module Dor
  module Governable
    extend ActiveSupport::Concern

    included do
      belongs_to :admin_policy_object, :property => :is_governed_by, :class_name => "Dor::AdminPolicyObject"
      has_and_belongs_to_many :collections, :property => :is_member_of_collection, :class_name => "Dor::Collection"
      has_and_belongs_to_many :sets, :property => :is_member_of, :class_name => "Dor::Collection"
    end

    def initiate_apo_workflow(name)
      self.initialize_workflow(name, !self.new_object?)
    end

    # Returns the default lane_id from the item's APO.  Will return 'default' if the item does not have
    #   and APO, or if the APO does not have a default_lane
    # @return [String] the lane id
    def default_workflow_lane
      return 'default' if self.admin_policy_object.nil?  # TODO log warning?

      admin_md = admin_policy_object.datastreams['administrativeMetadata']
      return 'default' unless admin_md.respond_to? :default_workflow_lane
      lane = admin_md.default_workflow_lane
      return 'default' if lane.nil? || lane.strip == ''
      lane
    end

    def reset_to_apo_default()
      rights_metadata_ds = self.rightsMetadata
      rights_metadata_ds.content = admin_policy_object.rightsMetadata.ng_xml
    end

    # slight misnomer: also sets discover rights!
    def set_read_rights(rights)
      raise(ArgumentError, "Argument '#{rights}' is not a recognized value") unless ['world','stanford','none','dark'].include? rights
      rights_xml = self.rightsMetadata.ng_xml
      if (rights_xml.search('//rightsMetadata/access[@type=\'read\']').length==0)
        raise('The rights metadata stream doesnt contain an entry for machine read permissions. Consider populating it from the APO before trying to change it.')
      end
      label = rights=='dark' ? 'none' : 'world'
      rights_xml.search('//rightsMetadata/access[@type=\'discover\']/machine').each do |node|
        node.children.remove
        node.add_child Nokogiri::XML::Node.new(label,rights_xml)
      end
      rights_xml.search('//rightsMetadata/access[@type=\'read\']').each do |node|
        node.children.remove
        machine_node = Nokogiri::XML::Node.new('machine',rights_xml)
        node.add_child(machine_node)
        if rights == 'world'
          machine_node.add_child Nokogiri::XML::Node.new(rights,rights_xml)
        elsif rights == 'stanford'
          group_node = Nokogiri::XML::Node.new('group',rights_xml)
          group_node.content = "Stanford"
          machine_node.add_child(group_node)
        else  # we know it is none or dark by the argument filter (first line)
          machine_node.add_child Nokogiri::XML::Node.new('none',rights_xml)
        end
      end
    end

    def add_collection(collection_or_druid)
      collection = case collection_or_druid
        when String
          Dor::Collection.find(collection_or_druid)
        when Dor::Collection
          collection_or_druid
      end
      self.collections << collection
      self.sets << collection
    end

    def remove_collection(collection_or_druid)

      collection = case collection_or_druid
        when String
          Dor::Collection.find(collection_or_druid)
        when Dor::Collection
          collection_or_druid
      end

      self.collections.delete(collection)
      self.sets.delete(collection)
    end
    #set the rights metadata datastream to the content of the APO's default object rights
    def reapplyAdminPolicyObjectDefaults
      rightsMetadata.content=admin_policy_object.datastreams['defaultObjectRights'].content
    end
    def rights
      return nil unless self.respond_to? :rightsMetadata
      xml = self.rightsMetadata.ng_xml
      return nil if xml.search('//rightsMetadata').length != 1      # ORLY?
      if xml.search('//rightsMetadata/access[@type=\'read\']/machine/group').length == 1
        'Stanford'
      elsif xml.search('//rightsMetadata/access[@type=\'read\']/machine/world').length == 1
        'World'
      elsif xml.search('//rightsMetadata/access[@type=\'discover\']/machine/none').length == 1
        'Dark'
      else
        'None'
      end
    end
    def groups_which_manage_item
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor']
    end
    def groups_which_manage_desc_metadata
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor', 'dor-apo-metadata']
    end
    def groups_which_manage_system_metadata
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor']
    end
    def groups_which_manage_content
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor']
    end
    def groups_which_manage_rights
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor']
    end
    def groups_which_manage_embargo
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor']
    end
    def groups_which_view_content
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor', 'dor-viewer', 'sdr-viewer']
    end
    def groups_which_view_metadata
      ['dor-administrator', 'sdr-administrator', 'dor-apo-manager', 'dor-apo-depositor', 'dor-viewer', 'sdr-viewer']
    end
    def intersect arr1, arr2
      return (arr1 & arr2).length > 0
    end
    def can_manage_item? roles
      intersect roles, groups_which_manage_item
    end
    def can_manage_desc_metadata? roles
      intersect roles, groups_which_manage_desc_metadata
    end
    def can_manage_system_metadata? roles
      intersect roles, groups_which_manage_system_metadata
    end
    def can_manage_content? roles
      intersect roles, groups_which_manage_content
    end
    def can_manage_rights? roles
      intersect roles, groups_which_manage_rights
    end
    def can_manage_embargo? roles
      intersect roles, groups_which_manage_embargo
    end
    def can_view_content? roles
      intersect roles, groups_which_view_content
    end
    def can_view_metadata? roles
      intersect roles, groups_which_view_metadata
    end
  end
end