From ed08ed3787ed259ac5c599a36660cd443b21f758 Mon Sep 17 00:00:00 2001
From: maziggy <mz@v8w.de>
Date: Sat, 23 May 2026 14:52:04 +0200
Subject: [PATCH]   fix(timelapse): capture baseline on restart-recovery so
 post-reboot timelapses attach (follow up issue #1485)
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  When Bambuddy is restarted mid-print, the first MQTT push from the
  printer carries `_previous_gcode_state = None`. The #1304 guard
  deliberately suppresses on_print_start on that first push to prevent
  duplicate archive creation — but on_print_start is also where
  _capture_timelapse_baseline_at_start runs, so the in-memory
  _timelapse_baselines dict stays empty for the resumed session.

  At PRINT COMPLETE, _scan_for_timelapse_with_retries finds no baseline
  and falls into its "take baseline now" fallback. By that point the
  printer has already uploaded the in-flight MP4, so the snapshot
  includes the new file. Every "Found N files / no new files since
  baseline" retry then fails to detect a diff, and the archive ends up
  with no timelapse attached — pwostran's report (#1485 follow-up): card
  shows the finish snapshot but no video.

  Add a sibling callback on_print_running_observed that bambu_mqtt fires
  in the "Now tracking RUNNING state" branch when on_print_start was
  suppressed. main.py wires it to a thin handler that looks up the
  printer row and calls the existing _capture_timelapse_baseline_at_start.
  Idempotent — skips if a baseline already exists (handles the rare
  same-session race where on_print_start also fires for some reason).

  The printer doesn't upload the timelapse until after PRINT COMPLETE,
  so a baseline captured any time during the print is still pre-upload —
  no narrow window to hit.

  Verified against the in-the-field logs in #1485 (pwostran's 2026-05-23
  support bundle):
    pre-reboot: baseline = 7 files
    reboot
    post-reboot completion: fallback baseline = 8 files (includes new MP4)
    -> all 4 retry attempts report "no new files since baseline"

  10 new tests cover both the MQTT-side fire decision (fires when
  suppressed, doesn't fire when on_print_start handles it, once per
  session, payload shape mirrors on_print_start) and the main.py
  handler (snapshot capture, double-capture guard, missing-printer-row
  guard).
---
 CHANGELOG.md                                  |   1 +
 backend/app/main.py                           |  47 +++++
 backend/app/services/bambu_mqtt.py            |  37 ++++
 backend/app/services/printer_manager.py       |  15 ++
 .../tests/unit/services/test_bambu_mqtt.py    | 191 ++++++++++++++++++
 ...est_timelapse_baseline_restart_recovery.py | 152 ++++++++++++++
 6 files changed, 443 insertions(+)
 create mode 100644 backend/tests/unit/test_timelapse_baseline_restart_recovery.py

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c14e0c98..a97152c30 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ All notable changes to Bambuddy will be documented in this file.
 - **PyJWT CVE-2025-45768 (PYSEC-2025-183 / GHSA-65pc-fj4g-8rjx): permanently ignored in pip-audit** — Advisory is disputed by the PyJWT maintainers, with the advisory description literally noting *"this is disputed by the Supplier because the key length is chosen by the application that uses the library."* `fix_versions=[]` on the advisory confirms no PyJWT patch exists or will exist. Bambuddy is not affected: `backend/app/core/auth.py:184` auto-generates secrets via `secrets.token_urlsafe(64)` (~86 chars of entropy, far above any sane minimum) and the file-loaded path at `:177` rejects secrets shorter than 32 chars. Added a permanent `--ignore-vuln CVE-2025-45768` to `.github/workflows/security.yml` with an inline comment citing the file:line evidence so a future maintainer reviewing the ignore list sees why it's load-bearing. Also dropped the stale `--ignore-vuln CVE-2026-4539` for Pygments — Pygments has since shipped a patched version and the ignore is no longer load-bearing (verified: `pip-audit --ignore-vuln CVE-2025-45768` alone reports clean).
 
