discourse/app/controllers/draft_controller.rb

# frozen_string_literal: true

class DraftController < ApplicationController
  requires_login

  skip_before_action :check_xhr, :preload_json

  def show
    seq = params[:sequence] || DraftSequence.current(current_user, params[:draft_key])
    render json: { draft: Draft.get(current_user, params[:draft_key], seq), draft_sequence: seq }
  end

  def update
    sequence =
      begin
        Draft.set(
          current_user,
          params[:draft_key],
          params[:sequence].to_i,
          params[:data],
          params[:owner]
        )
      rescue Draft::OutOfSequence

        begin
          if !Draft.exists?(user_id: current_user.id, draft_key: params[:draft_key])
            Draft.set(
              current_user,
              params[:draft_key],
              DraftSequence.current(current_user, params[:draft_key]),
              params[:data],
              params[:owner]
            )
          else
            raise Draft::OutOfSequence
          end

        rescue Draft::OutOfSequence
          render_json_error I18n.t('draft.sequence_conflict_error.title'),
            status: 409,
            extras: {
              description: I18n.t('draft.sequence_conflict_error.description')
            }
          return
        end
      end

    json = success_json.merge(draft_sequence: sequence)

    if data = JSON::parse(params[:data])
      # this is a bit of a kludge we need to remove (all the parsing) too many special cases here
      # we need to catch action edit and action editSharedDraft
      if data["postId"].present? && data["originalText"].present? && data["action"].to_s.start_with?("edit")
        post = Post.find_by(id: data["postId"])
        if post && post.raw != data["originalText"]
          conflict_user = BasicUserSerializer.new(post.last_editor, root: false)
          render json: json.merge(conflict_user: conflict_user)
          return
        end
      end
    end

    render json: json
  end

  def destroy
    begin
      Draft.clear(current_user, params[:draft_key], params[:sequence].to_i)
    rescue Draft::OutOfSequence
      # nothing really we can do here, if try clearing a draft that is not ours, just skip it.
    end
    render json: success_json
  end

end