//+------------------------------------------------------------------+
//|                                                 VisualSystem.mqh |
//|                                  Copyright 2025, MetaQuotes Ltd. |
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"

#include "VisualInterfaces.mqh"
#include "ZoneLevel.mqh"

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
class VisualSystem : public ViewEvents
  {
private:
   long              m_chart_id;
   int               m_width, m_height;
   long              m_zoom;

   datetime          m_from_time, m_to_time;
   double            m_min_price, m_max_price;

   bool              m_auto_update;
   long              m_min_zoom_to_keep_texts;
   bool              m_min_zoom_reached_already;

   // Manual dynamic array
   ZoneLevel*        m_levels[];
   int               m_count;
   int               m_capacity;

   void              ResizeArray(int newCapacity);

public:
                     VisualSystem();
                    ~VisualSystem();

   void              SetMinZoomForTexts(long zoomLevel) { m_min_zoom_to_keep_texts = zoomLevel; }
   void              SetAutoUpdate(bool enable) { m_auto_update = enable; }

   long              Zoom() const { return m_zoom; }
   int               GetScaledFontSize(int baseSizePoints) const;

   // Level management
   void              AddLevel(ZoneLevel *level);
   bool              RemoveLevel(int index);
   bool              RemoveLevel(ZoneLevel *level);

   ZoneLevel*        GetLevel(int index) const;
   ZoneLevel*        GetLevelByName(string levelName);

   int               GetSize() const { return m_count; }
   int               GetCapacity() const { return m_capacity; }
   void              SetCapacity(int newCapacity);
   void              ClearLevels();
   void              DeleteLevel(int index);

   // Rendering – now uses dirty tracking
   void              Render();

   // Event handlers
   void              UpdateViewBounds();
   void              OnChartEvent(const int id, const long &lparam, const double &dparam, const string &sparam);

   // Virtual overrides
   virtual void      OnViewChanged() override;
   virtual void      OnZoomChanged(long newZoom, long oldZoom) override;
   virtual void      OnMinZoomReached() override { }
   virtual void      OnBeforeRender() override { UpdateViewBounds(); }
   virtual void      OnAfterRender() override { }

private:
   void              DeleteAllTextObjects();
   // DeleteAllVisualObjects no longer used in Render, kept for emergency
   void              DeleteAllVisualObjects();
  };

//+------------------------------------------------------------------+
//| Constructor                                                      |
//+------------------------------------------------------------------+
VisualSystem::VisualSystem()
   : m_chart_id(ChartID()), m_width(0), m_height(0), m_zoom(0),
     m_auto_update(true), m_min_zoom_to_keep_texts(2), m_min_zoom_reached_already(false),
     m_count(0), m_capacity(0)
  {
   UpdateViewBounds();
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
VisualSystem::~VisualSystem()
  {
   ClearLevels();
  }

//+------------------------------------------------------------------+
//| Array management                                                 |
//+------------------------------------------------------------------+
void VisualSystem::ResizeArray(int newCapacity)
  {
   if(newCapacity <= 0)
     {
      ArrayResize(m_levels, 0);
      m_capacity = 0;
      return;
     }
   ArrayResize(m_levels, newCapacity);
   m_capacity = newCapacity;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::SetCapacity(int newCapacity)
  {
   if(newCapacity <= m_count)
      return;
   ResizeArray(newCapacity);
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::AddLevel(ZoneLevel *level)
  {
   if(CheckPointer(level) == POINTER_INVALID)
      return;
   if(m_count >= m_capacity)
     {
      int newCap = (m_capacity == 0) ? 4 : m_capacity * 2;
      ResizeArray(newCap);
     }
   m_levels[m_count] = level;
   m_count++;

  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
bool VisualSystem::RemoveLevel(int index)
  {
   if(index < 0 || index >= m_count)
      return false;
   for(int i = index; i < m_count - 1; i++)
      m_levels[i] = m_levels[i + 1];
   m_count--;
   if(m_count > 0)
      m_levels[m_count] = NULL;
   return true;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
bool VisualSystem::RemoveLevel(ZoneLevel *level)
  {
   if(level == NULL)
      return false;
   for(int i = 0; i < m_count; i++)
      if(m_levels[i] == level)
         return RemoveLevel(i);
   return false;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
ZoneLevel* VisualSystem::GetLevelByName(string levelName)
  {
   for(int i = 0; i < m_count; i++)
      if(m_levels[i].GetName() == levelName)
         return m_levels[i];
   return NULL;
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::DeleteLevel(int index)
  {
   if(index < 0 || index >= m_count)
      return;
   ZoneLevel* p = m_levels[index];
   if(CheckPointer(p) != POINTER_INVALID)
      delete p;
   RemoveLevel(index);
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
ZoneLevel* VisualSystem::GetLevel(int index) const
  {
   if(index < 0 || index >= m_count)
      return NULL;
   return m_levels[index];
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::ClearLevels()
  {
   for(int i = 0; i < m_count; i++)
     {
      if(CheckPointer(m_levels[i]) != POINTER_INVALID)
         delete m_levels[i];
      m_levels[i] = NULL;
     }
   m_count = 0;
  }

