class Video
  module HTTPParamConverter
    def self.from_rs(rs)
      HTTP::Params.parse(rs.read(String))
    end
  end

  add_mapping({
    id:   String,
    info: {
      type:      HTTP::Params,
      default:   HTTP::Params.parse(""),
      converter: Video::HTTPParamConverter,
    },
    updated:            Time,
    title:              String,
    views:              Int64,
    likes:              Int32,
    dislikes:           Int32,
    wilson_score:       Float64,
    published:          Time,
    description:        String,
    language:           String?,
    author:             String,
    ucid:               String,
    allowed_regions:    Array(String),
    is_family_friendly: Bool,
    genre:              String,
  })
end

def get_video(id, db, refresh = true)
  if db.query_one?("SELECT EXISTS (SELECT true FROM videos WHERE id = $1)", id, as: Bool)
    video = db.query_one("SELECT * FROM videos WHERE id = $1", id, as: Video)

    # If record was last updated over an hour ago, refresh (expire param in response lasts for 6 hours)
    if refresh && Time.now - video.updated > 1.hour
      begin
        video = fetch_video(id)
        video_array = video.to_a
        args = arg_array(video_array[1..-1], 2)

        db.exec("UPDATE videos SET (info,updated,title,views,likes,dislikes,wilson_score,\
          published,description,language,author,ucid, allowed_regions, is_family_friendly, genre)\
          = (#{args}) WHERE id = $1", video_array)
      rescue ex
        db.exec("DELETE FROM videos * WHERE id = $1", id)
        raise ex
      end
    end
  else
    video = fetch_video(id)
    video_array = video.to_a
    args = arg_array(video_array)

    db.exec("INSERT INTO videos VALUES (#{args}) ON CONFLICT (id) DO NOTHING", video_array)
  end

  return video
end

def fetch_video(id)
  html_channel = Channel(XML::Node).new
  info_channel = Channel(HTTP::Params).new

  spawn do
    client = make_client(YT_URL)
    html = client.get("/watch?v=#{id}&bpctr=#{Time.new.epoch + 2000}&disable_polymer=1")
    html = XML.parse_html(html.body)

    html_channel.send(html)
  end

  spawn do
    client = make_client(YT_URL)
    info = client.get("/get_video_info?video_id=#{id}&el=detailpage&ps=default&eurl=&gl=US&hl=en&disable_polymer=1")
    info = HTTP::Params.parse(info.body)

    if info["reason"]?
      info = client.get("/get_video_info?video_id=#{id}&ps=default&eurl=&gl=US&hl=en&disable_polymer=1")
      info = HTTP::Params.parse(info.body)
    end

    info_channel.send(info)
  end

  html = html_channel.receive
  info = info_channel.receive

  if info["reason"]?
    raise info["reason"]
  end

  title = info["title"]
  views = info["view_count"].to_i64
  author = info["author"]
  ucid = info["ucid"]

  likes = html.xpath_node(%q(//button[@title="I like this"]/span))
  likes = likes.try &.content.delete(",").try &.to_i
  likes ||= 0

  dislikes = html.xpath_node(%q(//button[@title="I dislike this"]/span))
  dislikes = dislikes.try &.content.delete(",").try &.to_i
  dislikes ||= 0

  description = html.xpath_node(%q(//p[@id="eow-description"]))
  description = description ? description.to_xml : ""

  wilson_score = ci_lower_bound(likes, likes + dislikes)

  published = html.xpath_node(%q(//meta[@itemprop="datePublished"])).not_nil!["content"]
  published = Time.parse(published, "%Y-%m-%d", Time::Location.local)

  allowed_regions = html.xpath_node(%q(//meta[@itemprop="regionsAllowed"])).not_nil!["content"].split(",")
  is_family_friendly = html.xpath_node(%q(//meta[@itemprop="isFamilyFriendly"])).not_nil!["content"] == "True"
  genre = html.xpath_node(%q(//meta[@itemprop="genre"])).not_nil!["content"]

  video = Video.new(id, info, Time.now, title, views, likes, dislikes, wilson_score, published, description,
    nil, author, ucid, allowed_regions, is_family_friendly, genre)

  return video
end

def itag_to_metadata(itag : String)
  # See https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/youtube.py#L380-#L476
  formats = {"5"  => {"ext" => "flv", "width" => 400, "height" => 240, "acodec" => "mp3", "abr" => 64, "vcodec" => "h263"},
             "6"  => {"ext" => "flv", "width" => 450, "height" => 270, "acodec" => "mp3", "abr" => 64, "vcodec" => "h263"},
             "13" => {"ext" => "3gp", "acodec" => "aac", "vcodec" => "mp4v"},
             "17" => {"ext" => "3gp", "width" => 176, "height" => 144, "acodec" => "aac", "abr" => 24, "vcodec" => "mp4v"},
             "18" => {"ext" => "mp4", "width" => 640, "height" => 360, "acodec" => "aac", "abr" => 96, "vcodec" => "h264"},
             "22" => {"ext" => "mp4", "width" => 1280, "height" => 720, "acodec" => "aac", "abr" => 192, "vcodec" => "h264"},
             "34" => {"ext" => "flv", "width" => 640, "height" => 360, "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "35" => {"ext" => "flv", "width" => 854, "height" => 480, "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},