 ### Fixed
+- **Timelapse now attaches to the archive after a backend restart mid-print (#1485 follow-up, reported by @pwostran)** — With the duplicate-archive fix from #1485 in place, a restart mid-print stopped creating ghosts — but the resulting archive came back without its timelapse video (only the finish snapshot was attached). Cause is a side-effect of the #1304 first-push guard: on the first MQTT push after Bambuddy starts (`_previous_gcode_state = None`), `is_new_print` is deliberately False so `on_print_start` doesn't fire — which prevents duplicate archive creation **but also** prevents the timelapse-baseline capture, since both live behind the same callback. At PRINT COMPLETE, `_scan_for_timelapse_with_retries` finds an empty `_timelapse_baselines` for the printer and falls into the "take baseline now" fallback in `main.py`. By that point the printer has already uploaded the in-flight MP4, so the snapshot includes it. Every retry then reports "N files found / no new files since baseline" and the scan gives up. The reporter's support bundle is the smoking gun — pre-reboot baseline of 7 files, post-reboot fallback baseline of 8 files (including the just-uploaded one), 4 retries all unable to see the diff. **Fix**: `bambu_mqtt.py` now fires a sibling `on_print_running_observed` callback inside the "Now tracking RUNNING state" branch when the first-push guard suppresses `on_print_start`. `main.py` wires it to a thin handler that fetches the printer row from DB and calls the existing `_capture_timelapse_baseline_at_start`. The callback only fires the first time we observe RUNNING per session (gated on the same `not self._was_running` branch the timelapse-flag restore already lives in), so a normal print start path is unaffected. The handler is also idempotent: if a baseline already exists for that printer, it returns without touching it. Safe because the printer doesn't upload the timelapse until *after* PRINT COMPLETE, so a baseline captured any time during the in-flight print is still pre-upload — no narrow window. The plumbing (`set_print_running_observed_callback` setter, in-`connect_printer` wrapper, constructor pass-through) mirrors the existing `on_print_start` / `on_print_complete` callback chain in `printer_manager.py`. **Tests**: 7 new in `TestPrintRunningObservedCallback` in `test_bambu_mqtt.py` (fires on first RUNNING after startup, doesn't double up with `on_print_start`, fires only once per session, skips on non-RUNNING / missing file / no-callback-set, payload shape mirrors `on_print_start`); 3 new in a dedicated `test_timelapse_baseline_restart_recovery.py` (handler captures the printer's existing-videos snapshot into `_timelapse_baselines`, skips when a baseline already exists, skips when the printer row was deleted between push and handler). 336 MQTT + print-start + timelapse tests green; backend ruff clean.
 - **SliceModal: process / filament dropdowns now filter for users who haven't uploaded slicer bundles (#1325 follow-up, reported by @IndividualGhost1905)** — The original #1325 fix replaced a stale hardcoded `@BBL <model>` allow-list with bundle-based compatibility: a process / filament preset was classified against the selected printer by consulting the user's uploaded Slicer Bundles (.bbscfg). That works perfectly for users who have uploaded bundles for every printer their cloud catalogue covers — and silently no-ops for everyone else: every cloud preset resolves to `'unknown'`, nothing moves into "Other printers", and the dropdown looks identical to the pre-fix state. **Fix**: restored the `@BBL <token>` name fallback as a third tier *below* the bundle path, but with the token-to-printer mapping driven by **the backend's canonical `PRINTER_MODEL_MAP`** (`backend/app/utils/printer_models.py`) instead of a duplicated frontend table. A new `GET /api/v1/slicer/printer-models` route ships the mapping unmodified; `slicerPrinterMatch.buildCompatibilityIndex` accepts it as a second arg, inverts it into a short-code → display-fragment table (`X1C` → `X1 Carbon`, `P2S` → `P2S`, `A1 Mini` → `A1 mini`, …), and `presetCompatibility` uses it only after `compatible_printers` and the bundle index have already returned `'unknown'`. The match is case- and whitespace-insensitive (`"A1 mini"`, `"A1 Mini"` and `"a1mini"` all compare equal). When the registry doesn't list a token, the matcher falls back to comparing the raw token against the printer-preset model fragment — so a brand-new "Q1" printer with `@BBL Q1`-tagged presets matches without any code change. Adding a new model only requires updating the existing backend `PRINTER_MODEL_MAP` (already the single source of truth for `is_dual_nozzle_model`, the rod-type/ethernet registries, and 3MF metadata normalisation) — no frontend table to keep in sync. **Tests**: 2 new in `test_slicer_presets.py` (`/printer-models` returns the full `PRINTER_MODEL_MAP`; the route hands back a copy, not the live module dict); the existing 25 `slicerPrinterMatch.test.ts` cases were extended to 36 covering: registry-driven X1C vs X1 Carbon match, A1 vs A1 mini disambiguation, H2D vs H2D Pro disambiguation, the previously-missing P2S / H2C / H2S / X2D, raw-token fallback for unregistered models, graceful degradation when the registry fetch hasn't resolved yet, the `compatible_printers`-wins-over-name rule, and the bundle-wins-over-name rule. 38 slicer-presets + 36 slicerPrinterMatch tests green; backend ruff clean; frontend build clean.
 - **Cloudflare-fronted Bambuddy no longer needs an `unsafe-inline` override to load (#1460 follow-up, reported by @Soopahfly)** — A Bambuddy instance behind Cloudflare logged an inline-script CSP violation on every page load: Cloudflare's bot-detection script (`/cdn-cgi/challenge-platform/scripts/jsd/main.js`) is injected into the HTML on the edge with a hash that changes per request, so it can never be allowlisted by `script-src` hash. The contributor's workaround was to relax `script-src` to `'unsafe-inline'` in their Nginx Proxy Manager — which works but defeats most of the CSP. **Fix**: the SPA CSP now stamps a fresh per-request **nonce** into `script-src` (`'self' 'nonce-<base64>'`). Per [Cloudflare's documented behaviour](https://developers.cloudflare.com/cloudflare-challenges/challenge-types/javascript-detections/#if-you-have-a-content-security-policy-csp), when a nonce is present in the CSP header Cloudflare clones the same nonce onto its injected `<script>` and the inline script passes without `'unsafe-inline'`. Bambuddy's own `index.html` has had no inline scripts since the SW registration moved to `/sw-register.js` (#1460 first PR), so no HTML body rewriting is needed — `'self'` continues to cover every script the app ships. Implemented via a 16-byte `secrets.token_urlsafe()` nonce computed per request in `security_headers_middleware`. **Separately**, `/manifest.json`, `/sw.js` and `/sw-register.js` are now registered with `@app.api_route(methods=["GET", "HEAD"])` instead of `@app.get` — a plain `curl -I https://host/manifest.json` (and several uptime scanners) HEAD-probe these routes and were getting `405 Method Not Allowed`, which surfaced in the issue as an apparent manifest-server bug. **Tests**: 3 new in `test_security_headers.py` — `'nonce-…'` is stamped into the SPA `script-src` directive while `'self'` remains and `'unsafe-inline'` does not; the nonce is fresh per request across 5 sequential calls (collision probability ~0); HEAD on `/manifest.json`, `/sw.js`, `/sw-register.js` never returns 405. 22 security-header tests green; backend ruff clean.
 - **Insufficient-filament pre-print warning now fires on every dispatch path (#1496, reported by @needo37)** — The "Pre-print checks now also warn when the spool has insufficient material" guard from #720 only fired on the `PrintModal` submit path. Two other queue-dispatch paths bypassed it entirely: the green ▶ Play button on a staged (`manual_start`) queue row called `POST /queue/{id}/start`, which only flipped the manual_start flag with no filament check; and the Virtual Printer queue-mode intake (`virtual_printer/manager._add_to_print_queue`) parsed per-slot requirements for *type* matching only — never weight. With `auto_dispatch=True` the scheduler would then dispatch unsupervised onto a doomed-to-fail spool. **Fix**: extracted the per-slot deficit calculation into a single backend helper (`backend/app/services/filament_deficit.py`) that both the route and the dispatch scheduler call against live spool state. Works for internal-inventory mode (`SpoolAssignment` → `Spool.label_weight - weight_used`) and Spoolman mode (`SpoolmanSlotAssignment` → `SpoolmanClient.get_spool`); Spoolman unreachability returns no deficit rather than wedging the queue. The `disable_filament_warnings` setting is honoured at the service boundary. `POST /queue/{id}/start` now returns `409 {detail: {code: 'insufficient_filament', deficit: [...]}}` when short; the `?skip_filament_check=true` query param is the "Print Anyway" bypass. The dispatch scheduler runs the same check just before each `_start_print` call: a deficit promotes the item to `manual_start=True` + `filament_short=True` (so the user must consciously click ▶) and a previously-flagged item whose spool was swapped to one with enough material clears the flag automatically on the next tick. A new `filament_short` boolean column on `print_queue` carries the flag; the queue row now renders a yellow "Insufficient filament for the assigned spool" badge when set, and the ▶ button catches the 409, opens an `Insufficient Filament / Print Anyway` confirm modal showing each shorted slot's required-vs-remaining grams, and on confirm re-issues the start with the skip flag. Migration is idempotent and branches on `is_sqlite()` for the `BOOLEAN DEFAULT` syntax. **Tests**: 8 in `test_filament_deficit.py` (deficit + sufficient + missing mapping + no printer + disabled-warnings + no-assignment + missing 3MF + multi-slot only-shorted-returned), 4 in `test_scheduler_filament_deficit.py` (block-on-deficit, clear-stale-flag, no-deficit no-op, helper-exception doesn't wedge), 2 new in `test_print_queue_api.py` (`/start` returns 409 + structured payload, `?skip_filament_check=true` bypasses), and 2 frontend tests in `QueuePage.test.tsx` (badge renders on flagged row, ▶ click → 409 → modal → retry with `skip_filament_check=true`). 3392 unit + 63 print-queue integration green; backend ruff clean; frontend build + i18n parity (9 locales × 4979 keys) clean.
diff --git a/backend/app/main.py b/backend/app/main.py
index a6c89a6b2..4ee71179d 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -3024,6 +3024,52 @@ async def _scan_for_timelapse_with_retries(archive_id: int, baseline_names: set[
     logger.warning("[TIMELAPSE] All attempts exhausted for archive %s, giving up", archive_id)
 
