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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int tankheight = 20; //22cm
int fillheight = 20;  //in cm
int bufferheight = 3;
int data = 1;
int trig = 2, echo = 3;
int buttonPin = 8;
int buttonState = 0;
// long time, height

void testdrawstyles(int a) {
  display.clearDisplay();
  display.setTextSize(2);             // Normal 1:1 pixel scale
  display.setTextColor(WHITE);        // Draw white text
  display.setCursor(0, 0);            // Start at top-left corner
  display.print(F("Level= "));
  display.setTextSize(2);             // Draw 2X-scale text
  display.setTextColor(WHITE);
  display.print(a);
  display.setTextSize(2);             // Draw 2X-scale text
  display.setTextColor(WHITE);
  display.print(F("%"));
  display.display();
  delay(500);
}

void setup() {
  Serial.begin(9600);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  // pinMode(buttonPin, INPUT);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
  display.drawPixel(10, 10, WHITE);
  display.display();
  delay(1000);
}



void loop() {
  long time, height, waterpercent = 0, waterheight = 0;
  
  // buttonState = digitalRead(buttonPin);

  // if (buttonState == HIGH) {
  //   Serial.println(buttonState);
  //   buttonState = LOW;
  //   data = data + 2;
  //   if(data > 7){
  //     data = 1;
  //   }
  // }
  // switch (data) {
  //   case 1:
  //     trig = data + 1;
  //     echo = data + 2;
  //     break;
  //   case 3:
  //     trig = data + 1;
  //     echo = data + 2;
  //     break;
  // }
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  time = pulseIn(echo, HIGH);
  height = time / 29 / 2;

  if (height <= 23 && height > 3) {
    waterheight = tankheight - (height - bufferheight);
    waterpercent = waterheight * 5;
    // if(waterheight = fillheight)
    Serial.print(waterheight);
    Serial.println(" cm");
  }
  else {
    Serial.println("Tank Full.");
  }
  delay(1000);
  testdrawstyles(waterpercent);

}