/*-------------------------------------------------------
  DISTINCTION TASK QUESTION2
  STUDENT ID:103495874
  SARAH SALEEM
  -----------------------------------------------------------
*/

//left to right 13 - 6 column connetion
//top to bottom  22 - 29 row connection
#include"Text.h"
#include <EEPROM.h>
int index_words[31];//stores the indexes to which the alphabets of the word corresponds to in the 3-d array defined in the library "Text.h"
int length_word;//will store the lenth of the string that needs to be printed
//int library_display
int scroll_speed = 1900; //controls the speed of scrolling
String Word;//word that needs to be displayed
int button = 18;
volatile unsigned int start, stop; //to store the millis() values for the instant when the button was pushed and when it was released
volatile float time; //to store the time for which the button was pressed
volatile int lastState = HIGH;
volatile bool time_flag;
bool rightToLeft, LeftToRight;
void setup() {

  Serial.begin(9600);


  //if anything has been previously written in the memory the 0 of eeprom will be 9
  if (EEPROM.read(0) == 9) {
    //will go to the function to read the data from the eeprom
    read_fromEEPROM();
  }
  else { //if nothing has been written the code will be prompted to the read_and_store function
    read_and_store();

  }
  for (int i = 6; i < 14; i++) { //setting pin modes for left to right connection
    pinMode(i, OUTPUT);
    digitalWrite(i, HIGH);
  }
  for (int i = 22; i < 30; i++) { //setting pin mode for top to bottom connection
    pinMode(i, OUTPUT);
    digitalWrite(i, LOW);
  }
  pinMode(button, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(button), timer, CHANGE);
  //Serial.println("start");
  Serial.println(">Push the button for more than 3 seconds to make the text scroll from Right to Left");
  Serial.println(">Push the button for less than 3 seconds to make the text scroll from Left to Right");


  //delay(1000);
}
void loop() {
  //using time_flag to make sure that for one button press option_select function is triggered just once
  if (time_flag == 1) {
    option_select(time);
  }
  time_flag = 0;

  if (rightToLeft == 1)
  {
    Scroll_right_to_left();
  }
  else if (LeftToRight == 1)
  {
    Scroll_left_to_right();
  }


}

void timer() { //this function finds out the time for which the buton has been pressed
  int value = digitalRead(button);
  if (lastState != value) {
    lastState = value;
    if (value == LOW) {
      start = millis();
      Serial.println("pressed");
    }
    else if (value == HIGH) {
      Serial.println("released");
      stop = millis();
      time = (stop - start) / 1000.f;
      Serial.println("time");
      Serial.println(time);
      time_flag = 1;
    }
  }
}
void option_select(int time) {

  if (time >= 3) {
    //if the time for which the button was pressed is more than 3 seconds then right to left scrolling will be enabled
    rightToLeft = 1;
    LeftToRight = 0;
  }
  else if (time < 3) {
    //if the time for which the button was pressed is less than 3 seconds then left to right scrolling will be enabled
    LeftToRight = 1;
    rightToLeft = 0;
  }

}


//this function will read the text from the serial and store it in eeprom
void read_and_store() {
  //Serial.begin(9600);
  Serial.flush();
  Serial.println("Enter the text that you want to display:");

  while (Serial.available() == 0) {} //waits for data available
  Word = Serial.readString();
  Serial.print("the word"); Serial.println(Word);
  length_word = Word.length() - 1; //length of the word that needs to be displayed
  // one is being subtracted because .readString adds an extra space at the end which is identified as a character

  Serial.println("length of word");
  Serial.println(length_word);

  index_words[0] = length_word; //storing the length in the zeroth index of this array

  Serial.print("index zero: ");
  Serial.println(index_words[0]);

  for (int a = 1; a <= length_word; a++) { //storing the indexes to which the alphabets of the word corresponds to in the 3-d array defined in the library "Text.h"
    index_words[a] = alpha_toindex(Word.charAt(a - 1));
    Serial.println(index_words[a]);
  }
  //Now writing to eeprom
  EEPROM.write(0, 9); //writing 9 to the zero of eeprom, so that later on we can verify that something was written to the memory
  EEPROM.write(1, length_word);


  for (int a = 1; a <= length_word; a++) { //writing to eeprom the elements of the array index words