 
+async def on_print_running_observed(printer_id: int, data: dict):
+    """Restart-recovery: capture a fresh timelapse baseline for a print that
+    started before Bambuddy came up.
+
+    bambu_mqtt.py suppresses ``on_print_start`` on the first RUNNING push
+    after Bambuddy startup (#1304 guard, prevents duplicate archive
+    creation). Without that path, ``_capture_timelapse_baseline_at_start``
+    never runs and ``_scan_for_timelapse_with_retries`` falls into its
+    "take baseline now" fallback at completion time — but by then the
+    printer has already uploaded the in-flight MP4, so the baseline
+    includes it and no diff ever matches (#1485 follow-up).
+
+    Fires once per session, in lieu of on_print_start when restart-recovery
+    kicks in. The printer doesn't upload the timelapse until after PRINT
+    COMPLETE, so a baseline captured any time during the print is still
+    pre-upload.
+    """
+    logger = logging.getLogger(__name__)
+
+    # Avoid double-capture: on_print_start may have run earlier in this
+    # Bambuddy process if the print started AFTER startup and we crashed
+    # later in the same session. (Realistically this can't happen — the
+    # MQTT client object would have been recreated — but the cheap guard
+    # is correct regardless.)
+    if printer_id in _timelapse_baselines:
+        logger.debug(
+            "[TIMELAPSE] on_print_running_observed: baseline already present for printer %s, skipping",
+            printer_id,
+        )
+        return
+
+    async with async_session() as db:
+        from backend.app.models.printer import Printer
+
+        result = await db.execute(select(Printer).where(Printer.id == printer_id))
+        printer = result.scalar_one_or_none()
+        if not printer:
+            logger.warning(
+                "[TIMELAPSE] on_print_running_observed: printer %s not found in DB, skipping baseline",
+                printer_id,
+            )
+            return
+
+    await _capture_timelapse_baseline_at_start(printer, printer_id, logger)
+
+
 async def on_print_complete(printer_id: int, data: dict):
     """Handle print completion - update the archive status."""
     import time
@@ -4721,6 +4767,7 @@ async def lifespan(app: FastAPI):
     printer_manager.set_status_change_callback(on_printer_status_change)
     printer_manager.set_print_start_callback(on_print_start)
     printer_manager.set_print_complete_callback(on_print_complete)
+    printer_manager.set_print_running_observed_callback(on_print_running_observed)
     printer_manager.set_ams_change_callback(on_ams_change)
 
