countdown config to LittleFS + FIX: leave config via short-/long-button

platformio.ini

@@ -2,6 +2,7 @@
 platform = espressif32
 board = esp32dev
 framework = arduino
+board_build.filesystem = littlefs
 lib_deps = https://github.com/adafruit/Adafruit_NeoPixel
 upload_port = /dev/ttyUSB0
 upload_speed = 460800

src/countdown.cpp

@@ -1,5 +1,5 @@
 #include "countdown.h"
-
+#include <LittleFS.h>
 #include "display.h"
 
 enum State {
@@ -8,9 +8,11 @@ enum State {
 
 State state = CONFIG;
 
-long countdownConfig = 6 * 60 * 1000;
+bool countdownConfigDirty = false;
 
-long countdownRest = countdownConfig;
+long countdownMillis = 6 * 60 * 1000;
+
+long countdownRest = countdownMillis;
 
 unsigned long last = 0;
 
@@ -51,11 +53,11 @@ void setState(const State newState) {
   const char* name;
   switch (state) {
     case CONFIG:
-      countdownRest = countdownConfig;
+      countdownRest = countdownMillis;
       name = "CONFIG";
       break;
     case READY:
-      countdownRest = countdownConfig;
+      countdownRest = countdownMillis;
       name = "READY";
       break;
     case RUNNING:
@@ -103,7 +105,50 @@ void countdownUpdate() {
   }
 }
 
+void countdownConfigLoad() {
+  if (LittleFS.begin(true)) {
+    Serial.println("Filesystem mounted.");
+    File file = LittleFS.open("/countdownMillis");
+    if (file) {
+      const String content = file.readString();
+      if (content) {
+        countdownMillis = content.toInt();
+        Serial.printf("Read countdownMillis from file: countdownMillis=%lu, file=%s", countdownMillis, file.path());
+      } else {
+        Serial.printf("WARN: Cannot parse content of: %s\n", file.path());
+      }
+      file.close();
+    } else {
+      Serial.printf("WARN: Cannot open file for READ: %s\n", file.path());
+    }
+    LittleFS.end();
+    Serial.println("Filesystem unmounted.");
+  } else {
+    Serial.println("ERROR: Failed to mount filesystem.");
+  }
+}
+
+void countdownConfigWrite() {
+  if (LittleFS.begin(true)) {
+    Serial.println("Filesystem mounted.");
+    File file = LittleFS.open("/countdownMillis", "w", true);
+    if (file) {
+      file.printf("%lu", countdownMillis);
+      Serial.printf("Wrote countdownMillis to file: countdownMillis=%lu, file=%s", countdownMillis, file.path());
+      file.close();
+      countdownConfigDirty = false;
+    } else {
+      Serial.printf("WARN: Cannot open file for WRITE: %s\n", file.path());
+    }
+    LittleFS.end();
+    Serial.println("Filesystem unmounted.");
+  } else {
+    Serial.println("ERROR: failed to mount filesystem");
+  }
+}
+
 void countdownSetup() {
+  countdownConfigLoad();
   setState(READY);
 }
 
@@ -114,9 +159,13 @@ void countdownLoop() {
 
 void buttonShortPressed() {
   switch (state) {
-    case CONFIG:
-      setState(READY);
+    case CONFIG: {
+      const auto seconds = (countdownMillis / 30000) * 30 % (15 * 60) + 30;
+      countdownMillis = seconds * 1000;
+      countdownRest = countdownMillis;
+      countdownConfigDirty = true;
       break;
+    }
     case READY:
     case END:
       setState(CONFIG);
@@ -130,12 +179,12 @@ void buttonShortPressed() {
 
 void buttonLongPressed() {
   switch (state) {
-    case CONFIG: {
-      const auto seconds = (countdownConfig / 30000) * 30 % (15 * 60) + 30;
-      countdownConfig = seconds * 1000;
-      countdownRest = countdownConfig;
+    case CONFIG:
+      if (countdownConfigDirty) {
+        countdownConfigWrite();
+      }
+      setState(READY);
       break;
-    }
     case RUNNING:
       setState(PAUSED);
       break;