//+------------------------------------------------------------------+
//|                                                 AccountGuard.mqh |
//|                                                     AnimateDread |
//|                                                                  |
//| THE ACCOUNT, NOT THE CHART. One Warrior instance trades one       |
//| symbol, but the prop account is judged on ALL of them together -  |
//| and equity indices fall together. Four charts at 0.25% each are   |
//| one 1% bet on a selloff. So every instance that shares a Magic    |
//| number shares three things, through terminal global variables:    |
//|                                                                   |
//|   OPEN-RISK CAP  the money at risk to the stops of every position |
//|                  carrying this magic, on any symbol, as % of      |
//|                  equity. An entry that would take it past the cap |
//|                  is DROPPED, not queued - by the time room frees  |
//|                  up the dip it measured is gone. Measured: a      |
//|                  7-index basket at 0.25% each crossed 4.5% equity |
//|                  DD within five months of 2022 without it.        |
//|   LOCK           "check the cap, then open" is serialised, so two |
//|                  charts rolling to the same H4 bar cannot both    |
//|                  read the cap before either has opened.           |
//|   KILL SWITCH    equity drawdown from its peak. One trip halts    |
//|                  and flattens every instance, and the state       |
//|                  survives a restart: a VPS reboot must not reset  |
//|                  the drawdown clock to "at the peak".             |
//|                  Delete <prefix>_halt_<magic> by hand to re-arm.  |
//|                                                                   |
//| And one thing per symbol:                                         |
//|   FRIDAY FLAT    from N minutes before THIS symbol's own Friday   |
//|                  session close (the broker's session table, so it |
//|                  is right on every symbol and both sides of DST)  |
//|                  until the week reopens. Swap was 23% of gross    |
//|                  profit without it; with it, ret/DD 2.55 -> 4.11. |
//|                  The original Warrior design (CH_MARKET_CLOSE).   |
//|                                                                   |
//| Same magic on every chart of one strategy - that IS the grouping. |
//| Never reuse it for another EA on the account: its positions would |
//| count against the cap and its losses toward the kill switch.      |
//+------------------------------------------------------------------+
#ifndef WARRIOR_ACCOUNTGUARD_MQH
#define WARRIOR_ACCOUNTGUARD_MQH

class CAccountGuard
  {
protected:
   string            m_symbol;
   long              m_magic;
   double            m_riskPct;        // what one new entry adds to open risk
   double            m_capPct;         // 0 = no cap
   double            m_killPct;        // 0 = no kill switch
   int               m_fridayMin;      // -1 = no Friday flat
   double            m_peak;
   bool              m_halted;
   int               m_capDropped;     // entries dropped at the cap, reported at deinit
   int               m_lockBusy;       // opens deferred because another chart held the lock

   string            Gv(const string what) const
                       { return "Warrior_" + what + "_" + IntegerToString(m_magic); }

public:
                     CAccountGuard(void) : m_symbol(""), m_magic(0), m_riskPct(0.0), m_capPct(0.0),
                                           m_killPct(0.0), m_fridayMin(-1), m_peak(0.0),
                                           m_halted(false), m_capDropped(0), m_lockBusy(0) {}
                    ~CAccountGuard(void) {}

   void              Init(const string symbol, const long magic, const double riskPct,
                          const double capPct, const double killPct, const int fridayMin);
   //--- Once per tick: track the peak, trip or honour the kill switch.
   void              Update(void);
   bool              Halted(void) const { return m_halted; }
   //--- Nothing of this symbol may be held right now (halted, or inside the Friday window).
   bool              MustBeFlat(void) const { return m_halted || FridayBlock(); }
   //--- Would one more entry of m_riskPct stay inside the cap?