    EEPROM.write(a + 1, index_words[a]);
    //Serial.println(EEPROM.read(a+1));
  }
}
//This function will read from the eeprom
void read_fromEEPROM() {
  length_word = EEPROM.read(1);
  for (int a = 0; a <= length_word; a++) {
    index_words[a] = EEPROM.read(a + 1);
    Serial.println(index_words[a]);
  }

}


void Scroll_left_to_right() {
  int e;
  int ii;
  for (int i = length_word; i > 0; i--) {
    ii = index_words[i];
    if (i == length_word) { //loops inside this if will create an effect of scrolling in of the last alphabet from left to right
      for (int f = 7; f >= 1; f--) {
        //when f=7 led matrix displays the last column of the last alphabet of the string in the first column of the matrix
        //when f=6 led matrix displays the last 2 columns of the last alphabet of the string in the first and second column of matrix and so on
        //when f=5 led matrix displays the last 3 columns of the last alphabet of the string
        //when f=4 led matrix displays the last 4 columns of the last alphabet of the string
        //when f=3 led matrix displays the last 5 columns of the last alphabet of the string
        //when f=2 led matrix displays the last 6 columns of the last alphabet of the string
        //when f=1 led matrix displays the last 7 columns of the last alphabet of the string
        for (int time = 0; time < scroll_speed; time++) {
          for (int j = 7; j >= f; j--) {
            digitalWrite(22, library_display[ii][0][j]) ;
            digitalWrite(23, library_display[ii][1][j]);
            digitalWrite(24, library_display[ii][2][j]);
            digitalWrite(25, library_display[ii][3][j]);
            digitalWrite(26, library_display[ii][4][j]);
            digitalWrite(27, library_display[ii][5][j]);
            digitalWrite(28, library_display[ii][6][j]);
            /*
              for example
              for f=7 j=7 we want column number 1 of the led matrix to be On
              which is pin number 6 so (6+j-f)=(6+7-7)=6
            */
            digitalWrite((6 + j - f), LOW);
            digitalWrite((6 + j - f), HIGH);

          }
        }
      }

    }


    for (int time = 0; time < scroll_speed; time++) {
      for (int j = 7; j >= 0; j--) { //displays the alphabet in full form
        digitalWrite(22, library_display[ii][0][j]);
        digitalWrite(23, library_display[ii][1][j]);
        digitalWrite(24, library_display[ii][2][j]);
        digitalWrite(25, library_display[ii][3][j]);
        digitalWrite(26, library_display[ii][4][j]);
        digitalWrite(27, library_display[ii][5][j]);
        digitalWrite(28, library_display[ii][6][j]);

        digitalWrite((6 + j), LOW);
        digitalWrite((6 + j), HIGH);

      }
    }
    if (i - 1 >= 1) { //this will check if there is an alphabet in the user entered string before the current one

      for (int f = 1; f <= 7; f++) {
        //the for loops below this will create a scrolling effect by changing the columns of the alphabets that are being displayed
        for (int time = 0; time < scroll_speed; time++) { //displays first column of of current alphabet and last 7 column of next alphabet

          for (int j = 7; j >= 0; j--) {
            e = j - f;
            //when f=1 then led matrix displays last column of the alphabet that needs to be printed next and first 7 column of current alphabet
            //when f=2 then led matrix displays last 2 column of the alphabet that needs to be printed next and first 6 columns of current alphabet
            //when f=3 then led matrix displays last 3 column of the alphabet that needs to be printed next and first 5 columns of current alphabet
            //when f=4 then led matrix displays last 4 column of the alphabet that needs to be printed next and first 4 columns of current alphabet
            //when f=5 then led matrix displays last 5 column of the alphabet that needs to be printed next and first 3 columns of current alphabet
            //when f=6 then led matrix displays last 6 column of the alphabet that needs to be printed next and first 2 columns of current alphabet
            //when f=7 then led matrix displays last 7 column of the alphabet that needs to be printed next and first 1 column of current alphabet
            if (e == -1) {
              e = 7;
              ii = index_words[i - 1];
            }
            else if (e == -2) {
              e = 6;
              ii = index_words[i - 1];
            }
            else if (e == -3) {
              e = 5;
              ii = index_words[i - 1];
            }
            else if (e == -4) {
              e = 4;
              ii = index_words[i - 1];
            }
            else if (e == -5) {
              e = 3;
              ii = index_words[i - 1];
            }
            else if (e == -6) {
              e = 2;
              ii = index_words[i - 1];
            }
            else if (e == -7) {
              e = 1;
              ii = index_words[i - 1];
            }

