#include <SPI.h>
#include <SD.h>

const int chipSelect = 10;
String userInput = "";

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // Wait for Serial Monitor
  }

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

  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present.");
    return;
  }
  Serial.println("Card initialized.");
  Serial.println("Enter text to save to SD card:");
}

void loop() {
  // Wait for user input
  if (Serial.available()) {
    userInput = Serial.readStringUntil('\n');
    userInput.trim(); // Remove leading/trailing whitespace

    if (userInput.length() > 0) {
      // Append input to SD card file
      File dataFile = SD.open("log.txt", FILE_WRITE);
      if (dataFile) {
        dataFile.println(userInput);
        dataFile.close();
        Serial.println("Data saved to log.txt");
      } else {
        Serial.println("Error opening log.txt for writing.");
      }

      // Read and display entire file content
      dataFile = SD.open("log.txt");
      if (dataFile) {
        Serial.println("Contents of log.txt:");
        while (dataFile.available()) {
          Serial.write(dataFile.read());
        }
        dataFile.close();
      } else {
        Serial.println("Error opening log.txt for reading.");
      }

      Serial.println("\nEnter more text to save:");
    }
  }
}





/*
#include <SPI.h>
#include <SD.h>

const int chipSelect = 10; // CS pin for SD card module

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // Wait for Serial Monitor to open
  }

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

  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present.");
    return;
  }
  Serial.println("Card initialized.");

  // Write to file
  File dataFile = SD.open("test.txt", FILE_WRITE);
  if (dataFile) {
    dataFile.println("Hello from Wokwi!");
    dataFile.close();
    Serial.println("Data written to test.txt");
  } else {
    Serial.println("Error opening test.txt for writing.");
  }

  // Read from file
  dataFile = SD.open("test.txt");
  if (dataFile) {
    Serial.println("Reading test.txt:");
    while (dataFile.available()) {
      Serial.write(dataFile.read());
    }
    dataFile.close();
  } else {
    Serial.println("Error opening test.txt for reading.");
  }
}

void loop() {
  // Nothing here
}
*/