foodspot_friend.rb

#!/usr/bin/env ruby

# This script uses Selenium WebDriver and Firefox to scrape the friends and
# followers lists of a Foodspotting user.
# Then it groups the contacts into 3 sets: mutual friends, only followers, and
# only following.

require 'selenium-webdriver'
require 'set'
require 'optparse'

# Get the user name.
def get_user_name web
  puts 'Getting user name...'
  url = 'http://foodspotting.com/me'
  web.get url
  m = web.current_url.match(%r{foodspotting\.com/([^/]+)$})
  raise 'Unable to retrieve user name.' unless m
  m[1]
end

# Find the highest-numbered page by parsing the pages links.
def get_last_page web
  web.find_elements(:css, 'div.pagination a[href*="?page="]').map { |elem|
    elem.attribute('href').match(/\?page=(\d+)/)[1].to_i
  }.max
end

# Parse user IDs and names from the contact list.
def get_names web
  web.find_elements(:css, 'div.title a').map { |elem|
    id = elem.attribute('href').sub(%r{^/}, '')
    name = elem.text.strip
    { id: id, name: name }
  }
end

# Process the contact list, returning a list of users from all the pages in
# the list.
def process_list what, username, web
  puts "Fetching #{what} page 1..."

  url = "http://www.foodspotting.com/#{username}/#{what}"
  web.get url

  last_page = get_last_page web
  names = get_names web

  (2..last_page).each { |page|
    puts "Fetching #{what} page #{page}..."
    web.get "#{url}?page=#{page}"

    names += get_names web
  }

  names
end

def show_list flist
  flist.each_with_index { |name, i|
    puts "#{i + 1}: #{name[:id]} - #{name[:name]}"
  }
end

# Wait for user to log in to Foodspotting, if necessary.
def check_login web
  url = 'https://www.foodspotting.com'
  web.get url
  begin
    web.find_element(id: 'mini-profile')
  rescue Selenium::WebDriver::Error::NoSuchElementError
    puts 'Please log in to Foodspotting'
    wait = Selenium::WebDriver::Wait.new(timeout: 900)
    wait.until { web.find_element(id: 'mini-profile') }
  end
end

# Use Spotlight to find the Firefox binary.
def setup_firefox_path
  firefox_app = nil
  IO.popen('mdfind "kMDItemFSName = Firefox*.app"') { |io|
    firefox_app = io.gets
  }
  raise "Can't find Firefox app bundle" unless firefox_app
  firefox_app.chomp!

  Selenium::WebDriver::Firefox::Binary.path = File.join(firefox_app, 'Contents/MacOS/firefox')
end

def parse_opts
  options = {}

  optp = OptionParser.new

  optp.banner = <<-EOM
This script uses Selenium WebDriver and Firefox to scrape the friends and
followers lists of a Foodspotting user.
Then it groups the contacts into 3 sets: mutual friends, only followers, and
only following.

Usage: #{File.basename $PROGRAM_NAME} [options]
  EOM

  optp.on('-h', '-?', '--help', 'Option help') {
    puts optp
    exit
  }

  optp.on('-m', '--mutual', 'Show mutual friends') {
    options[:mutual_friends] = true
  }

  optp.on('-r', '--only-friends', 'Show only-friends') {
    options[:only_friends] = true
  }

  optp.on('-o', '--only-followers', 'Show only-followers') {
    options[:only_followers] = true
  }

  optp.separator '  If none of -m/-r/-o are specified, display all 3 categories.'

  begin
    optp.parse!
  rescue OptionParser::ParseError => err
    warn "Error parsing command line: #{err}\n\n"
    warn optp
    exit 1
  end

  if !options[:mutual_friends] && !options[:only_friends] && !options[:only_followers]
    # If none of the 3 options are specified, show everything.
    options[:mutual_friends] = options[:only_friends] = options[:only_followers] = true
  end

  options
end

options = parse_opts
web = nil
begin
  setup_firefox_path
  web = Selenium::WebDriver.for :firefox

  check_login web

  username = get_user_name web

  followers = Set.new(process_list(:followers, username, web))
  following = Set.new(process_list(:following, username, web))

  if options[:mutual_friends]
    puts 'Mutual followers:'
    show_list(following & followers)
  end

  if options[:only_followers]
    puts 'Only followers:'
    show_list(followers - following)
  end

  if options[:only_friends]
    puts 'Only following:'
    show_list(following - followers)
  end
ensure
  web.close if web
end

__END__