chatgpt added offline items update

items.py

@@ -3,6 +3,7 @@ from flask_login import login_required, current_user
 from models import db
 from models import Item, ListOfItems
 from sqlalchemy import desc, text
+from datetime import datetime
 import os
 from log import Log
 from auth import create_cookie
@@ -23,6 +24,28 @@ def require_item_access(itemid):
         abort(403)
     return item
 
+def client_update_time():
+    client_updated_at = request.args.get("client_updated_at")
+    if not client_updated_at:
+        return None
+
+    try:
+        return datetime.fromtimestamp(int(client_updated_at) / 1000)
+    except ValueError:
+        return None
+
+def item_update_is_current(item):
+    updated_at = client_update_time()
+    if updated_at is None:
+        return True
+
+    return item.updated_at is None or updated_at >= item.updated_at
+
+def stamp_item_update(item):
+    updated_at = client_update_time()
+    if updated_at is not None:
+        item.updated_at = updated_at
+
 # home screen for items
 @items_bp.route("/items/<listid>")
 @login_required
@@ -42,7 +65,10 @@ def items(listid):
 @login_required
 def item_update(itemid, itemchecked):
     i = require_item_access(itemid)
+    if not item_update_is_current(i):
+        return '', 204
     i.is_checked = True if itemchecked == 'true' else False
+    stamp_item_update(i)
     db.session.commit()
     return '', 204
 
@@ -170,6 +196,8 @@ def items_multiappend(listid):
 @login_required
 def item_delete(itemid):
     i = require_item_access(itemid)
+    if not item_update_is_current(i):
+        return redirect(url_for("items.items_append", listid=i.listofitems_id))
     listid = i.listofitems_id
     db.session.delete(i)
     db.session.commit()
@@ -195,6 +223,12 @@ def items_clean(listid):
 @login_required
 def item_addone(itemid):
     i = require_item_access(itemid)
+    if not item_update_is_current(i):
+        resp = make_response(render_template("items_append.html", user=current_user,
+                               items=Item.query.filter_by(listofitems_id=i.listofitems_id).order_by(Item.label).all(),
+                               logo_url=url_for("items.items", listid=i.listofitems_id)))
+        resp.set_cookie('username', create_cookie(current_user.id))
+        return resp
     listid = i.listofitems_id
     # if it is checked or not on the list yet, set quantity to one 
     if i.is_suggestion or i.is_checked:
@@ -208,6 +242,7 @@ def item_addone(itemid):
     # if no unit given, make it 'x'
     if not i.unit:
         i.unit = 'x'
+    stamp_item_update(i)
     db.session.commit()
 
     resp = make_response(render_template("items_append.html", user=current_user, 
@@ -221,6 +256,12 @@ def item_addone(itemid):
 @login_required
 def item_addquantity(itemid, quantity):
     i = require_item_access(itemid)
+    if not item_update_is_current(i):
+        resp = make_response(render_template("items_append.html", user=current_user,
+                               items=Item.query.filter_by(listofitems_id=i.listofitems_id).order_by(Item.label).all(),
+                               logo_url=url_for("items.items", listid=i.listofitems_id)))
+        resp.set_cookie('username', create_cookie(current_user.id))
+        return resp
     listid = i.listofitems_id
     # always add the item to the active todo
     if i.is_suggestion or i.is_checked:
@@ -229,6 +270,7 @@ def item_addquantity(itemid, quantity):
         i.is_checked = False
     else:
         i.quantity += int(quantity)
+    stamp_item_update(i)
     db.session.commit()
 
     resp = make_response(render_template("items_append.html", user=current_user, 
@@ -242,6 +284,9 @@ def item_addquantity(itemid, quantity):
 @login_required
 def item_upitem_update_categorydate(itemid, category):
     i = require_item_access(itemid)
+    if not item_update_is_current(i):
+        return '', 204
     i.category = category
+    stamp_item_update(i)
     db.session.commit()
     return '', 204