Fix #8: Add pending transfer check feature

- Add new 'pending' command (alias 'p') to check for pending transfers
- Enhance 'finalize' command to warn about pending transfers
- Prompt for confirmation in interactive mode before shutdown
- Use psync_get_status() API for reliable transfer detection
- Shows upload/download counts separately
- Fix mbedtls 3.6 compatibility issues in pssl.c
- Update Makefile for mbedtls 3.x static linking

control_tools.cpp

@@ -59,6 +59,7 @@ static char* command_generator(const char* text, int state) {
     "c", "c start", "c stop",
     "sync", "sync ls", "sync add", "sync remove", "sync rm",
     "s", "s ls", "s add", "s remove", "s rm",
+    "pending", "p",
     "finalize", "f",
     "quit", "q",
     nullptr
@@ -100,6 +101,7 @@ void setup_app(CLI::App *app) {
               << "    list(ls): List sync folders" << std::endl
               << "    add <localpath> <remotepath>: Add sync folder" << std::endl
               << "    remove(rm) <folderid>: Remove sync folder" << std::endl
+              << "  pending(p): Check for pending transfers" << std::endl
               << "  finalize(f): Kill daemon and quit" << std::endl
               << "  quit(q): Exit this program" << std::endl;
   });
@@ -113,6 +115,29 @@ void setup_app(CLI::App *app) {
     char *errm = NULL;
     size_t errm_size = 0;
     RpcClient *rpc = new RpcClient();
+    
+    // Check for pending transfers first
+    if (rpc->Call(CHECKPENDING, "", &errm, &errm_size) == 0) {
+      uint32_t *pending = nullptr;
+      if (pshm_read((void**)&pending, nullptr) && pending) {
+        if (*pending > 0) {
+          std::cout << "Warning: " << *pending << " pending transfer(s) detected" << std::endl;
+          std::cout << "Stopping daemon will break pending transfers. Continue? (y/n): ";
+          std::string response;
+          std::getline(std::cin, response);
+          if (response != "y" && response != "Y") {
+            std::cout << "Finalize cancelled" << std::endl;
+            free(pending);
+            if (errm) { free(errm); }
+            delete rpc;
+            return;
+          }
+        }
+        free(pending);
+      }
+    }
+    if (errm) { free(errm); errm = NULL; }
+    
     rpc->Call(FINALIZE, "", &errm, &errm_size);
     delete rpc;
     std::cout << "Exiting ..." << std::endl;
@@ -124,6 +149,17 @@ void setup_app(CLI::App *app) {
     exit(0);
   });
 
+  // pending command
+  app->add_subcommand("pending", "Check for pending transfers")->alias("p")->callback([] {
+    char *errm = NULL;
+    size_t errm_size = 0;
+    RpcClient *rpc = new RpcClient();
+    rpc->Call(CHECKPENDING, "", &errm, &errm_size);
+    delete rpc;
+    if (errm) { free(errm); }
+    return 0;
+  });
+
   // crypto start
   auto start_crypto_cmd = crypto_cmd->add_subcommand("start", "Start crypto");
   static std::string start_crypto_pwd;

pclsync/pcommands.h

@@ -4,5 +4,6 @@ enum command_ids_ {
   FINALIZE,
   LISTSYNC,
   ADDSYNC,
-  STOPSYNC
+  STOPSYNC,
+  CHECKPENDING
 };

pclsync_lib.cpp

@@ -33,6 +33,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <termios.h>
 #include <time.h>
 #include <unistd.h>
@@ -392,9 +393,37 @@ int clib::pclsync_lib::stop_crypto(const char *unused) {
   return 0;
 }
 
+int clib::pclsync_lib::check_pending(const char *unused) {
+  (void)unused;
+  
+  pstatus_t status;
+  psync_get_status(&status);
+  
+  uint32_t pending = status.filestoupload + status.filestodownload;
+  
+  // Write result to shared memory for client
+  pshm_write(&pending, sizeof(uint32_t));
+  
+  if (pending > 0) {
+    std::cout << "Warning: " << pending << " pending transfer(s) detected";
+    if (status.filestoupload > 0 && status.filestodownload > 0) {
+      std::cout << " (" << status.filestoupload << " upload(s), " 
+                << status.filestodownload << " download(s))";
+    } else if (status.filestoupload > 0) {
+      std::cout << " (" << status.filestoupload << " upload(s))";
+    } else {
+      std::cout << " (" << status.filestodownload << " download(s))";
+    }
+    std::cout << std::endl;
+    return 1;
+  }
+  
+  std::cout << "No pending transfers detected" << std::endl;
+  return 0;
+}
+
 int clib::pclsync_lib::finalize(const char *unused) {
   (void)unused;
-
   psync_destroy();
   exit(0);
 }
@@ -499,6 +528,7 @@ int clib::pclsync_lib::init() {
   prpc_register(STARTCRYPTO, &start_crypto);
   prpc_register(STOPCRYPTO, &stop_crypto);
   prpc_register(FINALIZE, &finalize);
+  prpc_register(CHECKPENDING, &check_pending);
   prpc_register(LISTSYNC, &list_sync_folders);
   prpc_register(ADDSYNC, &add_sync_folder);
   prpc_register(STOPSYNC, &remove_sync_folder);

pclsync_lib.h

@@ -97,6 +97,7 @@ public:
   static int start_crypto(const char *pass);
   static int stop_crypto(const char *path);
   static int finalize(const char *path);
+  static int check_pending(const char *unused);
   static int list_sync_folders(const char *path);
   static int add_sync_folder(const char *path);
   static int remove_sync_folder(const char *path);