require 'omniauth/oauth'
require 'multi_json'

module OmniAuth
  module Strategies
    #
    # Authenticate to Gowalla utilizing OAuth 2.0 and retrieve
    # basic user information.
    #
    # @example Basic Usage
    #     use OmniAuth::Strategies::Gowalla, 'API Key', 'Secret Key'
    class Gowalla < OAuth2
      # @param [Rack Application] app standard middleware application parameter
      # @param [String] api_key the application id as [registered on Gowalla](http://gowalla.com/api/keys)
      # @param [String] secret_key the application secret as [registered on Gowalla](http://gowalla.com/api/keys)
      # @option options ['read','read-write'] :scope ('read') the scope of your authorization request; must be `read` or `read-write`
      def initialize(app, api_key = nil, secret_key = nil, options = {}, &block)
        client_options = {
          :site => 'https://api.gowalla.com/api/oauth',
          :authorize_url => 'https://gowalla.com/api/oauth/new',
          :access_token_url => 'https://api.gowalla.com/api/oauth/token'
        }

        super(app, :gowalla, api_key, secret_key, client_options, options, &block)
      end

      protected

      def user_data
        @data ||= MultiJson.decode(@access_token.get("/users/me.json"))
      end

      def request_phase
        options[:scope] ||= "read"
        super
      end

      def user_info
        {
          'name' => "#{user_data['first_name']} #{user_data['last_name']}",
          'nickname' => user_data["username"],
          'first_name' => user_data["first_name"],
          'last_name' => user_data["last_name"],
          'location' => user_data["hometown"],
          'description' => user_data["bio"],
          'image' => user_data["image_url"],
          'phone' => nil,
          'urls' => {
            'Gowalla' => "http://www.gowalla.com#{user_data['url']}",
            'Website' => user_data["website"]
          }
        }
      end

      def auth_hash
        OmniAuth::Utils.deep_merge(super, {
          'uid' => user_data["url"].split('/').last,
          'user_info' => user_info,
          'extra' => {'user_hash' => user_data}
        })
      end
    end
  end
end