//----------------------------------------------------------------//
//For DHT22 Sensor
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>
#define DHTPIN 2
#define DHTTYPE    DHT22 

DHT dht(DHTPIN, DHTTYPE);

//For Sampling Rate Millis
unsigned long currentMillis;
unsigned long previousMillis;
unsigned long samplingRate = 2000;   //This will be change to 2sec
//----------------------------------------------------------------//

//----------------------------------------------------------------//
//For Button Pin Assignment and States
#define left_btn A0
#define ok_btn A1
#define right_btn A2

//For Button States
int left_State;
int ok_State;
int right_State;

//For Buttons Flags
int LeftClick;
int RightClick;
//----------------------------------------------------------------//

//----------------------------------------------------------------//
//For Switching Menu
int EnterMode = 0;
int MainMenu = 0;
int SubMenu_2 = 0;
int SubMenu_3 = 0;
int SubMenu_4 = 0;

//For LCD Pins
#include <LiquidCrystal.h>
#define RS 13
#define EN 12
#define D4 11
#define D5 10
#define D6 9
#define D7 8
LiquidCrystal lcd(RS, EN, D4, D5, D6, D7);
//----------------------------------------------------------------//

//----------------------------------------------------------------//
//For PID Control
#include <PID_v1.h>

#define TempSensor 2
#define HeatingElement 3

//For Storing Precious Variables
//float SV_h = 20.0;      //incase Humidity PID is used
float PV_h;               //For Storing Humidity Input

//For Offset Values
float offset_t;
float offset_h;


//Define Variables we'll be connecting to
double SV_t = 35.0, PV_t, Output;

//Specify the links and initial tuning parameters
double kP_T = 2, kI_T = 5, kD_T = 1;
PID tempPID(&PV_t, &Output, &SV_t, kP_T, kI_T, kD_T, DIRECT);

int OnTimeInterval = 250;
unsigned long OnStartTime;
//----------------------------------------------------------------//


void setup() {
  //For Serial Communication
  Serial.begin(9600);

  //For DHT Sensor to Begin
  dht.begin();
  sensor_t sensor;

  //For PID Library
  tempPID.SetOutputLimits(0, OnTimeInterval);   //tell the PID to range between 0 and the full window size
  tempPID.SetMode(AUTOMATIC);                   //turn the PID on
  OnStartTime = millis();

  //For Input Buttons
  pinMode(left_btn, INPUT_PULLUP);
  pinMode(ok_btn, INPUT_PULLUP);
  pinMode(right_btn, INPUT_PULLUP);

  //For Outputs
  pinMode(HeatingElement,OUTPUT);
  
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
}

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  ButtonStates();
  Display();

  switch (EnterMode) {
    case 1:
      switch (MainMenu) {
        case 1:
          //Starts the Loop
          sensorData();   //Runs the sensor Data gathering
          PID();          //Runs the PID Controlling
        break;
      }
    break;
  }
}

void sensorData() {
  //Will read DHT sensor every 2 seconds
  currentMillis = millis();
  if (currentMillis - previousMillis >= samplingRate) {
    previousMillis = currentMillis;
    PV_t = dht.readTemperature() + offset_t;
  }
}

void PID() {
  Serial.print("OnStartTime: ");
  Serial.println(OnStartTime);
  Serial.print("OUTPUT: ");
  Serial.println(Output);
  tempPID.Compute();

  /************************************************
   * turn the output pin on/off based on pid output
   ************************************************/
  if (millis() - OnStartTime > OnTimeInterval)
  { //time to shift the Relay Window
    OnStartTime += OnTimeInterval;
  }

  //Output Control
  if (Output < millis() - OnStartTime) digitalWrite(HeatingElement, LOW);
  else if (Output > millis() - OnStartTime) digitalWrite(HeatingElement, HIGH);
}

void Display() {
  //For Ok BTN Selection
  switch (EnterMode) {

    case 0:       //No Menu is selected yet; scanning all the menus

      switch (MainMenu) {
        case 0:       //WELCOME SCREEN
          
          //Prints at the LCD
          lcd.setCursor(0,0);
          lcd.print("Arduino PID Fish");

          lcd.setCursor(0,1);
          lcd.print("Tank Temp. Cntrl");
        break;

        case 1:       //DISPLAY INFO

          //Turns off the Relay if Display info is exited
          digitalWrite(HeatingElement, LOW);