     # Rehydrate persisted awaiting-plate-clear gate (#961) so prompts survive restarts
diff --git a/backend/app/services/bambu_mqtt.py b/backend/app/services/bambu_mqtt.py
index f7f0f1bfc..b30c55201 100644
--- a/backend/app/services/bambu_mqtt.py
+++ b/backend/app/services/bambu_mqtt.py
@@ -333,6 +333,7 @@ class BambuMQTTClient:
         on_layer_change: Callable[[int], None] | None = None,
         on_bed_temp_update: Callable[[float], None] | None = None,
         on_drying_complete: Callable[[int], None] | None = None,
+        on_print_running_observed: Callable[[dict], None] | None = None,
     ):
         self.ip_address = ip_address
         self.serial_number = serial_number
@@ -348,6 +349,14 @@ class BambuMQTTClient:
         # the drying cycle just finished (auto- or manually-triggered).
         # Receives the AMS id of the unit that finished drying.
         self.on_drying_complete = on_drying_complete
+        # #1485 follow-up: fired the first time we see RUNNING state in a
+        # session WHEN on_print_start was suppressed (Bambuddy started mid-
+        # print, the #1304 first-push guard skipped the start event). Lets
+        # main.py capture a fresh timelapse baseline at restart-recovery
+        # time so the completion-time snapshot-diff still works. Receives
+        # the same shape as on_print_start (filename / subtask_name /
+        # remaining_time / raw_data / ams_mapping).
+        self.on_print_running_observed = on_print_running_observed
         # Per-AMS previous dry_time, used to detect the falling edge above.
         # Seeded lazily as we observe each AMS unit.
         self._previous_dry_times: dict[int, int] = {}
@@ -2909,6 +2918,7 @@ class BambuMQTTClient:
         )
 
