using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MTG_CollectionVerwaltung.API_Connector;
using MTG_CollectionVerwaltung.Data.MTGCollection;
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;

public class ScryfallDBUpdater : BackgroundService
{
    private readonly ILogger<ScryfallDBUpdater> _logger;
    private readonly IServiceProvider _serviceProvider;
    private readonly TimeSpan interval = TimeSpan.FromDays(7);
    private const string actFile = "nextActualisation.txt";
    private const string dwlFile = "nextDownload.txt";

    public ScryfallDBUpdater(ILogger<ScryfallDBUpdater> logger, IServiceProvider serviceProvider)
    {
        _logger = logger;
        _serviceProvider = serviceProvider;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        DateTime nextUpdate = DateTime.MinValue;
        if (File.Exists(actFile) && DateTime.TryParse(File.ReadAllText(actFile), out var fileTime))
        {
            nextUpdate = fileTime;
        }

        var delay = TimeSpan.FromDays(7) - (DateTime.Now-nextUpdate);
        if (delay < TimeSpan.Zero) delay = TimeSpan.Zero;
        bool dwupdate = true;
        await Task.Delay(delay, stoppingToken);

        while (!stoppingToken.IsCancellationRequested)
        {
            try
            {
                using var scope = _serviceProvider.CreateScope();
                var dbContext = scope.ServiceProvider.GetRequiredService<MTGContext>();
                var connector = new ScryfallConnector(dbContext);
                _logger.LogInformation("Scryfall DB Update startet...");
                if (File.Exists(dwlFile) && DateTime.TryParse(File.ReadAllText(dwlFile), out var dwTime))
                {
                    dwupdate = dwTime.Day != DateTime.Now.Day;
                }
                if(dwupdate) await connector.LoadDataAsync();
                File.WriteAllText(dwlFile, DateTime.Now.ToString());
                await connector.ActualizeDbAsync();
                File.WriteAllText(actFile, DateTime.Now.ToString());
                _logger.LogInformation("Scryfall DB Update abgeschlossen.");
                dbContext.ChangeTracker.Clear();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Fehler beim Scryfall DB Update");
            }
            
            await Task.Delay(interval, stoppingToken);
        }
    }
}