radio-web/app.rb

require 'sinatra'
require 'sinatra/contrib'
require 'json'

get '/' do
  erb :index
end

post '/add' do
  puts params.to_s
  if params[:link] and params[:link] =~ /http(s):\/\/(?:www\.)?youtu(?:be\.com\/watch\?v=|\.be\/)([\w\-]+)(&(amp;)?[\w\?=]*)?/
    File.open('/tmp/radio', 'w') do |f|
      f.puts(params[:link])
      f.flush
    end
    200
  else
    403
  end                       
end

get '/playlist', :provides => [:html, :json]  do
  songs =  `mpc playlist | cut -d '#' -f 2 | base64 -d`
  songs = songs.split("\n")
  respond_to do |format|
    format.json { songs.to_json }
    format.html { erb :playlist, locals: { songs: songs } }
  end
end

get '/info' do
  title = `mpc | head -n 1 | cut -d '#' -f 2 | base64 -d`
  title.gsub("\n", "")
  content_type :json
  {
    title: title
  }.to_json
end