         # Track RUNNING state for more robust completion detection
+        running_first_observed = False
         if self.state.state == "RUNNING" and current_file:
             if not self._was_running:
                 logger.debug("[%s] Now tracking RUNNING state for %s", self.serial_number, current_file)
@@ -2916,6 +2926,14 @@ class BambuMQTTClient:
                 if self.state.timelapse:
                     self._timelapse_during_print = True
                     logger.debug("[%s] Timelapse detected when entering RUNNING state", self.serial_number)
+                # Mark this as the first RUNNING observation of the session.
+                # If is_new_print also fires below, on_print_start handles
+                # baseline capture and we suppress on_print_running_observed
+                # to avoid double-capture. If is_new_print does NOT fire
+                # (Bambuddy started mid-print — the #1304 guard suppressed
+                # it), main.py needs this hook to catch the restart-recovery
+                # case (#1485 follow-up).
+                running_first_observed = True
             self._was_running = True
             self._completion_triggered = False
 
@@ -2961,6 +2979,25 @@ class BambuMQTTClient:
                     "ams_mapping": self._captured_ams_mapping,
                 }
             )
+        elif running_first_observed and self.on_print_running_observed:
+            # Restart-recovery hook (#1485 follow-up): Bambuddy started mid-
+            # print, so the #1304 first-push guard suppressed on_print_start,
+            # but we still need main.py to capture a fresh timelapse baseline
+            # before the printer uploads the in-flight MP4. Same payload
+            # shape as on_print_start so the consumer can reuse fields.
+            logger.info(
+                f"[{self.serial_number}] RUNNING observed without PRINT START "
+                f"(restart-recovery) - file: {current_file}, subtask: {self.state.subtask_name}"
+            )
+            self.on_print_running_observed(
+                {
+                    "filename": current_file,
+                    "subtask_name": self.state.subtask_name,
+                    "remaining_time": self.state.remaining_time * 60 if self.state.remaining_time > 0 else None,
+                    "raw_data": data,
+                    "ams_mapping": self._captured_ams_mapping,
+                }
+            )
 
         # Detect print completion (FINISH = success, FAILED = error, IDLE = aborted)
         # Use _was_running flag in addition to _previous_gcode_state for more robust detection
diff --git a/backend/app/services/printer_manager.py b/backend/app/services/printer_manager.py
index bebf28293..d2d867133 100644
--- a/backend/app/services/printer_manager.py
+++ b/backend/app/services/printer_manager.py
@@ -169,6 +169,7 @@ class PrinterManager:
         self._printer_info: dict[int, PrinterInfo] = {}  # Cache printer name/serial for callbacks
         self._on_print_start: Callable[[int, dict], None] | None = None
         self._on_print_complete: Callable[[int, dict], None] | None = None
+        self._on_print_running_observed: Callable[[int, dict], None] | None = None
         self._on_status_change: Callable[[int, PrinterState], None] | None = None
         self._on_ams_change: Callable[[int, list], None] | None = None
         self._on_layer_change: Callable[[int, int], None] | None = None
@@ -309,6 +310,15 @@ class PrinterManager:
         """Set callback for print completion events."""
         self._on_print_complete = callback
 
