drop the SSE, use client side fetch every 5s for thread updates

apps/api.lua

@@ -1,8 +1,6 @@
 local app = require("lapis").Application()
 local json_params = require("lapis.application").json_params
 
-local sse = require("lib.sse")
-
 local db = require("lapis.db")
 
 local html_escape = require("lapis.html").escape
@@ -10,33 +8,26 @@ local babycode = require("lib.babycode")
 
 local util = require("util")
 
-app:get("sse_thread_updates", "/thread-updates/:thread_id", function(self)
-  do
-    local thread = db.query("SELECT threads.id FROM threads WHERE threads.id = ?", self.params.thread_id)
-    if #thread == 0 then
-      return {status = 404, skip_render = true}
-    end
+app:post("api_get_thread_updates", "/thread-updates/:thread_id", json_params(function(self)
+  local thread = db.query("SELECT threads.id FROM threads WHERE threads.id = ?", self.params.thread_id)
+  if #thread == 0 then
+    return {json = {error = "no such thread"}, status = 404}
+  end
+  local target_time = self.params.since
+  if not target_time then
+    return {json = {error = "missing parameter 'since'"}, status = 400}
+  end
+  if not tonumber(target_time) then
+    return {json = {error = "parameter 'since' is not a number"}, status = 400}
   end
-  
-  local now = os.time()
-  local stream = sse:new()
-  
-  local thread_id = self.params.thread_id
   local new_posts_query = "SELECT id FROM posts WHERE thread_id = ? AND posts.created_at > ? ORDER BY posts.created_at ASC LIMIT 1"
-  
-  while stream.active do
-    stream:dispatch()
-    local new_post = db.query(new_posts_query, thread_id, now)
-    if #new_post > 0 then
-      local url = util.get_post_url(self, new_post[1].id)
-      stream:enqueue(url, "new_post_url")
-    end
-    
-    ngx.sleep(5)
+  local new_post = db.query(new_posts_query, self.params.thread_id, target_time)
+  if #new_post == 0 then
+    return {json = {status = "none"}, status = 200}
   end
-  
-  return {skip_render = true}
-end)
+  local url = util.get_post_url(self, new_post[1].id)
+  return {json = {status = "new_post", url = url}}
+end))
 
 app:post("babycode_preview", "/babycode-preview", json_params(function(self)
   local user = util.get_logged_in_user(self)