#include <SD.h>
#include <dht.h>
#include <LiquidCrystal_I2C.h>

// SD Card
#define SPI_SPEED SD_SCK_MHZ(4)
#define CS_PIN 10
// DHT22
#define DHT22_PIN 5
// Ultrasonic
#define PIN_TRIG 3
#define PIN_ECHO 2
//LCD
#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4
// Fan Relay
#define PIN_FAN 8

File file;
dht DHT;
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

double temp = 0.0;
double humidity = 0.0;
double pressure = 0.0;
double dust = 0.0;
double distance = 0.0;
int light = 0;
bool fanOn = false;

int setTemp = 24; // Celcius

void getDHT() {
  DHT.read22(DHT22_PIN);
  temp = DHT.temperature;
  humidity = DHT.humidity;
}

void getDistance() {
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  int duration = pulseIn(PIN_ECHO, HIGH);
  distance = (duration / 58.0);
}

void fanRun(bool state) {
  if (state)
    digitalWrite(PIN_FAN, HIGH);
  else
    digitalWrite(PIN_FAN, LOW);
  fanOn = state;
}

void updateLCD() {
  // Distance
  lcd.setCursor(0, 0);
  lcd.print("Distance:");
  lcd.setCursor(11, 0);
  if (distance >= 100) {
    lcd.print(distance, 0);
  } else if (distance >= 10) {
    lcd.print(" ");
    lcd.print(distance, 0);
  } else {
    lcd.print("  ");
    lcd.print(distance, 0);
  }
  lcd.print("cm");

  // Temperature
  lcd.setCursor(0, 1);
  lcd.print("T:");
  lcd.setCursor(2, 1);
  if (temp >= 10) {
    lcd.print(" ");
    lcd.print(temp, 1);
  } else if (temp >= 0) {
    lcd.print("  ");
    lcd.print(temp, 1);
  } else if (temp > -10) {
    lcd.print(" ");
    lcd.print(temp, 1);
  } else {
    lcd.print(temp, 1);
  }
  lcd.print("C");

  // Humidity
  lcd.setCursor(10, 1);
  lcd.print("H:");
  lcd.setCursor(12, 1);
  if (humidity >= 100) {
    lcd.print(humidity, 0);
  } else if (humidity >= 10) {
    lcd.print(" ");
    lcd.print(humidity, 0);
  } else {
    lcd.print("  ");
    lcd.print(humidity, 0);
  }
  lcd.print("%");
}

void sdWrite() {
  file = SD.open("log.txt");
  Serial.write(file.print(temp));
  file.close();
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  // Ultrasonic
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

  // Fan Relay
  pinMode(PIN_FAN, OUTPUT);

  // LCD
  lcd.init();
  lcd.backlight();
}

void loop() {
  // put your main code here, to run repeatedly:

  // get values
  getDHT();
  getDistance();

  // FAN
  if (fanOn && temp < setTemp)
    fanRun(false);
  else if (!fanOn && temp > setTemp)
    fanRun(true);
  
  // LCD
  updateLCD();

  // SD Card - log onto card
  sdWrite();
}