          //Prints at the LCD
          lcd.setCursor(0,0);
          lcd.print("  Show  Status  ");

          lcd.setCursor(0,1);
          lcd.print("<-     OK     ->");
        break;

        case 2:       //SET TARGET VALUES
          lcd.setCursor(0,0);
          lcd.print("Set  Temperature");

          lcd.setCursor(0,1);
          lcd.print("<-     OK     ->");
        break;

        case 3:       //CHANGE PID Gain
          lcd.setCursor(0,0);
          lcd.print("Adjust  PID Gain");

          lcd.setCursor(0,1);
          lcd.print("<-     OK     ->");
        break;

        case 4:       //CHANGE OFFSET VALUES
          lcd.setCursor(0,0);
          lcd.print(" Offset  Adjust ");

          lcd.setCursor(0,1);
          lcd.print("<-     OK     ->");
        break;

        case 5:       //IF SURPASSED THE TOTAL MENUS, GO BACK TO START
          MainMenu = 0;
        break;
        case -1:      //IF SURPASSED THE LOWEST VALUE, GOES BACK TO LAST
          MainMenu = 4;
        break;
      }
    break;

    //When on of the Menu is selected
    case 1:
      
      switch (MainMenu) {
        case 0:   //WELCOME SCREEN
          EnterMode = 0;    //disabling enter mode in welcome screen
        break;

        case 1:   //DISPLAY INFO
          //Prints the data at LCD
            //Shows the set Values
            //Temperature
            lcd.setCursor(0,0);
            lcd.print("SET:");
            lcd.setCursor(4,0);
            lcd.print(SV_t, 1);       //This will print the data in one decimal value instead of 2
            lcd.setCursor(8,0);
            lcd.print("C ");
            //Humidity
            lcd.setCursor(10,0);
            lcd.print("O:");

            //For Showing Output Value from 0~100%
            double showData;
            showData = map(Output, 0, OnTimeInterval, 0, 100);  //maps out the value to 0~100%
            lcd.setCursor(12,0);
            lcd.print(showData, 0);       //This will print the data with no decimal value
            if (showData != 100 && showData >= 1) {
              lcd.setCursor(14,0);
              lcd.print(" %");
            }
            else if (showData == 0) {
              lcd.setCursor(13,0);
              lcd.print("  %");
            }
            else {
              lcd.setCursor(15,0);
              lcd.print("%");
            }
            //Shows the processed values
            //Temperature
            lcd.setCursor(0,1);
            lcd.print("TankTemp: ");
            lcd.setCursor(10,1);
            lcd.print(PV_t, 1);       //This will print the data in once decimal value instead of 2
            lcd.setCursor(14,1);
            lcd.print(" C");

        break;

        case 2:   //SET VALUES
          //For SETTING TEMPERATURE
          switch (SubMenu_2) {
            //Set Temp Option
            case 0:   
              lcd.setCursor(0,1);
              lcd.print("    Setpoint    ");
            break;
            
            //For Exiting
            case 1:
              lcd.setCursor(0,1);
              lcd.print("      Exit      ");
            break;
            
            //LOOPING THE SCREEN
            //For Going back to first option
            case 2:
              SubMenu_2 = 0;
            break;
            //For Going back to last option
            case -1:
              SubMenu_2 = 1;
          }
        break;

        case 3:   //SET PID VALUES
          //For SETTING PID Values
          switch (SubMenu_3) {
            //Set Proportional Gain
            case 0:   
              lcd.setCursor(0,1);
              lcd.print("    Set kP_T    ");
            break;

            //Set Integral Gain
            case 1:
              lcd.setCursor(0,1);
              lcd.print("    Set kI_T    ");
            break;

            //Set Derivative Gain
            case 2:
              lcd.setCursor(0,1);
              lcd.print("    Set kD_T    ");
            break;

            //For Exiting
            case 3:
              lcd.setCursor(0,1);
              lcd.print("      Exit      ");
            break;
            
            //LOOPING THE SCREEN
            //For Going back to first option
            case 4:
              SubMenu_3 = 0;
            break;
            //For Going back to last option
            case -1:
              SubMenu_3 = 3;
            break;
          }

        break;

        case 4:   //SET OFFSET VALUES
          //For OFFSET Values
          switch (SubMenu_4) {
            //Temperature Offset
            case 0:   
              lcd.setCursor(0,1);
              lcd.print("  Temperature:  ");
            break;

