Search and download slack files from cli

seach_and_download_slack_file.rb

require 'date'
require 'json'
require 'net/https'
require 'optparse'
require 'uri'

# token: https://api.slack.com/custom-integrations/legacy-tokens

# Usage:
#   ruby ./retrieve_slack_image.rb --token "YOUR_SLACK_TOKEN" --query "in:#random type:images (IMG OR Slack OR iOS)"

class SlackImageDownloader
  attr_reader :token, :dir

  URL_FORMAT = 'https://slack.com/api/search.files?token=%<token>s&query=%<query>s&count=%<count>i&page=%<page>i'

  def initialize(token, dir = nil)
    @token = token
    @dir = dir ? dir : "."
  end

  def search_and_download(query)
    page = 1
    loop do
      slack_url = build_url(query, page)
      res = get(slack_url)
      res = JSON.parse res.body
      raise "Something wrong #{res.body}" unless res['ok']
      res['files']['matches'].each do |m|
        url = m['url_private_download']
        timestamp = m['timestamp']
        download url, timestamp
      end
      break if res['files']['pagination']['page_count'] == page
      page += 1
    end
  rescue => e
    puts e
  end

  private

  def build_url(query, page)
    URI.escape(format URL_FORMAT, token: self.token,
               query: query,
               count: 20,
               page: page)
  end

  def get(url, headers = {})
    url = URI.parse url
    req = Net::HTTP::Get.new(url)
    headers.each_pair { |k, v| req[k] = v }
    https = Net::HTTP.new(url.host, url.port)
    https.use_ssl = true
    https.start { |http| http.request(req) }
  end

  def download(url, timestamp)
    basename = File.basename url
    path = File.join(self.dir, "#{timestamp_to_time timestamp}-#{basename}")
    if File.exist?(path)
      puts "Already exists: #{url} => #{path}"
    else
      res = get url, 'Authorization': "Bearer #{self.token}"
      File.open(path, 'wb') do |f|
        f.write res.body
      end
      puts "Download: #{url} => #{path}"
    end
  end

  def timestamp_to_time(timestamp)
    DateTime.strptime(timestamp.to_s, '%s').strftime('%Y%m%d-%H%M%S')
  end
end

def main
  opt = OptionParser.new
  args = {}
  opt.on('--token=TOKEN')
  opt.on('--query=QUERY')
  opt.on('--dir=[DIR]')
  opt.parse! ARGV, into: args
  SlackImageDownloader.new(args[:token], args[:dir]).search_and_download(args[:query])
end

if __FILE__ == $0
  main
end