From 997449ab4b11124d11e638294ea35a4018343148 Mon Sep 17 00:00:00 2001
From: Omar Roth <omarroth@hotmail.com>
Date: Fri, 16 Mar 2018 19:36:49 -0500
Subject: [PATCH] Add language detection for top videos

---
 shard.yml        |  3 +++
 src/helpers.cr   | 31 +++++++++++++++++++++++++++----
 src/invidious.cr |  9 ++++++++-
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/shard.yml b/shard.yml
index f9017d62..dd66fd35 100644
--- a/shard.yml
+++ b/shard.yml
@@ -15,6 +15,9 @@ dependencies:
   pg:
     github: will/crystal-pg
     branch: master
+  detect_language:
+    github: omarroth/detectlanguage-crystal
+    branch: v0.24.2
 
 crystal: 0.24.2
 
diff --git a/src/helpers.cr b/src/helpers.cr
index f6b1e52b..c54dfb22 100644
--- a/src/helpers.cr
+++ b/src/helpers.cr
@@ -24,7 +24,8 @@ class Config
       port: Int32,
       dbname: String,
     ),
-    redirect: Bool,
+    redirect:   Bool,
+    dl_api_key: String | Nil,
   })
 end
 
@@ -229,7 +230,7 @@ def decrypt_signature(a)
   return a.join("")
 end
 
-def rank_videos(db, n)
+def rank_videos(db, n, pool, filter)
   top = [] of {Float64, String}
 
   db.query("SELECT id, wilson_score, published FROM videos WHERE views > 5000 ORDER BY published DESC LIMIT 10000") do |rs|
@@ -250,8 +251,30 @@ def rank_videos(db, n)
   top.reverse!
   top = top.map { |a, b| b }
 
-  # Return top
-  return top[0..n - 1]
+  if filter
+    language_list = [] of String
+    top.each do |id|
+      if language_list.size == n
+        break
+      else
+        client = get_client(pool)
+        video = get_video(id, client, db)
+        pool << client
+
+        description = XML.parse(video.description)
+        content = [video.title, description.content].join(" ")
+
+        results = DetectLanguage.detect(content)
+
+        if results[0].language == "en"
+          language_list << id
+        end
+      end
+    end
+    return language_list
+  else
+    return top[0..n - 1]
+  end
 end
 
 def make_client(url)
diff --git a/src/invidious.cr b/src/invidious.cr
index 6796008f..f373be42 100644
--- a/src/invidious.cr
+++ b/src/invidious.cr
@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+require "detect_language"
 require "kemal"
 require "option_parser"
 require "pg"
@@ -135,8 +136,14 @@ end
 top_videos = [] of Video
 
 spawn do
+  if CONFIG.dl_api_key
+    DetectLanguage.configure do |config|
+      config.api_key = CONFIG.dl_api_key.not_nil!
+    end
+  end
+
   loop do
-    top = rank_videos(PG_DB, 40)
+    top = rank_videos(PG_DB, 40, youtube_pool, true)
 
     if top.size > 0
       args = arg_array(top)