             "36" => {"ext" => "3gp", "width" => 320, "acodec" => "aac", "vcodec" => "mp4v"},
             "37" => {"ext" => "mp4", "width" => 1920, "height" => 1080, "acodec" => "aac", "abr" => 192, "vcodec" => "h264"},
             "38" => {"ext" => "mp4", "width" => 4096, "height" => 3072, "acodec" => "aac", "abr" => 192, "vcodec" => "h264"},
             "43" => {"ext" => "webm", "width" => 640, "height" => 360, "acodec" => "vorbis", "abr" => 128, "vcodec" => "vp8"},
             "44" => {"ext" => "webm", "width" => 854, "height" => 480, "acodec" => "vorbis", "abr" => 128, "vcodec" => "vp8"},
             "45" => {"ext" => "webm", "width" => 1280, "height" => 720, "acodec" => "vorbis", "abr" => 192, "vcodec" => "vp8"},
             "46" => {"ext" => "webm", "width" => 1920, "height" => 1080, "acodec" => "vorbis", "abr" => 192, "vcodec" => "vp8"},
             "59" => {"ext" => "mp4", "width" => 854, "height" => 480, "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "78" => {"ext" => "mp4", "width" => 854, "height" => 480, "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},

             # 3D videos
             "82"  => {"ext" => "mp4", "height" => 360, "format" => "3D", "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "83"  => {"ext" => "mp4", "height" => 480, "format" => "3D", "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "84"  => {"ext" => "mp4", "height" => 720, "format" => "3D", "acodec" => "aac", "abr" => 192, "vcodec" => "h264"},
             "85"  => {"ext" => "mp4", "height" => 1080, "format" => "3D", "acodec" => "aac", "abr" => 192, "vcodec" => "h264"},
             "100" => {"ext" => "webm", "height" => 360, "format" => "3D", "acodec" => "vorbis", "abr" => 128, "vcodec" => "vp8"},
             "101" => {"ext" => "webm", "height" => 480, "format" => "3D", "acodec" => "vorbis", "abr" => 192, "vcodec" => "vp8"},
             "102" => {"ext" => "webm", "height" => 720, "format" => "3D", "acodec" => "vorbis", "abr" => 192, "vcodec" => "vp8"},

             # Apple HTTP Live Streaming
             "91"  => {"ext" => "mp4", "height" => 144, "format" => "HLS", "acodec" => "aac", "abr" => 48, "vcodec" => "h264"},
             "92"  => {"ext" => "mp4", "height" => 240, "format" => "HLS", "acodec" => "aac", "abr" => 48, "vcodec" => "h264"},
             "93"  => {"ext" => "mp4", "height" => 360, "format" => "HLS", "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "94"  => {"ext" => "mp4", "height" => 480, "format" => "HLS", "acodec" => "aac", "abr" => 128, "vcodec" => "h264"},
             "95"  => {"ext" => "mp4", "height" => 720, "format" => "HLS", "acodec" => "aac", "abr" => 256, "vcodec" => "h264"},
             "96"  => {"ext" => "mp4", "height" => 1080, "format" => "HLS", "acodec" => "aac", "abr" => 256, "vcodec" => "h264"},
             "132" => {"ext" => "mp4", "height" => 240, "format" => "HLS", "acodec" => "aac", "abr" => 48, "vcodec" => "h264"},
             "151" => {"ext" => "mp4", "height" => 72, "format" => "HLS", "acodec" => "aac", "abr" => 24, "vcodec" => "h264"},

