#include "MyPngLib.h"
#include <SPIFFS.h>

 PNG _png;

 TFT_eSPI * _tft;
 File Myfile;

void PngClass::listDir(fs::FS &fs, const char * dirname, uint8_t levels) 
{
  Serial.printf("Listing directory: %s\n", dirname);

  File root = fs.open(dirname);
  if (!root) {
    Serial.println("Failed to open directory");
    return;
  }
  if (!root.isDirectory()) {
    Serial.println("Not a directory");
    return;
  }

  File file = root.openNextFile();
  while (file) {
    if (file.isDirectory()) {
      Serial.print("  DIR : ");
      Serial.println(file.name());
      if (levels) {
        listDir(fs, file.path(), levels - 1);
      }
    } else {
       Serial.print(file.name());
     }
    file = root.openNextFile();
  }
}


 void * PngClass::pngOpen(const char *filename, int32_t *size) 
{
Serial.printf("Attempting to open %s - File Size %d  \n", filename, Myfile.size());
 if (!Myfile)
 {
  Myfile =  SD.open(filename, "r");
  Serial.printf("Have to open Myfile");

 }
   *size = Myfile.size();
  return &Myfile;
}

void PngClass::pngClose(void *handle)
 {
 
  File Myfile = *((File*)handle);
  if (Myfile) Myfile.close();
}
 
int32_t PngClass::pngRead(PNGFILE *page, uint8_t *buffer, int32_t length) 
{
 
  if (!Myfile) return 0;
  page = page; // Avoid warning
  return Myfile.read(buffer, length);
}

int32_t PngClass::pngSeek(PNGFILE *page, int32_t position)
 {
  
  if (!Myfile) return 0;
  page = page; // Avoid warning
  return Myfile.seek(position);
}

//=========================================v==========================================
//                                      _pngDraw
//====================================================================================
// This next function will be called during decoding of the _png file to
// render each image line to the _tft.  If you use a different _tft library
// you will need to adapt this function to suit.
// Callback function to draw pixels to the display
void PngClass::pngDraw(PNGDRAW *pDraw)
 {
  uint16_t lineBuffer[MAX_IMAGE_WIDTH];
  //static uint16_t dmaBuffer[MAX_IMAGE_WIDTH]; // static so buffer persists after fn exit
  _png.getLineAsRGB565(pDraw, lineBuffer, PNG_RGB565_BIG_ENDIAN, 0xffffffff);
  _tft->pushImage(xpos, ypos + pDraw->y, pDraw->iWidth, 1, lineBuffer);


}


 void PngClass::DrawPng( TFT_eSPI tft, fs::FS &fs,const int x,const int y, const char * PngName)
{
      xpos = x;
      ypos = y;
      _tft = &tft;
      
      Myfile = fs.open(PngName, "r");
      int16_t rc = _png.open(PngName, pngOpen, pngClose, pngRead, pngSeek, pngDraw);
      if (rc == PNG_SUCCESS) {
   //     _tft->startWrite();
        Serial.printf("image specs: (%d x %d), %d bpp, pixel type: %d\n", _png.getWidth(), _png.getHeight(), _png.getBpp(), _png.getPixelType());
        uint32_t dt = millis();
        if (_png.getWidth() > MAX_IMAGE_WIDTH) {
          Serial.println("Image too wide for allocated lin buffer!");
        }
        else {
         
          rc = _png.decode(NULL, 0);
           Serial.printf("Decode PNG %d", rc);
          _png.close();
        }
        _tft->endWrite();
        // How long did rendering take...
        Serial.print(millis()-dt); Serial.println("ms");
      }
    }


String PngClass::readFile(fs::FS &fs, const char * path)
{
  Serial.printf("Reading file: %s\r\n", path);
  File file = fs.open(path, "r");
  if(!file || file.isDirectory()){
    Serial.println("- empty file or failed to open file");
    return String();
  }
  Serial.println("- read from file:");
  String fileContent;
  while(file.available()){
    fileContent+=String((char)file.read());
  }
  Serial.println(fileContent);
  return fileContent;
}