# encoding: UTF-8

# Copyright 2011 innoQ Deutschland GmbH
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

class Collection::Base < Concept::Base

  #*********** Associations

  has_many Note::SKOS::Definition.name.to_relation_name,
    :class_name => 'Note::SKOS::Definition',
    :as => :owner,
    :dependent => :destroy

  has_many :members,
    :class_name  => 'Collection::Member::Base',
    :foreign_key => 'collection_id',
    :dependent   => :destroy

  has_many :concept_members,
    :class_name  => 'Collection::Member::Concept',
    :foreign_key => 'collection_id',
    :dependent   => :destroy
  has_many :concepts,
    :through => :concept_members

  has_many :collection_members,
    :class_name  => 'Collection::Member::Collection',
    :foreign_key => 'collection_id',
    :dependent   => :destroy
  has_many :subcollections,
    :through => :collection_members

  has_many :parent_collection_members,
    :class_name  => 'Collection::Member::Collection',
    :foreign_key => 'target_id',
    :dependent   => :destroy
  has_many :parent_collections,
    :through => :parent_collection_members


  #********** Hooks

  after_save :regenerate_concept_members, :regenerate_collection_members

  #********** Scopes

  scope :by_origin, lambda { |origin|
    where(:origin => origin)
  }

  scope :by_label_value, lambda { |val|
    includes(:labels).merge(Label::Base.by_query_value(val))
  }

  scope :tops, lambda {
    includes(:parent_collection_members).
      where("#{Collection::Member::Collection.table_name}.target_id IS NULL")
  }

  #********** Validations

  validate :circular_subcollections

  #********** Methods

  def to_param
    origin
  end

  def label
    pref_label
  end

  def build_rdf_subject(document, controller, &block)
    IqRdf::Coll::build_uri(self.origin, IqRdf::Skos::build_uri("Collection"), &block)
  end

  def inline_member_concept_origins=(origins)
    @member_concept_origins = origins.to_s.
      split(Iqvoc::InlineDataHelper::Splitter).map(&:strip)
  end

  def inline_member_concept_origins
    @member_concept_origins || concept_members.map { |m| m.concept.origin }.uniq
  end

  def inline_member_concepts
    if @member_concept_origins
      Concept::Base.editor_selectable.where(:origin => @member_concept_origins)
    else
      concepts.select{|c| c.editor_selectable?}
    end
  end

  def inline_member_collection_origins=(origins)
    @member_collection_origins = origins.to_s.
      split(Iqvoc::InlineDataHelper::Splitter).map(&:strip)
  end

  def inline_member_collection_origins
    @member_collection_origins || collection_members.
      map { |m| m.subcollection.origin }.uniq
  end

  def inline_member_collections
    if @member_collection_origins
      Collection::Base.where(:origin => @member_collection_origins)
    else
      subcollections
    end
  end

  #********** Hook methods

  def regenerate_concept_members
    return if @member_concept_origins.nil? # There is nothing to do
    concept_members.destroy_all
    @member_concept_origins.each do |new_origin|
      Concept::Base.by_origin(new_origin).each do |c|
        concept_members.create!(:target_id => c.id)
      end
    end
  end

  def regenerate_collection_members
    return if @member_collection_origins.nil? # There is nothing to do
    collection_members.destroy_all
    @member_collection_origins.each do |new_origin|
      Iqvoc::Collection.base_class.where(:origin => new_origin).each do |c|
        collection_members.create!(:target_id => c.id)
      end
    end
  end

  #******** Validation methods

  # This only prevent circles of length 2.
  #   # TODO: This shuold be a real circle detector (but still performant) or be
  # removed (seems to me like the better idea).
  def circular_subcollections
    Iqvoc::Collection.base_class.by_origin(@member_collection_origins).each do |subcollection|
      if subcollection.subcollections.all.include?(self)
        errors.add(:base,
          I18n.t("txt.controllers.collections.circular_error") % subcollection.pref_label)
      end
    end
  end

end