Crêpe

# config.ru
require 'crepe'
require 'twitter_api/v1'

class TwitterAPI < Crepe::API
  extend Crepe::Streaming

  version '1.1' do
    let!(:current_user)       { User.authorize!(*request.credentials) }

    namespace :statuses do
      # helpers
      let(:tweet_params)      {
        params.require(:status).permit :message, :in_reply_to_status_id
      }
      let(:current_tweet)     { current_user.tweets.find params[:id] }

      # endpoints
      get(:home_timeline)     { current_user.timeline }
      get(:mentions_timeline) { current_user.mentions }
      get(:user_timeline)     { current_user.tweets }
      get(:retweets_of_me)    { current_user.tweets.retweeted }

      post(:update)           { current_user.tweets.create! tweet_params }
      get('show/:id')         { current_tweet }
      get('retweets/:id')     { current_tweet.retweets }
      post('destroy/:id')     { current_tweet.destroy }
      post('retweet/:id')     { current_user.retweet! Tweet.find params[:id] }

      stream(:firehose)       { Tweet.stream { |t| render t } }
      stream(:sample)         { Tweet.sample.stream { |t| render t } }
    end

    get('search/tweets')      { Tweet.search params.slice Tweet::SEARCH_KEYS }
    stream(:user)             { current_user.timeline.stream { |t| render t } }
  end

  mount TwitterAPI::V1 # legacy version 1

  rescue_from ActiveRecord::RecordNotFound do |e|
    error! :not_found, e.message
  end
  rescue_from ActiveRecord::InvalidRecord do |e|
    error! :unprocessable_entity, e.message, errors: e.record.errors
  end
  rescue_from User::Unauthorized do |e|
    unauthorized! realm: 'Twitter API'
  end
end

run TwitterAPI