using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Serilog;
using StockDBEF.Models;
using System;
using System.IO;
using System.Threading.Tasks;
using System.Threading;

// DI, SeriLog, Settings

namespace StockDBEF
{
    class Program
    {
        static void Main(string[] args)
        {
            var builder = new ConfigurationBuilder();
            BuildConfig(builder);

            Log.Logger = new LoggerConfiguration()
                .ReadFrom.Configuration(builder.Build())
                .Enrich.FromLogContext()
                .WriteTo.Console()
                .CreateLogger();

            Log.Logger.Information("Application starting");

            var host = Host.CreateDefaultBuilder()
                .ConfigureServices((context, services) =>
                {
                    services.AddEntityFrameworkSqlite();
                    services.AddHostedService<DatabaseStartup>();
                    //services.AddDbContext<StockDBContext>();
                    services.AddDbContextPool<StockDBContext>(o =>
                    {
                        o.UseSqlite("Data Source=Stocks.db");
                    });

                    services.AddTransient<IGreetingService, GreetingService>();
                })
                .UseSerilog()
                .Build();

            var svc = ActivatorUtilities.CreateInstance<GreetingService>(host.Services);
            svc.Run();
        }

        static void BuildConfig(IConfigurationBuilder builder)
        {
            builder.SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Production"}.json", optional: true)
                .AddEnvironmentVariables();
        }


    }

    public class DatabaseStartup : IHostedService
    {
        private readonly IServiceProvider serviceProvider;
        public DatabaseStartup(IServiceProvider serviceProvider)
        {
            this.serviceProvider = serviceProvider;
        }

        public async Task StartAsync(CancellationToken cancellationToken)
        {
            using (var scope = serviceProvider.CreateScope())
            {
                var db = scope.ServiceProvider.GetRequiredService<StockDBContext>();
                await db.Database.EnsureCreated();
                // or 
                await db.Database.MigrateAsync();
            }
        }

        public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
    }

}