#include <SD.h>
#include <ezButton.h>

File file;
int book_num=0;
int book_state=0;
int prev_book_num = -1;

ezButton next(2);
ezButton prev(3);
ezButton select_book(4);
ezButton open_book(5);

void setup(){

  Serial.begin(9600);
  SD.begin();

  next.setDebounceTime(50);
  prev.setDebounceTime(50);
  select_book.setDebounceTime(50);
  open_book.setDebounceTime(50);

  /*
  file=SD.open("harry.txt",FILE_READ);
  Serial.println("Total characters: ");
  Serial.println(file.size());

  if(file){
    Serial.println("HARRY POTTER");
    delay(2000);
    while(file.available()){
      char data=file.read();
      Serial.print(data);
    }
    Serial.println();
    file.close();
  }
  Serial.println("File read successfully !!");
  */
}


void loop(){

  next.loop();
  prev.loop();
  select_book.loop();
  open_book.loop();
  
  if(next.isPressed()){
    book_num++;
  }
  else if(prev.isPressed()){
    book_num--;
  }
  else if(select_book.isPressed()){
    book_state=0;
    prev_book_num=-1;
  }
  else if(open_book.isPressed()){
    book_state=1;
  }

  book_num=constrain(book_num,0,1);
  check_book();
  read_book();
  delay(10);
}

void check_book(){
  if(prev_book_num!=book_num){
    prev_book_num=book_num;
    if(book_num){
      Serial.print("Think and Grow Rich");
    }
    else{
      Serial.print("Harry Potter");
    }
  }
}

void read_book(){
  if(book_state){
    if(book_num){
      file=SD.open("think.txt",FILE_READ);
    }
    else{
      file=SD.open("harry.txt",FILE_READ);
    }
    String display_text="";
    if(file){
      while(file.available()){
        char data=file.read();
        Serial.print(data);
      }
    }
  }
  file.close();
}