WebSocket debug logging (#22)

* WebSocket debug logging

* Fix static analysis issues. TIL about [[maybe_unused]]

* Fix linker errors on ESP32

platformio.ini

@@ -17,6 +17,7 @@ framework = arduino
 lib_deps = 
 	bblanchon/ArduinoJson @ ^6.21.3
 	knolleary/PubSubClient @ ^2.8
+	me-no-dev/ESP Async [email protected]
 	https://github.com/SwiCago/HeatPump
 check_tool = clangtidy, cppcheck
 check_flags =
@@ -45,12 +46,25 @@ monitor_speed = 115200
 upload_speed = 460800
 board_build.ldscript = eagle.flash.4m2m.ld
 
+[env:WEMOS_D1_Mini_Testing]
+platform = ${env:WEMOS_D1_Mini.platform}
+board = ${env:WEMOS_D1_Mini.board}
+monitor_speed = ${env:WEMOS_D1_Mini.monitor_speed}
+upload_speed = ${env:WEMOS_D1_Mini.upload_speed}
+board_build.ldscript = ${env:WEMOS_D1_Mini.board_build.ldscript}
+build_flags = ${env:WEMOS_D1_Mini.build_flags} -D ENABLE_LOGGING
+
+
 [env:ESP32DEV]
 platform = espressif32
 board = esp32dev
 lib_deps = 
 	ArduinoJson @6.20.0
 	PubSubClient @2.8
+	me-no-dev/[email protected]
+	; latest master required for ESP32 because released version causes linker failures
+	; https://github.com/me-no-dev/ESPAsyncWebServer/pull/999
+	https://github.com/me-no-dev/ESPAsyncWebServer.git
 	https://github.com/SwiCago/HeatPump
 build_unflags = -std=gnu++11
 build_flags = -std=gnu++17 -D CORE_DEBUG_LEVEL=0 -Wall

src/mitsubishi2mqtt/logger.cpp

@@ -0,0 +1,45 @@
+#include "logger.hpp"
+
+#include <ESPAsyncWebServer.h>
+
+static AsyncWebServer server(81);
+static AsyncWebSocket webSocket("/log");
+
+const auto LOG_BUFFER_SIZE = 256;
+
+void onEvent(const AsyncWebSocket *server, AsyncWebSocketClient *client, AwsEventType type,
+             [[maybe_unused]] void *arg, [[maybe_unused]] uint8_t *data,
+             [[maybe_unused]] size_t len) {
+  if (type == WS_EVT_CONNECT) {
+    client->ping();
+  } else if (type == WS_EVT_PONG) {
+    Logger::log(F("log client connected ws://%s client ID:%u\n"), server->url(), client->id());
+  }
+}
+
+// cppcheck-suppress unusedFunction
+void Logger::initialize() {
+  webSocket.onEvent(onEvent);
+  server.addHandler(&webSocket);
+  server.begin();
+}
+
+void Logger::log(const char *format, ...) {
+  char logBuffer[LOG_BUFFER_SIZE];
+  va_list args;
+  va_start(args, format);
+  vsnprintf(logBuffer, LOG_BUFFER_SIZE, format, args);
+  webSocket.printfAll(logBuffer);
+  va_end(args);
+}
+
+void Logger::log(const __FlashStringHelper *format, ...) {
+  char logBuffer[LOG_BUFFER_SIZE];
+  va_list args;
+  va_start(args, format);
+  // See https://arduino-esp8266.readthedocs.io/en/latest/PROGMEM.html for more about PGM_P, PSTR,
+  // F, FlashStringHelper, etc.
+  vsnprintf_P(logBuffer, LOG_BUFFER_SIZE, reinterpret_cast<PGM_P>(format), args);
+  webSocket.printfAll(logBuffer);
+  va_end(args);
+}

src/mitsubishi2mqtt/logger.hpp

@@ -0,0 +1,13 @@
+#ifndef LOGGER_HPP
+#define LOGGER_HPP
+
+#include <Arduino.h>
+
+namespace Logger {
+void initialize();
+void log(const char* format, ...) __attribute__((format(printf, 1, 2)));
+void log(const __FlashStringHelper* format, ...);
+inline void log(const String& message) { return log(message.c_str()); }
+}  // namespace Logger
+
+#endif  // LOGGER_HPP