require 'omniauth/oauth'
require 'multi_json'

module OmniAuth
  module Strategies
    class Foursquare < OmniAuth::Strategies::OAuth2
      # Initialize the middleware
      #
      # @option options [Boolean, true] :sign_in When true, use a sign-in flow instead of the authorization flow.
      # @option options [Boolean, false] :mobile When true, use the mobile sign-in interface.
      def initialize(app, client_id=nil, client_secret=nil, options={}, &block)
        options[:sign_in] ||= true
        client_options = {
          :authorize_url => authorize_url(options),
          :token_url => 'https://foursquare.com/oauth2/access_token',
        }
        super(app, :foursquare, client_id, client_secret, client_options, options, &block)
      end

      def auth_hash
        OmniAuth::Utils.deep_merge(
          super, {
            'uid' => user_data['response']['user']['id'],
            'user_info' => user_info,
            'extra' => {
              'user_hash' => user_data['response']['user'],
            },
          }
        )
      end

      def authorize_url(options)
        "https://foursquare.com/#{'mobile/' if options[:mobile]}oauth2/#{options[:sign_in] ? 'authenticate' : 'authorize'}"
      end

      def user_data
        @data ||= MultiJson.decode(@access_token.get('https://api.foursquare.com/v2/users/self', { :params => { 'oauth_token' => @access_token.token } }).body)
      end

      def request_phase
        options[:response_type] ||= 'code'
        super
      end

      def callback_phase
        options[:grant_type] ||= 'authorization_code'
        super
      end

      def user_info
        {
          'nickname' => user_data['response']['user']['contact']['twitter'],
          'first_name' => user_data['response']['user']['firstName'],
          'last_name' => user_data['response']['user']['lastName'],
          'email' => user_data['response']['user']['contact']['email'],
          'name' => "#{user_data['response']['user']['firstName']} #{user_data['response']['user']['lastName']}".strip,
          'image' => user_data['response']['user']['photo'],
          'phone' => user_data['response']['user']['contact']['phone'],
        }
      end
    end
  end
end