+    def set_print_running_observed_callback(self, callback: Callable[[int, dict], None]):
+        """Set callback for restart-recovery RUNNING-state observations (#1485
+        follow-up). Fires the first time we see ``state == RUNNING`` for a
+        printer that started its print before Bambuddy came up — the #1304
+        guard suppresses ``on_print_start`` for these, so anything that
+        normally hangs off it (e.g. timelapse baseline capture) needs this
+        hook to recover."""
+        self._on_print_running_observed = callback
+
     def set_status_change_callback(self, callback: Callable[[int, PrinterState], None]):
         """Set callback for status change events."""
         self._on_status_change = callback
@@ -372,6 +382,10 @@ class PrinterManager:
             if self._on_print_complete:
                 self._schedule_async(self._on_print_complete(printer_id, data))
 
+        def on_print_running_observed(data: dict):
+            if self._on_print_running_observed:
+                self._schedule_async(self._on_print_running_observed(printer_id, data))
+
         def on_ams_change(ams_data: list):
             if self._on_ams_change:
                 self._schedule_async(self._on_ams_change(printer_id, ams_data))
@@ -400,6 +414,7 @@ class PrinterManager:
             on_layer_change=on_layer_change,
             on_bed_temp_update=on_bed_temp_update,
             on_drying_complete=on_drying_complete,
+            on_print_running_observed=on_print_running_observed,
         )
 
