require 'omniauth/strategies/oauth2'
require 'base64'
require 'rack/utils'

module OmniAuth
  module Strategies
    class Reddit < OmniAuth::Strategies::OAuth2
      option :name, "reddit"
      option :authorize_options, [:scope, :duration]

      option :client_options, {
        site: 'https://oauth.reddit.com',
        token_url: 'https://ssl.reddit.com/api/v1/access_token'
      }

      uid { raw_info['id'] }

      info do
        {
          name: raw_info['name']
        }
      end

      extra do
        {'raw_info' => raw_info}
      end
      def raw_info
        @raw_info ||= access_token.get('/api/v1/me').parsed || {}
      end

      def build_access_token
        options.token_params.merge!(:headers => {'Authorization' => basic_auth_header })
        super
      end

      def basic_auth_header
        "Basic " + Base64.strict_encode64("#{options[:client_id]}:#{options[:client_secret]}")
      end

      MOBILE_USER_AGENTS =  'webos|ipod|iphone|mobile'

      def request_phase
        options[:client_options].authorize_url = mobile_request? ? 'https://ssl.reddit.com/api/v1/authorize.compact' : 'https://ssl.reddit.com/api/v1/authorize'
        super
      end

      def mobile_request?
        ua = Rack::Request.new(@env).user_agent.to_s
        ua.downcase =~ Regexp.new(MOBILE_USER_AGENTS)
      end

      def callback_url
        options[:redirect_uri] || (full_host + script_name + callback_path)
      end
    end
  end
end