#ifndef _ESP32_VIRTUAL_MATRIX_PANEL_I2S_DMA
#define _ESP32_VIRTUAL_MATRIX_PANEL_I2S_DMA

/*******************************************************************
    Class contributed by Brian Lough, and expanded by Faptastic.
    
    Originally designed to allow CHAINING of panels together to create
    a 'bigger' display of panels. i.e. Chaining 4 panels into a 2x2
    grid.
    
    However, the function of this class has expanded now to also manage
    the output for 1/16 scan panels, as the core DMA library is designed
    ONLY FOR 1/16 scan matrix panels.

    YouTube: https://www.youtube.com/brianlough
    Tindie: https://www.tindie.com/stores/brianlough/
    Twitter: https://twitter.com/witnessmenow
 *******************************************************************/

#include "ESP32-HUB75-MatrixPanel-I2S-DMA.h"
#ifndef NO_GFX
 #include <Fonts/FreeSansBold12pt7b.h>
#endif

struct VirtualCoords {
  
  int16_t x;
  int16_t y;
  int16_t virt_row; // chain of panels row
  int16_t virt_col; // chain of panels col
  
  VirtualCoords()  : x(0), y(0)
  { }
	  
};

enum PANEL_SCAN_RATE {NORMAL_ONE_SIXTEEN, ONE_EIGHT};

#ifdef USE_GFX_ROOT
class VirtualMatrixPanel : public GFX
#elif !defined NO_GFX
class VirtualMatrixPanel : public Adafruit_GFX
#else
class VirtualMatrixPanel
#endif	
{

  public:
    int16_t virtualResX;
    int16_t virtualResY;

    int16_t vmodule_rows;
    int16_t vmodule_cols;

    int16_t panelResX;
    int16_t panelResY;
	
	int16_t dmaResX; // The width of the chain in pixels (as the DMA engine sees it)

    MatrixPanel_I2S_DMA *display;

    VirtualMatrixPanel(MatrixPanel_I2S_DMA &disp, int _vmodule_rows, int _vmodule_cols, int _panelResX, int _panelResY, bool serpentine_chain = true, bool top_down_chain = false)
#ifdef USE_GFX_ROOT
      : GFX(_vmodule_cols*_panelResX, _vmodule_rows*_panelResY)
#elif !defined NO_GFX
      : Adafruit_GFX(_vmodule_cols*_panelResX, _vmodule_rows*_panelResY)
#endif            
    {
      this->display = &disp;

      panelResX = _panelResX;
      panelResY = _panelResY;

      vmodule_rows = _vmodule_rows;
      vmodule_cols = _vmodule_cols;

      virtualResX = vmodule_cols*_panelResX;      
      virtualResY = vmodule_rows*_panelResY;	

	  dmaResX     = panelResX * vmodule_rows * vmodule_cols;

	 
	  
	  /* Virtual Display width() and height() will return a real-world value. For example:
	   * Virtual Display width: 128
	   * Virtual Display height: 64
	   *
	   * So, not values that at 0 to X-1
	   */

      _s_chain_party = serpentine_chain; // serpentine, or 'S' chain?
      _chain_top_down= top_down_chain;
	  
	  coords.x = coords.y = -1; // By default use an invalid co-ordinates that will be rejected by updateMatrixDMABuffer

    }

    // equivalent methods of the matrix library so it can be just swapped out.
    virtual void drawPixel(int16_t x, int16_t y, uint16_t color);
    virtual void fillScreen(uint16_t color); // overwrite adafruit implementation
    void clearScreen() 	{  display->clearScreen(); }
    void drawPixelRGB888(int16_t x, int16_t y, uint8_t r, uint8_t g, uint8_t b);

    uint16_t color444(uint8_t r, uint8_t g, uint8_t b) { return display->color444(r, g, b); }
    uint16_t color565(uint8_t r, uint8_t g, uint8_t b) { return display->color565(r, g, b); }
    uint16_t color333(uint8_t r, uint8_t g, uint8_t b) { return display->color333(r, g, b); }
	
	void flipDMABuffer() { display->flipDMABuffer(); }
	void drawDisplayTest();
    void setRotate(bool rotate);	
	
	void setPhysicalPanelScanRate(PANEL_SCAN_RATE rate);

  protected:
  
    virtual VirtualCoords getCoords(int16_t &x, int16_t &y); 
    VirtualCoords coords;
	
    bool _s_chain_party  = true; // Are we chained? Ain't no party like a... 
    bool _chain_top_down = false; // is the ESP at the top or bottom of the matrix of devices?
	bool _rotate 		 = false;
	
