require 'twitter_oauth'
require 'yaml'
require 'fileutils'

$CONFIG_FILE = 'config.yaml'
def load_config(config_file)
    # if the config file doesn't exist, we'll need to get our access token
    unless File.exists?(config_file)
        create_default_config_file($CONFIG_FILE)
        get_access_token
    end

    begin
        $CONFIG = YAML::load(File.read(config_file))
        $consumer_key = $CONFIG['oauth']['consumer_key']
        $consumer_secret = $CONFIG['oauth']['consumer_secret']
        $request_token = $CONFIG['oauth']['request_token']
        $request_secret = $CONFIG['oauth']['request_secret']
    rescue
        create_default_config_file($CONFIG_FILE)
    end

    if $request_token.nil? and $request_secret.nil?
        get_access_token
        # not yet authorized
    else
        # authorized
    end
end

def create_default_config_file(config_file)
    File.open(config_file, 'w') do |out|
        $CONFIG['oauth']['consumer_key'] = 'XXXXXXXXXXXXXXXXXXXXXXXXXX'
        $CONFIG['oauth']['consumer_key'] = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
        YAML::dump($CONFIG, out)
    end
    load_config($CONFIG_FILE)
end

def get_access_token()
    unless File.exists?($CONFIG_FILE)
        create_default_config_file($CONFIG_FILE)
    end

    client = TwitterOAuth::Client.new(:consumer_key => $consumer_key, :consumer_secret => $consumer_secret)
    request_token = client.request_token
    puts "Please open the following address in your browser to authorize this application:"
    puts "#{request_token.authorize_url}\n"

    puts "Enter the PIN from twitter.com and press [ENTER]"
    pin = STDIN.gets.strip
    $access_token = client.authorize(request_token.token, request_token.secret)
    File.open($CONFIG_FILE, 'w') do |out|
        $CONFIG['oauth']['request_token'] = access_token.token
        $CONFIG['oauth']['request_secret'] = access_token.secret
        YAML::dump($CONFIG, out)
    end
end