//+------------------------------------------------------------------+
//|                                               Dijkstars Algo.mq5 |
//|                                  Copyright 2025, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property strict
#include <Trade/Trade.mqh>
CTrade trade;

// Input Parameters
input int    TakeProfit   = 1000;     
input int   StopLoss = 385;
input double  In_Lot = 0.01;
input int    LeftBars    = 3;
input int    RightBars   = 3;
input int    MaxSwings   = 50;
input double Lots        = 0.1;
input double PointBuffer = 10;
input int    Slippage    = 5;
ENUM_TIMEFRAMES TimeFrame;

// Node Structure
struct SwingPoint {
   int index;
   datetime time;
   double price;
   bool isHigh;
   bool visited;
   double distance;
   bool   used;
   int previous;
};


SwingPoint swingPoints[];

//+------------------------------------------------------------------+
//| OnInit                                                           |
//+------------------------------------------------------------------+
int OnInit() {
   Print("Dijkstra Swing EA initialized");
   return INIT_SUCCEEDED;
}

//+------------------------------------------------------------------+
//| OnTick                                                           |
//+------------------------------------------------------------------+
void OnTick() {
   static datetime lastBarTime = 0;
   datetime currentBarTime = iTime(_Symbol, _Period, 0);

   if (currentBarTime != lastBarTime) {
      lastBarTime = currentBarTime;

      DetectSwings(LeftBars, RightBars);
      ApplyDijkstra();
      VisualizeSwings();
      GenerateSignalAndTrade();
      FilterAndMarkValidSwings(swingPoints);
      CleanOldSwingObjects();

   }
}

//+------------------------------------------------------------------+
//| Detect swing highs and lows                                      |
//+------------------------------------------------------------------+
void DetectSwings(int left, int right) {
   ArrayResize(swingPoints, 0);

   int totalBars = Bars(_Symbol, PERIOD_CURRENT) - right;
   for (int i = left; i < totalBars; i++) {
      bool isHigh = true, isLow = true;
      double high = High(i), low = Low(i);

      for (int j = 1; j <= left; j++) {
         if (High(i - j) >= high) isHigh = false;
         if (Low(i - j) <= low) isLow = false;
      }
      for (int j = 1; j <= right; j++) {
         if (High(i + j) >= high) isHigh = false;
         if (Low(i + j) <= low) isLow = false;
      }

      if (isHigh || isLow) {
         int idx = ArraySize(swingPoints);
         ArrayResize(swingPoints, idx + 1);
         swingPoints[idx].index = i;
         swingPoints[idx].time = Time(i);
         swingPoints[idx].price = isHigh ? high : low;
         swingPoints[idx].isHigh = isHigh;
         swingPoints[idx].visited = false;
         swingPoints[idx].distance = DBL_MAX;
         swingPoints[idx].previous = -1;

         if (idx >= MaxSwings) break;
      }
   }
}

//+------------------------------------------------------------------+
//| Apply Dijkstra's algorithm                                       |
//+------------------------------------------------------------------+
void ApplyDijkstra() {
   if (ArraySize(swingPoints) == 0) return;

   swingPoints[0].distance = 0;

   for (int i = 0; i < ArraySize(swingPoints); i++) {
      int u = -1;
      double minDist = DBL_MAX;

      for (int j = 0; j < ArraySize(swingPoints); j++) {
         if (!swingPoints[j].visited && swingPoints[j].distance < minDist) {
            minDist = swingPoints[j].distance;
            u = j;
         }
      }

      if (u == -1) break;

      swingPoints[u].visited = true;

      for (int v = 0; v < ArraySize(swingPoints); v++) {
         if (!swingPoints[v].visited) {
            double cost = MathAbs(swingPoints[u].price - swingPoints[v].price);
            if (swingPoints[u].distance + cost < swingPoints[v].distance) {
               swingPoints[v].distance = swingPoints[u].distance + cost;
               swingPoints[v].previous = u;
            }
         }
      }
   }
}

//+------------------------------------------------------------------+
//| Visualize Swing Points and Connections                           |
//+------------------------------------------------------------------+
void VisualizeSwings() {
   for (int i = 0; i < ArraySize(swingPoints); i++) {
      string objName = "Swing_" + IntegerToString(i);
      ObjectDelete(0, objName);

      ObjectCreate(0, objName, OBJ_ARROW, 0, swingPoints[i].time, swingPoints[i].price);
      ObjectSetInteger(0, objName, OBJPROP_ARROWCODE, swingPoints[i].isHigh ? 233 : 234);
      ObjectSetInteger(0, objName, OBJPROP_COLOR, swingPoints[i].isHigh ? clrRed : clrBlue);
   }

   for (int i = 1; i < ArraySize(swingPoints); i++) {
      int prev = swingPoints[i].previous;
      if (prev != -1) {
         string lineName = "Line_" + IntegerToString(i);
         ObjectDelete(0, lineName);