         client.connect()
diff --git a/backend/tests/unit/services/test_bambu_mqtt.py b/backend/tests/unit/services/test_bambu_mqtt.py
index 0e2b07507..12cf23b5d 100644
--- a/backend/tests/unit/services/test_bambu_mqtt.py
+++ b/backend/tests/unit/services/test_bambu_mqtt.py
@@ -5217,3 +5217,194 @@ class TestDryingCompleteCallback:
         # Drying genuinely finishes → the real edge still fires exactly once.
         mqtt_client._handle_ams_data({"ams": [{"id": "0", "dry_time": 0, "tray": []}]})
         assert mqtt_client._drying_events == [0]
+
+
+class TestPrintRunningObservedCallback:
+    """#1485 follow-up: on_print_running_observed fires the FIRST time we
+    see ``state == RUNNING`` for a printer whose print started before
+    Bambuddy came up. It lets main.py capture a timelapse baseline at
+    restart-recovery time — when on_print_start was suppressed by the
+    #1304 first-push guard. Must NOT fire when on_print_start handles the
+    transition (avoids double-capture), and must NOT fire again after
+    the first observation in the same session.
+    """
+
+    @pytest.fixture
+    def mqtt_client(self):
+        from backend.app.services.bambu_mqtt import BambuMQTTClient
+
+        return BambuMQTTClient(
+            ip_address="192.168.1.100",
+            serial_number="TEST123",
+            access_code="12345678",
+        )
+
+    def test_fires_on_first_running_push_after_startup(self, mqtt_client):
+        """First push the client sees has _previous_gcode_state=None, so the
+        #1304 guard suppresses on_print_start. on_print_running_observed
+        must fire instead so the consumer can recover."""
+        start_calls: list[dict] = []
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_start = lambda data: start_calls.append(data)
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+
+        # Pristine state — exactly what we have right after BambuMQTTClient
+        # construction following a Bambuddy restart.
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "RUNNING",
+                    "gcode_file": "/data/Metadata/test_print.gcode",
+                    "subtask_name": "Test_Print",
+                }
+            }
+        )
+
+        assert start_calls == [], "on_print_start must be suppressed by the #1304 guard"
+        assert len(running_observed_calls) == 1
+        assert running_observed_calls[0]["filename"] == "/data/Metadata/test_print.gcode"
+        assert running_observed_calls[0]["subtask_name"] == "Test_Print"
+
+    def test_does_not_fire_when_print_start_fires(self, mqtt_client):
+        """Normal print start (a real state transition from non-RUNNING to
+        RUNNING) goes through on_print_start; on_print_running_observed
+        must stay quiet so the consumer doesn't capture the baseline twice."""
+        start_calls: list[dict] = []
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_start = lambda data: start_calls.append(data)
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = "IDLE"  # Not None — past the #1304 guard
+
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "RUNNING",
+                    "gcode_file": "/data/Metadata/test_print.gcode",
+                    "subtask_name": "Test_Print",
+                }
+            }
+        )
+
+        assert len(start_calls) == 1, "on_print_start should fire on a real start transition"
+        assert running_observed_calls == [], "on_print_running_observed must not double up with on_print_start"
+
+    def test_fires_only_once_per_session(self, mqtt_client):
+        """Subsequent RUNNING pushes in the same session must not re-fire the
+        callback — the baseline only needs to be captured once, the consumer
+        treats repeat calls as a hint to skip via the in-memory dict guard."""
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        msg = {
+            "print": {
+                "gcode_state": "RUNNING",
+                "gcode_file": "/data/Metadata/test_print.gcode",
+                "subtask_name": "Test_Print",
+            }
+        }
+        mqtt_client._process_message(msg)
+        mqtt_client._process_message(msg)
+        mqtt_client._process_message(msg)
+
+        assert len(running_observed_calls) == 1
+
+    def test_does_not_fire_when_not_running(self, mqtt_client):
+        """An IDLE / PREPARE / FINISH first-push must not trigger the
+        restart-recovery path — there's no print to baseline."""
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "IDLE",
+                    "gcode_file": "",
+                    "subtask_name": "",
+                }
+            }
+        )
+
+        assert running_observed_calls == []
+
+    def test_does_not_fire_without_current_file(self, mqtt_client):
+        """RUNNING with no file is ill-formed (firmware glitch / transient).
+        We need ``current_file`` to find the right archive, so skip the
+        callback rather than fire it with a meaningless payload."""
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "RUNNING",
+                    "gcode_file": "",
+                    "subtask_name": "",
+                }
+            }
+        )
+
+        assert running_observed_calls == []
+
+    def test_safe_when_callback_not_set(self, mqtt_client):
+        """No callback configured → silently skip; no AttributeError on the
+        firing branch."""
+        mqtt_client.on_print_running_observed = None
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        # Should not raise.
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "RUNNING",
+                    "gcode_file": "/data/Metadata/test_print.gcode",
+                    "subtask_name": "Test_Print",
+                }
+            }
+        )
+
+        assert mqtt_client._was_running is True
+
+    def test_payload_shape_matches_print_start(self, mqtt_client):
+        """The payload shape must mirror on_print_start so main.py's
+        consumer can reuse the same dict fields (filename / subtask_name /
+        remaining_time / raw_data / ams_mapping). Test pins the keys."""
+        running_observed_calls: list[dict] = []
+        mqtt_client.on_print_running_observed = lambda data: running_observed_calls.append(data)
+        mqtt_client._was_running = False
+        mqtt_client._previous_gcode_state = None
+
+        mqtt_client._process_message(
+            {
+                "print": {
+                    "gcode_state": "RUNNING",
+                    "gcode_file": "/data/Metadata/test_print.gcode",
+                    "subtask_name": "Test_Print",
+                    "mc_remaining_time": 42,
+                }
