#include <Arduino.h>

const uint8_t N = 5;
const uint8_t PIN_PUMP[N]  = {4, 5, 6, 7, 8};
const uint8_t PIN_VALVE[N] = {9, 10, 11, 12, 13};
const uint8_t PIN_FLOW[N]  = {A0, A1, A2, A3, A4};

const uint8_t PIN_BTN_START = 2;
const uint8_t PIN_BTN_STOP  = 3;

uint32_t Vi_set[N] = {5, 3, 4, 2, 6};
uint32_t Vi_cur[N] = {0, 0, 0, 0, 0};

bool flowLast[N] = {false, false, false, false, false};
uint32_t flowLastEdgeMs[N] = {0, 0, 0, 0, 0};
const uint16_t FLOW_DEBOUNCE_MS = 30;

enum State { IDLE, DOSING, DONE, ABORT };
State state = IDLE;

bool readButton(uint8_t pin) {
  return digitalRead(pin) == LOW;
}

void setOutputs(bool pumpOn[N], bool valveOn[N]) {
  for (uint8_t i = 0; i < N; i++) {
    digitalWrite(PIN_PUMP[i], pumpOn[i] ? HIGH : LOW);
    digitalWrite(PIN_VALVE[i], valveOn[i] ? HIGH : LOW);
  }
}

bool allDone() {
  for (uint8_t i = 0; i < N; i++) {
    if (Vi_set[i] > 0 && Vi_cur[i] < Vi_set[i]) return false;
  }
  return true;
}

void flowPollAndCount() {
  for (uint8_t i = 0; i < N; i++) {
    bool now = digitalRead(PIN_FLOW[i]);
    bool prev = flowLast[i];
    flowLast[i] = now;
    if (!prev && now) {
      if (Vi_set[i] == 0) continue;
      uint32_t t = millis();
      if (t - flowLastEdgeMs[i] < FLOW_DEBOUNCE_MS) continue;
      flowLastEdgeMs[i] = t;

      uint32_t cur = Vi_cur[i];
      if (cur < Vi_set[i]) {
        cur++;
        if (cur > Vi_set[i]) cur = Vi_set[i];
        Vi_cur[i] = cur;
      }
    }
  }
}

void applyState(State newState) {
  state = newState;
  bool pumpOff[N] = {false,false,false,false,false};
  bool valveOff[N] = {false,false,false,false,false};

  switch (state) {
    case IDLE:
      for (uint8_t i = 0; i < N; i++) Vi_cur[i] = 0;
      setOutputs(pumpOff, valveOff);
      break;
    case DOSING:
      setOutputs(pumpOff, valveOff);
      break;
    case DONE:
    case ABORT:
      setOutputs(pumpOff, valveOff);
      break;
  }
}

void setup() {
  for (uint8_t i = 0; i < N; i++) {
    pinMode(PIN_PUMP[i], OUTPUT);
    pinMode(PIN_VALVE[i], OUTPUT);
    pinMode(PIN_FLOW[i], INPUT);
  }
  pinMode(PIN_BTN_START, INPUT_PULLUP);
  pinMode(PIN_BTN_STOP, INPUT_PULLUP);
  applyState(IDLE);
}

void loop() {
  static bool lastStart = HIGH;
  static bool lastStop  = HIGH;

  bool startNow = digitalRead(PIN_BTN_START);
  bool stopNow  = digitalRead(PIN_BTN_STOP);

  switch (state) {
    case IDLE:
      if (lastStart == HIGH && startNow == LOW) applyState(DOSING);
      break;
    case DOSING:
      flowPollAndCount();
      bool pumpOn[N], valveOn[N];
      for (uint8_t i = 0; i < N; i++) {
        bool active = (Vi_set[i] > 0 && Vi_cur[i] < Vi_set[i]);
        pumpOn[i] = valveOn[i] = active;
      }
      setOutputs(pumpOn, valveOn);
      if (allDone()) applyState(DONE);
      if (lastStop == HIGH && stopNow == LOW) applyState(ABORT);
      break;
    case DONE:
      if (lastStart == HIGH && startNow == LOW) applyState(DOSING);
      if (lastStop == HIGH && stopNow == LOW) applyState(IDLE);
      break;
    case ABORT:
      if (lastStart == HIGH && startNow == LOW) applyState(DOSING);
      if (lastStop == HIGH && stopNow == LOW) applyState(IDLE);
      break;
  }

  lastStart = startNow;
  lastStop  = stopNow;
}