From 8c0e261f449a80ef2a2da023d0be0ac915bcd4af Mon Sep 17 00:00:00 2001
From: Irini Kosmidou <st155836@stud.uni-stuttgart.de>
Date: Wed, 31 Aug 2022 10:58:21 +0200
Subject: [PATCH] ScexDeviceHandler: fileId includes date and time

---
 mission/devices/ScexDeviceHandler.cpp | 42 +++++++++++++++++----------
 mission/devices/ScexDeviceHandler.h   |  2 +-
 2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/mission/devices/ScexDeviceHandler.cpp b/mission/devices/ScexDeviceHandler.cpp
index 0c3049c8..bd9211a6 100644
--- a/mission/devices/ScexDeviceHandler.cpp
+++ b/mission/devices/ScexDeviceHandler.cpp
@@ -4,6 +4,7 @@
 #include <mission/memory/SdCardMountedIF.h>
 
 #include <algorithm>
+#include <ctime>
 #include <iostream>
 #include <random>
 
@@ -168,7 +169,7 @@ ReturnValue_t ScexDeviceHandler::handleValidReply(size_t remSize, DeviceCommandI
   ReturnValue_t result = OK;
   auto multiFileHandler = [&](std::string cmdName) {
     if ((helper.getPacketCounter() == 1) or (not fileNameSet)) {
-      fileId = random_string(6);
+      fileId = date_time_string();
       std::ostringstream oss("/tmp/scex-", std::ostringstream::ate);
       oss << cmdName << fileId << ".bin";
       fileName = oss.str();
@@ -230,7 +231,7 @@ ReturnValue_t ScexDeviceHandler::interpretDeviceReply(DeviceCommandId_t id, cons
 
   ReturnValue_t status = OK;
   auto oneFileHandler = [&](std::string cmdName) {
-    fileId = random_string(6);
+    fileId = date_time_string();
     std::ostringstream oss("/tmp/scex-", std::ostringstream::ate);
     oss << cmdName << fileId << ".bin";
     fileName = oss.str();
@@ -298,23 +299,32 @@ ReturnValue_t ScexDeviceHandler::initializeLocalDataPool(localpool::DataPool& lo
   return OK;
 }
 
-std::string ScexDeviceHandler::random_string(std::string::size_type length) {
-  static auto& chrs =
-      "0123456789"
-      "abcdefghijklmnopqrstuvwxyz"
-      "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+std::string ScexDeviceHandler::date_time_string() {
+  using namespace std;
+  string date_time;
+  time_t now = time(0);
+  tm* ltm = localtime(&now);
+  ostringstream oss(std::ostringstream::ate);
 
-  thread_local static std::mt19937 rg{std::random_device{}()};
-  thread_local static std::uniform_int_distribution<std::string::size_type> pick(0,
-                                                                                 sizeof(chrs) - 2);
+  if (ltm->tm_hour < 10) {
+    oss << 1900 + ltm->tm_year << 1 + ltm->tm_mon << ltm->tm_mday << "_0" << ltm->tm_hour;
+  } else {
+    oss << 1900 + ltm->tm_year << 1 + ltm->tm_mon << ltm->tm_mday << "_" << ltm->tm_hour;
+  }
+  if (ltm->tm_min < 10) {
+    oss << 0 << ltm->tm_min;
+  } else {
+    oss << ltm->tm_min;
+  }
+  if (ltm->tm_sec < 10) {
+    oss << 0 << ltm->tm_sec;
+  } else {
+    oss << ltm->tm_sec;
+  }
 
-  std::string s;
+  date_time = oss.str();
 
-  s.reserve(length);
-
-  while (length--) s += chrs[pick(rg)];
-
-  return s;
+  return date_time;
 }
 
 void ScexDeviceHandler::modeChanged() {}
diff --git a/mission/devices/ScexDeviceHandler.h b/mission/devices/ScexDeviceHandler.h
index 69436e0b..39d333f5 100644
--- a/mission/devices/ScexDeviceHandler.h
+++ b/mission/devices/ScexDeviceHandler.h
@@ -28,7 +28,7 @@ class ScexDeviceHandler : public DeviceHandlerBase {
   SdCardMountedIF *sdcMan = nullptr;
   Countdown finishCountdown = Countdown(LONG_CD);
 
-  std::string random_string(std::string::size_type length);
+  std::string date_time_string();
 
   // DeviceHandlerBase private function implementation
   void doStartUp() override;