   bool              RoomForOne(void);
   bool              LockTake(void);
   void              LockDrop(void);
   void              NoteLockBusy(void) { m_lockBusy++; }
   bool              FridayBlock(void) const;
   double            OpenRiskPct(void) const;
   void              Report(void) const;
   static int        MarketCloseSeconds(const string symbol, const int dayOfWeek);
  };
//+------------------------------------------------------------------+
void CAccountGuard::Init(const string symbol, const long magic, const double riskPct,
                         const double capPct, const double killPct, const int fridayMin)
  {
   m_symbol = symbol; m_magic = magic; m_riskPct = riskPct;
   m_capPct = capPct; m_killPct = killPct; m_fridayMin = fridayMin;
   m_peak = AccountInfoDouble(ACCOUNT_EQUITY);
   if(GlobalVariableCheck(Gv("peak")))
      m_peak = MathMax(m_peak, GlobalVariableGet(Gv("peak")));
   GlobalVariableSet(Gv("peak"), m_peak);
   m_halted = (m_killPct > 0.0 && GlobalVariableCheck(Gv("halt")) && GlobalVariableGet(Gv("halt")) > 0.0);
   if(m_halted)
      PrintFormat("CAccountGuard: HALTED by an earlier kill-switch trip - delete global variable %s"
                  " to re-arm.", Gv("halt"));
   const int fc = MarketCloseSeconds(m_symbol, 5);
   if(m_fridayMin >= 0 && fc > 0)
     {
      const int ff = fc - m_fridayMin * 60;
      PrintFormat("CAccountGuard: %s Friday session closes %02d:%02d server; flat from %02d:%02d"
                  " (%d min before).", m_symbol, fc / 3600, (fc % 3600) / 60, ff / 3600,
                  (ff % 3600) / 60, m_fridayMin);
     }
   PrintFormat("CAccountGuard: magic %I64d - open-risk cap %s across every chart with this magic,"
               " kill switch %s, Friday flat %s.", m_magic,
               (m_capPct > 0.0 ? DoubleToString(m_capPct, 2) + "%" : "off"),
               (m_killPct > 0.0 ? DoubleToString(m_killPct, 1) + "% equity DD from peak" : "off"),
               (m_fridayMin >= 0 ? "on" : "off"));
  }
//+------------------------------------------------------------------+
void CAccountGuard::Update(void)
  {
   const double eq = AccountInfoDouble(ACCOUNT_EQUITY);
   if(eq > m_peak)
     {
      m_peak = eq;
      GlobalVariableSet(Gv("peak"), m_peak);
     }
   if(m_killPct <= 0.0)
      return;
   if(!m_halted && m_peak > 0.0 && (m_peak - eq) / m_peak * 100.0 >= m_killPct)
     {
      m_halted = true;
      GlobalVariableSet(Gv("halt"), 1.0);
      PrintFormat("CAccountGuard: KILL SWITCH - equity %.2f is %.2f%% below peak %.2f; flattening"
                  " and halting every chart with magic %I64d.",
                  eq, (m_peak - eq) / m_peak * 100.0, m_peak, m_magic);
     }
   //--- Another instance may have tripped it: honour that here too.
