Add exporting CAN logs to .txt feature

Software/src/datalayer/datalayer.h

@@ -132,7 +132,7 @@ typedef struct {
   /** array with type of inverter used, for displaying on webserver */
   char inverter_protocol[64] = {0};
   /** array with incoming CAN messages, for displaying on webserver */
-  char logged_can_messages[10000] = {0};
+  char logged_can_messages[50000] = {0};
   /** bool, determines if CAN messages should be logged for webserver */
   bool can_logging_active = false;
 

Software/src/devboard/webserver/can_logging_html.cpp

@@ -19,6 +19,7 @@ String can_logger_processor(const String& var) {
         "monospace; }";
     content += "</style>";
     content += "<button onclick='refreshPage()'>Refresh data</button> ";
+    content += "<button onclick='exportLogs()'>Export to .txt</button> ";
     content += "<button onclick='stopLoggingAndGoToMainPage()'>Back to main page</button>";
 
     // Start a new block for the CAN messages
@@ -46,6 +47,7 @@ String can_logger_processor(const String& var) {
     // Add JavaScript for navigation
     content += "<script>";
     content += "function refreshPage(){ location.reload(true); }";
+    content += "function exportLogs() { window.location.href = '/export_logs'; }";
     content += "function stopLoggingAndGoToMainPage() {";
     content += "  fetch('/stop_logging').then(() => window.location.href = '/');";
     content += "}";

Software/src/devboard/webserver/webserver.cpp

@@ -1,5 +1,6 @@
 #include "webserver.h"
 #include <Preferences.h>
+#include <ctime>
 #include "../../datalayer/datalayer.h"
 #include "../../datalayer/datalayer_extended.h"
 #include "../../lib/bblanchon-ArduinoJson/ArduinoJson.h"
@@ -68,6 +69,33 @@ void init_webserver() {
     request->send_P(200, "text/plain", "Logging stopped");
   });
 
+  // Define the handler to export logs
+  server.on("/export_logs", HTTP_GET, [](AsyncWebServerRequest* request) {
+    String logs = String(datalayer.system.info.logged_can_messages);
+    if (logs.length() == 0) {
+      logs = "No logs available.";
+    }
+
+    // Get the current time
+    time_t now = time(nullptr);
+    struct tm timeinfo;
+    localtime_r(&now, &timeinfo);
+
+    // Ensure time retrieval was successful
+    char filename[32];
+    if (strftime(filename, sizeof(filename), "canlog_%H-%M-%S.txt", &timeinfo)) {
+      // Valid filename created
+    } else {
+      // Fallback filename if automatic timestamping failed
+      strcpy(filename, "battery_emulator_can_log.txt");
+    }
+
+    // Use request->send with dynamic headers
+    AsyncWebServerResponse* response = request->beginResponse(200, "text/plain", logs);
+    response->addHeader("Content-Disposition", String("attachment; filename=\"") + String(filename) + "\"");
+    request->send(response);
+  });
+
   // Route for going to cellmonitor web page
   server.on("/cellmonitor", HTTP_GET, [](AsyncWebServerRequest* request) {
     if (WEBSERVER_AUTH_REQUIRED && !request->authenticate(http_username, http_password))