add twitter-posting script that has been running for a while

closes #124

extras/twitter.rb

@@ -0,0 +1,50 @@
+class Twitter
+  cattr_accessor :CONSUMER_KEY, :CONSUMER_SECRET, :AUTH_TOKEN, :AUTH_SECRET
+
+  # these need to be overridden in config/initializers/production.rb
+  @@CONSUMER_KEY = nil
+  @@CONSUMER_SECRET = nil
+  @@AUTH_TOKEN = nil
+  @@AUTH_SECRET = nil
+
+  MAX_TWEET_LEN = 140
+
+  # https://t.co/eyW1U2HLtP
+  TCO_LEN = 23
+
+  def self.oauth_consumer
+    OAuth::Consumer.new(self.CONSUMER_KEY, self.CONSUMER_SECRET,
+      { :site => "https://api.twitter.com" })
+  end
+
+  def self.oauth_request(req, method = :get, post_data = nil)
+    if !self.AUTH_TOKEN
+      raise "no auth token configured"
+    end
+
+    begin
+      Timeout.timeout(120) do
+        at = OAuth::AccessToken.new(self.oauth_consumer, self.AUTH_TOKEN,
+          self.AUTH_SECRET)
+
+        if method == :get
+          res = at.get(req)
+        elsif method == :post
+          res = at.post(req, post_data)
+        else
+          raise "what kind of method is #{method}?"
+        end
+
+        if res.class == Net::HTTPUnauthorized
+          raise "not authorized"
+        end
+
+        if res.body.to_s == ""
+          raise res.inspect
+        else
+          return JSON.parse(res.body)
+        end
+      end
+    end
+  end
+end

script/post_to_twitter

@@ -0,0 +1,54 @@
+#!/usr/bin/env ruby
+
+ENV["RAILS_ENV"] ||= "production"
+
+APP_PATH = File.expand_path('../../config/application',  __FILE__)
+require File.expand_path('../../config/boot',  __FILE__)
+require APP_PATH
+Rails.application.require_environment!
+
+LAST_STORY_KEY = "twitter:last_story_id"
+
+last_story_id = (Keystore.value_for(LAST_STORY_KEY) || Story.last.id).to_i
+
+Story.where("id > ? AND is_expired = ?", last_story_id, false).
+order(:id).each do |s|
+  if !s.tags.map(&:tag).include?("meta")
+    status = "\n" + (s.url.present?? s.url + "\n" : "") + s.short_id_url
+
+    tco_status = "\n" + (s.url.present?? ("X" * Twitter::TCO_LEN) + "\n" :
+      "") + ("X" * Twitter::TCO_LEN)
+
+    left_len = Twitter::MAX_TWEET_LEN - tco_status.length
+
+    title = s.title
+
+    if title.match(/^([dm] |@)/i)
+      # prevent these tweets from activating twitter shortcuts
+      # https://dev.twitter.com/docs/faq#tweeting
+      title = "- #{title}"
+    end
+
+    if title.bytesize > left_len
+      status = title[0, left_len - 3] + "..." + status
+    else
+      status = title + status
+    end
+
+    res = Twitter.oauth_request("/1.1/statuses/update.json", :post,
+      { "status" => status })
+
+    begin
+      if !res["id_str"].match(/\d+/)
+        raise
+      end
+    rescue => e
+      puts "failed posting story #{s.id} (#{status.inspect}): #{e.inspect}\n" +
+        "#{res.inspect}"
+      exit
+    end
+  end
+
+  Keystore.put(LAST_STORY_KEY, s.id)
+  sleep 2
+end