svoop/ogn_client-ruby

#!/usr/bin/env ruby

require 'bundler/inline'
require 'optparse'
require 'json'

gemfile do
  source 'https://rubygems.org'
  ruby '>= 2.4'
  gem 'ogn_client-ruby', '~> 0.2', require: 'ogn_client'
end

class Converter
  RED = 140.freeze
  GREEN = 112.freeze

  def initialize
    OptionParser.new do |o|
      o.banner = <<~END
        Convert raw OGN APRS to GeoJSON.
        Usage: ogn2geojson [options] infile
      END
      o.on('-a', '--about', 'author and license information') { puts 'Written by Sven Schwyn (bitcetera.com) and distributed under MIT license.'; exit }
      o.on('-c', '--callsign STRING', String, 'aircraft callsign (e.g. FLRAABBCC)') { |v| @callsign = v }
      o.on('-d', '--date YYYY-MM-DD', String, 'date the APRS messages were recorded (default: today)') { |v| @date = v }
      o.on('-o', '--outfile FILE', String, 'generated GeoJSON file (default: INFILE.geojson)') { |v| @outfile = v.sub(/\.geojson$/, '') + '.geojson' }
    end.parse!
    @infile = ARGV.pop
    fail 'infile not found' unless @infile && File.exists?(@infile)
    @outfile ||= @infile.sub(/\.\w+$/, '') + '.geojson'
  end

  def feature(from_point, to_point, properties={})
    {
      type: 'Feature',
      geometry: {
        type: 'LineString',
        coordinates: [from_point, to_point]
      },
      properties: {
        'stroke-width': 2,
        'stroke-opacity': 1
      }.merge(properties)
    }
  end

  def stroke_for(climb_rate)
    case
    when climb_rate == 0
      "rgb(0, 0, 0)"
    when climb_rate < 0
      color = RED + ([climb_rate.abs, 5].min * ((250 - RED) / 5)).round
      "rgb(#{color}, 0, 0)"
    when climb_rate > 0
      color = GREEN + ([climb_rate, 5].min * ((250 - GREEN) / 5)).round
      "rgb(0, #{color}, 0)"
    end
  end

  def convert!
    lines = File.readlines(@infile)
    features = lines.each.with_object([]) do |line, features|
      if (sender = OGNClient::Message.parse(line, date: @date)).is_a? OGNClient::SenderBeacon
        if !@callsign || sender.callsign == @callsign
          to_point = [sender.longitude, sender.latitude, sender.altitude]
          if @from_point
            features << feature(@from_point, to_point,
              time: sender.time.getlocal.strftime('%H:%M:%S'),
              heading: sender.heading,
              'ground-speed': sender.ground_speed,
              'climb-rate': sender.climb_rate,
              'turn-rate': sender.turn_rate,
              stroke: stroke_for(sender.climb_rate)
            )
          end
          @from_point = to_point
        end
      end
    end
    File.write(@outfile, JSON.pretty_generate(type: "FeatureCollection", features: features))
  end
end

begin
  Converter.new.convert!
rescue => exception
  puts "#{File.basename($0)}: #{exception.message}"
  exit 1
end