            //For Exiting
            case 1:
              lcd.setCursor(0,1);
              lcd.print("      Exit      ");
            break;
            
            //LOOPING THE SCREEN
            //For Going back to first option
            case 2:
              SubMenu_4 = 0;
            break;
            //For Going back to last option
            case -1:
              SubMenu_4 = 1;
            break;
          }
        break;
      }

    break;

    //When a Sub-Menu is Selected
    case 2:
      //DISPLAY INFO
      if (MainMenu == 1) {    //if display info is selected,
        EnterMode = 0;          //EXITS back to MENU SELECTION
      }

      //SETTING VALUES
      else if (MainMenu == 2) {
        switch (SubMenu_2) {
          //Temp Set
          case 0:
            lcd.setCursor(0,1);
            lcd.print("Set Temp: ");
            lcd.setCursor(10,1);
            lcd.print(SV_t, 1);
            lcd.setCursor(14,1);
            lcd.print(" C");
          break;

          //Exits back to main menu
          case 1:
            //goes back to main menu
            EnterMode = 0;
            
            //resetting back the sub menu to 0
            SubMenu_2 = 0;
          break;
        }  
      }

      //SETTING PID VALUES
      else if (MainMenu == 3) {
        switch (SubMenu_3) {
          //Proportional Gain Set
          case 0:
            lcd.setCursor(0,1);
            lcd.print("Set kP: ");
            lcd.setCursor(8,1);
            lcd.print(kP_T, 1);

            //to clear uncertain spaces
            if (kP_T >= 9.50) {
              lcd.setCursor(12,1);
              lcd.print("    ");  
            }
            else if (kP_T >= 0.0 && kP_T <= 9.50) {
              lcd.setCursor(11,1);
              lcd.print("     ");  
            }
          break;

          //Integral Gain Set
          case 1:
            lcd.setCursor(0,1);
            lcd.print("Set kI: ");
            lcd.setCursor(8,1);
            lcd.print(kI_T, 1);
            
            //to clear uncertain spaces
            if (kI_T >= 9.50) {
              lcd.setCursor(12,1);
              lcd.print("    ");  
            }
            else if (kI_T >= 0.0 && kI_T <= 9.50) {
              lcd.setCursor(11,1);
              lcd.print("     ");  
            }
          break;

          //Derivative Gain Set
          case 2:
            lcd.setCursor(0,1);
            lcd.print("Set kD: ");
            lcd.setCursor(8,1);
            lcd.print(kD_T, 1);
            
            //to clear uncertain spaces
            if (kD_T >= 9.50) {
              lcd.setCursor(12,1);
              lcd.print("    ");  
            }
            else if (kD_T >= 0.0 && kD_T <= 9.50) {
              lcd.setCursor(11,1);
              lcd.print("     ");  
            }
          break;

          //Exits back to main menu
          case 3:
            //goes back to main menu
            EnterMode = 0;
            
            //resetting back the sub menu to 0
            SubMenu_3 = 0;
          break;
        }  
      }

      //SETTING OFFSET VALUES
      else if (MainMenu == 4) {
        switch (SubMenu_4) {
          //Temperature OFFSET
          case 0:
            lcd.setCursor(0,1);
            lcd.print("T Offset: ");
            lcd.setCursor(10,1);
            lcd.print(offset_t, 1);

            //to clear unsused spaces
            if (offset_t <= -0.50 && offset_t >= -9.50) {
              lcd.setCursor(14,1);
              lcd.print(" C");
            }
            else if (offset_t <= -10.0) {
              lcd.setCursor(15,1);
              lcd.print("C");
            }
            else if (offset_t >= 0.0 && offset_t <= 9.50) {
              lcd.setCursor(13,1);
              lcd.print("  C");
            }
            else if (offset_t >= 10.0) {
              lcd.setCursor(14,1);
              lcd.print(" C");
            }
            
            lcd.setCursor(15,1);
            lcd.print("C");
          break;

          //Exits back to main menu
          case 1:
            //goes back to main menu
            EnterMode = 0;
            
            //resetting back the sub menu to 0
            SubMenu_4 = 0;
          break;
        }  
      }

    break;

    //Already in a sub-menu
    case 3:
      //For exiting menu 2
      if (MainMenu == 2) {
        EnterMode = 1;
      }

      //For exiting menu 3
      else if (MainMenu == 3) {
        EnterMode = 1;
      }

      //For exiting menu 4
      else if (MainMenu == 4) {
        EnterMode = 1;
      }
    break;
  }
}

void ButtonStates() {
  Serial.println(EnterMode);
  //Serial.println(MainMenu);
  left_State = digitalRead(left_btn);
  ok_State = digitalRead(ok_btn);
  right_State = digitalRead(right_btn);
  
  if (ok_State == LOW) {
    EnterMode++;
    delay(150);
  }

  //For Changing Left and Right Keys during sub-menu or menu is selected
  switch (EnterMode) {
    //For MainMenu Switch
    case 0:
      if (left_State == LOW) {
        MainMenu++;
        delay(150);
      }
      else if (right_State == LOW) {
        MainMenu--;
        delay(150);
      }
    break;

    //For SubMenu Switching
    case 1:

      switch(MainMenu) {
        case 2:     //Set Target Values
          if (left_State == LOW) {
            SubMenu_2++;
            delay(150);
          }
          else if (right_State == LOW) {
            SubMenu_2--;
            delay(150);
          }
        break;

        case 3:     //Set PID Values
          if (left_State == LOW) {
            SubMenu_3++;
            delay(150);
          }
          else if (right_State == LOW) {
            SubMenu_3--;
            delay(150);
          }
        break;

        case 4:     //Set Offset Values
          if (left_State == LOW) {
            SubMenu_4++;
            delay(150);
          }
          else if (right_State == LOW) {
            SubMenu_4--;
            delay(150);
          }
        break;
      }
    break;

    //For SubMenu Values Change
    case 2:
      switch (MainMenu) {
        case 2:     //Set Target Values
          //For Selected SubMenu
          switch (SubMenu_2) {
            case 0:   //If TEMPERATURE Set
              if (left_State == LOW) {
                //MakI_Tng Sure SV is not above the max set value
                if (SV_t <= 100.00) {
                  SV_t = SV_t + 0.5;
                  delay(150);
                }
              }
              else if (right_State == LOW) {
                //MakI_Tng Sure SV is not Below the min set value
                if (SV_t > 28.00) {
                  SV_t = SV_t - 0.5;
                  delay(150);
                }
              }
            break;
          }
        break;

        case 3:   //Set PID Values
          //For Selected SubMenu
          switch (SubMenu_3) {
            case 0:   //If Proportional Gain is Set
              if (left_State == LOW) {
                //MakI_Tng Sure SV is not above the max set value
                if (kP_T <= 50.00) {
                  kP_T = kP_T + 00.5;
                  delay(150);
                }
              }
              else if (right_State == LOW) {
                //MakI_Tng Sure SV is not Below the min set value
                if (kP_T > 1.00) {
                  kP_T = kP_T - 00.5;
                  delay(150);
                }
              }
            break;

            case 1:   //If Integral Gain is Set
              if (left_State == LOW) {
                //MakI_Tng Sure SV is not above the max set value
                if (kI_T <= 50.00) {
                  kI_T = kI_T + 1;
                  delay(150);
                }
              }
              else if (right_State == LOW) {
                //MakI_Tng Sure SV is not Below the min set value
                if (kI_T > 1.00) {
                  kI_T = kI_T - 1;
                  delay(150);
                }
              }
            break;

            case 2:   //If Derivative Gain is Set
              if (left_State == LOW) {
                //MakI_Tng Sure SV is not above the max set value
                if (kD_T <= 50.00) {
                  kD_T = kD_T + 1;
                  delay(150);
                }
              }
              else if (right_State == LOW) {
                //MakI_Tng Sure SV is not Below the min set value
                if (kD_T > 1.00) {
                  kD_T = kD_T - 1;
                  delay(150);
                }
              }
            break;
          }
        break;

        case 4:
          //For Selected SubMenu
          switch (SubMenu_4) {
            case 0:   //If Temperature Offset is selected
              if (left_State == LOW) {
                //MakI_Tng Sure SV is not above the max set value
                if (offset_t <= 50.00) {
                  offset_t = offset_t + 00.5;
                  delay(150);
                }
              }
              else if (right_State == LOW) {
                //MakI_Tng Sure SV is not Below the min set value
                if (offset_t > -50.00) {
                  offset_t = offset_t - 00.5;
                  delay(150);
                }
              }
            break;
          }
        break;
      }

      //Enters Set PID Valuse Sub Menu

    break;

    case 4:
      EnterMode = 0;
    break;
  }
  

}