Twitch: Support new /directory/category/ URLs to look up game feeds.

Author: stefansundin

app.rb

@@ -701,6 +701,9 @@
   if /twitch\.tv\/directory\/game\/(?<game_name>[^\/?#]+)/ =~ params[:q]
     # https://www.twitch.tv/directory/game/Perfect%20Dark
     game_name = Addressable::URI.unescape(game_name)
+  elsif /twitch\.tv\/directory\/category\/(?<category_slug>[^\/?#]+)/ =~ params[:q]
+    # https://www.twitch.tv/directory/category/perfect-dark-2000
+    category_slug = Addressable::URI.unescape(category_slug)
   elsif /twitch\.tv\/directory/ =~ params[:q]
     # https://www.twitch.tv/directory/all/tags/7cefbf30-4c3e-4aa7-99cd-70aabb662f27
     return [404, "Unsupported url."]
@@ -728,6 +731,10 @@
     return [422, "Something went wrong. Try again later."] if path.nil?
     return [422, path] if path.start_with?("Error:")
     redirect Addressable::URI.new(path: "/twitch/directory/game/#{path}").normalize.to_s, 301
+  elsif category_slug
+    path = App::TwitchGraphQL.resolve_category_slug(category_slug)
+    return [422, path] if path.start_with?("Error:")
+    redirect Addressable::URI.new(path: "/twitch/directory/game/#{path}").normalize.to_s, 301
   elsif vod_id
     path, _ = App::Cache.cache("twitch.vod", vod_id, 60*60, 60) do
       response = App::Twitch.get("/videos", query: { id: vod_id })

app/http.rb

@@ -3,17 +3,21 @@
 module App
   class HTTP
     def self.get(url, options={})
-      relative_url = (url[0] == "/")
+      relative_url = (url.nil? || url[0] == "/")
 
-      if defined?(self::BASE_URL) && relative_url
-        url = self::BASE_URL+url
-      end
+      if url.nil?
+        url = self::BASE_URL
+      else
+        if defined?(self::BASE_URL) && relative_url
+          url = self::BASE_URL+url
+        end
 
-      if defined?(self::PARAMS) && relative_url
-        if url["?"]
-          url += "&"+self::PARAMS
-        else
-          url += "?"+self::PARAMS
+        if defined?(self::PARAMS) && relative_url
+          if url["?"]
+            url += "&"+self::PARAMS
+          else
+            url += "?"+self::PARAMS
+          end
         end
       end
 
@@ -46,17 +50,21 @@ def self.get(url, options={})
     end
 
     def self.post(url, data, options={})
-      relative_url = (url[0] == "/")
+      relative_url = (url.nil? || url[0] == "/")
 
-      if defined?(self::BASE_URL) && relative_url
-        url = self::BASE_URL+url
-      end
+      if url.nil?
+        url = self::BASE_URL
+      else
+        if defined?(self::BASE_URL) && relative_url
+          url = self::BASE_URL+url
+        end
 
-      if defined?(self::PARAMS) && relative_url
-        if url["?"]
-          url += "&"+self::PARAMS
-        else
-          url += "?"+self::PARAMS
+        if defined?(self::PARAMS) && relative_url
+          if url["?"]
+            url += "&"+self::PARAMS
+          else
+            url += "?"+self::PARAMS
+          end
         end
       end
 

app/services/twitch.rb

@@ -19,6 +19,32 @@ class TwitchToken < HTTP
     }
     ERROR_CLASS = TwitchError
   end
+
+  class TwitchGraphQL < HTTP
+    BASE_URL = "https://gql.twitch.tv/gql"
+    HEADERS = {
+      "Client-ID" => ENV["TWITCHTOKEN_CLIENT_ID"],
+      "Content-Type" => "application/json",
+    }
+    ERROR_CLASS = TwitchError
+
+    def self.resolve_category_slug(slug)
+      path, _ = Cache.cache("twitch.category", slug, 7*24*60*60, 60*60) do
+        response = self.post(nil,
+          {
+            "query": "query category($slug: String!) { game(slug: $slug) { id name } }",
+            "variables": { "slug": slug },
+          }.to_json,
+        )
+        raise(TwitchError, response) if !response.success? || !response.json
+        data = response.json["data"]["game"]
+        next "Error: Can't find a category with that name." if data.nil?
+
+        "#{data["id"]}/#{data["name"]}"
+      end
+      path
+    end
+  end
 end
 
 error App::TwitchError do |e|