fix: system_time template function crashed on Windows (glibc-only strftime codes) (#134)

* fix: system_time template function crashed on Windows (glibc-only strftime codes) #131

* review: type system_time format as Literal, pin C locale in exact-string tests

CHANGELOG.yaml

@@ -26,6 +26,7 @@
   - "Pi Bridge Client: The Docker image now ships with pi preinstalled, and pi's configuration directory (models.json, auth.json) is mounted from ./pi next to the compose file, so the client works in Docker out of the box."
   - "Scene Browser Landing Page: The Quick Load recent-scene cards are smaller and scale with the viewport width, so a full row of recents no longer pushes the Scene Library far down the page."
   fixes:
+  - "Prompt Templates: The `system_time` template function crashed with 'Invalid format string' on Windows — it used strftime codes only available on Linux/macOS. The time is now formatted platform-independently with identical output."
   - "Director Chat: Images created through the director chat's image generation action never appeared in the chat — the generation completed and the image was saved to the scene's assets, but the 'Image Generated' message was inserted into a newly created orphan chat instead of the conversation that requested it. The message is now inserted into the initiating chat."
   - "Node Editor: The Build Prompt node's `memory_prompt` input socket and the Generate Response node's `action_type` input socket were silently ignored — only the node property ever took effect, so a graph computing either value dynamically and wiring it in had no effect. Non-empty wired values now win over the property (the property still applies when the socket is unconnected or resolves empty). Note: graphs that already had something connected to these sockets will start honoring the connection."
   - "Scene Library: Deleting the save file of the currently loaded scene is now refused with an error - previously the file (and its version history) was deleted but silently recreated by the next save or autosave, making the delete appear to not work. Load a different scene first."

src/talemate/prompts/base.py

@@ -16,7 +16,7 @@ import re
 import uuid
 from contextvars import ContextVar
 from datetime import datetime
-from typing import Any
+from typing import Any, Literal
 from enum import Enum
 
 import jinja2
@@ -1067,7 +1067,9 @@ class Prompt(pydantic.BaseModel):
             return ""
         return iso8601_diff_to_human(iso8601_time, scene.ts)
 
-    def system_time(self, format: str = "full") -> str:
+    def system_time(
+        self, format: Literal["full", "date", "time", "iso", "datetime"] = "full"
+    ) -> str:
         """
         Returns the current system time in a clear, LLM-friendly format.
 
@@ -1084,18 +1086,21 @@ class Prompt(pydantic.BaseModel):
         """
         now = datetime.now()
 
-        if format == "full":
-            return now.strftime("%A, %B %-d, %Y at %-I:%M %p")
-        elif format == "date":
-            return now.strftime("%B %-d, %Y")
+        # %-d / %-I are glibc-only and raise ValueError on Windows, so the
+        # unpadded day and 12-hour clock are built from datetime attributes.
+        hour12 = now.hour % 12 or 12
+        time_str = f"{hour12}:{now:%M} {now:%p}"
+
+        if format == "date":
+            return f"{now:%B} {now.day}, {now.year}"
         elif format == "time":
-            return now.strftime("%-I:%M %p")
+            return time_str
         elif format == "iso":
             return now.strftime("%Y-%m-%dT%H:%M:%S")
         elif format == "datetime":
             return now.strftime("%Y-%m-%d %H:%M:%S")
         else:
-            return now.strftime("%A, %B %-d, %Y at %-I:%M %p")
+            return f"{now:%A}, {now:%B} {now.day}, {now.year} at {time_str}"
 
     def text_to_chunks(self, text: str, chunk_size: int = 512) -> list[str]:
         """

tests/prompts/test_base_extras.py

@@ -25,12 +25,15 @@ boundary, NOT Prompt.request).
 
 from __future__ import annotations
 
+import locale
 from collections import deque
+from datetime import datetime
 
 import pytest
 
 from conftest import client_responses
 
+import talemate.prompts.base as prompts_base
 from talemate.prompts.base import (
     JoinableList,
     Prompt,
@@ -244,23 +247,62 @@ class TestRandomAndBullet:
 
 
 class TestSystemTime:
-    def test_full_format(self):
-        p = Prompt.from_text("X")
-        s = p.system_time("full")
-        # Should contain weekday name and 'at'
-        assert " at " in s
+    @pytest.fixture
+    def fixed_now(self, monkeypatch):
+        # The exact-string assertions below assume the C locale for %A/%B/%p.
+        prev_locale = locale.setlocale(locale.LC_TIME)
+        locale.setlocale(locale.LC_TIME, "C")
 
-    def test_iso_format(self):
-        p = Prompt.from_text("X")
-        s = p.system_time("iso")
-        # ISO-like: "YYYY-MM-DDTHH:MM:SS"
-        assert s[4] == "-"
-        assert "T" in s
+        def _freeze(dt):
+            class _FrozenDatetime(datetime):
+                @classmethod
+                def now(cls, tz=None):
+                    return dt
 
-    def test_unknown_format_falls_back_to_full(self):
+            monkeypatch.setattr(prompts_base, "datetime", _FrozenDatetime)
+
+        yield _freeze
+        locale.setlocale(locale.LC_TIME, prev_locale)
+
+    def test_full_format(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
         p = Prompt.from_text("X")
-        s = p.system_time("totally-bogus")
-        assert " at " in s
+        assert p.system_time("full") == "Thursday, February 5, 2026 at 2:30 PM"
+
+    def test_date_format(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
+        p = Prompt.from_text("X")
+        assert p.system_time("date") == "February 5, 2026"
+
+    def test_time_format(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
+        p = Prompt.from_text("X")
+        assert p.system_time("time") == "2:30 PM"
+
+    def test_time_format_midnight(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 0, 5, 0))
+        p = Prompt.from_text("X")
+        assert p.system_time("time") == "12:05 AM"
+
+    def test_time_format_noon(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 12, 5, 0))
+        p = Prompt.from_text("X")
+        assert p.system_time("time") == "12:05 PM"
+
+    def test_iso_format(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
+        p = Prompt.from_text("X")
+        assert p.system_time("iso") == "2026-02-05T14:30:45"
+
+    def test_datetime_format(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
+        p = Prompt.from_text("X")
+        assert p.system_time("datetime") == "2026-02-05 14:30:45"
+
+    def test_unknown_format_falls_back_to_full(self, fixed_now):
+        fixed_now(datetime(2026, 2, 5, 14, 30, 45))
+        p = Prompt.from_text("X")
+        assert p.system_time("totally-bogus") == "Thursday, February 5, 2026 at 2:30 PM"
 
 
 class TestTimeDiff: