using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using StreakBot.Data;

namespace StreakBot.Services;

public class MonthlyRestoreBackgroundService : BackgroundService
{
    private readonly IServiceScopeFactory _scopeFactory;
    private readonly ILogger<MonthlyRestoreBackgroundService> _logger;
    private readonly TimeSpan _checkInterval = TimeSpan.FromHours(24);
    private int _lastResetMonth = -1;

    public MonthlyRestoreBackgroundService(
        IServiceScopeFactory scopeFactory,
        ILogger<MonthlyRestoreBackgroundService> logger)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            try
            {
                if (_lastResetMonth == -1)
                {
                    var now = DateTime.UtcNow;

                    _lastResetMonth = now.Month;
                }
                else
                {
                    await CheckAndResetMonthlyRestoresAsync();
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error checking monthly restore reset");
            }

            await Task.Delay(_checkInterval, stoppingToken);
        }
    }

    private async Task CheckAndResetMonthlyRestoresAsync()
    {
        var now = DateTime.UtcNow;

        var currentMonth = now.Month;

        // Only reset once per month (when the month changes)
        if (_lastResetMonth != currentMonth)
        {
            using var scope = _scopeFactory.CreateScope();
            var context = scope.ServiceProvider.GetRequiredService<StreakDbContext>();

            var streaks = await context.Streaks.ToListAsync();

            foreach (var streak in streaks)
            {
                streak.MonthlyRestores = 5;
            }

            if (context.ChangeTracker.HasChanges())
            {
                var count = await context.SaveChangesAsync();
                _logger.LogInformation("Reset monthly restores for {Count} streak(s)", count);
            }

            _lastResetMonth = currentMonth;
        }
    }
}