require 'omniauth/oauth'
require 'multi_json'

module OmniAuth
  module Strategies
    # Authenticate to TSina via OAuth and retrieve basic
    # user information.
    #
    # Usage:
    #    use OmniAuth::Strategies::TSina, 'APIKey', 'APIKeySecret'
    class Tsina < OmniAuth::Strategies::OAuth

      def initialize(app, consumer_key=nil, consumer_secret=nil, options={}, &block)
        @api_key = consumer_key
        client_options = {
          :access_token_path => '/oauth/access_token',
          :authorize_path => '/oauth/authorize',
          :realm => 'OmniAuth',
          :request_token_path => '/oauth/request_token',
          :site => 'http://api.t.sina.com.cn',
        }
        super(app, :tsina, consumer_key, consumer_secret, client_options, options, &block)
      end

      def auth_hash
        OmniAuth::Utils.deep_merge(
          super, {
            'uid' => @access_token.params[:user_id],
            'user_info' => user_info,
            'extra' => {
              'user_hash' => user_hash,
            },
          }
        )
      end

      def user_info
        user_hash = self.user_hash
        {
          'username' => user_hash['screen_name'],
          'name' => user_hash['name'],
          'location' => user_hash['location'],
          'image' => user_hash['profile_image_url'],
          'description' => user_hash['description'],
          'urls' => {
            'Tsina' => user_hash['url']
          }
        }
      end

      # MonkeyPatch session['oauth']['tsina']['callback_confirmed'] to true
      def request_phase
        request_token = consumer.get_request_token(:oauth_callback => callback_url)
        session['oauth'] ||= {}
        session['oauth'][name.to_s] = {'callback_confirmed' => true, 'request_token' => request_token.token, 'request_secret' => request_token.secret}
        r = Rack::Response.new

        if request_token.callback_confirmed?
          r.redirect(request_token.authorize_url)
        else
          r.redirect(request_token.authorize_url(:oauth_callback => callback_url))
        end

        r.finish
      rescue ::Timeout::Error => e
        fail!(:timeout, e)
      end

      # MonkeyPath to symbolize tina parameters
      def callback_phase
        session[:oauth].stringify_keys!
        session[:oauth][name.to_s].stringify_keys! if session[:oauth][name.to_s]
        super
      end

      def user_hash
        # http://api.t.sina.com.cn/users/show/:id.json?source=appkey
        # @access_token.params[:user_id] is the UID
        # @api_key is the appkey
        uid = @access_token.params[:user_id]
        @user_hash ||= MultiJson.decode(@access_token.get("http://api.t.sina.com.cn/users/show/#{uid}.json?source=#{@api_key}").body)
      end
    end
  end
end