            digitalWrite(22, library_display[ii][0][e]) ;
            digitalWrite(23, library_display[ii][1][e]);
            digitalWrite(24, library_display[ii][2][e]);
            digitalWrite(25, library_display[ii][3][e]);
            digitalWrite(26, library_display[ii][4][e]);
            digitalWrite(27, library_display[ii][5][e]);
            digitalWrite(28, library_display[ii][6][e]);

            digitalWrite((6 + j), LOW);
            digitalWrite((6 + j), HIGH);

          }
          ii = index_words[i];
        }
      }

    }
    else { //if the current alphabet is the first alphabet of the string or the last alphabet that needs to be printed

      for (int f = 6; f >= 0; f--) {
        //when f=6 column 1 till column 7 of the last alphabet will be printed
        //when f=5 column 1 till column 6 of the last alphabet will be printed
        //when f=4 column 1 till column 5 of the last alphabet will be printed
        //when f=3 column 1 till column 4 of the last alphabet will be printed
        //when f=2 column 1 till column 3 of the last alphabet will be printed
        //when f=1 column 1 till column 2 of the last alphabet will be printed
        //when f=0 the first column of last alphabet will be printed

        for (int time = 0; time < scroll_speed; time++) {
          for (int j = f; j >= 0; j--) {
            digitalWrite(22, library_display[ii][0][j]) ;
            digitalWrite(23, library_display[ii][1][j]);
            digitalWrite(24, library_display[ii][2][j]);
            digitalWrite(25, library_display[ii][3][j]);
            digitalWrite(26, library_display[ii][4][j]);
            digitalWrite(27, library_display[ii][5][j]);
            digitalWrite(28, library_display[ii][6][j]);
            /* for eample for f=6 we want j=6(the 7th column) to be printed
              on the 8th column of the led matrix i.e pin13(6+j+7-f)=(6+6+7-6)=13
              Similar pattern is followed for others*/
            digitalWrite((6 + j + 7 - f), LOW);
            digitalWrite((6 + j + 7 - f), HIGH);
          }
        }

      }


    }//of else



  }//of the for loop that changes alphabet
}//of function Scroll left_to_right

void Scroll_right_to_left() {
  int e;
  int ii;

  for (int i = 1; i <= length_word; i++) {
    ii = index_words[i];
    if (i == 1) { //loops inside this if will create an effect of scrolling in of the first alphabet from right to left
      for (int f = 1; f <= 7; f++) {
        //when f=1 first column of the first alphabet will be displayed in the right most column of led
        //when f=2 first 2 column of the first alphabet will be displayed in the right most column of led
        //when f=3 first 3 column of the first alphabet will be displayed in the right most column of led
        //when f=4 first 4 column of the first alphabet will be displayed in the right most column of led
        //when f=5 first 5 column of the first alphabet will be displayed in the right most column of led
        //when f=6 first 6 column of the first alphabet will be displayed in the right most column of led
        //when f=7 first 7 column of the first alphabet will be displayed in the right most column of led

        for (int time = 0; time < scroll_speed; time++) {
          for (int j = 0; j < f; j++) {
            digitalWrite(22, library_display[ii][0][j]) ;
            digitalWrite(23, library_display[ii][1][j]);
            digitalWrite(24, library_display[ii][2][j]);
            digitalWrite(25, library_display[ii][3][j]);
            digitalWrite(26, library_display[ii][4][j]);
            digitalWrite(27, library_display[ii][5][j]);
            digitalWrite(28, library_display[ii][6][j]);

            /*For example for f=5 we want j=0 to be printed on
              the column number 4 i.e.pin9
              so (6+j+8-f)=(6+0+8-5)=9
            */
            digitalWrite((6 + j + 8 - f), LOW);
            digitalWrite((6 + j + 8 - f), HIGH);

