Translation Bot

bot.rb

#!/usr/bin/env ruby
require 'mastodon'
require 'curb' # We'll need this for talking to Microsoft's Translator API

translator_token = '{TOKEN_FROM_TRANSLATOR_API}'
mastodon_token = '{ACCESS_TOKEN_FROM_MASTODON}'

# We're going to extend the String Class to do a bit of our dirty work
class String
  # We'll use this to strip XML/HTML tags out of strips
  def without_tags
    self.gsub(%r{</?[^>]+?>}, '')
  end

  # Use regex to check for Japanese Characters
  def japanese?
    # Using `!!` to make sure that we end up with a bool.
    # Also, \p will match Unicode properties. Here, we're looking for Japanese
    # characters.
    !!(self =~ /\p{Katakana}|\p{Hiragana}/)
  end
end

# Gets an access token for the Translator API
def get_token(translator_token)
  token_url = "https://api.cognitive.microsoft.com/sts/v1.0/issueToken"
  response = Curl.post(token_url) do |response|
    response.headers['Ocp-Apim-Subscription-key'] = translator_token
  end

  return response.body_str
end

# Connects to the API and translate the toot's content.
# If there's an issue with the connection, we return `false`
def translate_toot(toot, token)
  toot_content = toot.content.without_tags
  translation_url = 
    "http://api.microsofttranslator.com/v2/Http.svc/Translate?" +
    "text=" + toot_content + "&to=en&from=ja"

  begin
    response = Curl.get(translation_url) do |response|
      response.headers['Authorization'] = "Bearer " + token
    end
  rescue
    return false
  end

  if response.status != "200 OK"
    return false
  end

  return response.body_str.without_tags
end

# Connect to mastodon
mastodon = Mastodon::REST::Client.new(
  base_url: 'https://mastodon.cloud', bearer_token: mastodon_token
)

# Grab the 25 most recent toots from the Public Timeline
toots = mastodon.public_timeline(limit:25)

# Find all of the Japanese toots and translate them
japanese_toots = []
token = get_token(translator_token)
toots.each do |toot|
  toot_content = toot.content.without_tags
  if toot_content.japanese?
    translated = translate_toot(
      toot, token
    )
    if translated
      japanese_toots << [toot, translated]
    end
  end
end

# Loop through the Japanese toots and start replying
japanese_toots.each do |toot|
  begin
    # toot[1] is the content of the toot
    translated_toot = "English Translation:\n" + toot[1]

    # Make sure we don't go over the maximum toot length
    if translated_toot.length <= 500
      # toot[0] is the original toot we are replying to
      mastodon.create_status(
        translated_toot,
        toot[0].id
      )
      puts "Tooted @ " + toot[0].account.acct
    end
  rescue
    puts "Failed tooting!"
  end
end