From 0681171d691e1a5d82ad7f178eb80bef33a256c1 Mon Sep 17 00:00:00 2001
From: mvglasow <michael -at- vonglasow.com>
Date: Sat, 14 Jun 2025 21:14:00 +0300
Subject: [PATCH] [traffxml] Introduce timestamp shift operation

Signed-off-by: mvglasow <michael -at- vonglasow.com>
---
 traffxml/traff_model.cpp | 18 ++++++++++++++++++
 traffxml/traff_model.hpp | 21 +++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/traffxml/traff_model.cpp b/traffxml/traff_model.cpp
index 0a3581732..544ed73e0 100644
--- a/traffxml/traff_model.cpp
+++ b/traffxml/traff_model.cpp
@@ -153,6 +153,12 @@ IsoTime::IsoTime(std::chrono::time_point<std::chrono::utc_clock> tp)
 bool IsoTime::IsPast()
 {
   return m_tp < std::chrono::utc_clock::now();
+}\
+
+void IsoTime::Shift(IsoTime nowRef)
+{
+  auto const offset = std::chrono::utc_clock::now() - nowRef.m_tp;
+  m_tp += offset;
 }
 
 bool IsoTime::operator< (IsoTime & rhs)
@@ -256,6 +262,18 @@ std::optional<TrafficImpact> TraffMessage::GetTrafficImpact()
     return std::nullopt;
 }
 
+void TraffMessage::ShiftTimestamps()
+{
+  IsoTime nowRef = m_updateTime;
+  m_receiveTime.Shift(nowRef);
+  m_updateTime.Shift(nowRef);
+  m_expirationTime.Shift(nowRef);
+  if (m_startTime)
+    m_startTime.value().Shift(nowRef);
+  if (m_endTime)
+    m_endTime.value().Shift(nowRef);
+}
+
 void MergeMultiMwmColoring(MultiMwmColoring & delta, MultiMwmColoring & target)
 {
   // for each mwm in delta
diff --git a/traffxml/traff_model.hpp b/traffxml/traff_model.hpp
index a463098f1..26512b81e 100644
--- a/traffxml/traff_model.hpp
+++ b/traffxml/traff_model.hpp
@@ -72,6 +72,17 @@ public:
    */
   bool IsPast();
 
+  /**
+   * @brief Shifts time to the present.
+   *
+   * This method is intended for testing. It shifts the timestamp by a fixed amount, so that
+   * `nowRef` corresponds to current time. After this method returns, the timestamp will have the
+   * same offset from current time that it had from `nowRef` at the time the call was made.
+   *
+   * @param nowRef
+   */
+  void Shift(IsoTime nowRef);
+
   bool operator< (IsoTime & rhs);
   bool operator> (IsoTime & rhs);
 private:
@@ -362,6 +373,16 @@ struct TraffMessage
    */
   std::optional<TrafficImpact> GetTrafficImpact();
 
+  /**
+   * @brief Shifts timestamps to the present.
+   *
+   * This method is intended for testing. It shifts the timestamps of the message by a fixed amount,
+   * so that `m_updateTime` corresponds to current time, and all other timestamps maintain their
+   * offset to `m_updateTime`. If `m_startTime` and/or `m_endTime` are set, they may be adjusted
+   * further to maintain their offset from midnight or the full hour (currently not implemented).
+   */
+  void ShiftTimestamps();
+
   std::string m_id;
   IsoTime m_receiveTime = IsoTime::Now();
   IsoTime m_updateTime = IsoTime::Now();