Class methods discussion

gistfile1.rb

  def user_with_highest_kilometers
    highest = User.new
    users.each do |user|
      highest = user if user_distance_sum(user) > user_distance_sum(highest)
    end
    highest
  end

  def user_with_highest_ascent
    highest = User.new
    users.each do |user|
      highest = user if user_ascent_sum(user) > user_ascent_sum(highest)
    end
    highest
  end

  def user_with_highest_achievements
    highest = User.new
    users.each do |user|
      highest = user if user_achievement_sum(user) > user_achievement_sum(highest)
    end
    highest
  end

  private

  def user_distance_sum(user)
    sum_stat(user, :distance)
  end

  def user_ascent_sum(user)
    sum_stat(user, :ascent)
  end

  def user_achievement_sum(user)
    sum_stat(user, :achievements)
  end

  def sum_stat(user, stat_to_sum)
    user.activities.where("date >= '" + start_date.to_s + "' and date <= '"\
      + end_date.to_s + "'").sum(stat_to_sum)
  end

class Challenge
  def user_with_highest_kilometers
    User.highest_kilometers_for(users, period)
  end

  def period
    OpenStruct.new(start: start_date, finish: end_date)
  end
end

class User
  def self.highest_kilometers_for(users, period)
    users.max { |a, b| a.activities.total_stat_between(period) > b.activities.total_stat_between(period) }
  end
end

class Activity
  def self.total_stat_between(period)
    between(period).sum(:distance)
  end

  def self.between(period)
    where("date >= ? and date <= ?", period.start, period.finish)
  end
end

class Challenge
  def user_with_highest_kilometers
    users.highest_kilometers_within_period period
  end

  def period
    OpenStruct.new(start: start_date, finish: end_date)
  end
end

class User
  def self.highest_kilometers_within_period period
    all.max { |a, b| a.activities.total_distance_between(period)\
      <=> b.activities.total_distance_between(period) }
  end
end

class Activity
  def self.total_distance_between period
    between(period).sum(:distance)
  end

  def self.between period
    where(date: period.start..period.finish)
  end
end

NB - all. in a class method has replaced scope, this does the scoping of the data, tricky ha. :)