Add cache clear events to the database

lib/cache/cache.ex

@@ -93,13 +93,18 @@ defmodule Cache.Registry do
     # We have multiple clear_keys and need to update the state for it.
     %{cache: cache, caches_by_key: caches_by_key} = state
 
+    # IO.inspect(clear_keys, label: "Clearing these keys")
+    # IO.inspect(cache, label: "Cache before clearing the keys")
+
     cache =
       Enum.reduce(clear_keys, cache, fn clear_key, cache ->
         keys_to_remove = Map.get(caches_by_key, clear_key, [])
+        log_key_to_remove!(keys_to_remove)
         cache = Map.drop(cache, keys_to_remove)
         cache
       end)
 
+    # IO.inspect(cache, label: "Cache after clearing the keys")
     caches_by_key = Map.drop(caches_by_key, clear_keys)
 
     %{state | cache: cache, caches_by_key: caches_by_key}
@@ -135,4 +140,29 @@ defmodule Cache.Registry do
 
     %{state | cache: cache}
   end
+
+  defp log_key_to_remove!(request_key_to_remove) do
+    # Write to the database when a cache for a url is cleared
+    Enum.map(request_key_to_remove, fn req_key ->
+        {method, path, query, auth} = req_key
+        uuid = Support.generate_uuid()
+        auth_escaped = Support.sparql_escape(auth)
+        query = """
+        PREFIX mu: <http://mu.semte.ch/vocabularies/core/>
+        PREFIX mucache: <http://mu.semte.ch/vocabularies/cache/>
+        INSERT DATA {
+            GRAPH<http://mu.semte.ch/application> {
+                <http://semte.baert.jp.net/cache-clear/v0.1/#{uuid}>    a mucache:CacheClear ;
+                                                                        mu:uuid "#{uuid}";
+                                                                        mucache:path "#{path}";
+                                                                        mucache:method "#{method}";
+                                                                        mucache:query "#{query}";
+                                                                        mucache:muAuthAllowedGroups \"\"\"#{auth_escaped}\"\"\";
+                                                                        mucache:muAuthUsedGroups \"\"\"#{auth_escaped}\"\"\".
+            }
+        }
+        """
+        sparql_request = Support.update(query)
+    end)
+  end
 end