Add mixes

src/invidious/mixes.cr

@@ -0,0 +1,74 @@
+class MixVideo
+  add_mapping({
+    title:          String,
+    id:             String,
+    author:         String,
+    ucid:           String,
+    length_seconds: Int32,
+    index:          Int32,
+  })
+end
+
+class Mix
+  add_mapping({
+    title:  String,
+    id:     String,
+    videos: Array(MixVideo),
+  })
+end
+
+def fetch_mix(rdid, video_id, cookies = nil)
+  client = make_client(YT_URL)
+  headers = HTTP::Headers.new
+  headers["User-Agent"] = "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36"
+
+  if cookies
+    headers = cookies.add_request_headers(headers)
+  end
+  response = client.get("/watch?v=#{video_id}&list=#{rdid}&bpctr=#{Time.new.epoch + 2000}&gl=US&hl=en", headers)
+
+  yt_data = response.body.match(/window\["ytInitialData"\] = (?<data>.*);/)
+  if yt_data
+    yt_data = JSON.parse(yt_data["data"].rchop(";"))
+  else
+    raise "Could not create mix."
+  end
+
+  playlist = yt_data["contents"]["twoColumnWatchNextResults"]["playlist"]["playlist"]
+  mix_title = playlist["title"].as_s
+
+  contents = playlist["contents"].as_a
+  until contents[0]["playlistPanelVideoRenderer"]["videoId"].as_s == video_id
+    contents.shift
+  end
+
+  videos = [] of MixVideo
+  contents.each do |item|
+    item = item["playlistPanelVideoRenderer"]
+
+    id = item["videoId"].as_s
+    title = item["title"]["simpleText"].as_s
+    author = item["longBylineText"]["runs"][0]["text"].as_s
+    ucid = item["longBylineText"]["runs"][0]["navigationEndpoint"]["browseEndpoint"]["browseId"].as_s
+    length_seconds = decode_length_seconds(item["lengthText"]["simpleText"].as_s)
+    index = item["navigationEndpoint"]["watchEndpoint"]["index"].as_i
+
+    videos << MixVideo.new(
+      title,
+      id,
+      author,
+      ucid,
+      length_seconds,
+      index
+    )
+  end
+
+  if !cookies
+    next_page = fetch_mix(rdid, videos[-1].id, response.cookies)
+    videos += next_page.videos
+  end
+
+  videos.uniq! { |video| video.id }
+  videos = videos.first(50)
+  return Mix.new(mix_title, rdid, videos)
+end