using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Musify.Application.Configuration;
using Musify.Application.Contracts;
using Musify.Domain.ValueObjects;

namespace Musify.Infrastructure.Jobs;

public class UploadIntentExpirationJob(
    IServiceScopeFactory scopeFactory,
    ILogger<UploadIntentExpirationJob> logger,
    UploadIntentConfiguration uploadIntentConfiguration)
    : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        logger.LogInformation("UploadIntentExpirationJob started (interval: {Interval}s)", uploadIntentConfiguration.ExpirationJobIntervalSeconds);

        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(uploadIntentConfiguration.ExpirationJobIntervalSeconds));

        do
        {
            try
            {
                await RunAsync(stoppingToken);
            }
            catch (Exception exception) when (exception is not OperationCanceledException)
            {
                logger.LogError(exception, "Error in UploadIntentExpirationJob");
            }
        }
        while (await timer.WaitForNextTickAsync(stoppingToken));
    }

    private async Task RunAsync(CancellationToken cancellationToken)
    {
        await using var scope = scopeFactory.CreateAsyncScope();
        var database = scope.ServiceProvider.GetRequiredService<IDatabase>();

        var now = DateTime.UtcNow;

        var expiredIntents = await database.UploadIntents
            .Where(i => i.Status == UploadIntentStatus.Issued && i.ExpiresAt < now)
            .ToListAsync(cancellationToken);

        if (expiredIntents.Count > 0)
        {
            foreach (var intent in expiredIntents)
                intent.Status = UploadIntentStatus.Expired;

            await database.SaveChangesAsync(cancellationToken);
            logger.LogInformation("Marked {Count} upload intents as Expired", expiredIntents.Count);
        }

        var retentionCutoff = now.AddDays(-uploadIntentConfiguration.ExpiredIntentsRetentionDays);

        var oldExpiredIntents = await database.UploadIntents
            .Where(i => i.Status == UploadIntentStatus.Expired && i.ExpiresAt < retentionCutoff)
            .ToListAsync(cancellationToken);

        if (oldExpiredIntents.Count > 0)
        {
            database.UploadIntents.RemoveRange(oldExpiredIntents);
            await database.SaveChangesAsync(cancellationToken);
            logger.LogInformation("Deleted {Count} old Expired upload intents past retention window", oldExpiredIntents.Count);
        }
    }
}