#include <SD.h>

#define CS_PIN 10
File textFile;
File root;
uint32_t find(const char *target) {
  return findUntil(target, (char*) "");
}
uint32_t find(const char *target, size_t length) {
  return findUntil(target, length, NULL, 0);
}
uint32_t findUntil(const char *target, const char *terminator) {
  return findUntil(target, strlen(target), terminator, strlen(terminator));
}

uint32_t findUntil(const char *target, size_t targetLen, const char *terminator, size_t termLen) {
  size_t index = 0;  // maximum target string length is 64k bytes!
  size_t termIndex = 0;
  int c;
  uint32_t pos = 0;
  if (*target == 0)
    return 1;   // return true if target is a null string
  while ((c = timedRead()) > 0) {
    pos++;
    if (c != (unsigned char)target[index])
      index = 0; // reset index if any char does not match

    if (c == (unsigned char)target[index]) {
      //////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1);
      if (++index >= targetLen) { // return true if all chars in the target match
        return pos - targetLen;
      }
    }

    if (termLen > 0 && c == terminator[termIndex]) {
      if (++termIndex >= termLen)
        return 0;       // return false if terminate string found before target string
    } else
      termIndex = 0;
  }
  return 0;
}
int timedRead() {
  int c;
  unsigned long _startMillis;
  unsigned long _timeout = 1000;
  _startMillis = millis();
  do {
    c = textFile.read();
    if (c >= 0)
      return c;
    if (_timeout == 0)
      return -1;
    yield();
  } while (millis() - _startMillis < _timeout);
  return -1;     // -1 indicates timeout
}
void setup() {
  Serial.begin(115200);

  Serial.print("Initializing SD card... ");

  if (!SD.begin(CS_PIN)) {
    Serial.println("Card initialization failed!");
    while (true);
  }

  Serial.println("initialization done.");

  Serial.println("Files in the card:");
  root = SD.open("/");
  printDirectory(root, 0);
  Serial.println("");

  // Example of reading file from the card:

}

void loop() {
  if (Serial.available()) {
    String str = Serial.readStringUntil('\n');
    Serial.println(str.length());
    textFile = SD.open("wokwi.txt");
    if (textFile) {
      Serial.println("wokwi.txt: ");
      char charr[10];
      str.toCharArray(charr, 10);
      bool found = false;
      //int i = 0;
      while (!found) {
        find("p=\"");
        str = textFile.readStringUntil('&');
        //Serial.println(str);
        found = findUntil(charr, "lable");
      }
      //found = textFile.find(charr);
      Serial.println(str);
      textFile.close();
    } else {
      Serial.println("error opening wokwi.txt!");
    }
  }
}

void printDirectory(File dir, int numTabs) {
  while (true) {

    File entry =  dir.openNextFile();
    if (! entry) {
      // no more files
      break;
    }
    for (uint8_t i = 0; i < numTabs; i++) {
      Serial.print('\t');
    }
    Serial.print(entry.name());
    if (entry.isDirectory()) {
      Serial.println("/");
      printDirectory(entry, numTabs + 1);
    } else {
      // files have sizes, directories do not
      Serial.print("\t\t");
      Serial.println(entry.size(), DEC);
    }
    entry.close();
  }
}