//+------------------------------------------------------------------+
//| Optimized Render – uses dirty flags                              |
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
//| Optimized Render – reverse iteration + early culling             |
//+------------------------------------------------------------------+
void VisualSystem::Render()
  {
   OnBeforeRender();   // <-- updates m_from_time, m_to_time, m_min_price, m_max_price

// If bounds are invalid (chart not ready), just update all levels without culling
   bool boundsValid = (m_from_time < m_to_time && m_min_price < m_max_price);

   for(int i = m_count - 1; i >= 0; i--)   // reverse iteration: draw newest first
     {
      ZoneLevel* p = m_levels[i];
      if(p == NULL)
         continue;

 
         // Fast culling using level's stored time/price range
     /*    datetime levelFrom = p.GetFromTime();
         datetime levelTo   = p.GetToTime();
         double   levelMin  = p.GetMinPrice();
         double   levelMax  = p.GetMaxPrice();

         // Skip if completely outside visible time OR price range
         if(levelTo < m_from_time || levelFrom > m_to_time ||
            levelMax < m_min_price || levelMin > m_max_price)
           {
            // Level not visible at all – skip UpdateDraw entirely
            // (Objects will be deleted when they become invisible inside UpdateDraw later)
            continue;
           }
        //}     if(boundsValid)
        //{*/

      // Level intersects view (or bounds invalid) – update its drawing
      p.UpdateDraw(GetPointer(this), m_from_time, m_to_time, m_min_price, m_max_price);
     }

   OnAfterRender();
  }

//+------------------------------------------------------------------+
//| View bounds update                                               |
//+------------------------------------------------------------------+
void VisualSystem::UpdateViewBounds()
  {
   long old_zoom = m_zoom;
   datetime old_from = m_from_time, old_to = m_to_time;
   double old_minp = m_min_price, old_maxp = m_max_price;

   m_width  = (int)ChartGetInteger(m_chart_id, CHART_WIDTH_IN_PIXELS);
   m_height = (int)ChartGetInteger(m_chart_id, CHART_HEIGHT_IN_PIXELS);
   m_zoom   = ChartGetInteger(m_chart_id, CHART_SCALE);

   int sub_window = 0;
   ChartXYToTimePrice(m_chart_id, 0, 0, sub_window, m_from_time, m_max_price);
   ChartXYToTimePrice(m_chart_id, m_width, m_height, sub_window, m_to_time, m_min_price);

   if(m_zoom != old_zoom)
     {
      OnZoomChanged(m_zoom, old_zoom);
      bool below_threshold = (m_zoom < m_min_zoom_to_keep_texts);


      if(below_threshold && !m_min_zoom_reached_already)
        {
         DeleteAllTextObjects();
         OnMinZoomReached();
         m_min_zoom_reached_already = true;

        }
      else
         if(!below_threshold)
           {
            m_min_zoom_reached_already = false;
           }
     }

   if(m_from_time != old_from || m_to_time != old_to ||
      m_min_price != old_minp || m_max_price != old_maxp)
     {
      OnViewChanged();
     }
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int VisualSystem::GetScaledFontSize(int baseSizePoints) const
  {
   return (int)MathMax(6.0, baseSizePoints - (m_zoom - 2));
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::DeleteAllTextObjects()
  {
   for(int i = 0; i < m_count; i++)
      if(CheckPointer(m_levels[i]) != POINTER_INVALID)
         m_levels[i].DeleteText();


  }

// Emergency cleanup – not used in normal render but kept for completeness
void VisualSystem::DeleteAllVisualObjects()
  {
   for(int i = 0; i < m_count; i++)
      if(CheckPointer(m_levels[i]) != POINTER_INVALID)
         m_levels[i].Delete();
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::OnChartEvent(const int id, const long &lparam, const double &dparam, const string &sparam)
  {
   if(id == CHARTEVENT_CHART_CHANGE)
      UpdateViewBounds();
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::OnViewChanged(void)
  {
   Render();
// Print("OnViewChanged");
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void VisualSystem::OnZoomChanged(long newZoom, long oldZoom)
  {
   if(!m_min_zoom_reached_already)
      for(int i = 0; i < m_count; i++)
         if(CheckPointer(m_levels[i]) != POINTER_INVALID)
            m_levels[i].SetFontSize(GetScaledFontSize(12));
  }

//+------------------------------------------------------------------+