Add ability to load extension shards for Invidious

.gitignore

@@ -7,3 +7,5 @@
 /invidious
 /sentry
 /config/config.yml
+
+/src/addons/enabled.txt

src/addons/extract-addons.cr

@@ -0,0 +1,19 @@
+require "yaml"
+
+shardyml = File.open("shard.yml") do |file|
+  YAML.parse(file).as_h
+end
+
+# Finds all dependencies prefixed with extendious
+raw_addons = shardyml["dependencies"].as_h.keys.select(&.as_s.starts_with?("extendious"))
+addons = [] of String
+
+raw_addons.map do |addon_name|
+  addon_name = addon_name.as_s
+  addon_module = addon_name.lchop("extendious-")
+  addon_module = addon_module.split("-").map!(&.capitalize).join
+
+  addons << "#{addon_name},#{addon_module}"
+end
+
+File.write("src/addons/enabled.txt", addons.join("\n"))

src/invidious.cr

@@ -243,6 +243,17 @@ Kemal.config.host_binding = Kemal.config.host_binding != "0.0.0.0" ? Kemal.confi
 Kemal.config.port = Kemal.config.port != 3000 ? Kemal.config.port : CONFIG.port
 Kemal.config.app_name = "Invidious"
 
+# Loads optional extensions for Invidious
+# Essentially just glorified shards with a set naming scheme
+# and load method
+
+{{run("./addons/extract-addons.cr", "--minified")}}
+{% for addon in read_file("src/addons/enabled.txt").lines %}
+  {% shard_name, module_name = addon.split(",") %}
+  require {{shard_name.id.stringify}}
+  {{module_name.id}}Ext.invidious_load
+{% end %}
+
 # Use in kemal's production mode.
 # Users can also set the KEMAL_ENV environmental variable for this to be set automatically.
 {% if flag?(:release) || flag?(:production) %}