--- a/src/lib/Db.luan	Tue Mar 04 07:05:12 2025 -0700
+++ b/src/lib/Db.luan	Tue Mar 04 07:38:43 2025 -0700
@@ -2,6 +2,9 @@
 local error = Luan.error
 local new_error = Luan.new_error or error()
 local ipairs = Luan.ipairs or error()
+local Table = require "luan:Table.luan"
+local sort = Table.sort or error()
+local concat = Table.concat or error()
 local Lucene = require "luan:lucene/Lucene.luan"
 local Io = require "luan:Io.luan"
 local uri = Io.uri or error()
@@ -24,6 +27,7 @@
 
 Db.indexed_fields.chat_user_ids = Lucene.type.long
 Db.indexed_fields.chat_updated = Lucene.type.long
+Db.indexed_fields.chat_key = Lucene.type.string
 
 Db.indexed_fields.post_chat_id = Lucene.type.long
 Db.indexed_fields.post_date = Lucene.type.long
@@ -35,6 +39,12 @@
 	logger.error(new_error("not in transaction"))
 end
 
+-- copied from Chat
+local function get_chat_key(user_ids)
+	sort(user_ids)
+	return concat(user_ids,"~")
+end
+
 Db.update{
 	[1] = function()
 		local docs = Db.search("type:post",1,1000000)
@@ -49,6 +59,13 @@
 	[3] = function()
 		Db.delete("type:chatuser")
 	end
+	[4] = function()
+		local docs = Db.search("type:chat",1,1000000)
+		for _, doc in ipairs(docs) do
+			doc.chat_key = get_chat_key(doc.chat_user_ids)
+			Db.save(doc)
+		end
+	end
 }
 
 if Http.is_serving then