--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/chat.luan	Tue Mar 04 08:22:45 2025 -0700
@@ -0,0 +1,65 @@
+local Luan = require "luan:Luan.luan"
+local error = Luan.error
+local pairs = Luan.pairs or error()
+local Table = require "luan:Table.luan"
+local concat = Table.concat or error()
+local is_empty = Table.is_empty or error()
+local Http = require "luan:http/Http.luan"
+local Shared = require "site:/lib/Shared.luan"
+local http_push_to_users = Shared.http_push_to_users or error()
+local User = require "site:/lib/User.luan"
+local current_user = User.current or error()
+local get_user_by_email = User.get_by_email or error()
+local Utils = require "site:/lib/Utils.luan"
+local to_set = Utils.to_set or error()
+local Db = require "site:/lib/Db.luan"
+local run_in_transaction = Db.run_in_transaction or error()
+local Chat = require "site:/lib/Chat.luan"
+local get_chat_by_user_ids = Chat.get_by_user_ids or error()
+
+
+return function()
+	local with = Http.request.parameters.with
+	local user = current_user()
+	with = to_set(with)
+	if user == nil then
+		local url = "/login.html"
+		if not is_empty(with) then
+			local t = {}
+			for email in pairs(with) do
+				t[#t+1] = "with="..email
+			end
+			url = url.."?"..concat(t,"&")
+		end
+		Http.response.send_redirect(url)
+		return
+	end
+	if is_empty(with) then
+		Http.response.send_redirect("/")
+		return
+	end
+	with[user.email] = true
+	local ids = {}
+	for email in pairs(with) do
+		local with_user = get_user_by_email(email) or error()
+		local id = with_user.id
+		ids[#ids+1] = id
+	end
+	local need_push = false
+	local chat = run_in_transaction( function()
+		local chat = get_chat_by_user_ids(ids)
+		if chat == nil then
+			chat = Chat.new{
+				user_ids = ids
+			}
+			chat.save()
+			need_push = true
+		end
+		return chat
+	end )
+	if need_push then
+		local js = "getChats('"..chat.id.."')"
+		http_push_to_users( chat.user_ids, js )
+	end
+	Http.response.send_redirect("/?chat="..chat.id)
+end