#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
#include "DHT.h"

#define DHTPIN 2 
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 20, 4); // Set the LCD address to 0x27 for a 16 chars and 2 line display

float h; 
float t;
//int h_user;
//int t_user;
float h_user;
float t_user;


//Input & Button Logic
const int numOfInputs = 4;
const int inputPins[numOfInputs] = {8,9,10,11};
int inputState[numOfInputs];
int lastInputState[numOfInputs] = {LOW,LOW,LOW,LOW};
bool inputFlags[numOfInputs] = {LOW,LOW,LOW,LOW};
long lastDebounceTime[numOfInputs] = {0,0,0,0};
long debounceDelay = 5;

//LCD Menu Logic
const int numOfScreens = 2;
int currentScreen = 0;
String screens[numOfScreens][2] = {{"Select Temp",""}, {"Humidity", "%"}};
int parameters[numOfScreens];

// RELAYs
#define CH1 3      // Digital Pin 3 to CH1 on Relay Module - heater



void setup() {

   // declare all relays as outputs
   pinMode(CH1, OUTPUT);
  

   // turn OFF any power to the relay channels during startup
   digitalWrite(CH1,LOW);
   
  
  for(int i = 0; i < numOfInputs; i++) {
    pinMode(inputPins[i], INPUT);
    digitalWrite(inputPins[i], HIGH); // pull-up 20k
  }
  
  //Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Initializing.....        Please Wait");
   delay (4000);
  lcd.clear();  
  delay (3000);
  lcd.print("Beer Mash Controller       V1.0");  
  delay (6000);
  lcd.clear();
}


void loop() {

  static unsigned long int sensorTime=0;
  static bool startedDHT22=false;
  if(millis()-sensorTime > 10000) {   // start sensor read after 10 seconds
     startDHT22();
     sensorTime=millis();
     startedDHT22=true;
    }
  else
     if(startedDHT22  && millis()-sensorTime > 10)  // 10mSec
        {
          readDHT22();   // read sensor
          startedDHT22=false;
        }

  
  
  setInputFlags();
  resolveInputFlags();

  checkAndSwitchRelays();
   
}


void startDHT22(){
  dht.begin();
}

void readDHT22() {
  t = dht.readTemperature();
  displaySettings();
  displayReadings();
}

void checkAndSwitchRelays() { // compare sensor values with pot values to switch relays

  if (t_user < t) 
   {
    // switch relay heater off
    digitalWrite(CH1,LOW);
    
   }
  else if (t_user > t) 
   {
    // switch relay heater on 
    digitalWrite(CH1,HIGH);

   }
  //else
   //{ 
    // switch relay heater 
   // digitalWrite(CH1,LOW);
   //}
   
  //if (h_user < h) 
   //{
    // switch relay fan off
   // digitalWrite(CH2,LOW);
  // }
  //else if (h_user > h) 
  // {
    // switch relay fan on
    //digitalWrite(CH2,HIGH);
  // }
  // else
   //{ 
    // switch relay fan off
   // digitalWrite(CH2,LOW);
  // }
}

void displayReadings() {
  lcd.clear(); 
  lcd.setCursor(0, 0);
  lcd.print("Current Temperature "); 
  lcd.setCursor(7, 1);
  lcd.print(t);
  //lcd.print(h);  
  //Serial.print("Humidity: ");
  //Serial.print(h);
  //Serial.println(" %\t");
  //Serial.print("Temperature: ");
  //Serial.print(t);
  //Serial.println(" *C ");
  delay(1000);
}

void displaySettings() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temperature Target ");  
  lcd.setCursor(7, 1);
  lcd.print(t_user);  
  lcd.setCursor(0, 2);  
  delay(1000);
}

void setInputFlags() {
  for(int i = 0; i < numOfInputs; i++) {
    int reading = digitalRead(inputPins[i]);
    if (reading != lastInputState[i]) {
      lastDebounceTime[i] = millis();
    }
    if ((millis() - lastDebounceTime[i]) > debounceDelay) {
      if (reading != inputState[i]) {
        inputState[i] = reading;
        if (inputState[i] == HIGH) {
          inputFlags[i] = HIGH;
        }
      }
    }
    lastInputState[i] = reading;
  }
}

void resolveInputFlags() {
  for(int i = 0; i < numOfInputs; i++) {
    if(inputFlags[i] == HIGH) {
      inputAction(i);
      inputFlags[i] = LOW;
      printScreen();
    }
  }
}

void inputAction(int input) {
  if(input == 0) {
    if (currentScreen == 0) {
      currentScreen = numOfScreens-1;
    }else{
      currentScreen--;
    }
  }else if(input == 1) {
    if (currentScreen == numOfScreens-1) {
      currentScreen = 0;
    }else{
      currentScreen++;
    }
  }else if(input == 2) {
    parameterChange(0);
  }else if(input == 3) {
    parameterChange(1);
  }

//
t_user = (parameters[0]);
//

}

void parameterChange(int key) {
  if(key == 0) {
    parameters[currentScreen]++;
  }else if(key == 1) {
    parameters[currentScreen]--;
  }
}

void printScreen() {
  lcd.clear();
  lcd.print(screens[currentScreen][0]);
  lcd.setCursor(0,1);
  lcd.print(parameters[currentScreen]);
  lcd.print(" ");
  lcd.print(screens[currentScreen][1]);
  lcd.setCursor(0,2);
}