require "twitter"
require "tweet_sanitizer/version"
require "tweet_sanitizer/twitter_extension"

module TweetSanitizer
  # @param tweet [Twitter:Tweet]
  # @return [String]
  def self.sanitize(tweet)
    # Original RT status is exists in retweeted_status
    tweet = Twitter::Tweet.new(tweet.attrs[:retweeted_status]) if tweet.attrs[:retweeted_status]

    text = expand_urls_text(tweet)
    text = remove_media_urls_in_tweet(tweet, text)
    text = CGI.unescapeHTML(text)
    text
  end

  # @param tweet [Twitter:Tweet]
  # @return [String]
  def self.expand_urls_text(tweet)
    text = tweet_full_text(tweet)
    return text unless tweet.uris?

    tweet.uris.reverse.each_with_object(text.dup) do |uri, expanded|
      pos1 = uri.indices[0]
      pos2 = uri.indices[1]
      expanded[pos1, pos2-pos1] = uri.expanded_url
    end
  end

  # @param tweet [Twitter:Tweet]
  # @return [String] `full_text` attribute if exist
  def self.tweet_full_text(tweet)
    # NOTE: Twitter::Tweet#full_text doesn't returns full_text attribute
    # https://github.com/sferik/twitter/blob/v6.1.0/lib/twitter/tweet.rb#L37-L44
    tweet.attrs[:full_text] || tweet.text
  end

  # @param tweet [Twitter:Tweet]
  # @param text [String]
  # @return [String]
  def self.remove_media_urls_in_tweet(tweet, text)
    return text unless tweet.media?

    tweet.media.each_with_object(text.dup) do |media, t|
      t.gsub!(media.url, "")
      t.strip!
    end
  end
end