/*

  Forum: https://forum.arduino.cc/t/code-check-please/1240893/2
  (first Version Wokwi: https://wokwi.com/projects/393602101966308353)
  Wokwi: https://wokwi.com/projects/395791344414641153

  Sketch from TO at 2024/03/28
  Modified by ec2021 at 2024/03/28 and again at 2024/04/21

*/
// C++ code


enum States {UNKNOWN, LEVELLOW, LEVELNORMAL, LEVELHIGH};
States state     = LEVELNORMAL;
States lastState = UNKNOWN;

const unsigned long waitBeforePumpTwo =  4000; //30000;
const byte PUMP1_PIN = 9;
const byte PUMP2_PIN = 8;
const byte LOW_LEVEL_PIN = 5;
const byte HIGH_LEVEL_PIN = 4;
int PrimaryPump = 0; // Assuming 0 for Pump 1, 1 for Pump 2 (can be modified in loop)
const byte HIGH_LED_PIN = 7;
const byte LOW_LED_PIN = 6;
const byte ALARM_PIN = 12;

int primaryPumpPin;
int secondaryPumpPin;
boolean flashRed = false;
boolean secondPumpOn = false;
unsigned long levelHighStartTime;

void setup() {
  Serial.begin(115200);
  pinMode(PUMP1_PIN, OUTPUT);    // Pump 1 Output;
  pinMode(PUMP2_PIN, OUTPUT);    // Pump 2 Output;
  pinMode(HIGH_LED_PIN, OUTPUT);  // Red LED to indicate high water level;
  pinMode(LOW_LED_PIN, OUTPUT);   // Green LED to indicate Low water level;
  pinMode(ALARM_PIN, OUTPUT);    // Alarm buzzer
  pinMode(LOW_LEVEL_PIN, INPUT_PULLUP); // Low level switch pin goes here
  pinMode(HIGH_LEVEL_PIN, INPUT_PULLUP);  // High level switch pin goes here

  // Set pump pins based on PrimaryPump (can be adjusted in loop if needed)
  primaryPumpPin = PrimaryPump == 0 ? PUMP1_PIN : PUMP2_PIN;
  secondaryPumpPin = PrimaryPump == 0 ? PUMP2_PIN : PUMP1_PIN;
}

void loop() {
  checkLevel();
  stateMachine();
  flashRedLed();
}

void checkLevel() {
  boolean lowLevel  = !digitalRead(LOW_LEVEL_PIN);
  boolean highLevel = !digitalRead(HIGH_LEVEL_PIN);
  delay(30);// Simple debouncing ...
  if (lowLevel) {
    state = LEVELLOW;
  }
  if (highLevel) {
    state = LEVELHIGH;
  }
  // The next states are not simulated in Wokwi but
  // could be possible with a real limit switch
  if (!lowLevel && !highLevel) {
     state = LEVELNORMAL;
  }
  if (lowLevel && highLevel) {
     Serial.println("Sensor defect -> Error!!");
  }
}

void stateMachine() {
  switch (state) {
    case LEVELLOW:
      lowLevel();
      break;
    case LEVELNORMAL:
      normalLevel();
      break;
    case LEVELHIGH:
      highLevel();
      break;
  }
}

void lowLevel() {
  if (lastState != LEVELLOW) {
    Serial.println("LOW");
    flashRed = false;
    digitalWrite(ALARM_PIN, LOW);  // Alarm Off
    digitalWrite(LOW_LED_PIN, HIGH); // Green LED ON
    digitalWrite(HIGH_LED_PIN, LOW); // Red LED Off
    digitalWrite(primaryPumpPin, LOW); // Stop Pump (assuming any pump was running)
    digitalWrite(secondaryPumpPin, LOW);
    // Now we exchange the pumpPins for the next cycle
    byte tempPin = primaryPumpPin;
    primaryPumpPin = secondaryPumpPin;
    secondaryPumpPin = tempPin; 
    secondPumpOn = false;
    lastState = state;
  }
}

void normalLevel() {
  // Normal Level - Turn off LEDs and Alarm
  if (lastState != LEVELNORMAL) {
    Serial.println("NORMAL");
    flashRed = false;
    digitalWrite(ALARM_PIN, LOW);  // Alarm Off
    digitalWrite(LOW_LED_PIN, LOW); // Green LED Off
    digitalWrite(HIGH_LED_PIN, LOW); // Red LED Off
    lastState = state;
  }
}

void highLevel() {
  // High Level Detected - Red LED ON and activate Pump sequence
  if (lastState != LEVELHIGH) {
    Serial.println("HIGH");
    flashRed = false;
    digitalWrite(ALARM_PIN, HIGH);  // Alarm On
    digitalWrite(LOW_LED_PIN, LOW); // Green LED Off
    digitalWrite(HIGH_LED_PIN, HIGH); // Red LED On
    digitalWrite(primaryPumpPin, HIGH);  // Start Pump 1
    levelHighStartTime = millis();  // Store the start time of LEVELHIGH here
    lastState = state;
  }
  // Check if waitBeforePumpTwo has expired after start of the first pump
  // If it has expired and pump 2 is off switch it on
  if (millis() - levelHighStartTime >= waitBeforePumpTwo && !secondPumpOn) {
    startSecondPump();
  }
  // The following part is not required but nice for this demo ...
  static unsigned long lastPrint = 0;
  if (millis() - lastPrint >= 1000 && !secondPumpOn) {
    lastPrint = millis();
    Serial.print(".");
  }
}

void startSecondPump() {
  // and flash Red Led
  Serial.println("Start Second Pump");
  flashRed = true;
  secondPumpOn = true;
  digitalWrite(ALARM_PIN, HIGH);
  digitalWrite(secondaryPumpPin, HIGH); // Start Pump 2
}

void flashRedLed() {
  static unsigned long lastChange = 0;
  static byte ledState = HIGH;
  if (!flashRed) {
    return;
  }
  if (millis() - lastChange > 300) {
    lastChange = millis();
    digitalWrite(HIGH_LED_PIN, ledState);
    ledState = !ledState;
  }
}