using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.CommandLineUtils;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Serilog;
using Strata.Configuration.Client.DependencyInjection;
using Strata.ContinuousImprovement.Biz.DbContexts;
using Strata.healthchecks.Biz;
using Strata.Logging.DependencyInjection;
using Strata.Snowflake.Migrations.Client;
using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Threading.Tasks;

namespace Strata.ContinuousImprovement.Api
{
    [ExcludeFromCodeCoverage]
    public class Program
    {
        public static void Main(string[] args)
        {
            try
            {
                var commandLineApplication = new CommandLineApplication(false);
                var doMigrate = commandLineApplication.Option(
                    "--ef-migrate",
                    "Apply entity framework migrations and exit",
                    CommandOptionType.NoValue);

                commandLineApplication.HelpOption("-? | -h | --help");
                commandLineApplication.OnExecute(async () =>
                {
                    await ExecuteApp(args, doMigrate);
                    return 0;
                });
                commandLineApplication.Execute(args);
            }
            catch (Exception ex)
            {
                Log.Error(ex, "There was an unhandled exception that caused the program to crash");

                //This is for serilog to ensure that all of the cached logs are flushed when the app crashes
                //This is useful so we can capture logs when the application crashes during startup:
                Log.CloseAndFlush();
            }
        }

        public static async Task ExecuteApp(string[] args, CommandOption doMigrate)
        {
            var webHost = CreateWebHostBuilder(args).Build();

            if (doMigrate.HasValue())
            {
                using var scope = webHost.Services.CreateScope();
                var logger = scope.ServiceProvider.GetRequiredService<ILogger<Program>>();

                try
                {
                    // Snowflake Migrations
                    logger.LogInformation("Uploading and applying Snowflake migrations");
                    var snowflakeMigrationService = scope.ServiceProvider.GetRequiredService<ISnowflakeMigrationService>();
                    var snowflakeMigrationDirectory = Path.Combine(Environment.CurrentDirectory, "SnowflakeMigrations");
                    var success = await snowflakeMigrationService.PackageMigrations(snowflakeMigrationDirectory);
                    if (!success)
                    {
                        logger.LogError("Failed to package migrations.");
                        Environment.Exit(1);
                    }
                    logger.LogInformation("Snowflake migrations successfully uploaded to S3. Begin apply migrations.");
                    success = await snowflakeMigrationService.ApplyClientMigrations();
                    if (!success)
                    {
                        logger.LogError("Failed to apply migrations.");
                        Environment.Exit(1);
                    }

                    // EF Migrations
                    logger.LogInformation("Applying Entity Framework migrations");
                    using var context = scope.ServiceProvider.GetService<CentralDbContext>();
                    var hostEnv = scope.ServiceProvider.GetService<IHostEnvironment>();

                    context.Database.SetCommandTimeout(TimeSpan.FromMinutes(10));
                    context.Database.Migrate();
                    logger.LogInformation("All done, closing app");
                    Environment.Exit(Environment.ExitCode);
                }
                catch (Exception ex)
                {
                    logger.LogError(ex, "There was an unhandled exception that caused the program to crash");
                    Environment.Exit(1);
                }
            }

            // no flags provided, so just run the webhost
            webHost.Run();
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStrataConfiguration()
                .UseStrataLogging()
                .UseSetting(WebHostDefaults.HostingStartupAssembliesKey, "Strata.healthchecks.Jazz")
                .UseStrataHealthChecks()
                .UseStartup<Startup>();
    }
}