educoder/app/controllers/cooperative/files_controller.rb

class Cooperative::FilesController < Cooperative::BaseController
  before_action :convert_file!, :check_permission!, only: [:create]

  def create
    File.delete(file_path) if File.exist?(file_path) # 删除之前的文件

    Util.write_file(@file, file_path)

    render_ok(source_id: params[:source_id], source_type: params[:source_type].to_s, url: file_url + "?t=#{Random.rand}")
  rescue StandardError => ex
    logger_error(ex)
    render_error('上传失败')
  end

  private

  def convert_file!
    max_size = 10 * 1024 * 1024 # 10M
    if params[:file].class == ActionDispatch::Http::UploadedFile
      @file = params[:file]
      render_error('请上传文件') if @file.size.zero?
      render_error('文件大小超过限制') if @file.size > max_size
    else
      file = params[:file].to_s.strip
      return render_error('请上传正确的图片') if file.blank?
      @file = Util.convert_base64_image(file, max_size: max_size)
    end
  rescue Base64ImageConverter::Error => ex
    render_error(ex.message)
  end

  def check_permission!
    permission =
      case params[:source_type].to_s
      when '' then false
      when 'Shixun' then
        current_laboratory.laboratory_shixuns.exists?(ownership: true, shixun_id: params[:source_id])
      when 'Subject' then
        current_laboratory.laboratory_subjects.exists?(ownership: true, subject_id: params[:source_id])
      else true
      end

    return if permission

    render_forbidden
  end

  def file_path
    @_file_path ||= begin
      case params[:source_type].to_s
      when 'Shixun' then
        Util::FileManage.disk_filename('Shixun', params[:source_id])
      else
        Util::FileManage.disk_filename(params[:source_type].to_s, params[:source_id].to_s)
      end
    end
  end

  def file_url
    Util::FileManage.disk_file_url(params[:source_type].to_s, params[:source_id].to_s)
  end
end