# frozen_string_literal: true

class MediaProxyController < ApplicationController
  include RoutingHelper
  include Authorization
  include Redisable
  include Lockable

  skip_before_action :require_functional!

  before_action :authenticate_user!, if: :limited_federation_mode?
  before_action :set_media_attachment

  rescue_from ActiveRecord::RecordInvalid, with: :not_found
  rescue_from Mastodon::UnexpectedResponseError, with: :not_found
  rescue_from Mastodon::NotPermittedError, with: :not_found
  rescue_from(*Mastodon::HTTP_CONNECTION_ERRORS, with: :internal_server_error)

  def show
    if @media_attachment.needs_redownload? && !reject_media?
      with_redis_lock("media_download:#{params[:id]}") do
        @media_attachment.reload # Reload once we have acquired a lock, in case the file was downloaded in the meantime
        redownload! if @media_attachment.needs_redownload?
      end
    end

    if requires_file_streaming?
      send_file(media_attachment_file.path, type: media_attachment_file.instance_read(:content_type), disposition: 'inline')
    else
      redirect_to media_attachment_file_path, allow_other_host: true
    end
  end

  private

  def set_media_attachment
    @media_attachment = MediaAttachment.attached.find(params[:id])
    authorize @media_attachment, :download?
  end

  def redownload!
    @media_attachment.download_file!
    @media_attachment.download_thumbnail!
    @media_attachment.created_at = Time.now.utc
    @media_attachment.save!
  end

  def attachment_style
    if @media_attachment.thumbnail.blank? && preview_requested?
      :small
    else
      :original
    end
  end

  def reject_media?
    @media_attachment.account.remote? && DomainBlock.reject_media?(@media_attachment.account.domain)
  end

  def media_attachment_file_path
    if @media_attachment.discarded?
      expiring_asset_url(media_attachment_file, 10.minutes)
    else
      full_asset_url(media_attachment_file.url(attachment_style))
    end
  end

  def media_attachment_file
    if @media_attachment.thumbnail.present? && preview_requested?
      @media_attachment.thumbnail
    else
      @media_attachment.file
    end
  end

  def preview_requested?
    request.path.end_with?('/small')
  end

  def requires_file_streaming?
    Paperclip::Attachment.default_options[:storage] == :filesystem && @media_attachment.discarded?
  end
end