explorer.rb

#!/usr/bin/env ruby

require 'net/http'
require 'json'

def make_query_inner(max_depth = 3, depth = 0)
  return [] if depth >= max_depth

  indent = ' ' * (6 + (depth * 2))
  ["\n#{indent}",
   "previousBlock {\n#{indent}  id",
   *make_query_inner(max_depth, depth + 1),
   "\n#{indent}}"]
end

def make_query
  <<-GRAPHQL
query History {
  status {
    latestBlock {
      id
      #{make_query_inner(ARGV[0].to_i).join}
    }
  }
}
  GRAPHQL
end

def render_previous(parent_id, obj)
  return unless obj
  puts %("#{obj['id']}" -> "#{parent_id}";)
  render_previous(obj['id'], obj['previousBlock'])
end

def render(graph)
  start = graph['data']['status']['latestBlock']
  start_id = start['id']

  puts "digraph chain {"
  render_previous(start_id, start['previousBlock'])
  puts "}"
end

uri = URI.parse('http://127.0.0.1:3101/explorer/graphql')
headers = {
  'Content-Type' => 'application/json',
  'Accept' => 'application/json'
}

request = Net::HTTP::Post.new(uri.request_uri, headers)
request.body = {
  query: make_query,
  variables: nil,
  operationName: 'History'
}.to_json
response = Net::HTTP.new(uri.host, uri.port).request(request)

pp response unless response.code == 200

graph = JSON.parse(response.body, max_nesting: 1000)
render(graph)