Refactor JSON subdomain redirector logic

Reworks the JsonSubdomainRedirector to explicitly redirect API calls to the API domain and GUI calls to the GUI domain. Introduces clearer separation of redirect logic and improves method naming for better readability and maintainability.

Author: lmrodriguezr

app/middleware/json_subdomain_redirector.rb

@@ -1,7 +1,11 @@
 require 'uri'
 
+##
+# Make sure that the API calls are channeled through the API domain and the
+# GUI calls are channeled through the GUI domain
 class JsonSubdomainRedirector
   def initialize(app)
+    @gui_domain = 'registry.seqco.de'
     @api_domain = 'api.seqco.de'
     @api_version = 'v1'
     @app = app
@@ -10,11 +14,14 @@ def initialize(app)
   def call(env)
     request = Rack::Request.new(env)
 
-    return @app.call(env) if
-      !is_json?(request) ||
-      is_core_json?(request) ||
-      already_on_api_subdomain?(request)
+    if on_api_subdomain?(request)
+      redirect_to_gui(request) unless is_api_call?(request)
+    else
+      redirect_to_api(request) if is_api_call?(request)
+    end
+  end
 
+  def redirect_to_api(request)
     is_versioned = request.path.match?(/^\/v\d+\//)
     new_path = is_versioned ? request.path : "/#{@api_version}#{request.path}"
 
@@ -30,6 +37,21 @@ def call(env)
     ]
   end
 
+  def redirect_to_gui(request)
+    new_path = request.path.gsub(/^\/v\d+\//, '/')
+
+    # Reconstruct URL
+    uri = URI.parse(request.url)
+    uri.host = @gui_domain
+    uri.path = new_path
+
+    return [
+      301,
+      { 'Location' => uri.to_s, 'Content-Type' => 'text/html' },
+      ['Moved Permanently']
+    ]
+  end
+
   def is_json?(request)
     request.get_header('HTTP_ACCEPT')&.include?('application/json') ||
       request.path.end_with?('.json')
@@ -42,7 +64,11 @@ def is_core_json?(request)
       path.match?(/check\/\d+\.json$/)
   end
 
-  def already_on_api_subdomain?(request)
+  def is_api_call?(request)
+    is_json?(request) && !is_core_json?(request)
+  end
+
+  def on_api_subdomain?(request)
     request.host == @api_domain
   end
 end