	PANEL_SCAN_RATE _panelScanRate = NORMAL_ONE_SIXTEEN;

}; // end Class header

/**
 * Calculate virtual->real co-ordinate mapping to underlying single chain of panels connected to ESP32.
 * Updates the private class member variable 'coords', so no need to use the return value. 
 * Not thread safe, but not a concern for ESP32 sketch anyway... I think.
 */
inline VirtualCoords VirtualMatrixPanel::getCoords(int16_t &x, int16_t &y) {
	//Serial.println("Called Base.");
	coords.x = coords.y = -1; // By defalt use an invalid co-ordinates that will be rejected by updateMatrixDMABuffer

	if ( x < 0 || x >= virtualResX || y < 0 || y >= virtualResY ) { // Co-ordinates go from 0 to X-1 remember! otherwise they are out of range!
	//Serial.printf("VirtualMatrixPanel::getCoords(): Invalid virtual display coordinate. x,y: %d, %d\r\n", x, y);
		return coords;
	}

	// We want to rotate?
	if (_rotate){
		uint16_t temp_x=x;
		x=y;
		y=virtualResY-1-temp_x;
    }  

    // Stupidity check
	if ( (vmodule_rows == 1) && (vmodule_cols == 1)) // single panel...
	{
		coords.x = x;
		coords.y = y;			
		return coords;
	}

    uint8_t row = (y / panelResY) + 1; //a non indexed 0 row number
    if(   ( _s_chain_party && !_chain_top_down && (row % 2 == 0) )  // serpentine vertically stacked chain starting from bottom row (i.e. ESP closest to ground), upwards
          ||
          ( _s_chain_party && _chain_top_down  && (row % 2 != 0) )  // serpentine vertically stacked chain starting from the sky downwards
    )
    {
      // First portion gets you to the correct offset for the row you need
      // Second portion inverts the x on the row
	  coords.x = ((y / panelResY) * (virtualResX)) + (virtualResX - x) - 1;
	  
      // inverts the y the row
      coords.y = panelResY - 1 - (y % panelResY);  
    } 
    else 
    {
	  // Normal chain pixel co-ordinate
      coords.x = x + ((y / panelResY) * (virtualResX)) ;
      coords.y = y % panelResY;
    }

    // Reverse co-ordinates if panel chain from ESP starts from the TOP RIGHT
    if (_chain_top_down)
    {
		/*
		const HUB75_I2S_CFG _cfg = this->display->getCfg();
		coords.x = (_cfg.mx_width * _cfg.chain_length - 1) - coords.x;
		coords.y = (_cfg.mx_height-1) - coords.y;
		*/
		coords.x = (dmaResX - 1) - coords.x;
		coords.y = (panelResY-1) - coords.y;	  
    }
	
	
	/* START: Pixel remapping AGAIN to convert 1/16 SCAN output that the
	 *        the underlying hardware library is designed for (because 
	 *        there's only 2 x RGB pins... and convert this to 1/8 or something
	 */
	if ( _panelScanRate == ONE_EIGHT)
	{
		/* Convert Real World 'VirtualMatrixPanel' co-ordinates (i.e. Real World pixel you're looking at
		   on the panel or chain of panels, per the chaining configuration) to a 1/8 panels
		   double 'stretched' and 'squished' coordinates which is what needs to be sent from the
		   DMA buffer.

