Merge pull request #1189 from ascholerChemeketa/canvas-tz-fix

LTI1p3: update timezone handling to accomodate Canvas change

Author: bnmnetp

bases/rsptx/admin_server_api/routers/lti1p3.py

@@ -22,6 +22,7 @@
 import uuid
 import os
 import tldextract
+from zoneinfo import ZoneInfo
 
 # Third-party imports
 # -------------------
@@ -42,6 +43,7 @@
 # -------------------
 from rsptx.db.models import (
     AuthUserValidator,
+    Courses,
     CoursesValidator,
     Lti1p3Conf,
     Lti1p3User,
@@ -461,7 +463,7 @@ async def launch(request: Request):
         # make sure RS assignment is up to date (e.g. end date)
         course_attributes = await fetch_all_course_attributes(course.id)
         await update_rsassignment_from_lti(
-            rs_assign, assign_lineitem, course_attributes
+            rs_assign, assign_lineitem, course_attributes, course
         )
 
         # start redirect to assignment
@@ -508,14 +510,34 @@ async def update_lti_assignment_record(
 
 
 async def update_rsassignment_from_lti(
-    assign: AssignmentValidator, line_item: LineItem, course_attributes: dict
+    assign: AssignmentValidator,
+    line_item: LineItem,
+    course_attributes: dict,
+    course: Courses,
 ) -> AssignmentValidator:
     """
     Update a runestone assignment from LTI data.
     """
     try:
         lms_due_string = line_item.get_end_date_time()
-        lms_due = datetime.datetime.fromisoformat(lms_due_string)
+        rslogger.info(
+            f"LTI1p3 - Received {lms_due_string} for assignment {assign.name}"
+        )
+
+        # Parse ISO datetime. Normalize trailing Z so fromisoformat can parse UTC.
+        normalized_due_string = (
+            lms_due_string.replace("Z", "+00:00")
+            if lms_due_string.endswith("Z")
+            else lms_due_string
+        )
+        lms_due = datetime.datetime.fromisoformat(normalized_due_string)
+
+        # If LMS provided timezone info and course has a timezone, convert to course local time.
+        if lms_due.tzinfo is not None and course.timezone:
+            lms_due = lms_due.astimezone(ZoneInfo(course.timezone))
+            rslogger.info(
+                f"LTI1p3 - Converted to {lms_due} in timezone {course.timezone}"
+            )
         lms_due = lms_due.replace(tzinfo=None)
         if (
             lms_due is not None
@@ -1125,7 +1147,9 @@ async def assign_select(launch_id: str, request: Request, course=None):
                 )
                 await ags.update_lineitem(line_item)
                 # update RS due date
-                await update_rsassignment_from_lti(assign, line_item, course_attributes)
+                await update_rsassignment_from_lti(
+                    assign, line_item, course_attributes, course
+                )
     deep_link = message_launch.get_deep_link()
     response_html = deep_link.output_response_form(response_list)
     response = HTMLResponse(content=response_html, status_code=200)