require 'omniauth/oauth'
require 'multi_json'

module OmniAuth
  module Strategies
    # Authenticate to Facebook utilizing OAuth 2.0 and retrieve
    # basic user information.
    #
    # @example Basic Usage
    #   use OmniAuth::Strategies::Instagram, 'client_id', 'client_secret'
    class Instagram < OmniAuth::Strategies::OAuth2
      # @option options [String] :scope separate the scopes by a space
      def initialize(app, client_id=nil, client_secret=nil, options={}, &block)
        client_options = {
          :authorize_url => 'https://api.instagram.com/oauth/authorize',
          :token_url => 'https://api.instagram.com/oauth/access_token',
        }
        super(app, :instagram, client_id, client_secret, client_options, options, &block)
      end

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

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

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

      def user_data
        @access_token.options.merge!({:param_name => 'access_token', :mode => :query})
        @data ||= MultiJson.decode(@access_token.get('/v1/users/self'))
      end

      def user_info
        {
          'nickname' => user_data['data']['username'],
          'name' => user_data['data']['full_name'],
          'image' => user_data['data']['profile_picture'],
        }
      end
    end
  end
end