Websites/app/jobs/e621_thumbnail_job.rb

# frozen_string_literal: true

class E621ThumbnailJob < ApplicationJob
  queue_as :default

  def perform(entry)
    infile = Tempfile.new(%W[e621-thumbnail-#{entry.stripped_md5} .webm])
    outfile = Tempfile.new(%W[e621-thumbnail-#{entry.stripped_md5} .#{entry.filetype}])
    cutfile = Tempfile.new(%W[e621-thumbnail-#{entry.stripped_md5} .cut.webm])
    palettefile = Tempfile.new(%W[e621-thumbnail-#{entry.stripped_md5} .palette.png])
    Timeout.timeout(120) do
      infile.binmode
      io = FileDownload.new("https://static1.e621.net/data/#{entry.stripped_md5[0..1]}/#{entry.stripped_md5[2..3]}/#{entry.stripped_md5}.webm").download!
      IO.copy_stream(io, infile)
      duration = `ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 #{infile.path}`.to_f
      offset = duration > 10 ? rand(0..(duration - 10)) : duration / 2
      if entry.filetype == "gif"
        `ffmpeg -y -i #{infile.path} -ss #{offset} -t 3 -c:v copy -an #{cutfile.path} 1>&2`
        `ffmpeg -y -i #{cutfile.path} -filter_complex "[0:v] palettegen" #{palettefile.path} 1>&2`
        `ffmpeg -y -i #{cutfile.path} -i #{palettefile.path} -filter_complex "[0:v][1:v] paletteuse" #{outfile.path} 1>&2`
      else
        `ffmpeg -y -i #{infile.path} -ss #{offset} -vframes 1 #{outfile.path} 1>&2`
      end
      ImageOptim.new.optimize_image!(outfile.path)
      Websites.config.e621_thumbnails_storage.upload("/#{entry.stripped_md5}.#{entry.filetype}", outfile)
      entry.update!(status: "complete")
      execute_webhook(entry, title: "Thumbnail Generated (#{entry.filetype})")
    end
  rescue Timeout::Error
    entry.update!(status: "timeout")
    execute_webhook(entry, title: "Thumbnail Generation Timed Out (#{entry.filetype})", error: true)
  rescue StandardError => e
    code = Requests::Pastebin.default.create(title: "E621 Thumbnail Generation Error (#{entry.stripped_md5})", content: "#{e}\n#{e.backtrace&.join("\n") || ''}")
    entry.update!(status: "error", error_code: code)
    execute_webhook(entry, title: "Thumbnail Generation Errored (#{entry.filetype})", body: "Backtrace: https://pastebin.com/#{code}", error: true)
    raise(e)
  ensure
    [infile, outfile, palettefile, cutfile].each do |file|
      file&.close
      file&.unlink
    end
  end

  def execute_webhook(entry, title:, body: "", error: false)
    if error
      entry.update(expires_at: 5.minutes.from_now)
      E621ThumbnailErrorCleanupJob.set(wait: 5.minutes).perform_later(entry)
    end
    thumb = {}
    if entry.complete?
      thumb = {
        thumbnail: {
          url: entry.url,
        },
      }
    end
    Websites.config.e621_thumbnails_webhook.execute({
      embeds: [
        {
          title:       title,
          description: <<~DESC,
            Key: ##{entry.api_key_id} (`#{entry.api_key.application_name}`)
            Post: [##{entry.post_id}](https://e621.net/posts/#{entry.post_id})
            #{body}
          DESC
          color:       error ? 0xDC143C : 0x008000,
          timestamp:   Time.now.iso8601,
          **thumb,
        },
      ],
    })
  end
end