class CallForPaper < ActiveRecord::Base
  belongs_to :conference

  validates_presence_of :start_date, :end_date
  validates :rating, numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: 10 }
  validate :before_end_of_conference
  validate :start_after_end_date

  ##
  # Calculates how many weeks the call for paper is.
  #
  # ====Returns
  # * +Integer+ -> start week
  def weeks
    result = end_week - start_week + 1
    weeks = Date.new(start_date.year, 12, 31).strftime('%W').to_i
    result < 0 ? result + weeks : result
  end

  ##
  # Calculates the end week of the cfp
  #
  # ====Returns
  def start_week
    start_date.strftime('%W').to_i
  end

  ##
  # Calculates the end week of the cfp
  #
  # ====Returns
  def end_week
    end_date.strftime('%W').to_i
  end

  ##
  # Checks whether cfp dates is updated
  #
  # ====Returns
  # * +True+ -> If cfp dates is updated and all other parameters are set
  # * +False+ -> Either cfp date is not updated or one or more parameter is not set
  def notify_on_cfp_date_update?
    !self.end_date.blank? && !self.start_date.blank?\
    && (self.start_date_changed? || self.end_date_changed?)\
    && self.conference.email_settings.send_on_call_for_papers_dates_updated\
    && !self.conference.email_settings.call_for_papers_dates_updated_subject.blank?\
    && !self.conference.email_settings.call_for_papers_dates_updated_body.blank?
  end
  ##
  # Checks whether cfp dates is updated
  #
  # ====Returns
  # * +True+ -> If cfp dates is updated and all other parameters are set
  # * +False+ -> Either cfp date is not updated or one or more parameter is not set
  def notify_on_schedule_public?
    !self.end_date.blank? && !self.start_date.blank?\
    && (self.start_date_changed? || self.end_date_changed?)\
    && self.conference.email_settings.send_on_call_for_papers_dates_updated\
    && !self.conference.email_settings.call_for_papers_dates_updated_subject.blank?\
    && !self.conference.email_settings.call_for_papers_dates_updated_body.blank?
  end

  def remaining_days(date = Date.today)
    result = (self.end_date - date).to_i
    result > 0 ? result : 0
  end

  private

  def before_end_of_conference
    errors.
    add(:end_date, "can't be after the conference end date (#{conference.end_date})") if conference && conference.end_date && end_date && (end_date > conference.end_date)

    errors.
    add(:start_date, "can't be after the conference end date (#{conference.end_date})") if conference && conference.end_date && start_date && (start_date > conference.end_date)
  end

  def start_after_end_date
    errors.
    add(:start_date, "can't be after the end date") if start_date && end_date && start_date > end_date
  end
end