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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define TRIG_PIN 2
#define ECHO_PIN 3
#define LED_PIN 7
#define SD_CS_PIN 10

const float tankHeight = 100.0; // Višina cisterne v cm
unsigned long lastLogTime = 0;

void setup() {
  // Inicializacija serijskega vmesnika
  Serial.begin(9600);
  while (!Serial) {
    ; // Počakaj na povezavo
  }
  
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  
  // Poskus inicializacije OLED z naslovom 0x3C
  Serial.println("Poskus inicializacije OLED z naslovom 0x3C...");
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("Napaka pri naslovu 0x3C, poskus z 0x3D...");
    // Poskus z naslovom 0x3D
    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3D)) {
      Serial.println("Napaka pri inicializaciji OLED na obeh naslovih!");
      while (1); // Ustavitev programa
    } else {
      Serial.println("OLED uspešno inicializiran na naslovu 0x3D.");
    }
  } else {
    Serial.println("OLED uspešno inicializiran na naslovu 0x3C.");
  }
  
  // Počistimo zaslon in prikažemo začetni napis
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Merilec vode");
  display.display();
  delay(1000);

  // Inicializacija SD kartice
  Serial.println("Inicializacija SD kartice...");
  if (!SD.begin(SD_CS_PIN)) {
    Serial.println("Napaka pri inicializaciji SD kartice!");
    display.clearDisplay();
    display.setCursor(0,0);
    display.println("SD kartica napaka!");
    display.display();
    while(1);
  }
  Serial.println("SD kartica uspešno inicializirana.");
}

float measureDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;
  return distance;
}

void loop() {
  float distance = measureDistance();
  float waterLevel = tankHeight - distance;
  float percentage = (waterLevel / tankHeight) * 100;
  
  if (percentage < 10 || percentage > 90) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
  }

  display.clearDisplay();
  display.setCursor(0,0);
  display.print("Nivo vode: ");
  display.print(percentage);
  display.println("%");
  
  if (percentage < 10) {
    display.println("Opozorilo: Nizek nivo!");
  } else if (percentage > 90) {
    display.println("Opozorilo: Visok nivo!");
  } else {
    display.println("Normalno");
  }
  display.display();

  if (millis() - lastLogTime >= 3600000) {
    File dataFile = SD.open("water_log.txt", FILE_WRITE);
    if (dataFile) {
      dataFile.print("Cas: ");
      dataFile.print(millis() / 3600000);
      dataFile.print("h, Nivo: ");
      dataFile.print(percentage);
      dataFile.println("%");
      dataFile.close();
      Serial.println("Podatki zapisani na SD kartico.");
    } else {
      Serial.println("Napaka pri odpiranju datoteke!");
    }
    lastLogTime = millis();
  }

  Serial.print("Nivo vode: ");
  Serial.print(percentage);
  Serial.println("%");

  delay(1000);
}