class ReferentialMetadata < ActiveRecord::Base
  belongs_to :referential
  belongs_to :referential_source, class_name: 'Referential'
  has_array_of :lines, class_name: 'Chouette::Line'

  validates :referential, presence: true
  validates :lines, presence: true
  validates :periodes, presence: true

  scope :include_lines, -> (line_ids) { where('line_ids && ARRAY[?]', line_ids) }
  scope :include_dateranges, -> (dateranges) { where('periodes && ARRAY[?]', dateranges) }

  class Period
    include ActiveAttr::Model

    attribute :id, type: Integer
    attribute :begin, type: Date
    attribute :end, type: Date

    validates :begin, :end, presence: true
    validate :check_end_greather_than_begin

    def check_end_greather_than_begin
      if self.begin and self.end and self.begin > self.end
        errors.add(:end, :invalid)
      end
    end

    def self.from_range(index, range)
      Period.new id: index, begin: range.begin, end: range.end
    end

    def range
      if self.begin and self.end and self.begin <= self.end
        Range.new self.begin, self.end
      end
    end

    def intersect?(*other)
      return false if range.nil?

      other = other.flatten
      other = other.delete_if { |o| o.id == id } if id

      other.any? do |period|
        if other_range = period.range
          (range & other_range).present?
        end
      end
    end

    # Stuff required for coocon
    def new_record?
      !persisted?
    end
    def persisted?
      id.present?
    end


    def mark_for_destruction
      self._destroy = true
    end

    attribute :_destroy, type: Boolean
    alias_method :marked_for_destruction?, :_destroy
  end

  # Required by coocon
  def build_period
    Period.new
  end

  def periods
    @periods ||= init_periods
  end

  def init_periods
    if periodes
      periodes.each_with_index.map { |r, index| Period.from_range(index, r) }
    else
      []
    end
  end
  private :init_periods

  validate :validate_periods

  def validate_periods
    periods_are_valid = true

    unless periods.all?(&:valid?)
      periods_are_valid = false
    end

    periods.each do |period|
      if period.intersect?(periods)
        period.errors.add(:base, I18n.t("referentials.errors.overlapped_period"))
        periods_are_valid = false
      end
    end

    unless periods_are_valid
      errors.add(:periods, :invalid)
    end
  end

  def periods_attributes=(attributes = {})
    @periods = []
    attributes.each do |index, period_attribute|
      period = Period.new(period_attribute.merge(id: index))
      @periods << period unless period.marked_for_destruction?
    end

    # if self.periodes != @periods.map(&:range).compact
      periodes_will_change!
    # end
  end

  before_validation :fill_periodes

  def fill_periodes
    if @periods
      self.periodes = @periods.map(&:range).compact.sort_by(&:begin)
    end
  end

  after_save :clear_periods

  def clear_periods
    @periods = nil
  end
  private :clear_periods

  def self.new_from from
    from.dup.tap do |metadata|
      metadata.referential_id = nil
    end
  end
end

class Range
  def intersection(other)
    return nil if (self.max < other.begin or other.max < self.begin)
    [self.begin, other.begin].max..[self.max, other.max].min
  end
  alias_method :&, :intersection
end