Improve timezone handling (#62)

src/game/ChatCommands/BanAndKickCommands.cpp

@@ -88,22 +88,25 @@ bool ChatHandler::HandleBanListHelper(QueryResult* result)
                 Field* fields2 = banInfo->Fetch();
                 do
                 {
-                    time_t t_ban = fields2[0].GetUInt64();
-                    tm* aTm_ban = localtime(&t_ban);
+                    time_t timeBan = fields2[0].GetUInt64();
+                    tm tmBan;
+                    localtime_r(&timeBan, &tmBan);
 
                     if (fields2[0].GetUInt64() == fields2[1].GetUInt64())
                     {
                         PSendSysMessage("|%-15.15s|%02d-%02d-%02d %02d:%02d|   permanent  |%-15.15s|%-15.15s|",
-                                        account_name.c_str(), aTm_ban->tm_year % 100, aTm_ban->tm_mon + 1, aTm_ban->tm_mday, aTm_ban->tm_hour, aTm_ban->tm_min,
+                                        account_name.c_str(), tmBan.tm_year % 100, tmBan.tm_mon + 1, tmBan.tm_mday, tmBan.tm_hour, tmBan.tm_min,
                                         fields2[2].GetString(), fields2[3].GetString());
                     }
                     else
                     {
-                        time_t t_unban = fields2[1].GetUInt64();
-                        tm* aTm_unban = localtime(&t_unban);
+                        time_t timeUnban = fields2[1].GetUInt64();
+                        tm tmUnban;
+                        localtime_r(&timeUnban, &tmUnban);
+
                         PSendSysMessage("|%-15.15s|%02d-%02d-%02d %02d:%02d|%02d-%02d-%02d %02d:%02d|%-15.15s|%-15.15s|",
-                                        account_name.c_str(), aTm_ban->tm_year % 100, aTm_ban->tm_mon + 1, aTm_ban->tm_mday, aTm_ban->tm_hour, aTm_ban->tm_min,
-                                        aTm_unban->tm_year % 100, aTm_unban->tm_mon + 1, aTm_unban->tm_mday, aTm_unban->tm_hour, aTm_unban->tm_min,
+                                        account_name.c_str(), tmBan.tm_year % 100, tmBan.tm_mon + 1, tmBan.tm_mday, tmBan.tm_hour, tmBan.tm_min,
+                                        tmUnban.tm_year % 100, tmUnban.tm_mon + 1, tmUnban.tm_mday, tmUnban.tm_hour, tmUnban.tm_min,
                                         fields2[2].GetString(), fields2[3].GetString());
                     }
                 }

src/game/Object/ObjectMgr.cpp

@@ -5098,8 +5098,12 @@ void ObjectMgr::LoadGossipTextLocales()
 /// @param serverUp true if the server is already running, false when the server is started
 void ObjectMgr::ReturnOrDeleteOldMails(bool serverUp)
 {
-    time_t basetime = time(NULL);
-    DEBUG_LOG("Returning mails current time: hour: %d, minute: %d, second: %d ", localtime(&basetime)->tm_hour, localtime(&basetime)->tm_min, localtime(&basetime)->tm_sec);
+    time_t curTime = time(NULL);
+    tm lt;
+    localtime_r(&curTime, &lt);
+    uint64 basetime(curTime);
+    sLog.outString("Returning mails current time: hour: %d, minute: %d, second: %d ", lt.tm_hour, lt.tm_min, lt.tm_sec);
+
     // delete all old mails without item and without body immediately, if starting server
     if (!serverUp)
     {

src/game/WorldHandlers/Weather.cpp

@@ -108,8 +108,9 @@ bool Weather::ReGenerate()
     // 78 days between January 1st and March 20nd; 365/4=91 days by season
     // season source http://aa.usno.navy.mil/data/docs/EarthSeasons.html
     time_t gtime = sWorld.GetGameTime();
-    struct tm* ltime = localtime(&gtime);
-    uint32 season = ((ltime->tm_yday - 78 + 365) / 91) % 4;
+    struct tm ltime;
+    localtime_r(&gtime, &ltime);
+    uint32 season = ((ltime.tm_yday - 78 + 365) / 91) % 4;
 
     static char const* seasonName[WEATHER_SEASONS] = { "spring", "summer", "fall", "winter" };
 

src/game/WorldHandlers/Weather.h

@@ -32,6 +32,7 @@
 #include "Common.h"
 #include "SharedDefines.h"
 #include "Timer.h"
+#include "Util.h"
 
 class Player;
 class Map;

src/game/WorldHandlers/World.cpp

@@ -2308,7 +2308,9 @@ void World::InitDailyQuestResetTime()
 
     // generate time by config
     time_t curTime = time(NULL);
-    tm localTm = *localtime(&curTime);
+    tm localTm;
+    localtime_r(&curTime, &localTm);
+
     localTm.tm_hour = getConfig(CONFIG_UINT32_QUEST_DAILY_RESET_HOUR);
     localTm.tm_min  = 0;
     localTm.tm_sec  = 0;

src/shared/Log/Log.cpp

@@ -358,8 +358,9 @@ FILE* Log::openGmlogPerAccount(uint32 account)
 void Log::outTimestamp(FILE* file)
 {
     time_t tt = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
-    std::tm aTm = localtime_r(tt);
 