   if(!m_halted && GlobalVariableCheck(Gv("halt")) && GlobalVariableGet(Gv("halt")) > 0.0)
     {
      m_halted = true;
      PrintFormat("CAccountGuard: halted by another chart's kill switch (magic %I64d).", m_magic);
     }
  }
//+------------------------------------------------------------------+
//| Money at risk to the stops across ALL positions with this magic,  |
//| any symbol, as % of equity. A position without a stop has         |
//| unbounded risk and fills the whole cap.                           |
//+------------------------------------------------------------------+
double CAccountGuard::OpenRiskPct(void) const
  {
   const double eq = AccountInfoDouble(ACCOUNT_EQUITY);
   if(eq <= 0.0)
      return 100.0;
   double money = 0.0;
   for(int i = PositionsTotal() - 1; i >= 0; i--)
     {
      const ulong tk = PositionGetTicket(i);
      if(tk == 0 || PositionGetInteger(POSITION_MAGIC) != m_magic)
         continue;
      const string sym = PositionGetString(POSITION_SYMBOL);
      const double op  = PositionGetDouble(POSITION_PRICE_OPEN);
      const double sl  = PositionGetDouble(POSITION_SL);
      const double vol = PositionGetDouble(POSITION_VOLUME);
      const double tv  = SymbolInfoDouble(sym, SYMBOL_TRADE_TICK_VALUE);
      const double ts  = SymbolInfoDouble(sym, SYMBOL_TRADE_TICK_SIZE);
      if(sl <= 0.0 || ts <= 0.0)
         return 100.0;
      const bool isLong = (PositionGetInteger(POSITION_TYPE) == POSITION_TYPE_BUY);
      const double dist = isLong ? op - sl : sl - op;
      if(dist > 0.0)
         money += dist * vol * tv / ts;
     }
   return money / eq * 100.0;
  }
//+------------------------------------------------------------------+
bool CAccountGuard::RoomForOne(void)
  {
   if(m_capPct <= 0.0)
      return true;
   if(OpenRiskPct() + m_riskPct <= m_capPct + 1e-9)
      return true;
   m_capDropped++;
   return false;
  }
//+------------------------------------------------------------------+
//| Terminal-global lock around "check the cap, then open". A stale   |
//| lock (a crashed holder) expires after 30 s. The tester runs one   |
//| instance per agent, so there is nothing to serialise there.       |
//+------------------------------------------------------------------+
bool CAccountGuard::LockTake(void)
  {
   if(MQLInfoInteger(MQL_TESTER))
      return true;
   const string gv = Gv("lock");
   const double now = (double)TimeCurrent();
   if(!GlobalVariableCheck(gv))
      GlobalVariableSet(gv, 0.0);
   const double v = GlobalVariableGet(gv);
   if(v != 0.0 && now - v < 30.0)
      return false;
   return GlobalVariableSetOnCondition(gv, now, v);
  }
//+------------------------------------------------------------------+
void CAccountGuard::LockDrop(void)
  {
   if(!MQLInfoInteger(MQL_TESTER))
      GlobalVariableSet(Gv("lock"), 0.0);
  }
//+------------------------------------------------------------------+
//| The LAST trade-session close of a weekday, in seconds from that   |
//| day's midnight (86400 = trades to midnight), -1 = no session.     |
//+------------------------------------------------------------------+
int CAccountGuard::MarketCloseSeconds(const string symbol, const int dayOfWeek)
  {
   datetime from = 0, to = 0;
   int lastTo = -1;
   for(uint k = 0; SymbolInfoSessionTrade(symbol, (ENUM_DAY_OF_WEEK)dayOfWeek, k, from, to); k++)
      lastTo = (int)to;
   return lastTo;
  }
//+------------------------------------------------------------------+
//| From (Friday close - N minutes) until the week reopens.           |
//+------------------------------------------------------------------+
bool CAccountGuard::FridayBlock(void) const
  {
   if(m_fridayMin < 0)
      return false;
   MqlDateTime d;
   TimeToStruct(TimeCurrent(), d);
   if(d.day_of_week == 6 || d.day_of_week == 0)
      return true;
   if(d.day_of_week != 5)
      return false;
   const int close = MarketCloseSeconds(m_symbol, 5);
   if(close <= 0)
      return true;                       // no Friday session: nothing may be held into it
   const int now = d.hour * 3600 + d.min * 60 + d.sec;
   return now >= close - m_fridayMin * 60;
  }
//+------------------------------------------------------------------+
void CAccountGuard::Report(void) const
  {
   PrintFormat("CAccountGuard: %d entr%s dropped at the open-risk cap, %d open(s) deferred for the"
               " cross-chart lock; kill switch %s.", m_capDropped, (m_capDropped == 1 ? "y" : "ies"),
               m_lockBusy, (m_halted ? "TRIPPED" : "not tripped"));
  }
#endif // WARRIOR_ACCOUNTGUARD_MQH