routes: move error 404 logic to its own module

src/invidious.cr

@@ -187,49 +187,7 @@ end
 Invidious::Routing.register_all
 
 error 404 do |env|
-  if md = env.request.path.match(/^\/(?<id>([a-zA-Z0-9_-]{11})|(\w+))$/)
+  Invidious::Routes::ErrorRoutes.error_404(env)
-    item = md["id"]
-
-    # Check if item is branding URL e.g. https://youtube.com/gaming
-    response = YT_POOL.client &.get("/#{item}")
-
-    if response.status_code == 301
-      response = YT_POOL.client &.get(URI.parse(response.headers["Location"]).request_target)
-    end
-
-    if response.body.empty?
-      env.response.headers["Location"] = "/"
-      halt env, status_code: 302
-    end
-
-    html = XML.parse_html(response.body)
-    ucid = html.xpath_node(%q(//link[@rel="canonical"])).try &.["href"].split("/")[-1]
-
-    if ucid
-      env.response.headers["Location"] = "/channel/#{ucid}"
-      halt env, status_code: 302
-    end
-
-    params = [] of String
-    env.params.query.each do |k, v|
-      params << "#{k}=#{v}"
-    end
-    params = params.join("&")
-
-    url = "/watch?v=#{item}"
-    if !params.empty?
-      url += "&#{params}"
-    end
-
-    # Check if item is video ID
-    if item.match(/^[a-zA-Z0-9_-]{11}$/) && YT_POOL.client &.head("/watch?v=#{item}").status_code != 404
-      env.response.headers["Location"] = url
-      halt env, status_code: 302
-    end
-  end
-
-  env.response.headers["Location"] = "/"
-  halt env, status_code: 302
 end
 
 error 500 do |env, ex|

src/invidious/routes/errors.cr

@@ -0,0 +1,47 @@
+module Invidious::Routes::ErrorRoutes
+  def self.error_404(env)
+    if md = env.request.path.match(/^\/(?<id>([a-zA-Z0-9_-]{11})|(\w+))$/)
+      item = md["id"]
+
+      # Check if item is branding URL e.g. https://youtube.com/gaming
+      response = YT_POOL.client &.get("/#{item}")
+
+      if response.status_code == 301
+        response = YT_POOL.client &.get(URI.parse(response.headers["Location"]).request_target)
+      end
+
+      if response.body.empty?
+        env.response.headers["Location"] = "/"
+        haltf env, status_code: 302
+      end
+
+      html = XML.parse_html(response.body)
+      ucid = html.xpath_node(%q(//link[@rel="canonical"])).try &.["href"].split("/")[-1]
+
+      if ucid
+        env.response.headers["Location"] = "/channel/#{ucid}"
+        haltf env, status_code: 302
+      end
+
+      params = [] of String
+      env.params.query.each do |k, v|
+        params << "#{k}=#{v}"
+      end
+      params = params.join("&")
+
+      url = "/watch?v=#{item}"
+      if !params.empty?
+        url += "&#{params}"
+      end
+
+      # Check if item is video ID
+      if item.match(/^[a-zA-Z0-9_-]{11}$/) && YT_POOL.client &.head("/watch?v=#{item}").status_code != 404
+        env.response.headers["Location"] = url
+        haltf env, status_code: 302
+      end
+    end
+
+    env.response.headers["Location"] = "/"
+    haltf env, status_code: 302
+  end
+end