app.rb

# frozen_string_literal: true

require 'bundler/setup'
Bundler.require :default

require_relative 'lib/demo'
require_relative 'lib/message'

require_relative 'lib/loader'
Loader.get :latest

class Dingus < Sinatra::Base
  # Set maximum sizes
  MAX_PATH_SIZE = 1900
  MAX_BODY_SIZE = 1400

  # initialize new sprockets environment
  set :environment, Sprockets::Environment.new

  # append assets paths
  environment.append_path 'assets/images'
  environment.append_path 'assets/stylesheets'
  environment.append_path 'assets/javascripts'

  # compress assets
  environment.js_compressor  = Uglifier.new(harmony: true)
  environment.css_compressor = :scssc

  # get assets
  get '/assets/*' do
    env['PATH_INFO'].sub!('/assets', '')
    settings.environment.call(env)
  end

  before do
    halt 413 if request.path.length > MAX_PATH_SIZE ||
                request.content_length.to_i > MAX_BODY_SIZE
  end

  get '/' do
    flash = Message[params['error'].to_i]
    erb :index, locals: { demo: Demo.new, flash: flash }
  end

  get '/message/:code' do
    content_type :json
    { message: Message[params['code'].to_i] }.to_json
  end

  post '/parse' do
    case request.content_type
    when 'application/json'
      payload = JSON.parse request.body.read

      demo = begin
        Demo.new payload['ver'],
                 payload['lang'],
                 payload['source']
      rescue StandardError
        halt 400
      end

      content_type :json
      { ver: demo.version, source: demo.source, result: demo.result }.to_json
    else
      halt 400 if params['parse'].nil?

      ver = params['parse']['version']
      lang = params['parse']['language']
      source = params['parse']['source']
      halt 400 if ver.nil? || lang.nil? || source.nil?

      source = Base64.urlsafe_encode64 source, padding: false
      redirect to("/#{ver}/#{lang}/#{source}")
    end
  end

  get '/:ver/:lang/:source?' do
    if params['source'].nil? || params['source'] == 'draft'
      demo = begin
        Demo.new params['ver'], params['lang']
      rescue StandardError
        halt 400
      end
    else
      source = Base64.urlsafe_decode64(params['source']).force_encoding('utf-8')
      demo = begin
        Demo.new params['ver'], params['lang'], source
      rescue StandardError
        halt 400
      end
    end

    erb :index, locals: { demo: demo, flash: nil }
  end

  error 400..500 do
    case request.content_type
    when 'application/json'
      content_type :json
      { message: Message[response.status] }.to_json
    else
      redirect to("/?error=#{response.status}")
    end
  end
end