class Mood < ApplicationRecord
  class << self
    def history_for_a_year
      history(Date.today - 1.year, Date.today)
    end

    private
    def history(from, to)
      return [] if Mood.count < 1

      first_monday = monday_of_the_week(first_mood_date(from))

      current_date = first_monday
      current_mode = last_mode_before(current_date)
      log_mood = []
      mood_range = Mood.order(:recorded_at).where(recorded_at: (first_monday..to))
      mood_range.each do |mood|
        while current_date < mood.recorded_at.to_date do
          log_mood << [ current_date.to_s, current_mode ]
          current_date += 1
        end
        current_mode = mood.mode
      end

      while current_date <= to.to_date do
        log_mood << [ current_date.to_s, current_mode ]
        current_date += 1
      end
      log_mood.each_slice(7).to_a
    end

    def first_mood_date(from)
      Mood.order(recorded_at: :asc).where("recorded_at >= ?", from).first.recorded_at.to_date
    end

    def monday_of_the_week(date)
      date - date.wday + 1
    end

    def last_mode_before(date)
      mood = Mood.where("recorded_at < ?", date).last
      mood&.mode || "croisiere"
    end
  end
end