+    std::tm aTm;
+    localtime_r(&tt, &aTm);
     //       YYYY   year
     //       MM     month (2 digits 01-12)
     //       DD     day (2 digits 01-31)
@@ -372,8 +373,9 @@ void Log::outTimestamp(FILE* file)
 void Log::outTime()
 {
     time_t tt = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
-    std::tm aTm = localtime_r(tt);
 
+    std::tm aTm;
+    localtime_r(&tt, &aTm);
     //       YYYY   year
     //       MM     month (2 digits 01-12)
     //       DD     day (2 digits 01-31)
@@ -386,8 +388,9 @@ void Log::outTime()
 std::string Log::GetTimestampStr()
 {
     time_t tt = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
-    std::tm aTm = localtime_r(tt);
 
+    std::tm aTm;
+    localtime_r(&tt, &aTm);
     //       YYYY   year
     //       MM     month (2 digits 01-12)
     //       DD     day (2 digits 01-31)

src/shared/Utilities/ByteBuffer.h

@@ -476,6 +476,11 @@ class ByteBuffer
             return _rpos;
         }
 
+        void rfinish()
+        {
+            _rpos = wpos();
+        }
+
         /**
          * @brief
          *

src/shared/Utilities/Util.cpp

@@ -154,15 +154,83 @@ void stripLineInvisibleChars(std::string& str)
     }
 }
 
-std::tm localtime_r(const time_t& time)
-{
-    std::tm tm_snapshot;
+/**
+ * It's a wrapper for the localtime_r function that works on Windows
+ *
+ * @param time The time to convert.
+ * @param result A pointer to a tm structure to receive the broken-down time.
+ *
+ * @return A pointer to the result.
+ */
 #if (defined(WIN32) || defined(_WIN32) || defined(__WIN32__))
-    localtime_s(&tm_snapshot, &time);
-#else
-    localtime_r(&time, &tm_snapshot); // POSIX
+struct tm* localtime_r(time_t const* time, struct tm *result)
+{
+    localtime_s(result, time);
+    return result;
+}
 #endif
-    return tm_snapshot;
+
+/**
+ * It takes a time_t value and returns a tm structure with the same time, but in local time
+ *
+ * @param time The time to break down.
+ *
+ * @return A struct tm
+ */
+tm TimeBreakdown(time_t time)
+{
+    tm timeLocal;
+    localtime_r(&time, &timeLocal);
+    return timeLocal;
+}
+
+/**
+ * Convert local time to UTC time.
+ *
+ * @param time The time to convert.
+ *
+ * @return The time in UTC.
+ */
+time_t LocalTimeToUTCTime(time_t time)
+{
+    #if (defined(WIN32) || defined(_WIN32) || defined(__WIN32__))
+        return time + _timezone;
+    #else
+        return time + timezone;
+    #endif
+}
+
+/**
+ * "Get the timestamp of the next time the given hour occurs in the local timezone."
+ *
+ * The function takes a timestamp, an hour, and a boolean. The timestamp is the time you want to find
+ * the next occurrence of the given hour. The hour is the hour you want to find the next occurrence of.
+ * The boolean is whether or not you want to find the next occurrence of the hour after the given
+ * timestamp
+ *
+ * @param time The time you want to get the hour timestamp for.
+ * @param hour The hour of the day you want to get the timestamp for.
+ * @param onlyAfterTime If true, the function will return the next hour after the current time. If
+ * false, it will return the current hour.
+ *
+ * @return A timestamp for the given hour of the day.
+ */
+time_t GetLocalHourTimestamp(time_t time, uint8 hour, bool onlyAfterTime)
+{
+    tm timeLocal = TimeBreakdown(time);
+    timeLocal.tm_hour = 0;
+    timeLocal.tm_min  = 0;
+    timeLocal.tm_sec  = 0;
+
+    time_t midnightLocal = mktime(&timeLocal);
+    time_t hourLocal = midnightLocal + hour * HOUR;
+
+    if (onlyAfterTime && hourLocal < time)
+    {
+        hourLocal += DAY;
+    }
+
+    return hourLocal;
 }
 
 std::string secsToTimeString(time_t timeInSecs, TimeFormat timeFormat, bool hoursOnly)
@@ -316,7 +384,8 @@ uint32 TimeStringToSecs(const std::string& timestring)
 
 std::string TimeToTimestampStr(time_t t)
 {
-    tm aTm = localtime_r(t);
+    tm aTm;
+    localtime_r(&t, &aTm);
     //       YYYY   year
     //       MM     month (2 digits 01-12)
     //       DD     day (2 digits 01-31)

src/shared/Utilities/Util.h

@@ -79,12 +79,11 @@ float GetFloatValueFromArray(Tokens const& data, uint16 index);
  */
 void stripLineInvisibleChars(std::string& src);
 
-/**
- * @brief
- *
- * @param localtime
- */
-std::tm localtime_r(const time_t& time);
+struct tm* localtime_r(const time_t* time, struct tm* result);
+
+time_t LocalTimeToUTCTime(time_t time);
+time_t GetLocalHourTimestamp(time_t time, uint8 hour, bool onlyAfterTime = true);
+tm TimeBreakdown(time_t t);
 
 /**
  * @brief