#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 an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// 'TCPC logo (1)', 128x64px
const unsigned char epd_bitmap_TCPC_logo__1_ [] PROGMEM = {
  // Bitmap data (truncated for brevity)
};

const int sumpPumpRelayPin = 2;
const int tankFloatSwitchInputPin = 3;
const int phLowInputPin = 4;
const int phHighInputPin = 5;
const int phUpPin = 6;
const int phDownPin = 7;
const int stirPin = 10;
const int drainPumpRelayPin = 11;

// Cycle count variable
unsigned long cycleCount = 0;

void setup() {
  Serial.begin(115200);

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.drawBitmap(0, 0, epd_bitmap_TCPC_logo__1_, 128, 64, WHITE);
  display.display();
  delay(3000); // Display logo for 3 seconds

  pinMode(sumpPumpRelayPin, OUTPUT);
  pinMode(tankFloatSwitchInputPin, INPUT);
  pinMode(phLowInputPin, INPUT);
  pinMode(phHighInputPin, INPUT);
  pinMode(phUpPin, OUTPUT);
  pinMode(phDownPin, OUTPUT);
  pinMode(stirPin, OUTPUT);
  pinMode(drainPumpRelayPin, OUTPUT);
}

void loop() {
  // Increment cycle count at the start of each loop iteration
  cycleCount++;

  // Tank fill sequence
  if (digitalRead(tankFloatSwitchInputPin) == LOW) {
    digitalWrite(sumpPumpRelayPin, HIGH);
    displayProcessAndCountdown("Filling Tank...", -1); // No countdown needed
    while (digitalRead(tankFloatSwitchInputPin) == LOW);
    digitalWrite(sumpPumpRelayPin, LOW);
  }

  // pH read sequence
  while (true) {
    if (digitalRead(phLowInputPin) == HIGH) {
      digitalWrite(phUpPin, HIGH);
      displayProcessAndCountdown("Adjusting pH Up...", 10); // 10 seconds countdown for pH adjustment
      digitalWrite(phUpPin, LOW);
    }
    if (digitalRead(phHighInputPin) == HIGH) {
      digitalWrite(phDownPin, HIGH);
      displayProcessAndCountdown("Adjusting pH Down...", 10); // 10 seconds countdown for pH adjustment
      digitalWrite(phDownPin, LOW);
    }
    if (digitalRead(tankFloatSwitchInputPin) == HIGH) {
      digitalWrite(stirPin, HIGH);
      displayProcessAndCountdown("Stirring...", 10); // 10 seconds countdown for stirring
      digitalWrite(stirPin, LOW);
    }
    if (digitalRead(phLowInputPin) == LOW && digitalRead(phHighInputPin) == LOW) break; // Exit loop if pH is within desired range
  }

  displayProcessAndCountdown("Settling Tank...", 10); // 30 minutes countdown for settling
  digitalWrite(drainPumpRelayPin, HIGH);
  displayProcessAndCountdown("Draining Tank...", 10); // Time to allow draining. Float switch will stop pump until timer runs out.
  while (digitalRead(tankFloatSwitchInputPin) == HIGH);
  digitalWrite(drainPumpRelayPin, LOW);
}

void displayProcessAndCountdown(const char* process, int seconds) {
  if (seconds >= 0) {
    for (int count = seconds; count >= 0; count--) {
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(0, 0);
      display.println(process);
      display.setCursor(0, 10);
      display.print("Time left: ");
      display.print(count);
      display.println(" sec");
      // Display the cycle count
      display.setCursor(0, 20);
      display.print("Cycle: ");
      display.println(cycleCount);
      display.display();
      delay(1000);
    }
  } else {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0, 0);
    display.println(process);
    // Display the cycle count even if no countdown is needed
    display.setCursor(0, 10);
    display.print("Cycle: ");
    display.println(cycleCount);
    display.display();
    delay(2000); // Just display the process for 2 seconds if no countdown
  }
}