#!/usr/bin/env ruby
# -*- coding: utf-8 -*-
# (C)2016-12-19 by HIROSE, Yuuji [yuuji>at<gentei.org]
require 'json'
myname = File.basename($0)

if !ARGV[0] || !test(?s, ARGV[0]) then
  STDERR.puts "#{myname} - Shift longitude in GeoJson file specified degrees."
  STDERR.puts "Usage: #{myname} GeoJsonFile [OffsetDegree]\n\n"
  STDERR.puts "eg.) % #{myname} hoge.geojson 360 > new-hoge.geojson\n\n"
  STDERR.puts "OffsetDegree defaults to +360"
  exit 0
end

json = JSON.load(open(ARGV[0]){|j|j.read})
offsetlon = (ARGV[1]||360).to_i

json["features"].each do |f|
  g = f["geometry"]
  if g then
    co = g["coordinates"]
    STDERR.puts g["type"].inspect
    if co then
      coords = if co[0].is_a?(Numeric)
                 [[co]]
               elsif co[0][0].is_a?(Numeric)
                 [co]
               else
                 co
               end
      for cs in coords
        for c in cs
          if c[0] < 0 then
            STDERR.printf("%f -> %f\n", c[0], c[0]+offsetlon)
            c[0] += offsetlon
          end
        end
      end
    end
  end
end
print JSON.pretty_generate(json)