From 5c9f5df0ceace3deb7a53af96083d7970e390d41 Mon Sep 17 00:00:00 2001
From: Peter Woolery <peter@research.bike>
Date: Thu, 23 Apr 2026 13:54:55 -0700
Subject: [PATCH] feat(firmware): include diagnostics in heartbeat payload

Heartbeat v1.1.0 now carries heap stats (free + min_free since boot),
esp_reset_reason(), last WiFi disconnect code, and the last 8
persisted event-log entries. Makes field failures diagnosable
server-side without retrieving the device: the post-reboot heartbeat
will include EVT_BOOT with reset reason and whatever EVT_WIFI_DOWN
or EVT_HTTP_FAIL entries preceded it.
---
 firmware/src/reporter.cpp | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/firmware/src/reporter.cpp b/firmware/src/reporter.cpp
index 8880f4c..b3ed72b 100644
--- a/firmware/src/reporter.cpp
+++ b/firmware/src/reporter.cpp
@@ -2,6 +2,7 @@
 #include "reporter.h"
 #include "hmac.h"
 #include "event_log.h"
+#include "net_guard.h"
 #include <HTTPClient.h>
 #include <ArduinoJson.h>
 #include <WiFi.h>
@@ -9,6 +10,8 @@
 #include <time.h>
 #include <freertos/semphr.h>
 #include <esp_task_wdt.h>
+#include <esp_system.h>
+#include <esp_heap_caps.h>
 
 static std::vector<CameraHourlyRecord> s_cam_buf;
 static std::vector<BLEHourlyRecord>    s_ble_buf;
@@ -175,11 +178,31 @@ void reporter_submit_ble(const DeviceConfig& cfg, const BLEHourlyRecord& rec) {
 bool reporter_heartbeat(const DeviceConfig& cfg, uint32_t uptime_s, int wifi_rssi) {
     JsonDocument doc;
     doc["device_id"]         = cfg.device_id;
-    doc["firmware_version"]  = "1.0.0";
+    doc["firmware_version"]  = "1.1.0";
     doc["free_storage_pct"]  = 100;
     doc["wifi_rssi"]         = wifi_rssi;
     doc["pending_records"]   = (int)(s_cam_buf.size() + s_ble_buf.size());
     doc["uptime_seconds"]    = uptime_s;
+
+    // Diagnostics (new in 1.1.0)
+    doc["reset_reason"]         = (int)esp_reset_reason();
+    doc["heap_free"]            = (int)esp_get_free_heap_size();
+    doc["heap_min_free"]        = (int)esp_get_minimum_free_heap_size();
+    doc["last_disconnect_code"] = (int)net_guard_last_disconnect_reason();
+
+    // Last 8 event-log entries, newest first
+    EventLogEntry recent[8];
+    size_t n = event_log_read_recent(recent, 8);
+    JsonArray evs = doc["recent_events"].to<JsonArray>();
+    for (size_t i = 0; i < n; i++) {
+        JsonObject e = evs.add<JsonObject>();
+        e["t"]  = recent[i].tag;
+        e["d0"] = recent[i].data0;
+        e["d1"] = recent[i].data1;
+        e["ts"] = recent[i].ts_unix;
+        e["up"] = recent[i].uptime_s;
+    }
+
     String body; serializeJson(doc, body);
     return post_json(cfg, "/api/v1/heartbeat", body);
 }