          }
        }
      }
    }


    for (int time = 0; time < scroll_speed; time++) {
      for (int j = 0; j < 8; j++) { //displays the alphabet in full form
        digitalWrite(22, library_display[ii][0][j]) ;
        digitalWrite(23, library_display[ii][1][j]);
        digitalWrite(24, library_display[ii][2][j]);
        digitalWrite(25, library_display[ii][3][j]);
        digitalWrite(26, library_display[ii][4][j]);
        digitalWrite(27, library_display[ii][5][j]);
        digitalWrite(28, library_display[ii][6][j]);

        digitalWrite((6 + j), LOW);
        digitalWrite((6 + j), HIGH);

      }
    }
    if (i + 1 <= length_word) { //this will check if there is an alphabet in the user entered string after the current one
      //the for loops below this will create a scrolling effect by changing the columns of the alphabets that are being displayed

      for (int f = 1; f < 8; f++) {
        for (int time = 0; time < scroll_speed; time++) {
          for (int j = 0; j < 8; j++) {
            e = j + f;
            // when f=1 then led matrix displays last 7 columns of of current alphabet and 1st column of next alphabet
            //when f=2 the led matrix displays last 6 columns of of current alphabet and 1st and 2nd column of next alphabet
            //when f=3 then led matrix displays last 5 columns of of current alphabet and first 3 column of next alphabet
            //when f=4 led matrix displays last 4 columns of of current alphabet and first 4 column of next alphabet
            //when f=5 led matrix displays last 3 columns of of current alphabet and first 5 column of next alphabet
            //when f=6 displays last 2 columns of of current alphabet and first 6 column of next alphabet
            //when f=7 then led matrix displays last column of of current alphabet and first 7 column of next alphabet
            if (e == 8) {
              e = 0;
              ii = index_words[i + 1];
            }
            else if (e == 9) {
              e = 1;
              ii = index_words[i + 1];
            }
            else if (e == 10) {
              e = 2;
              ii = index_words[i + 1];
            }
            else if (e == 11) {
              e = 3;
              ii = index_words[i + 1];
            }
            else if (e == 12) {
              e = 4;
              ii = index_words[i + 1];
            }
            else if (e == 13) {
              e = 5;
              ii = index_words[i + 1];
            }
            else if (e == 14) {
              e = 6;
              ii = index_words[i + 1];
            }

            digitalWrite(22, library_display[ii][0][e]) ;
            digitalWrite(23, library_display[ii][1][e]);
            digitalWrite(24, library_display[ii][2][e]);
            digitalWrite(25, library_display[ii][3][e]);
            digitalWrite(26, library_display[ii][4][e]);
            digitalWrite(27, library_display[ii][5][e]);
            digitalWrite(28, library_display[ii][6][e]);

            digitalWrite((6 + j), LOW);
            digitalWrite((6 + j), HIGH);

          }
          ii = index_words[i];
        }

      }

    }
    else { //if the current alphabet is the last one then it will scroll out

      for (int f = 6; f >= 0; f--) {
        //when f=6 the last alphabet will be printed from the 2nd column
        //when f=5 the last alphabet will be printed from the 3rd column
        //when f=4 the last alphabet will be printed from the 4th column
        //when f=3 the last alphabet will be printed from the 5th column
        //when f=2 the last alphabet will be printed from the 6th column
        //when f=1 the last alphabet will be printed from the 7th column
        //when f=0 the last column of the last alphabet will be printed

        for (int time = 0; time < scroll_speed; time++) {
          for (int j = 0; j < f; j++) {
            /*for example when f=6 then for j=0 [j+7-f]=1 and when j=f=6 [j+7-f]=7
              so this means the alphabet will start printing from its 2nd column(index 1)
              and will print till its last column(index 7)
              similar pattern will be followed as the value of f changes */
            digitalWrite(22, library_display[ii][0][j + 7 - f]) ;
            digitalWrite(23, library_display[ii][1][j + 7 - f]);
            digitalWrite(24, library_display[ii][2][j + 7 - f]);
            digitalWrite(25, library_display[ii][3][j + 7 - f]);
            digitalWrite(26, library_display[ii][4][j + 7 - f]);
            digitalWrite(27, library_display[ii][5][j + 7 - f]);
            digitalWrite(28, library_display[ii][6][j + 7 - f]);

            digitalWrite((6 + j), LOW);
            digitalWrite((6 + j), HIGH);
          }
        }
      }
    }//of else

  }//of the for loop that changes alphabet
}