/*
  This code initializes an OLED display (SSD1306) using the Adafruit SSD1306 library, 
  and displays various text, numbers, and scroll animations on the screen.

  Board: ESP32 Development Board
  Component: OLED (SSD1306)
  Library: https://github.com/adafruit/Adafruit_SSD1306 (Adafruit SSD1306 by Adafruit)  
           https://github.com/adafruit/Adafruit-GFX-Library (Adafruit GFX Library by Adafruit) 
*/

/*
To do
Add segments on the screen for timer and face and other functions
So different functions can only change part of the screen 
*/

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128  // OLED display width, in pixels
#define SCREEN_HEIGHT 64  // OLED display height, in pixels

// Declaration for SSD1306 display connected using I2C
#define OLED_RESET -1  // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
#define buttonPullup 19
long currentTime = 0;
bool startStopTimer = false;
long referenceTime;
long referenceTimeForDisplay;
int cursorPosition[][2] = 
{
  {0,0},
  {51,57},
  {102,57}
};

// Include the libraries we need
#include <OneWire.h>
#include <DallasTemperature.h>

// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS 2

// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);

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

  // initialize the OLED object
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;)
      ;
  }
  pinMode(buttonPullup, INPUT_PULLUP);
  // Clear the buffer.
  display.setTextSize(1);
  display.clearDisplay();
  display.setTextColor(WHITE);  // Set text color
  display.setCursor(cursorPosition[0][0],cursorPosition[0][1]);
  sensors.begin();
  }
  /*// Display Text
  display.setTextSize(1);       // Set text size
  display.setTextColor(WHITE);  // Set text color
  display.setCursor(0, 28);     // Set cursor position
  display.println("Hello world!");
  display.display();  // Display the content on the screen
  delay(2000);
  display.clearDisplay();  // Clear the screen

  // Display Inverted Text
  display.setTextColor(BLACK, WHITE);  // 'inverted' text
  display.setCursor(0, 28);
  display.println("Hello world!");
  display.display();
  delay(2000);
  display.clearDisplay();

  // Changing Font Size
  display.setTextColor(WHITE);
  display.setCursor(0, 24);
  display.setTextSize(2);
  display.println("Hello!");
  display.display();
  delay(2000);
  display.clearDisplay();

  // Display Numbers
  display.setTextSize(1);
  display.setCursor(0, 28);
  display.println(123456789);
  display.display();
  delay(2000);
  display.clearDisplay();

  // Display ASCII Characters
  display.setCursor(0, 24);
  display.setTextSize(2);
  for (int i = 1; i < 8; i++) {
    display.write(i);
  }
  display.display();
  delay(2000);
  display.clearDisplay();

  // Scroll full screen
  display.setCursor(0, 0);
  display.setTextSize(1);
  display.println("Full");
  display.println("screen");
  display.println("scrolling!");
  display.display();
  display.startscrollright(0x00, 0x07);  // Scroll the screen to the right
  delay(5000);
  display.stopscroll();
  delay(1000);
  display.startscrollleft(0x00, 0x07);  // Scroll the screen to the left
  delay(5000);
  display.stopscroll();
  delay(1000);
  display.clearDisplay();

  // Scroll part of the screen
  display.setCursor(0, 0);
  display.setTextSize(1);
  display.println("Scroll");
  display.println("some part");
  display.println("of the screen.");
  display.display();
  display.startscrollright(0x00, 0x00);  // Scroll the first column of the screen to the right
  delay(4000);
  display.stopscroll();
  display.clearDisplay();

  // Display bitmap
  display.drawBitmap(32, 0, sunfounderIcon, 64, 64, WHITE);
  display.display();*/
void functionToSetTeCursor(int arrayNumber)
{
  display.setCursor(cursorPosition[arrayNumber][0],cursorPosition[arrayNumber][1]);
}
void DisplayTemperature()
{
  sensors.requestTemperatures(); // Send the command to get temperatures
  //Serial.println("DONE");
  // After we got the temperatures, we can print them here.
  // We use the function ByIndex, and as an example get the temperature from the first sensor only.
  float tempC = sensors.getTempCByIndex(0);
  //display.setCursor(102, 57);
  //functionToSetTeCursor(2);
  // Check if reading was successful
  if(tempC != DEVICE_DISCONNECTED_C) 
  {
    //Serial.print("Temperature for the device 1 (index 0) is: ");
    //Serial.println(tempC);
    display.print((int)tempC);
    //display.print("°C");

  } 
  else
  {
    //Serial.println("Error: Could not read temperature data");
    display.print("0000");
  }
}
void StartTimer()
{
  startStopTimer = !startStopTimer;
  if(startStopTimer)
  {
    referenceTime = millis();
    referenceTimeForDisplay = (referenceTime + 900000) - millis();
  }
  else
  {
    display.clearDisplay();
    display.display();
  }
  
}
void DisplayTimer()
{
 
  //long displayNumber = (referenceTime + 900000) - millis();
  //display.setTextSize(1);
  //display.setCursor(51, 57);
  //functionToSetTeCursor(1);
  //display.println(displayNumber);
 /* int minutes = (displayNumber/60000);
  int seconds = (displayNumber % 60000);*/
  //int minutes = map(displayNumber, referenceTimeForDisplay, 0, 15, 0);
  //float seconds = (displayNumber % 60000);
  //seconds = map(seconds, (displayNumber- minutes*1500), 0, 60, 0);
  int seconds = 900000 - (millis()-referenceTime);
  seconds = seconds/1000;
  int minutes = seconds/60;
  minutes = (int)minutes;
  seconds = seconds - (minutes*60);
  display.print(minutes);
  display.print(":");
  display.print(seconds);

  
}

void makeScreenAppear()
{
  display.clearDisplay();
  functionToSetTeCursor(0);
  functionToSetTeCursor(1);
   if(startStopTimer)
  {
    DisplayTimer();
  }
  functionToSetTeCursor(2);
  DisplayTemperature();
  display.display();
}

void loop() {
  if(digitalRead(buttonPullup)==0)
  {
    while((digitalRead(buttonPullup)==0)){}
    delay(50);
    //Serial.println("It works");
    StartTimer();
  }
   //display.clearDisplay();
  makeScreenAppear();
  
    //display.display();
  delay(100);
}