+            }
+        )
+
+        assert len(running_observed_calls) == 1
+        payload = running_observed_calls[0]
+        assert set(payload.keys()) == {
+            "filename",
+            "subtask_name",
+            "remaining_time",
+            "raw_data",
+            "ams_mapping",
+        }
diff --git a/backend/tests/unit/test_timelapse_baseline_restart_recovery.py b/backend/tests/unit/test_timelapse_baseline_restart_recovery.py
new file mode 100644
index 000000000..67e3654d6
--- /dev/null
+++ b/backend/tests/unit/test_timelapse_baseline_restart_recovery.py
@@ -0,0 +1,152 @@
+"""Regression for #1485 follow-up: timelapse baseline on restart-recovery.
+
+When Bambuddy restarts mid-print, the first MQTT push has
+``_previous_gcode_state = None`` which the #1304 guard treats as "first push
+after Bambuddy startup, don't fire on_print_start" — avoiding duplicate
+archive creation. But that path is also where ``_capture_timelapse_baseline_at_start``
+lives, so without a separate hook the baseline is never captured. The
+completion-time scan then falls into its "take baseline now" fallback
+that snapshots the SD card AFTER the in-flight MP4 has landed, the new
+file ends up in the baseline set, and no diff ever matches.
+
+bambu_mqtt.py:_process_message now fires a sibling ``on_print_running_observed``
+callback in this case. main.py wires it to ``on_print_running_observed``
+which captures the baseline. These tests verify that handler.
+"""
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from backend.app.main import _timelapse_baselines
+
+
+@pytest.fixture(autouse=True)
+def _clear_baselines():
+    _timelapse_baselines.clear()
+    yield
+    _timelapse_baselines.clear()
+
+
+@pytest.mark.asyncio
+async def test_running_observed_captures_baseline_on_restart_recovery():
+    """The handler must capture the printer's existing-videos snapshot so
+    the completion-time scan has something to set-diff against. This is
+    the case the in-the-field pwostran report (#1485) hits: pre-reboot
+    baseline of 7 files lost on restart, post-reboot fallback baseline
+    sees the 8 files (including the just-uploaded one) → no new file."""
+    mock_printer = MagicMock()
+    mock_printer.id = 1
+    mock_printer.name = "TestP1S"
+    mock_printer.ip_address = "192.168.1.100"
+    mock_printer.access_code = "12345678"
+    mock_printer.model = "P1S"
+
+    existing_videos = [
+        {"name": "earlier_a.mp4", "is_directory": False, "path": "/timelapse/earlier_a.mp4"},
+        {"name": "earlier_b.mp4", "is_directory": False, "path": "/timelapse/earlier_b.mp4"},
+        {"name": "earlier_c.mp4", "is_directory": False, "path": "/timelapse/earlier_c.mp4"},
+    ]
+
+    def execute_router(stmt, *args, **kwargs):
+        return MagicMock(scalar_one_or_none=MagicMock(return_value=mock_printer))
+
+    mock_session = AsyncMock()
+    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+    mock_session.__aexit__ = AsyncMock()
+    mock_session.execute = AsyncMock(side_effect=execute_router)
+
+    with (
+        patch("backend.app.main.async_session") as mock_session_maker,
+        patch(
+            "backend.app.main._list_timelapse_videos",
+            new=AsyncMock(return_value=(existing_videos, "/timelapse")),
+        ),
+    ):
+        mock_session_maker.return_value = mock_session
+
+        from backend.app.main import on_print_running_observed
+
+        await on_print_running_observed(
+            1,
+            {
+                "filename": "/data/Metadata/test_print.gcode",
+                "subtask_name": "Test_Print",
+                "remaining_time": 3600,
+                "raw_data": {},
+                "ams_mapping": None,
+            },
+        )
+
+    assert _timelapse_baselines.get(1) == {"earlier_a.mp4", "earlier_b.mp4", "earlier_c.mp4"}, (
+        "restart-recovery handler must capture the printer's existing-videos "
+        "baseline so the completion-time scan can set-diff to find the new file"
+    )
+
+
+@pytest.mark.asyncio
+async def test_running_observed_skips_when_baseline_already_present():
+    """If on_print_start already ran in this Bambuddy process for the same
+    printer (the realistic same-session race), a second capture would
+    overwrite the correct pre-print baseline with one taken later — which
+    could include the in-flight MP4. Skip when a baseline exists."""
+    _timelapse_baselines[1] = {"pre_existing_a.mp4", "pre_existing_b.mp4"}
+
+    with (
+        patch("backend.app.main.async_session") as mock_session_maker,
+        patch("backend.app.main._list_timelapse_videos", new=AsyncMock()) as mock_list,
+    ):
+        from backend.app.main import on_print_running_observed
+
+        await on_print_running_observed(
+            1,
+            {
+                "filename": "/data/Metadata/test_print.gcode",
+                "subtask_name": "Test_Print",
+                "remaining_time": 3600,
+                "raw_data": {},
+                "ams_mapping": None,
+            },
+        )
+
+        # Neither the DB lookup nor the FTP scan should have run.
+        mock_session_maker.assert_not_called()
+        mock_list.assert_not_called()
+
+    # Original baseline preserved.
+    assert _timelapse_baselines[1] == {"pre_existing_a.mp4", "pre_existing_b.mp4"}
+
+
+@pytest.mark.asyncio
+async def test_running_observed_skips_when_printer_row_missing():
+    """If the printer was deleted between the MQTT push and this handler
+    running, we can't capture anything — log and return without raising."""
+    mock_session = AsyncMock()
+    mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+    mock_session.__aexit__ = AsyncMock()
+    mock_session.execute = AsyncMock(return_value=MagicMock(scalar_one_or_none=MagicMock(return_value=None)))
+
+    with (
+        patch("backend.app.main.async_session") as mock_session_maker,
+        patch("backend.app.main._list_timelapse_videos", new=AsyncMock()) as mock_list,
+    ):
+        mock_session_maker.return_value = mock_session
+
+        from backend.app.main import on_print_running_observed
+
+        # Should not raise.
+        await on_print_running_observed(
+            999,
+            {
+                "filename": "/data/Metadata/test_print.gcode",
+                "subtask_name": "Test_Print",
+                "remaining_time": 3600,
+                "raw_data": {},
+                "ams_mapping": None,
+            },
+        )
+
+        # FTP scan must not run if the printer row didn't resolve.
+        mock_list.assert_not_called()
+
+    assert 999 not in _timelapse_baselines