From 9ae968b1085ebd675f24f103d5994997cc47e81b Mon Sep 17 00:00:00 2001
From: Brian Harrison <brianharrison02@gmail.com>
Date: Tue, 14 Apr 2026 17:46:38 -0400
Subject: [PATCH] fix: peak0c scope bug and strt cross check fix

---
 minimateplus/client.py   | 46 +++++++++++++++++++++++++++++-----------
 sfm/waveform_viewer.html |  6 +++++-
 2 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/minimateplus/client.py b/minimateplus/client.py
index d3e596d..e7637fe 100644
--- a/minimateplus/client.py
+++ b/minimateplus/client.py
@@ -1397,29 +1397,51 @@ def _decode_a5_waveform(
     total_samples   = struct.unpack_from(">H", strt, 14)[0]
     pretrig_samples = struct.unpack_from(">H", strt, 16)[0]
 
-    # Sanity check: pretrig must be less than total_samples.
-    # If not, the STRT layout is suspect (DLE-stuffing shift, different record variant, etc.).
-    # Log the raw bytes for diagnosis and clamp pretrig to 0 for now — will try to derive
-    # a better value from the compliance config after the full waveform is decoded.
+    # ── STRT sanity checks ───────────────────────────────────────────────────
+    # Check 1: pretrig must be strictly less than total_samples.
+    # Check 2 (cross-check): if compliance_config is available, the STRT-derived
+    #   post-trigger record time must be within 2× of the configured record_time.
+    #   A 3-second record at 1024 sps = 3072 post-trig samples; if STRT gives
+    #   e.g. 21 s, something is wrong with the byte offsets.
+    #
+    # Both failures trigger the same fallback: derive pretrig from the compliance
+    # monitoring standard (0.25 s) and total from compliance record_time.
     _strt_invalid = False
+    _sample_rate_default = 1024
+
     if pretrig_samples >= total_samples:
         log.warning(
-            "_decode_a5_waveform: pretrig_samples=%d >= total_samples=%d — "
-            "STRT layout suspect. Raw strt[0:21]: %s  "
-            "Will attempt to derive pretrig from compliance config after decode.",
+            "_decode_a5_waveform: STRT check1 FAIL — pretrig_samples=%d >= "
+            "total_samples=%d. Raw strt[0:21]: %s  "
+            "Will derive pretrig from compliance config.",
             pretrig_samples, total_samples, strt[0:21].hex(' '),
         )
         pretrig_samples = 0
-        total_samples = 0   # also invalid; will be filled from decoded count below
+        total_samples = 0
         _strt_invalid = True
+    elif compliance_config is not None and compliance_config.record_time:
+        cc_rt = compliance_config.record_time
+        cc_sr = compliance_config.sample_rate or _sample_rate_default
+        strt_post_trig = (total_samples - pretrig_samples) / cc_sr
+        # Allow up to 2× tolerance to account for zero-padding beyond the window.
+        # Anything more than that is a layout error, not zero-padding.
+        if strt_post_trig > cc_rt * 2.0 or strt_post_trig < cc_rt * 0.5:
+            log.warning(
+                "_decode_a5_waveform: STRT check2 FAIL — STRT-derived rectime "
+                "%.1fs is implausible vs compliance record_time=%.1fs (ratio=%.1f×). "
+                "Raw strt[0:21]: %s  Falling back to compliance-config values.",
+                strt_post_trig, cc_rt, strt_post_trig / cc_rt,
+                strt[0:21].hex(' '),
+            )
+            pretrig_samples = 0
+            total_samples = 0
+            _strt_invalid = True
 
     # strt[18] is a record-mode/type byte, NOT rectime in seconds.
     # Confirmed from analysis of 4-9-26 ACH capture (15 distinct events):
     #   flags=0xFFFE (single-shot) → strt[18]=0x46 ('F') for all events regardless of duration
     #   flags=0xFFFD (continuous)  → strt[18]=0x0E for all events regardless of duration
     # The actual post-trigger record time must be derived from total_samples and pretrig_samples.
-    # Default sample rate of 1024 is used here; the server overrides with compliance config sr.
-    _sample_rate_default = 1024
     rectime_seconds = int(round(
         max(0, total_samples - pretrig_samples) / _sample_rate_default
     ))
@@ -1428,9 +1450,9 @@ def _decode_a5_waveform(
     event.pretrig_samples = pretrig_samples
     event.rectime_seconds = rectime_seconds
 
-    log.debug(
+    log.info(
         "_decode_a5_waveform: STRT total_samples=%d pretrig=%d "
-        "strt[18]=0x%02X (mode byte, not seconds) computed_rectime=%ds  "
+        "strt[18]=0x%02X (mode byte) computed_rectime=%ds  "
         "raw strt[0:21]: %s",
         total_samples, pretrig_samples, strt[18], rectime_seconds,
         strt[0:21].hex(' '),
diff --git a/sfm/waveform_viewer.html b/sfm/waveform_viewer.html
index c719793..2208f12 100644
--- a/sfm/waveform_viewer.html
+++ b/sfm/waveform_viewer.html
@@ -527,6 +527,10 @@
         ? samples.slice(0, displayCount)
         : samples;
 
+      // peak0C declared here (function scope) so it is visible in the Chart.js
+      // config block below (which lives outside the if(isGeo) block).
+      let peak0C = null;
+
       if (isGeo) {
         // Geo channels: counts × (range / 32767) → in/s
         // Scale factor for the waveform shape (may need calibration per unit)
@@ -535,7 +539,7 @@
 
         // Use the device-computed 0C record peak for the label (authoritative).
         // The raw-sample-computed peak can be inflated by frame-boundary artifacts.
-        const peak0C = peakValues0C[ch];
+        peak0C = peakValues0C[ch];
         const peakIns = (peak0C !== null && peak0C !== undefined)
           ? peak0C
           : Math.max(...plotSamples.map(Math.abs));