using MongoDB.Entities;

using PrivaPub.Infrastructure.Jobs;
using PrivaPub.Models.Jobs;
using PrivaPub.Models.Media;

namespace PrivaPub.Domain.Media
{
	// Audio and video sent to /api/v2/media, processed off the request (its lease renewed while ffmpeg runs): playable, or
	// marked failed with why. One at a time, since a transcode takes the machine's cores.
	public class ProcessMediaJob : IJobHandler
	{
		readonly IMediaService _media;
		readonly ILogger<ProcessMediaJob> _logger;

		public ProcessMediaJob(IMediaService media, ILogger<ProcessMediaJob> logger)
		{
			_media = media;
			_logger = logger;
		}

		public JobKind Kind => JobKind.ProcessMedia;
		public int Concurrency => 1;
		public int MaxAttempts => 3;
		public int PerHostLimit => 1;

		public static Job JobFor(MediaAttachment pending, string host) => new()
		{
			Kind = JobKind.ProcessMedia,
			Payload = pending.ID,
			Host = host,
			DedupeKey = $"media|{pending.ID}"
		};

		public async Task<JobOutcome> Handle(Job job, CancellationToken token)
		{
			var pending = await DB.Default.Find<MediaAttachment>().Match(m => m.ID == job.Payload && m.ProcessingState == "pending" && m.TrashedAt == null).ExecuteFirstAsync(token);
			if (pending == default)
				return JobOutcome.Done;//processed already, or trashed meanwhile
			if (!await _media.ProcessPending(pending, token))
				_logger.LogInformation("Upload {Id} could not be processed", pending.ID);
			return JobOutcome.Done;
		}
	}
}