Reacolle - Reaction Collection for Slack

reacolle.rb

# coding: utf-8

=begin

# Reacolle

"Reacolle" is the simple slack bot application written by Ruby.

When happen event `add_reaction` in any public channel, Reacolle post message to your channel.

## Required gems

gem 'slack-api'
gem 'dotenv' # optional

## Required ENV

ENV['SLACK_TOKEN'] = 'Your Slack bot application token'
ENV['TEAM_DOMAIN'] = 'Your Slack team domain ( example.slack.com )'

## Usage

$ gem install slack-api
$ SLACK_TOKEN='xxxxx' TEAM_DOMAIN='example.slack.com' ruby reacolle.rb

## License

MIT

=end

require 'slack'
begin
  require 'dotenv'
  Dotenv.load
rescue
end

# ------------------------------------------------------------------------------

Slack.configure do |config|
  config.token = ENV['SLACK_TOKEN']
end

# ------------------------------------------------------------------------------

class Reacolle
  def initialize(settings = {})
    @client = Slack::Web::Client.new
    @rtm_client = Slack::RealTime::Client.new
    @settings = settings.map do |emoji, channels|
      [emoji.to_s, channels.map { |c| resolve_channel(c) }.uniq]
    end.to_h
    @uid_caches = []
  end
  attr_reader :client, :rtm_client

  def start!
    rtm_client.on :reaction_added do |m|
      if can_notify?(m['item'])
        uid = uid_from_item(m['item'])
        emoji = m['reaction']
        channels = @settings[emoji]
        if channels && !@uid_caches.include?(uid)
          @uid_caches.push(uid)
          channels.each do |channel|
            client.chat_postMessage(
              channel: channel,
              text: ":#{emoji}: https://#{ENV['TEAM_DOMAIN']}/archives/#{channel_name(m['item']['channel'])}/p#{m['item']['ts'].gsub('.', '')}",
              parse: 'full',
              unfurl_links: true,
              unfurl_media: true,
              as_user: true
            )
          end
        end
      end
    end
    rtm_client.start!
  end

  private

  def can_notify?(item)
    case item['type']
    when 'message'
      item['channel'].index('C') == 0
    end
  end

  def uid_from_item(item)
    "#{item['channel']}-#{item['ts']}"
  end

  def resolve_channel(name)
    list = client.channels_list.channels
    channel = list.find { |n| n.name == name }
    channel ? channel.id : nil
  end

  def channel_name(uid)
    list = client.channels_list.channels
    channel = list.find { |n| n.id == uid }
    channel ? channel.name : nil
  end
end

# ------------------------------------------------------------------------------

Reacolle.new({
  # ex) post to #random when receive `:ok_woman:` reaction
  ok_woman: ['random'],
}).start!