youtube-info.coffee

# Description
#   Show video metadata when YouTube URLs are seen.
#
# Dependencies:
#   None
#
# Configuration:
#   None
#
# Commands:
#   [YouTube video URL] - shows title and time length for the URL
#
# Notes:
#   For text-based adapters like IRC.
#
# Author:
#   mmb
querystring = require 'querystring'
url = require 'url'

module.exports = (robot) ->
  robot.hear /(https?:\/\/www\.youtube\.com\/watch\?.+?)(?:\s|$)/i, (msg) ->
    url_parsed = url.parse(msg.match[1])
    query_parsed = querystring.parse(url_parsed.query)

    if query_parsed.v
      video_hash = query_parsed.v
      showInfo msg, video_hash

  robot.hear /(https?:\/\/youtu\.be\/)([a-z0-9\-_]+)/i, (msg) ->
    video_hash = msg.match[2]
    showInfo msg, video_hash

showInfo = (msg, video_hash) ->
  msg.http("http://gdata.youtube.com/feeds/api/videos/#{video_hash}")
    .query({
      alt: 'json'
    }).get() (err, res, body) ->
      if res.statusCode is 200
        data = JSON.parse(body)
        entry = data.entry
        r = entry.gd$rating
        thumbs_up = Math.round(((r.average-r.min)/(r.max-r.min))*r.numRaters)
        thumbs_down = r.numRaters - thumbs_up
        msg.send "YouTube: #{entry.title.$t} (#{formatTime(entry.media$group.yt$duration.seconds)}, #{humanizeNumber(entry.yt$statistics.viewCount)} views, #{humanizeNumber(thumbs_up)} thumbs up, #{humanizeNumber(thumbs_down)} thumbs down)"
      else
        msg.send "YouTube: error: #{video_hash} returned #{res.statusCode}: #{body}"

formatTime = (seconds) ->
  min = Math.floor(seconds / 60)
  sec = seconds % 60

  result = ''
  if (min > 0)
    result += "#{min}m"
  if (sec > 0)
    result += "#{sec}s"

  result

humanizeNumber = (n) ->
  n = n.toString()
  while true
    n2 = n.replace(/(\d)(\d{3})($|,)/g, '$1,$2$3')
    break if n == n2
    n = n2
  n