class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def facebook
    oauthorize "Facebook"
  end

  def twitter
    oauthorize "Twitter"
  end

  def passthru
    render :file => "#{Rails.root}/public/404.html", :status => 404, :layout => false
  end

private

  def oauthorize(kind)
    omniauth = request.env['omniauth.auth']
    @user = User.includes(:authentications).merge(Authentication.where(:provider => omniauth['provider'], :uid => omniauth['uid'])).first

    if @user # if user exists and has used this authentication before, update details and sign in
      @user.set_token_from_hash(provider_auth_hash(kind, omniauth), provider_user_hash(kind, omniauth))
      sign_in_and_redirect @user, :event => :authentication
    elsif current_user # if user exists then new authentication is being added - so update details and redirect to
      current_user.set_token_from_hash(provider_auth_hash(kind, omniauth), provider_user_hash(kind, omniauth))
      redirect_to edit_user_registration_url
    else # create new user and new authentication
      user = User.new
      user.password = Devise.friendly_token[0,20]
      user.authentications.build(provider_auth_hash(kind, omniauth))
      if user.save :validate => false # validate false handles cases where email not provided - such as Twitter
        sign_in_and_redirect(:user, user)
      else # validate false above makes it almost impossible to get here
        session["devise.#{kind.downcase}_data"] = provider_auth_hash(kind,omniauth).merge(provider_user_hash(kind,omniauth))
        redirect_to new_user_registration_url
      end
    end
  end

  def provider_auth_hash(provider, hash)
  # Create provider specific hash's to populate authentication record
    case provider
    when "Facebook"
      {
        :provider => hash['provider'],
        :uid => hash['uid'],
        :name => hash['extra']['user_hash']['name'],
        :link => hash['extra']['user_hash']['link'],
        :token => hash['credentials']['token'],
        :secret => nil
      }
    when "Twitter"
      {
        :provider => hash['provider'],
        :uid => hash['uid'],
        :name => hash['user_info']['nickname'],
        :link => hash['user_info']['urls']['Twitter'],
        :token => hash['credentials']['token'],
        :secret => hash['credentials']['secret']
      }
    end
  end

  def provider_user_hash(provider, hash)
  # Create provider specific hash's to populate user record if appropriate
    case provider
    when "Facebook"
      {
        :name => hash['extra']['user_hash']['name'],
        :email => hash['extra']['user_hash']['email']
      }
    when "Twitter"
      {
        :name => hash['user_info']['name']
      }
    end
  end

end