/*
 * STM32 Akıllı Şebeke İzleme ve Arıza Tespit Sistemi
 * Wokwi Simülasyonu - v4 (SD kütüphanesiz, sade)
 */

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

#define V_SENSE_PIN   PA0
#define I_SENSE_PIN   PA1
#define LED_ALARM     PB0
#define BUZZER_PIN    PB1
#define RELAY_PIN     PB10

#define OLED_ADDR     0x3C
#define BUFFER_SIZE   50
#define V_PEAK_MAX    330.0f
#define I_PEAK_MAX    15.0f
#define AC_FREQ       50.0f
#define ADC_RES       4095.0f

#define V_HIGH_TH     250.0f
#define V_LOW_TH      180.0f
#define I_HIGH_TH     10.0f

#define SENSOR_PERIOD   50
#define FAULT_PERIOD    100
#define COMM_PERIOD     1000
#define DISPLAY_PERIOD  500

typedef struct {
  float    vrms;
  float    irms;
  float    power_active;
  float    frequency;
  bool     fault_ov;
  bool     fault_uv;
  bool     fault_oi;
  uint32_t cycle_count;
} SystemData_t;

SystemData_t gData = {0};
Adafruit_SSD1306 oled(128, 64, &Wire, -1);
bool g_oled_ok = false;

unsigned long lastSensor  = 0;
unsigned long lastFault   = 0;
unsigned long lastComm    = 0;
unsigned long lastDisplay = 0;

float v_buf[BUFFER_SIZE];
float i_buf[BUFFER_SIZE];

void SensorAndProcessingTask() {
  uint16_t v_pot = analogRead(V_SENSE_PIN);
  uint16_t i_pot = analogRead(I_SENSE_PIN);
  float v_peak = ((float)v_pot / ADC_RES) * V_PEAK_MAX;
  float i_peak = ((float)i_pot / ADC_RES) * I_PEAK_MAX;

  for (int i = 0; i < BUFFER_SIZE; i++) {
    float t = (float)i * 0.001f;
    float wave = sinf(2.0f * (float)PI * AC_FREQ * t);
    v_buf[i] = v_peak * wave;
    i_buf[i] = i_peak * wave;
  }

  float v_sum_sq = 0.0f, i_sum_sq = 0.0f, p_sum = 0.0f;
  for (int i = 0; i < BUFFER_SIZE; i++) {
    v_sum_sq += v_buf[i] * v_buf[i];
    i_sum_sq += i_buf[i] * i_buf[i];
    p_sum    += v_buf[i] * i_buf[i];
  }
  gData.vrms         = sqrtf(v_sum_sq / BUFFER_SIZE);
  gData.irms         = sqrtf(i_sum_sq / BUFFER_SIZE);
  gData.power_active = p_sum / BUFFER_SIZE;

  int zc = 0;
  for (int i = 1; i < BUFFER_SIZE; i++) {
    if ((v_buf[i-1] <= 0.0f && v_buf[i] > 0.0f) ||
        (v_buf[i-1] >= 0.0f && v_buf[i] < 0.0f)) {
      zc++;
    }
  }
  float freq = (zc / 2.0f) / ((float)BUFFER_SIZE * 0.001f);
  gData.frequency = (freq < 1.0f) ? AC_FREQ : freq;
  gData.cycle_count++;
}

void FaultDetectionTask() {
  gData.fault_ov = (gData.vrms > V_HIGH_TH);
  gData.fault_uv = (gData.vrms < V_LOW_TH);
  gData.fault_oi = (gData.irms > I_HIGH_TH);

  bool any_fault = gData.fault_ov || gData.fault_uv || gData.fault_oi;
  if (any_fault) {
    digitalWrite(LED_ALARM, HIGH);
    digitalWrite(RELAY_PIN, HIGH);
    tone(BUZZER_PIN, 2000, 80);
  } else {
    digitalWrite(LED_ALARM, LOW);
    digitalWrite(RELAY_PIN, LOW);
  }
}

void CommunicationTask() {
  Serial.print("{\"v\":");   Serial.print(gData.vrms, 2);
  Serial.print(",\"i\":");   Serial.print(gData.irms, 3);
  Serial.print(",\"p\":");   Serial.print(gData.power_active, 2);
  Serial.print(",\"f\":");   Serial.print(gData.frequency, 2);
  Serial.print(",\"ov\":");  Serial.print(gData.fault_ov ? 1 : 0);
  Serial.print(",\"uv\":");  Serial.print(gData.fault_uv ? 1 : 0);
  Serial.print(",\"oi\":");  Serial.print(gData.fault_oi ? 1 : 0);
  Serial.print(",\"n\":");   Serial.print(gData.cycle_count);
  Serial.print(",\"t\":");   Serial.print(millis());
  Serial.println("}");
}

void DisplayTask() {
  if (!g_oled_ok) return;
  oled.clearDisplay();
  oled.setTextSize(1);
  oled.setTextColor(SSD1306_WHITE);

  oled.setCursor(0, 0);
  oled.println("STM32 Sebeke Izleme");
  oled.drawLine(0, 9, 127, 9, SSD1306_WHITE);

  oled.setCursor(0, 13);
  oled.print("V: "); oled.print(gData.vrms, 1); oled.println(" V");
  oled.print("I: "); oled.print(gData.irms, 2); oled.println(" A");
  oled.print("P: "); oled.print(gData.power_active, 1); oled.println(" W");
  oled.print("F: "); oled.print(gData.frequency, 1); oled.println(" Hz");

  oled.drawLine(0, 53, 127, 53, SSD1306_WHITE);
  oled.setCursor(0, 56);
  if (gData.fault_ov || gData.fault_uv || gData.fault_oi) {
    oled.print("ALARM:");
    if (gData.fault_ov) oled.print(" OV");
    if (gData.fault_uv) oled.print(" UV");
    if (gData.fault_oi) oled.print(" OI");
  } else {
    oled.print("Durum: NORMAL");
  }
  oled.display();
}

void setup() {
  Serial.begin(115200);
  delay(500);
  Serial.println();
  Serial.println("==============================================");
  Serial.println(" STM32 Akilli Sebeke Izleme Sistemi");
  Serial.println(" Final Proje - Wokwi Simulasyonu");
  Serial.println("==============================================");

  pinMode(LED_ALARM, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(LED_ALARM, LOW);
  digitalWrite(RELAY_PIN, LOW);

  analogReadResolution(12);

  Wire.begin();
  Wire.setClock(400000);
  if (oled.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
    g_oled_ok = true;
    oled.clearDisplay();
    oled.setTextSize(1);
    oled.setTextColor(SSD1306_WHITE);
    oled.setCursor(0, 20);
    oled.println(" STM32 Sebeke");
    oled.println(" Izleme Sistemi");
    oled.println("");
    oled.println(" Baslatiliyor...");
    oled.display();
    Serial.println("[OK] OLED hazir");
  } else {
    Serial.println("[UYARI] OLED bulunamadi");
  }

  Serial.println("[OK] Sistem hazir");
  Serial.println("----------------------------------------------");
  delay(1500);
}

void loop() {
  unsigned long now = millis();
  if (now - lastSensor  >= SENSOR_PERIOD)  { lastSensor  = now; SensorAndProcessingTask(); }
  if (now - lastFault   >= FAULT_PERIOD)   { lastFault   = now; FaultDetectionTask(); }
  if (now - lastComm    >= COMM_PERIOD)    { lastComm    = now; CommunicationTask(); }
  if (now - lastDisplay >= DISPLAY_PERIOD) { lastDisplay = now; DisplayTask(); }
}