Arie/serveme

# frozen_string_literal: true

class Statistic
  def self.top_10_users
    top_10_user_id_count_hash = Reservation.joins(:user).order(Arel.sql('count_all DESC')).limit(10).group('users.id').count
    top_10_users              = User.where(id: top_10_user_id_count_hash.keys).includes(:groups).to_a
    top_10_hash = {}
    top_10_user_id_count_hash.map do |user_id, count|
      user = top_10_users.find { |u| u.id == user_id.to_i }
      top_10_hash[user] = count
    end
    top_10_hash
  end

  def self.top_10_servers
    Reservation.joins(:server).order(Arel.sql('count_all DESC')).limit(10).group('servers.name').count
  end

  def self.total_reservations
    Reservation.count
  end

  def self.total_playtime_seconds
    Reservation.sum(:duration)
  end

  def self.reservations_per_day_chart
    reservations_per_time_unit('Date', reservations_per_day, 'Reservations in the last 50 days')
  end

  def self.reserved_hours_per_month_chart
    reservations_per_time_unit('Month', reserved_hours_per_month, 'Hours played', 'Hours played')
  end

  def self.reservations_per_time_unit(time_unit, statistics_array, title, bar_title = 'Reservation')
    data_table = GoogleVisualr::DataTable.new
    data_table.new_column('string', time_unit)
    data_table.new_column('number', bar_title)
    data_table.add_rows(statistics_array)
    option = { width: 1100, height: 240, title: title, colors: ['#0044cc', '#0055cc', '#0066cc', '#0077cc', '0088cc'], legend: { position: 'none' } }
    GoogleVisualr::Interactive::ColumnChart.new(data_table, option)
  end

  def self.reservations_per_day
    Rails.cache.fetch "reservations_per_day_#{Date.current}", expires_in: 1.hour do
      Reservation.order(Arel.sql('DATE(starts_at) DESC')).group(Arel.sql('DATE(starts_at)')).limit(50).count(:id).collect do |date, count|
        [date.to_s, count]
      end.reverse
    end
  end

  def self.reserved_hours_per_month
    Rails.cache.fetch "reserved_hours_per_month_#{Date.current}", expires_in: 1.hour do
      result = ActiveRecord::Base.connection.execute("SELECT TO_CHAR(starts_at, 'YYYY-MM') AS year_month,
                                                      SUM(duration) as duration
                                                      FROM reservations
                                                      GROUP BY 1
                                                      ORDER BY 1")
      result.to_a.map do |duration_per_month|
        year_month = duration_per_month['year_month']
        seconds = duration_per_month['duration']
        year = year_month.split('-').first.to_i
        month = year_month.split('-').last.to_i
        date = Date.new(year, month)
        formatted_date = date.strftime('%b %Y')
        [formatted_date, (seconds.to_f / 3600.0).round]
      end
    end
  end
end