             # DASH mp4 video
             "133" => {"ext" => "mp4", "height" => 240, "format" => "DASH video", "vcodec" => "h264"},
             "134" => {"ext" => "mp4", "height" => 360, "format" => "DASH video", "vcodec" => "h264"},
             "135" => {"ext" => "mp4", "height" => 480, "format" => "DASH video", "vcodec" => "h264"},
             "136" => {"ext" => "mp4", "height" => 720, "format" => "DASH video", "vcodec" => "h264"},
             "137" => {"ext" => "mp4", "height" => 1080, "format" => "DASH video", "vcodec" => "h264"},
             "138" => {"ext" => "mp4", "format" => "DASH video", "vcodec" => "h264"}, # Height can vary (https=>//github.com/rg3/youtube-dl/issues/4559)
             "160" => {"ext" => "mp4", "height" => 144, "format" => "DASH video", "vcodec" => "h264"},
             "212" => {"ext" => "mp4", "height" => 480, "format" => "DASH video", "vcodec" => "h264"},
             "264" => {"ext" => "mp4", "height" => 1440, "format" => "DASH video", "vcodec" => "h264"},
             "298" => {"ext" => "mp4", "height" => 720, "format" => "DASH video", "vcodec" => "h264", "fps" => 60},
             "299" => {"ext" => "mp4", "height" => 1080, "format" => "DASH video", "vcodec" => "h264", "fps" => 60},
             "266" => {"ext" => "mp4", "height" => 2160, "format" => "DASH video", "vcodec" => "h264"},

             # Dash mp4 audio
             "139" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "aac", "abr" => 48, "container" => "m4a_dash"},
             "140" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "aac", "abr" => 128, "container" => "m4a_dash"},
             "141" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "aac", "abr" => 256, "container" => "m4a_dash"},
             "256" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "aac", "container" => "m4a_dash"},
             "258" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "aac", "container" => "m4a_dash"},
             "325" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "dtse", "container" => "m4a_dash"},
             "328" => {"ext" => "m4a", "format" => "DASH audio", "acodec" => "ec-3", "container" => "m4a_dash"},

             # Dash webm
             "167" => {"ext" => "webm", "height" => 360, "width" => 640, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "168" => {"ext" => "webm", "height" => 480, "width" => 854, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "169" => {"ext" => "webm", "height" => 720, "width" => 1280, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "170" => {"ext" => "webm", "height" => 1080, "width" => 1920, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "218" => {"ext" => "webm", "height" => 480, "width" => 854, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "219" => {"ext" => "webm", "height" => 480, "width" => 854, "format" => "DASH video", "container" => "webm", "vcodec" => "vp8"},
             "278" => {"ext" => "webm", "height" => 144, "format" => "DASH video", "container" => "webm", "vcodec" => "vp9"},
             "242" => {"ext" => "webm", "height" => 240, "format" => "DASH video", "vcodec" => "vp9"},
             "243" => {"ext" => "webm", "height" => 360, "format" => "DASH video", "vcodec" => "vp9"},
             "244" => {"ext" => "webm", "height" => 480, "format" => "DASH video", "vcodec" => "vp9"},
             "245" => {"ext" => "webm", "height" => 480, "format" => "DASH video", "vcodec" => "vp9"},
             "246" => {"ext" => "webm", "height" => 480, "format" => "DASH video", "vcodec" => "vp9"},
             "247" => {"ext" => "webm", "height" => 720, "format" => "DASH video", "vcodec" => "vp9"},
             "248" => {"ext" => "webm", "height" => 1080, "format" => "DASH video", "vcodec" => "vp9"},
             "271" => {"ext" => "webm", "height" => 1440, "format" => "DASH video", "vcodec" => "vp9"},
             # itag 272 videos are either 3840x2160 (e.g. RtoitU2A-3E) or 7680x4320 (sLprVF6d7Ug)
             "272" => {"ext" => "webm", "height" => 2160, "format" => "DASH video", "vcodec" => "vp9"},
             "302" => {"ext" => "webm", "height" => 720, "format" => "DASH video", "vcodec" => "vp9", "fps" => 60},
             "303" => {"ext" => "webm", "height" => 1080, "format" => "DASH video", "vcodec" => "vp9", "fps" => 60},
             "308" => {"ext" => "webm", "height" => 1440, "format" => "DASH video", "vcodec" => "vp9", "fps" => 60},
             "313" => {"ext" => "webm", "height" => 2160, "format" => "DASH video", "vcodec" => "vp9"},
             "315" => {"ext" => "webm", "height" => 2160, "format" => "DASH video", "vcodec" => "vp9", "fps" => 60},

             # Dash webm audio
             "171" => {"ext" => "webm", "acodec" => "vorbis", "format" => "DASH audio", "abr" => 128},
             "172" => {"ext" => "webm", "acodec" => "vorbis", "format" => "DASH audio", "abr" => 256},

             # Dash webm audio with opus inside
             "249" => {"ext" => "webm", "format" => "DASH audio", "acodec" => "opus", "abr" => 50},
             "250" => {"ext" => "webm", "format" => "DASH audio", "acodec" => "opus", "abr" => 70},
             "251" => {"ext" => "webm", "format" => "DASH audio", "acodec" => "opus", "abr" => 160},
  }

  return formats[itag]
end