		   Note: Look at the One_Eight_1_8_ScanPanel code and you'll see that the DMA buffer is setup
		   as if the panel is 2 * W and 0.5 * H !
		*/
	
		/*
		  Serial.print("VirtualMatrixPanel Mapping ("); Serial.print(x, DEC); Serial.print(","); Serial.print(y, DEC); Serial.print(") ");
		  // to
		  Serial.print("to ("); Serial.print(coords.x, DEC);  Serial.print(",");  Serial.print(coords.y, DEC);   Serial.println(") ");  
		 */
		  if ( (y & 8) == 0) { 
			coords.x += ((coords.x / panelResX)+1)*panelResX; // 1st, 3rd 'block' of 8 rows of pixels, offset by panel width in DMA buffer
		  }
		  else {
			coords.x += (coords.x / panelResX)*panelResX; // 2nd, 4th 'block' of 8 rows of pixels, offset by panel width in DMA buffer
		  }

		  // http://cpp.sh/4ak5u
		  // Real number of DMA y rows is half reality
		  // coords.y = (y / 16)*8 + (y & 0b00000111);   
		  coords.y = (y >> 4)*8 + (y & 0b00000111);   

		 /*
		  Serial.print("OneEightScanPanel Mapping ("); Serial.print(x, DEC); Serial.print(","); Serial.print(y, DEC); Serial.print(") ");
		  // to
		  Serial.print("to ("); Serial.print(coords.x, DEC);  Serial.print(",");  Serial.print(coords.y, DEC);   Serial.println(") ");
		 */
	}
		

    //Serial.print("Mapping to x: "); Serial.print(coords.x, DEC);  Serial.print(", y: "); Serial.println(coords.y, DEC);  
	return coords; 
}

inline void VirtualMatrixPanel::drawPixel(int16_t x, int16_t y, uint16_t color) { // adafruit virtual void override
  getCoords(x, y);
  this->display->drawPixel(coords.x, coords.y, color);
}

inline void VirtualMatrixPanel::fillScreen(uint16_t color) { // adafruit virtual void override
  this->display->fillScreen(color);
}

inline void VirtualMatrixPanel::drawPixelRGB888(int16_t x, int16_t y, uint8_t r, uint8_t g, uint8_t b) {
  getCoords(x, y);
  this->display->drawPixelRGB888( coords.x, coords.y, r, g, b);
}

inline void VirtualMatrixPanel::setRotate(bool rotate) {
	_rotate=rotate;	

#ifndef NO_GFX
	// We don't support rotation by degrees.
	if (rotate) { setRotation(1); } else { setRotation(0); }
#endif
}

inline void VirtualMatrixPanel::setPhysicalPanelScanRate(PANEL_SCAN_RATE rate) {
	_panelScanRate=rate;
}



#ifndef NO_GFX
inline void VirtualMatrixPanel::drawDisplayTest()
{  
   this->display->setFont(&FreeSansBold12pt7b);
   this->display->setTextColor(this->display->color565(255, 255, 0));
   this->display->setTextSize(1); 

  for ( int panel = 0; panel < vmodule_cols*vmodule_rows; panel++ ) {
    int top_left_x = (panel == 0) ? 0:(panel*panelResX);
    this->display->drawRect( top_left_x, 0, panelResX, panelResY, this->display->color565( 0, 255, 0));
    this->display->setCursor(panel*panelResX, panelResY-3); 
    this->display->print((vmodule_cols*vmodule_rows)-panel);    
  } 

}
#endif
/*
// need to recreate this one, as it wouldn't work to just map where it starts.
inline void VirtualMatrixPanel::drawIcon (int *ico, int16_t x, int16_t y, int16_t icon_cols, int16_t icon_rows) {
  int i, j;
  for (i = 0; i < icon_rows; i++) {
    for (j = 0; j < icon_cols; j++) {
      // This is a call to this libraries version of drawPixel
      // which will map each pixel, which is what we want.
      //drawPixelRGB565 (x + j, y + i, ico[i * module_cols + j]);
	  drawPixel (x + j, y + i, ico[i * icon_cols + j]);
    }
  }
}
*/

#endif