dealer_search.rb

  def dealers
    return [] unless self.zip && self.distance

    require 'haversine'

    return @dealers if @dealers.present?
    @dealers = []
    
    # Convert zip to lat-long
    starting_location = to_lat_long_hash(self.zip)

    # Loop through all USA dealers that have a storefront_zip
    temp_dealers = User.where("storefront_country = ? AND storefront_zip IS NOT NULL AND dealer = ?", "USA", true).all
    temp_dealers.each do |d|
      # Convert the zip code to a lat-long
      storefront_location = to_lat_long_hash(d.storefront_zip)
      
      # and check if the two lat-long sets are within the given distance
      if Haversine.distance(starting_location, storefront_location).to_miles.to_i <= self.distance.to_i
        @dealers << d
      end
    end
    
    @dealers
  end

  def to_lat_long_hash(zip)
    require 'area'

    [zip.to_s.to_lat.to_f, zip.to_s.to_lon.to_f]
  end