// ESP32 + SSD1306 OLED + HC-SR04 + 2 Buton
// Namaz Rekat Sayacı — el yaklaşımıyla secde algılama
// State machine: SELECT_MODE -> READY -> COUNTING -> COMPLETE

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

#define SCREEN_W 128
#define SCREEN_H 64
#define OLED_ADDR 0x3C

#define TRIG_PIN     25
#define ECHO_PIN     26
#define BTN_MODE     32   // Yesil: rekat sayisini degistir
#define BTN_OK       33   // Kirmizi: onayla / sifirla

#define DETECT_CM    15   // Bu mesafeden yakın → secde
#define RELEASE_CM   25   // Bu mesafeden uzak → ayrıldı
#define DEBOUNCE_MS  2500 // İki secde arası min süre

Adafruit_SSD1306 oled(SCREEN_W, SCREEN_H, &Wire, -1);

enum State { ST_SELECT, ST_READY, ST_COUNT, ST_DONE };
State state = ST_SELECT;

uint8_t  targetRakats  = 4;
uint8_t  currentRakats = 0;
bool     waitRelease   = false;
unsigned long lastDetectMs = 0;
unsigned long lastBtnMode  = 0;
unsigned long lastBtnOk    = 0;

void lcdAt(int x, int y, uint8_t size, const String &text) {
  oled.setTextSize(size);
  oled.setCursor(x, y);
  oled.print(text);
}

long readDistanceCm() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH, 30000);  // 30ms timeout
  if (duration == 0) return 999;
  return duration / 58;
}

// ============ Ekranlar ============
void drawSplash() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  lcdAt(8, 8, 2, "BlueGrays");
  lcdAt(12, 36, 1, "Rekat Sayaci v1");
  oled.drawRoundRect(2, 2, 124, 60, 6, SSD1306_WHITE);
  oled.display();
}

void drawSelect() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  lcdAt(0, 0, 1, "> Rekat Modu Sec");
  oled.drawLine(0, 10, 127, 10, SSD1306_WHITE);
  lcdAt(0, 14, 1, "Toplam Rekat:");
  oled.setTextSize(4);
  oled.setCursor(54, 24);
  oled.print(targetRakats);
  lcdAt(0, 56, 1, "Yesil:degis Kirmizi:OK");
  oled.display();
}

void drawReady() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  lcdAt(0, 0, 1, "> Namaza Hazir");
  oled.drawLine(0, 10, 127, 10, SSD1306_WHITE);
  lcdAt(38, 18, 2, "Hazir!");
  lcdAt(34, 42, 1, "0 / " + String(targetRakats));
  lcdAt(0, 56, 1, "Secdeye gidince baslar");
  oled.display();
}

void drawCount() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  lcdAt(0, 0, 1, "> Sayim aktif");
  oled.drawLine(0, 10, 127, 10, SSD1306_WHITE);

  // Buyuk sayi ortali: "1/4"
  oled.setTextSize(4);
  String s = String(currentRakats) + "/" + String(targetRakats);
  int w = s.length() * 24;
  oled.setCursor((128 - w) / 2, 18);
  oled.print(s);

  lcdAt(0, 56, 1, "Kirmizi: yeni namaz");
  oled.display();
}

void drawDetected() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  oled.fillRect(0, 0, 128, 64, SSD1306_WHITE);
  oled.setTextColor(SSD1306_BLACK);
  oled.setTextSize(2);
  oled.setCursor(20, 8);
  oled.print("+1 Rekat");
  oled.setTextSize(4);
  String s = String(currentRakats) + "/" + String(targetRakats);
  int w = s.length() * 24;
  oled.setCursor((128 - w) / 2, 30);
  oled.print(s);
  oled.display();
  delay(800);
}

void drawDone() {
  oled.clearDisplay();
  oled.setTextColor(SSD1306_WHITE);
  lcdAt(0, 0, 1, "> Namaz Tamamlandi");
  oled.drawLine(0, 10, 127, 10, SSD1306_WHITE);
  lcdAt(34, 16, 2, "TAMAM");
  oled.drawRoundRect(20, 13, 90, 22, 4, SSD1306_WHITE);
  lcdAt(0, 42, 1, "Allah kabul etsin");
  lcdAt(0, 55, 1, "Kirmizi: yeni namaz");
  oled.display();
}

// ============ SETUP ============
void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BTN_MODE, INPUT_PULLUP);
  pinMode(BTN_OK,   INPUT_PULLUP);

  Wire.begin(21, 22);
  if (!oled.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
    while (1);
  }

  drawSplash();
  delay(2500);

  state = ST_SELECT;
  drawSelect();
}

// ============ LOOP ============
void loop() {
  // ---- Buton: Mod degistir ----
  if (digitalRead(BTN_MODE) == LOW && millis() - lastBtnMode > 300) {
    lastBtnMode = millis();
    if (state == ST_SELECT) {
      if (targetRakats == 4) targetRakats = 2;
      else targetRakats++;
      drawSelect();
    }
  }

  // ---- Buton: OK / Reset ----
  if (digitalRead(BTN_OK) == LOW && millis() - lastBtnOk > 300) {
    lastBtnOk = millis();
    if (state == ST_SELECT) {
      currentRakats = 0;
      state = ST_READY;
      drawReady();
      delay(1500);
      state = ST_COUNT;
      waitRelease = false;
      lastDetectMs = 0;
      drawCount();
    } else {
      // COUNT veya DONE → yeni namaza geç
      currentRakats = 0;
      state = ST_SELECT;
      drawSelect();
    }
  }

  // ---- Mesafe algılama (yalnızca COUNT state) ----
  if (state == ST_COUNT) {
    long d = readDistanceCm();

    if (waitRelease) {
      if (d > RELEASE_CM) waitRelease = false;
    } else {
      if (d < DETECT_CM && (millis() - lastDetectMs > DEBOUNCE_MS)) {
        lastDetectMs = millis();
        currentRakats++;
        waitRelease = true;

        drawDetected();

        if (currentRakats >= targetRakats) {
          state = ST_DONE;
          drawDone();
        } else {
          drawCount();
        }
      }
    }
    delay(80);
  } else {
    delay(40);
  }
}