require 'httparty'
require 'json'
require 'selenium-webdriver'

module SlackMattermostEmoji
  class SlackClient
    def initialize(username:, password:, domain:, download_path: nil, headless: true, log: true)
      @username = username
      @password = password
      @domain = domain
      @download_path = File.expand_path(download_path || './slack-emoji')
      @log = log
      @authenticated = false

      if [@username, @password, @domain].any? { |el| el.nil? || el.empty? }
        raise 'Slack username, password, and domain are all required'
      end

      Dir.mkdir(@download_path) unless Dir.exist?(@download_path)

      options = Selenium::WebDriver::Chrome::Options.new
      options.headless! unless headless == false
      @driver = Selenium::WebDriver.for :chrome, options: options
    end

    def authenticate
      print "Logging into Slack at #{@domain} as #{@username}... " if @log
      @driver.navigate.to "https://#{@domain}"
      @driver.find_element(name: 'email').send_keys(@username)
      @driver.find_element(name: 'password').send_keys(@password)
      @driver.find_element(id: 'signin_btn').click

      begin
        @driver.find_element(css: 'p.alert.alert_error')
        raise 'Invalid Slack credentials'
      rescue Selenium::WebDriver::Error::NoSuchElementError
        nil
      end

      puts 'success' if @log

      @authenticated = true
    end

    def download_emoji
      print "Finding emoji... " if @log

      token = @driver.execute_script(<<~JS)
        const config = JSON.parse(window.localStorage.localConfig_v2);
        const teams = Object.values(config.teams);
        const team = teams.find((team) => team.url.match('#{@domain}'));
        if (!team) {
          return null;
        } else {
          return team.token;
        }
      JS

      @driver.navigate.to("https://#{@domain}/api/emoji.list?token=#{token}")
      body = @driver.find_element(tag_name: 'body')
      data = JSON.parse(body.text)
      emoji_count = data['emoji'].size
      digits = emoji_count.to_s.size

      puts "found #{emoji_count} emoji" if @log

      data['emoji'].each_with_index do |emoji, index|
        next if URI(image_url).scheme == 'alias'

        name, image_url = emoji

        puts "#{(index + 1).to_s.rjust(digits, ' ')}/#{emoji_count} :#{name}:" if @log

        extension = File.extname(image_url)
        file_name = "#{name}#{extension}"
        file_path = File.join(@download_path, file_name)

        File.open(file_path, "wb") do |f|
          image = HTTParty.get(image_url)
          f.write(image.body)
        end
      end

      data['emoji']
    end

    def authenticated?
      @authenticated
    end
  end
end