bdurand/us_geo

# frozen_string_literal: true

module USGeoData
  class Division
    include Processor

    class << self
      def name(id)
        unless defined?(@name_map)
          map = {}
          processor = new
          processor.foreach(processor.data_file(USGeoData::DIVISIONS_FILE)) do |row|
            map[row["ID"].to_i] = row["Name"]
          end
          @name_map = map
        end
        @name_map[id&.to_i]
      end
    end

    def initialize(states: nil)
      @states = states
    end

    def dump_csv(output)
      CSV.new(output).tap do |csv|
        csv << ["ID", "Name", "Region ID", "Population", "Housing Units", "Land Area", "Water Area"]
        division_data.each_value do |data|
          csv << [
            data[:id],
            data[:name],
            data[:region_id],
            data[:population],
            data[:housing_units],
            data[:land_area].round(3),
            data[:water_area].round(3)
          ]
        end
      end
      output
    end

    def division_data
      unless defined?(@division_data)
        data = {}
        foreach(data_file(USGeoData::DIVISIONS_FILE)) do |row|
          id = row["ID"].to_i
          data[id] = {
            id: id,
            name: row["Name"],
            region_id: row["Region ID"].to_i,
            population: 0,
            housing_units: 0,
            land_area: 0.0,
            water_area: 0.0
          }
        end

        add_state_values(data)

        @division_data = data
      end
      @division_data
    end

    private

    def add_state_values(data)
      state_data.each_value do |state_data|
        next unless state_data[:division_id]
        division_data = data[state_data[:division_id]]
        division_data[:population] += state_data[:population]
        division_data[:housing_units] += state_data[:housing_units]
        division_data[:land_area] += state_data[:land_area].to_f
        division_data[:water_area] += state_data[:water_area].to_f
      end
    end

    def state_data
      @states ||= USGeoData::State.new
      @states.state_data
    end
  end
end