         ObjectCreate(0, lineName, OBJ_TREND, 0,
                      swingPoints[prev].time, swingPoints[prev].price,
                      swingPoints[i].time, swingPoints[i].price);
         ObjectSetInteger(0, lineName, OBJPROP_COLOR, clrGray);
         ObjectSetInteger(0, lineName, OBJPROP_WIDTH, 1);
      }
   }
}

double High(int index){return (iHigh(_Symbol, _Period, index));}
double Low(int index){return (iLow(_Symbol, _Period, index));}
datetime Time(int index){return (iTime(_Symbol, _Period, index));}

//+------------------------------------------------------------------+
//|                          Filter and mark                         |
//+------------------------------------------------------------------+
void FilterAndMarkValidSwings(SwingPoint &points[]) {
   int count = ArraySize(points);
   if(count < 2) return;

   for(int i = 0; i < count; i++) {
      if(points[i].used) continue;

      bool isValid = true;
      double swingPrice = points[i].price;
      int swingIndex = points[i].index;

      // Scan forward in time from the swing point
      for(int j = swingIndex - 1; j >= 0; j--) {
         double high = iHigh(_Symbol, TimeFrame, j);
         double low  = iLow(_Symbol, TimeFrame, j);

         // Invalidate swing high if price went higher later
         if(points[i].isHigh && high > swingPrice) {
            isValid = false;
            break;
         }

         // Invalidate swing low if price went lower later
         if(!points[i].isHigh && low < swingPrice) {
            isValid = false;
            break;
         }
      }

      if(isValid) {
         points[i].used = true;

         // Draw object on chart
         string objName = points[i].isHigh ? 
            StringFormat("SwingHigh_%d", TimeToString(iTime(_Symbol, TimeFrame, swingIndex))) :
            StringFormat("SwingLow_%d", TimeToString(iTime(_Symbol, TimeFrame, swingIndex)));

         color swingColor = points[i].isHigh ? clrRed : clrBlue;

         ObjectCreate(0, objName, OBJ_HLINE, 0, 0, swingPrice);
         ObjectSetInteger(0, objName, OBJPROP_COLOR, swingColor);
         ObjectSetInteger(0, objName, OBJPROP_STYLE, STYLE_DASH);
         ObjectSetInteger(0, objName, OBJPROP_WIDTH, 1);
      }
   }
}

//+------------------------------------------------------------------+
//|                        Cleaning up old swings                    |
//+------------------------------------------------------------------+
void CleanOldSwingObjects(int keepBars = 100) {
   datetime oldestDate = iTime(_Symbol, TimeFrame, keepBars);
   int total = ObjectsTotal(0);

   for(int i = total - 1; i >= 0; i--) {
      string name = ObjectName(0, i);
      if(StringFind(name, "SwingHigh_") == 0 || StringFind(name, "SwingLow_") == 0) {
         datetime swingTime = (datetime)ObjectGetInteger(0, name, OBJPROP_TIME);
         if(swingTime < oldestDate) {
            ObjectDelete(0, name);
         }
      }
   }
}


//+------------------------------------------------------------------+
//| Generate Signal & Trade                                          |
//+------------------------------------------------------------------+
void GenerateSignalAndTrade() {
   if (ArraySize(swingPoints) < 2) return;

   int last = ArraySize(swingPoints) - 1;
   int prev = swingPoints[last].previous;
   if (prev == -1) return;

   double entry = swingPoints[last].price;
   double reference = swingPoints[prev].price;
   double sl, tp;
   bool isBuy = entry > reference, isSell = entry < reference;

   SetSLTP(entry, reference, isBuy, sl, tp);

   if (PositionSelect(_Symbol)) return;

   if (isBuy)
      ExecuteTrade(ORDER_TYPE_BUY);
   else if(isSell)
      ExecuteTrade(ORDER_TYPE_SELL); 
}

//+------------------------------------------------------------------+
//| Calculate SL and TP based on distance to previous node           |
//+------------------------------------------------------------------+
void SetSLTP(double entry, double ref, bool isBuy, double &sl, double &tp) {
   double distance = MathAbs(entry - ref) + PointBuffer * _Point;
   if (isBuy) {
      sl = entry - distance;
      tp = entry + distance;
   } else {
      sl = entry + distance;
      tp = entry - distance;
   }
}


//+------------------------------------------------------------------+
//| Execute trade with risk parameters                               |
//+------------------------------------------------------------------+
void ExecuteTrade(ENUM_ORDER_TYPE tradeType){

   double point = SymbolInfoDouble(_Symbol, SYMBOL_POINT);
   double price = (tradeType == ORDER_TYPE_BUY) ? SymbolInfoDouble(_Symbol, SYMBOL_ASK) :
                                                  SymbolInfoDouble(_Symbol, SYMBOL_BID);

   // Convert StopLoss and TakeProfit from pips to actual price distances
   double sl_distance = StopLoss * point;
   double tp_distance = TakeProfit * point;
   
   double sl = (tradeType == ORDER_TYPE_BUY) ? price - sl_distance :
                                               price + sl_distance;
   
   double tp = (tradeType == ORDER_TYPE_BUY) ? price + tp_distance :
                                               price - tp_distance;

   trade.PositionOpen(_Symbol, tradeType, In_Lot, price, sl, tp, NULL);
}