shared.Helpers;
using Skoruba.Duende.IdentityServer.Shared.Configuration.Helpers;

namespace LiteCharmsSecurity.Admin.Api
{
    public class Program
    {
        private const string SeedArgs = "/seed";
        private const string MigrateOnlyArgs = "/migrateonly";

        public static async Task Main(string[] args)
        {
            var configuration = GetConfiguration(args);

            Log.Logger = new LoggerConfiguration()
                .ReadFrom.Configuration(configuration)
                .CreateLogger();
            try
            {
                DockerHelpers.ApplyDockerConfiguration(configuration);

                var host = CreateHostBuilder(args).Build();

                var migrationComplete = await ApplyDbMigrationsWithDataSeedAsync(args, configuration, host);
                if (await MigrateOnlyOperationAsync(args, host, migrationComplete)) return;

                await host.RunAsync();
            }
            catch (Exception ex)
            {
                Log.Fatal(ex, "Host terminated unexpectedly");
            }
            finally
            {
                await Log.CloseAndFlushAsync();
            }
        }

        private static async Task<bool> MigrateOnlyOperationAsync(string[] args, IHost host, bool migrationComplete)
        {
            if (args.All(x => x != MigrateOnlyArgs)) return false;

            await host.StopAsync();

            if (!migrationComplete)
            {
                Environment.ExitCode = -1;
            }

            return true;
        }

        private static async Task<bool> ApplyDbMigrationsWithDataSeedAsync(string[] args, IConfiguration configuration,
            IHost host)
        {
            var applyDbMigrationWithDataSeedFromProgramArguments = args.Any(x => x == SeedArgs);
            if (applyDbMigrationWithDataSeedFromProgramArguments) args = args.Except(new[] { SeedArgs }).ToArray();

            var seedConfiguration = configuration.GetSection(nameof(SeedConfiguration)).Get<SeedConfiguration>();
            var databaseMigrationsConfiguration = configuration.GetSection(nameof(DatabaseMigrationsConfiguration))
                .Get<DatabaseMigrationsConfiguration>();

            return await DbMigrationHelpers
                .ApplyDbMigrationsWithDataSeedAsync<IdentityServerConfigurationDbContext, AdminIdentityDbContext,
                    IdentityServerPersistedGrantDbContext, AdminLogDbContext, AdminAuditLogDbContext,
                    IdentityServerDataProtectionDbContext, AdminConfigurationDbContext, UserIdentity, UserIdentityRole>(host,
                    applyDbMigrationWithDataSeedFromProgramArguments, seedConfiguration,
                    databaseMigrationsConfiguration);
        }


        private static IConfiguration GetConfiguration(string[] args)
        {
            var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
            var isDevelopment = environment == Environments.Development;

            var configurationBuilder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{environment}.json", optional: true, reloadOnChange: true)
                .AddJsonFile("serilog.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"serilog.{environment}.json", optional: true, reloadOnChange: true);

            if (isDevelopment)
            {
                configurationBuilder.AddUserSecrets<Startup>(true);
            }

            var configuration = configurationBuilder.Build();

            configuration.AddAzureKeyVaultConfiguration(configurationBuilder);

            configurationBuilder.AddCommandLine(args);
            configurationBuilder.AddEnvironmentVariables();

            return configurationBuilder.Build();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureAppConfiguration((hostContext, configApp) =>
                {
                    var configurationRoot = configApp.Build();

                    configApp.AddJsonFile("serilog.json", optional: true, reloadOnChange: true);
                    configApp.AddJsonFile("identitydata.json", optional: true, reloadOnChange: true);
                    configApp.AddJsonFile("identityserverdata.json", optional: true, reloadOnChange: true);

                    var env = hostContext.HostingEnvironment;

                    configApp.AddJsonFile($"serilog.{env.EnvironmentName}.json", optional: true, reloadOnChange: true);
                    configApp.AddJsonFile($"identitydata.{env.EnvironmentName}.json", optional: true,
                        reloadOnChange: true);
                    configApp.AddJsonFile($"identityserverdata.{env.EnvironmentName}.json", optional: true,
                        reloadOnChange: true);

                    if (env.IsDevelopment())
                    {
                        configApp.AddUserSecrets<Startup>(true);
                    }

                    configurationRoot.AddAzureKeyVaultConfiguration(configApp);

                    configApp.AddEnvironmentVariables();
                    configApp.AddCommandLine(args);
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.ConfigureKestrel(options => options.AddServerHeader = false);
                    webBuilder.UseStartup<Startup>();
                })
                .UseSerilog((hostContext, loggerConfig) =>
                {
                    loggerConfig
                        .ReadFrom.Configuration(hostContext.Configuration)
                        .Enrich.WithProperty("ApplicationName", hostContext.HostingEnvironment.ApplicationName);
                });
    }
}