From 03f201b40683435bb7da2ce218ac7e4260dab9e2 Mon Sep 17 00:00:00 2001
From: Torsten Stauder <stauder@ts-cs.de>
Date: Sat, 3 Jul 2021 14:28:26 +0200
Subject: [PATCH] Fix to break bootloops when PLAY_LAST_RFID_AFTER_REBOOT is
 active

---
 src/Log.h              |  2 +-
 src/LogMessages_DE.cpp |  2 ++
 src/LogMessages_EN.cpp |  2 ++
 src/logmessages.h      |  2 ++
 src/main.cpp           | 40 ++++++++++++++++++++++++++++++++++++++--
 5 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/Log.h b/src/Log.h
index c9f39ea..97cd381 100644
--- a/src/Log.h
+++ b/src/Log.h
@@ -1,5 +1,5 @@
 #pragma once
-#include "LogMessages.h"
+#include "logmessages.h"
 
 // Loglevels available (don't change!)
 #define LOGLEVEL_ERROR 1  // only errors
diff --git a/src/LogMessages_DE.cpp b/src/LogMessages_DE.cpp
index bcf9193..7635134 100644
--- a/src/LogMessages_DE.cpp
+++ b/src/LogMessages_DE.cpp
@@ -192,5 +192,7 @@
     const char playlistGenModeUncached[] PROGMEM = "Playlist-Generierung: uncached";
     const char playlistGenModeCached[] PROGMEM = "Playlist-Generierung: cached";
     const char playlistCacheFoundBut0[] PROGMEM = "Playlist-Cache-File gefunden, jedoch 0 Bytes groß";
+    const char bootLoopDetected[] PROGMEM = "Bootschleife erkannt! Letzte RFID wird nicht aufgerufen.";
+    const char noBootLoopDetected[] PROGMEM = "Keine Bootschleife erkannt. Wunderbar :-)";
 
 #endif
diff --git a/src/LogMessages_EN.cpp b/src/LogMessages_EN.cpp
index 9d3c19e..2a76445 100644
--- a/src/LogMessages_EN.cpp
+++ b/src/LogMessages_EN.cpp
@@ -192,5 +192,7 @@
     const char playlistGenModeUncached[] PROGMEM = "Playlist-generation: uncached";
     const char playlistGenModeCached[] PROGMEM = "Playlist-generation: cached";
     const char playlistCacheFoundBut0[] PROGMEM = "Playlist-cache-file found but 0 bytes";
+    const char bootLoopDetected[] PROGMEM = "Bootloop detected! Last RFID won't be restored.";
+    const char noBootLoopDetected[] PROGMEM = "No bootloop detected. Great :-)";
 
 #endif
diff --git a/src/logmessages.h b/src/logmessages.h
index 711e09a..49cffcc 100644
--- a/src/logmessages.h
+++ b/src/logmessages.h
@@ -188,3 +188,5 @@ extern const char warningRefactoring[];
 extern const char playlistGenModeUncached[];
 extern const char playlistGenModeCached[];
 extern const char playlistCacheFoundBut0[];
+extern const char bootLoopDetected[];
+extern const char noBootLoopDetected[];
diff --git a/src/main.cpp b/src/main.cpp
index b6cab6e..32fa464 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -26,6 +26,9 @@
 
 #ifdef PLAY_LAST_RFID_AFTER_REBOOT
     bool recoverLastRfid = true;
+    bool recoverBootCount = true;
+    bool resetBootCount = false;
+    uint32_t bootCount = 0;
 #endif
 
 ////////////
@@ -42,8 +45,40 @@
 #endif
 
 #ifdef PLAY_LAST_RFID_AFTER_REBOOT
+    // If a problem occurs, remembering last rfid can lead into a boot loop that's hard to escape of.
+    // That reason for a mechanism is necessary to prevent this.
+    // At start of a boot, bootCount is incremented by one and after 30s decremented because
+    // uptime of 30s is considered as "successful boot".
+    void recoverBootCountFromNvs(void) {
+        if (recoverBootCount) {
+            recoverBootCount = false;
+            resetBootCount = true;
+            bootCount = gPrefsSettings.getUInt("bootCount", 999);
+
+            if (bootCount == 999) {         // first init
+                bootCount = 1;
+                gPrefsSettings.putUInt("bootCount", bootCount);
+            } else if (bootCount >= 3) {    // considered being a bootloop => don't recover last rfid!
+                bootCount = 1;
+                gPrefsSettings.putUInt("bootCount", bootCount);
+                gPrefsSettings.putString("lastRfid", "-1");     // reset last rfid
+                Log_Println((char *) FPSTR(bootLoopDetected), LOGLEVEL_ERROR);
+                recoverLastRfid = false;
+            } else {                        // normal operation
+                gPrefsSettings.putUInt("bootCount", ++bootCount);
+            }
+        }
+
+        if (resetBootCount && millis() >= 30000) {      // reset bootcount
+            resetBootCount = false;
+            bootCount = 0;
+            gPrefsSettings.putUInt("bootCount", bootCount);
+            Log_Println((char *) FPSTR(noBootLoopDetected), LOGLEVEL_INFO);
+        }
+    }
+
     // Get last RFID-tag applied from NVS
-    void recoverLastRfidPlayed(void) {
+    void recoverLastRfidPlayedFromNvs(void) {
         if (recoverLastRfid) {
             if (System_GetOperationMode() == OPMODE_BLUETOOTH) { // Don't recover if BT-mode is desired
                 recoverLastRfid = false;
@@ -220,7 +255,8 @@ void loop() {
     Rfid_PreferenceLookupHandler();
 
     #ifdef PLAY_LAST_RFID_AFTER_REBOOT
-        recoverLastRfidPlayed();
+        recoverBootCountFromNvs();
+        recoverLastRfidPlayedFromNvs();
     #endif
 
     IrReceiver_Cyclic();