class GuidanceGroup < ActiveRecord::Base
  include GlobalHelpers

  #associations between tables
  belongs_to :organisation

  has_and_belongs_to_many :guidances, join_table: "guidance_in_group"

  has_and_belongs_to_many :projects, join_table: "project_guidance"
  has_and_belongs_to_many :dmptemplates, join_table: "dmptemplates_guidance_groups"

  accepts_nested_attributes_for :dmptemplates

  attr_accessible :organisation_id, :name, :optional_subset, :published, :as => [:default, :admin]
  attr_accessible :dmptemplate_ids, :as => [:default, :admin]

  ##
  # Converts a guidance group to a string containing the display name
  #
  # @return [String] the name of the organisation, with or without the name of the guidance group
	def to_s
		"#{display_name}"
	end

  ##
  # 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 organisation.guidance_groups.count > 1
			return "#{organisation.name}: #{name}"
		else
			return organisation.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
		excluded_orgs.each do |org|
			excluded_org_ids << org.id
		end
		return_orgs =  GuidanceGroup.where("organisation_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.organisation == user.organisation
      viewable = true
    end
    # groups are viewable if they are owned by the managing curation center
    Organisation.where( name: GlobalHelpers.constant("organisation_types.managing_organisation")).find_each do |managing_group|
      if guidance_group.organisation.id == managing_group.id
        viewable = true
      end
    end
    # groups are viewable if they are owned by a funder
    if guidance_group.organisation.organisation_type == OrganisationType.find_by( name: GlobalHelpers.constant("organisation_types.funder"))
      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 = []
    Organisation.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 = OrganisationType.find_by( name: GlobalHelpers.constant("organisation_types.funder"))
    funders.organisations.each do |funder|
      funder_groups = funder_groups + funder.guidance_groups
    end
    organisation_groups = [user.organisation.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.uniq{|x| x.id}
    return all_viewable_groups
  end
end