From a3104a6047d16c50bcb204238c2368fd334e9ee9 Mon Sep 17 00:00:00 2001
From: "Adrian A. Baumann" <ade@adebaumann.com>
Date: Mon, 29 Jun 2026 00:06:00 +0200
Subject: [PATCH] Add reset endpoint, button, and auto-restart on hostname
 change

---
 src/main.cpp | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 8f89161..18f5983 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -293,7 +293,8 @@ static void handleRoot() {
   html += "fieldset .row label{width:70px;margin-bottom:0;flex-shrink:0}";
   html += "fieldset .row input{margin-bottom:0}";
   html += ".btn{width:100%;margin-top:8px;padding:12px;background:#4361ee;color:#fff;border:none;border-radius:8px;font-size:15px;font-weight:600;cursor:pointer;transition:background .2s}";
-  html += ".btn:hover{background:#3651d4}.mac{font-size:12px;color:#999;text-align:center;margin-top:20px}";
+  html += ".btn:hover{background:#3651d4}.btn-danger{background:#dc2626}.btn-danger:hover{background:#b91c1c}";
+  html += ".mac{font-size:12px;color:#999;text-align:center;margin-top:20px}";
   html += ".tgl-lbl{margin-bottom:0!important;line-height:18px}.switch{position:relative;display:inline-block;width:32px;height:18px;margin-left:auto;flex-shrink:0}fieldset .row label.switch{width:32px}";
   html += ".switch input{opacity:0;width:0;height:0;margin-bottom:0}.slid{position:absolute;cursor:pointer;top:0;left:0;right:0;bottom:0;background:#ccc;border-radius:18px;transition:.3s}";
   html += ".slid::before{content:\"\";position:absolute;height:14px;width:14px;left:2px;top:2px;background:#fff;border-radius:50%;transition:.3s;box-shadow:0 1px 3px rgba(0,0,0,.2)}";
@@ -307,16 +308,29 @@ static void handleRoot() {
   html += authSection;
   html += mqttSection;
   html += "<button class=btn type=submit>Save</button></form>";
+  html += "<form action=/reset method=post style=margin-top:8px>";
+  html += "<button class='btn btn-danger' type=submit>Reset Device</button></form>";
   html += "<div class=mac>" + WiFi.macAddress() + "</div></div>";
   html += "</body></html>";
   server.send(200, "text/html", html);
   Serial.printf("[HTTP] GET / -> 200 (%u bytes)\n", html.length());
 }
 
+static void handleReset() {
+  if (!requireAuth()) { Serial.println("[HTTP] POST /reset -> 401"); return; }
+  Serial.println("[HTTP] POST /reset -> restarting");
+  server.send(200, "text/plain", "Restarting...");
+  delay(200);
+  ESP.restart();
+}
+
 static void handleConfig() {
   if (!requireAuth()) { Serial.println("[HTTP] POST /config -> 401"); return; }
   Serial.println("[HTTP] POST /config");
 
+  char oldHostname[32];
+  strlcpy(oldHostname, hostname, sizeof(oldHostname));
+
   if (server.hasArg("hostname")) {
     String val = server.arg("hostname");
     val.trim();
@@ -324,6 +338,8 @@ static void handleConfig() {
       val.toCharArray(hostname, sizeof(hostname));
   }
 
+  bool hostnameChanged = strcmp(hostname, oldHostname) != 0;
+
   // Persist connection fields regardless of enable checkbox so edits made while
   // disabling MQTT aren't discarded.
   if (server.hasArg("mqtt_host"))
@@ -359,11 +375,18 @@ static void handleConfig() {
 
   server.sendHeader("Location", "/", true);
   server.send(303);
+
+  if (hostnameChanged) {
+    Serial.printf("[HTTP] hostname changed %s -> %s, restarting\n", oldHostname, hostname);
+    delay(200);
+    ESP.restart();
+  }
 }
 
 static void startServer() {
   server.on("/", handleRoot);
   server.on("/config", HTTP_POST, handleConfig);
+  server.on("/reset", HTTP_POST, handleReset);
   server.begin();
   Serial.println("HTTP server started");
 }