class ReverseGeo

# File lib/reverse_geo/reverse_geo.rb, line 7
def initialize(file = nil)
  file ||= File.join(File.dirname(__FILE__), @@default_shapefile)
  raise ArgumentError, 'Did not supply a valid geojson file.' unless File.exist?(file)

  @factory = RGeo::Geos.factory(srid: 4326)
  @countries = RGeo::GeoJSON.decode(File.open(file).read, :json_parser => :json, :geo_factory => @factory)
end

# File lib/reverse_geo/reverse_geo.rb, line 19
def country(opts = {})
  country_search('Country', opts)
end

# File lib/reverse_geo/reverse_geo.rb, line 15
def country_code(opts = {})
  country_search('ISO_A3', opts)
end

# File lib/reverse_geo/reverse_geo.rb, line 25
def country_search(property_name, opts)
  raise ArgumentError, "Did not supply a valid lat ([-90,90]) and lng ([-180,180]). You supplied lat: #{opts[:lat]}, lng: #{opts[:lng]}" unless opts[:lat] && opts[:lat].between?(-90, 90) && opts[:lng] && opts[:lng].between?(-180, 180)

  poi = @factory.point(opts[:lng], opts[:lat])
  @countries.each do |country|
    return country.properties[property_name] if poi.within?(country.geometry)
  end

  nil#fallback if we didn't find anything
end