// Setup for LCD screen
#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7735.h> // Hardware-specific library for ST7735
#include <avr/pgmspace.h>

#define TFT_CS    10
#define TFT_RST   6 
#define TFT_DC    7 
#define TFT_SCLK 13   
#define TFT_MOSI 11   

// Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS,  TFT_DC, TFT_RST);
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);

// Setup for PROGMEM
const char string_0[] PROGMEM = "104002013";
const char string_1[] PROGMEM = "Azelea Isip";
const char string_2[] PROGMEM = "ENG20009 Engineering Technology Inquiry Project";
const char string_3[] PROGMEM = "Semester 2, 2023";

// list of all the strings in PROGMMEM
const char *const string_table[] PROGMEM = {string_0, string_1, string_2, string_3};

char buffer[50];
int listSize = 4;

int longestStr = 0; // Var for determining which string is the longest (List index)
char comp[50], longestLength[50], displayText[50];

void setup() {
  Serial.begin(9600);

  // LCD Setup
  tft.initR(INITR_BLACKTAB);
  tft.setRotation(1);
  tft.fillScreen(ST7735_BLACK);

  // Read from PROGMEM
  for (int i = 0; i < listSize; i++) {
    /* Using the string table in program memory requires the use of special functions to retrieve the data.
     The strcpy_P function copies a string from program space to a string in RAM. */
    strcpy_P(comp, (char *)pgm_read_word(&(string_table[i])));
    strcpy_P(longestLength, (char *)pgm_read_word(&(string_table[longestStr])));
    if (strlen(comp) > strlen(longestLength)) { // Compare length of each string in the table to determine the longest one
      longestStr = i;
    }
  }
  strcpy_P(longestLength, (char *)pgm_read_word(&(string_table[longestStr])));
}

int x = 0, y = 10, dw = 3;
void loop()
{
  int16_t x1, y1, wid = tft.width();
  uint16_t w, h; // Width and height of boundary of longest string

  tft.setTextColor(ST7735_WHITE, ST7735_BLACK);
  tft.setTextWrap(false);
  tft.getTextBounds(longestLength, x, y, &x1, &y1, &w, &h); // Helper to determine size of a string (longestLength) with current font/size, returns boundary W H

  // Scroll the text
  for (int steps = wid + w; steps >= 0; steps -= dw) {
    for (int i = 0; i < listSize; i++) {
      strcpy_P(displayText, (char *)pgm_read_word(&(string_table[i])));
      x = steps - w;
      x -= dw;
      tft.setCursor(x, y+10*i);
      tft.print(displayText);
      tft.print("  ");
    }
  }
}