add code to fetch post ids from listbooru for a saved search

app/models/saved_search.rb

@@ -86,4 +86,22 @@ class SavedSearch < ActiveRecord::Base
     end
   end
 
+  def post_ids
+    params = {
+      "key" => Danbooru.config.listbooru_auth_key,
+      "user_id" => user_id,
+      "name" => category
+    }
+    uri = URI.parse("#{Danbooru.config.listbooru_server}/users")
+    uri.query = URI.encode_www_form(params)
+
+    Net::HTTP.start(uri.host, uri.port) do |http|
+      resp = http.request_get(uri.request_uri)
+      if resp.is_a?(Net::HTTPSuccess)
+        resp.body.scan(/\d+/)
+      else
+        raise "HTTP error code: #{resp.code} #{resp.message}"
+      end
+    end
+  end
 end