class GeoProximityMonster

# File lib/geo_proximity_monster.rb, line 4
def initialize( lat1 , long1 )
  @loc_1_lat  = lat1
  @loc_1_long = long1
end

# File lib/geo_proximity_monster.rb, line 25
def get_closet_from_pool( pool = [])
  pool_locations = pool
  closest_loc = nil
  smallest_distance = nil
  unless pool_locations.empty?
    pool_locations.each do |this_loc|
      this_distance = get_distance_to( this_loc[:latitude] , this_loc[:longitude] )
      if smallest_distance.nil?
        smallest_distance = this_distance
        closest_loc = this_loc
      else
        if this_distance.abs < smallest_distance.abs
          smallest_distance = this_distance
          closest_loc = this_loc
        end
      end
    end
  end
  return closest_loc
end

# File lib/geo_proximity_monster.rb, line 9
def get_distance_to( lat2 , long2 , options = {:unit => :meters})
  a = [loc_1_lat.to_f , loc_1_long.to_f]
  b = [lat2.to_f , long2.to_f]
  rad_per_deg = Math::PI/180  # PI / 180
  rkm = 6371                  # Earth radius in kilometers
  rm = rkm * 1000             # Radius in meters
  dlon_rad = (b[1].to_f-a[1].to_f) * rad_per_deg  # Delta, converted to rad
  dlat_rad = (b[0].to_f-a[0].to_f) * rad_per_deg
  lat1_rad, lon1_rad = a.map! {|i| i * rad_per_deg }
  lat2_rad, lon2_rad = b.map! {|i| i * rad_per_deg }
  a = Math.sin(dlat_rad/2)**2 + Math.cos(lat1_rad) * Math.cos(lat2_rad) * Math.sin(dlon_rad/2)**2
  c = 2 * Math.asin(Math.sqrt(a))
  return rm * c if options[:unit] == :meters # Delta in meters
  return ((rm * c).to_f)*(0.000621371) if options[:unit] == :miles # Delta in miles
end