gui: add FormatPeerAge() utility helper

Co-authored-by: randymcmillan <randy.lee.mcmillan@gmail.com>

src/qt/guiutil.cpp

@@ -79,6 +79,8 @@
 void ForceActivation();
 #endif
 
+using namespace std::chrono_literals;
+
 namespace GUIUtil {
 
 QString dateTimeStr(const QDateTime &date)
@@ -727,6 +729,16 @@ QString formatDurationStr(std::chrono::seconds dur)
     return str_list.join(" ");
 }
 
+QString FormatPeerAge(std::chrono::seconds time_connected)
+{
+    const auto time_now{GetTime<std::chrono::seconds>()};
+    const auto age{time_now - time_connected};
+    if (age >= 24h) return QObject::tr("%1 d").arg(age / 24h);
+    if (age >= 1h) return QObject::tr("%1 h").arg(age / 1h);
+    if (age >= 1min) return QObject::tr("%1 m").arg(age / 1min);
+    return QObject::tr("%1 s").arg(age / 1s);
+}
+
 QString formatServicesStr(quint64 mask)
 {
     QStringList strList;

src/qt/guiutil.h

@@ -223,6 +223,9 @@ namespace GUIUtil
     /** Convert seconds into a QString with days, hours, mins, secs */
     QString formatDurationStr(std::chrono::seconds dur);
 
+    /** Convert peer connection time to a QString denominated in the most relevant unit. */
+    QString FormatPeerAge(std::chrono::seconds time_connected);
+
     /** Format CNodeStats.nServices bitmask into a user-readable string */
     QString formatServicesStr(quint64 mask);