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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// ---------------- GPIO DEFINICE ----------------

// Drinking water
#define DW_A 10
#define DW_B 11

// Bypass
#define BY_A 12
#define BY_B 13

// Service water
#define SW_A 14
#define SW_B 15

// Tlačítka (HIGH při stisku)
#define BTN_UP      8
#define BTN_DOWN    9
#define BTN_ENTER   6
#define BTN_ESCAPE  7

// ---------------- FUNKCE VENTILŮ ----------------

// Drinking water
void openDrinking() {
  digitalWrite(DW_A, HIGH);
  digitalWrite(DW_B, HIGH);
}

void closeDrinking() {
  digitalWrite(DW_A, LOW);
  digitalWrite(DW_B, HIGH);
}

// Bypass
void openBypass() {
  digitalWrite(BY_A, HIGH);
  digitalWrite(BY_B, HIGH);
}

void closeBypass() {
  digitalWrite(BY_A, LOW);
  digitalWrite(BY_B, HIGH);
}

// Service water
void openService() {
  digitalWrite(SW_A, HIGH);
  digitalWrite(SW_B, HIGH);
}

void closeService() {
  digitalWrite(SW_A, LOW);
  digitalWrite(SW_B, HIGH);
}

// ---------------- BEZPEČNÉ UKONČENÍ ----------------
// Po každé akci se musí vypnout B vodič všech ventilů
void safeEnd() {
  digitalWrite(DW_B, LOW);  // Drinking GP11
  digitalWrite(BY_B, LOW);  // Bypass GP13
  digitalWrite(SW_B, LOW);  // Service GP15
}

// ---------------- OLED ANIMACE ----------------
void processValve(const char* name, bool opening,
                  void (*openFunc)(), void (*closeFunc)()) 
{
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);

  // Odpočet 20 → 0
  for (int i = 20; i >= 0; i--) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println(name);

    display.setCursor(0, 25);
    if (opening)
      display.println("OPENING");
    else
      display.println("CLOSING");

    display.setCursor(0, 50);
    display.print("T-");
    display.print(i);

    display.display();
    delay(200);  // DEMO rychlost (20×200ms = 4s)
  }

  // Provedení akce
  if (opening)
    openFunc();
  else
    closeFunc();

  // Bezpečné ukončení
  safeEnd();

  // Výsledný stav
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println(name);

  display.setCursor(0, 25);
  if (opening)
    display.println("OPEN");
  else
    display.println("CLOSED");

  display.display();
  delay(1500);
}

// ---------------- SETUP ----------------
void setup() {
  // I2C
  Wire.setSDA(4);
  Wire.setSCL(5);
  Wire.begin();

  // OLED
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Valve System Ready");
  display.display();
  delay(1000);

  // Tlačítka
  pinMode(BTN_UP, INPUT_PULLDOWN);
  pinMode(BTN_DOWN, INPUT_PULLDOWN);
  pinMode(BTN_ENTER, INPUT_PULLDOWN);
  pinMode(BTN_ESCAPE, INPUT_PULLDOWN);

  // Výstupy ventilů
  pinMode(DW_A, OUTPUT);
  pinMode(DW_B, OUTPUT);

  pinMode(BY_A, OUTPUT);
  pinMode(BY_B, OUTPUT);

  pinMode(SW_A, OUTPUT);
  pinMode(SW_B, OUTPUT);

  // Výchozí stav – vše CLOSED
  closeDrinking();
  closeBypass();
  closeService();
  safeEnd();
}

// ---------------- LOOP – DEMO ----------------
void loop() {

  // Drinking water
  processValve("DRINKING", true,  openDrinking,  closeDrinking);
  processValve("DRINKING", false, openDrinking,  closeDrinking);

  // Bypass
  processValve("BYPASS", true,  openBypass,  closeBypass);
  processValve("BYPASS", false, openBypass,  closeBypass);

  // Service water
  processValve("SERVICE", true,  openService,  closeService);
  processValve("SERVICE", false, openService,  closeService);

  delay(2000);
}