zhdk/madek

# -*- encoding : utf-8 -*-

module MediaResourceModules
  module MediaFile

    def self.included(base)
      base.class_eval do
        has_one :media_file, foreign_key: :media_entry_id, dependent: :destroy
        delegate :content_type, to: :media_file
        delegate :media_type, to: :media_file
      end
    end

    # Instance method to update a copy (referenced by path) of a media file with the meta_data tags provided
    # args: blank_all_tags = flag indicating whether we clean all the tags from the file, or update the tags in the file
    # returns: the path and filename of the updated copy or nil (if the copy failed)
    def updated_resource_file(blank_all_tags = false, size = nil)
      source_filename, content_type = if size
                                        p = media_file.get_preview(size)
                                        [p.full_path, p.content_type]
                                      else
                                        [media_file.file_storage_location, media_file.content_type]
                                      end
      FileUtils.cp( source_filename, DOWNLOAD_STORAGE_DIR )
      # remember we want to handle the following:
      # include all madek tags in file
      # remove all (ok, as many as we can) tags from the file.
      cleaner_tags = (blank_all_tags ? "-All= " : "-IPTC:All= ") + "-XMP-madek:All= -IFD0:Artist= -IFD0:Copyright= -IFD0:Software= " # because we do want to remove IPTC tags, regardless
      tags = cleaner_tags + (blank_all_tags ? "" : to_metadata_tags)

      path = File.join(DOWNLOAD_STORAGE_DIR, File.basename(source_filename))
      # TODO Tom ask: why is this called from here and not when the meta_key_definitions are updated? 
      Exiftool.generate_exiftool_config if IoInterface.find("default").io_mappings.maximum("updated_at").to_i > File.stat(EXIFTOOL_CONFIG).mtime.to_i

      resout = `#{EXIFTOOL_PATH} #{tags} "#{path}"`
      FileUtils.rm("#{path}_original") if resout.include?("1 image files updated") # Exiftool backs up the original before editing. We don't need the backup.
      return [path.to_s, content_type]
    end
      
    def get_media_file(user = nil)
      media_file
    end

  end

end