Use `athena-negotiation` to detect language through Accept-Language header (#2324)

Detect language through Accept-Language header

shard.lock

@@ -1,5 +1,9 @@
 version: 2.0
 shards:
+  athena-negotiation:
+    git: https://github.com/athena-framework/negotiation.git
+    version: 0.1.1
+
   db:
     git: https://github.com/crystal-lang/crystal-db.git
     version: 0.10.1

shard.yml

@@ -25,6 +25,9 @@ dependencies:
   lsquic:
     github: iv-org/lsquic.cr
     version: ~> 2.18.1-2
+  athena-negotiation:
+    github: athena-framework/negotiation
+    version: ~> 0.1.1
 
 crystal: ">= 1.0.0, < 2.0.0"
 

src/invidious.cr

@@ -17,6 +17,7 @@
 require "digest/md5"
 require "file_utils"
 require "kemal"
+require "athena-negotiation"
 require "openssl/hmac"
 require "option_parser"
 require "pg"
@@ -166,10 +167,20 @@ def popular_videos
 end
 
 before_all do |env|
-  preferences = begin
-    Preferences.from_json(URI.decode_www_form(env.request.cookies["PREFS"]?.try &.value || "{}"))
+  preferences = Preferences.from_json("{}")
+
+  begin
+    if prefs_cookie = env.request.cookies["PREFS"]?
+      preferences = Preferences.from_json(URI.decode_www_form(prefs_cookie.value))
+    else
+      if language_header = env.request.headers["Accept-Language"]?
+        if language = ANG.language_negotiator.best(language_header, LOCALES.keys)
+          preferences.locale = language.header
+        end
+      end
+    end
   rescue
-    Preferences.from_json("{}")
+    preferences = Preferences.from_json("{}")
   end
 
   env.set "preferences", preferences

src/invidious/routes/login.cr

@@ -434,6 +434,13 @@ module Invidious::Routes::Login
 
         sid = Base64.urlsafe_encode(Random::Secure.random_bytes(32))
         user, sid = create_user(sid, email, password)
+
+        if language_header = env.request.headers["Accept-Language"]?
+          if language = ANG.language_negotiator.best(language_header, LOCALES.keys)
+            user.preferences.locale = language.header
+          end
+        end
+
         user_array = user.to_a
         user_array[4] = user_array[4].to_json # User preferences