module GeoRecord
  # This scaling factor is used to convert between the float lat/lon that is
  # returned by the API, and the integer lat/lon equivalent that is stored in
  # the database.
  SCALE = 10000000

  def self.included(base)
    base.scope :bbox, ->(bbox) { base.where(OSM.sql_for_area(bbox)) }
    base.before_save :update_tile
  end

  # Is this node within -90 >= latitude >= 90 and -180 >= longitude >= 180
  # * returns true/false
  def in_world?
    return false if lat < -90 || lat > 90
    return false if lon < -180 || lon > 180
    true
  end

  def update_tile
    self.tile = QuadTile.tile_for_point(lat, lon)
  end

  def lat=(l)
    self.latitude = (l * SCALE).round
  end

  def lon=(l)
    self.longitude = (l * SCALE).round
  end

  # Return WGS84 latitude
  def lat
    latitude.to_f / SCALE
  end

  # Return WGS84 longitude
  def lon
    longitude.to_f / SCALE
  end

  private

  def lat2y(a)
    180 / Math::PI * Math.log(Math.tan(Math::PI / 4 + a * (Math::PI / 180) / 2))
  end
end