class GuidanceGroup < ActiveRecord::Base
  include GlobalHelpers
  ##
  # Associations
  belongs_to :org
  has_many :guidances
  # depricated but needed for migration "single_group_for_guidance"
  # has_and_belongs_to_many :guidances, join_table: "guidance_in_group"

  ##
  # Possibly needed for active_admin
  #   -relies on protected_attributes gem as syntax depricated in rails 4.2
  attr_accessible :org_id, :name, :optional_subset, :published, :org, :guidances,
                  :as => [:default, :admin]

  validates :name, :org, presence: true


  # EVALUATE CLASS AND INSTANCE METHODS BELOW
  #
  # What do they do? do they do it efficiently, and do we need them?




  

  ##
  # Converts the current guidance group to a string containing the display name.
  # If it's organisation has no other guidance groups, then the name is simply
  # the name of the parent organisation, otherwise it returns the name of the
  # organisation followed by the name of the guidance group.
  #
  # @return [String] the display name for the guidance group
	def display_name
		if org.guidance_groups.count > 1
			return "#{org.name}: #{name}"
		else
			return org.name
		end
	end

  ##
  # Returns the list of all guidance groups not coming from the given organisations
  #
  # @param excluded_orgs [Array<Organisation>] a list of organisations to exclude in the result
  # @return [Array<GuidanceGroup>] a list of guidance groups
  def self.guidance_groups_excluding(excluded_orgs)
    excluded_org_ids = Array.new
    
    if excluded_orgs.is_a?(Array)
      excluded_orgs.each do |org|
        excluded_org_ids << org.id
      end
    else
      excluded_org_ids << excluded_orgs
    end
    
    return_orgs =  GuidanceGroup.where("org_id NOT IN (?)", excluded_org_ids)
    return return_orgs
  end

  ##
  # Returns whether or not a given user can view a given guidance group
  # we define guidances viewable to a user by those owned by:
  #   the managing curation center
  #   a funder organisation
  #   an organisation, of which the user is a member
  #
  # @param id [Integer] the integer id for a guidance group
  # @param user [User] a user object
  # @return [Boolean] true if the specified user can view the specified guidance group, false otherwise
  def self.can_view?(user, id)
    guidance_group = GuidanceGroup.find_by(id: id)
    viewable = false

    # groups are viewable if they are owned by any of the user's organisations
    if guidance_group.org == user.org
      viewable = true
    end
    # groups are viewable if they are owned by the managing curation center
    Org.where( name: GlobalHelpers.constant("organisation_types.managing_organisation")).find_each do |managing_group|
      if guidance_group.org.id == managing_group.id
        viewable = true
      end
    end
    # groups are viewable if they are owned by a funder
    if guidance_group.org.org_type == 2
      viewable = true
    end

    return viewable
  end

    ##
    # Returns a list of all guidance groups which a specified user can view
    # we define guidance groups viewable to a user by those owned by:
    #   the Managing Curation Center
    #   a funder organisation
    #   an organisation, of which the user is a member
    #
    # @param user [User] a user object
    # @return [Array<GuidanceGroup>] a list of all "viewable" guidance groups to a user
  def self.all_viewable(user)
    # first find all groups owned by the Managing Curation Center
    managing_org_groups = []
    Org.where(name: GlobalHelpers.constant("organisation_types.managing_organisation")).find_each do |managing_org|
      managing_org_groups = managing_org_groups + managing_org.guidance_groups
    end

    # find all groups owned by  a Funder organisation
    funder_groups = []
    funders = Org.where(org_type: 2)
    funders.each do |funder|
      funder_groups = funder_groups + funder.guidance_groups
    end
    organisation_groups = [user.org.guidance_groups]

    # pass this organisation guidance groups to the view with respond_with @all_viewable_groups
    all_viewable_groups = managing_org_groups + funder_groups + organisation_groups
    all_viewable_groups = all_viewable_groups.flatten.uniq{|x| x.id}
    return all_viewable_groups
  end
end