#include <LiquidCrystal_I2C.h>
#include <Encoder.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
Encoder myEnc(2, 3);
#define button 4
long oldPosition  = -999;
float angleValue;
float stockValue;
float encoderValue;
bool stockSet = false;
bool angleSet = false;
bool bigAngle;
byte customBackslash[8] = {
  0b00000,
  0b10000,
  0b01000,
  0b00100,
  0b00010,
  0b00001,
  0b00000,
  0b00000
};




void setup() { 
    lcd.begin(16, 2);
    pinMode(button, INPUT_PULLUP);
    Serial.begin(115200);
  
}
 
void loop() { 
    if (stockSet == false){
        setStock();
    }
    if (stockSet == true && angleSet == false){
        setAngle();
    }
    if (stockSet == true && angleSet == true){
        calculate(stockValue, angleValue);
    }
}

void(* resetFunc) (void) = 0; 

void setStock(){
    lcd.setCursor(0,0);
    lcd.print("stock = ");
    long newPosition = myEnc.read();

    if (newPosition != oldPosition) {
        oldPosition = newPosition;
        lcd.setCursor(8, 0);
        encoderValue = newPosition/4;
        stockValue = encoderValue/2 + 20;
        lcd.print(stockValue,1);
        lcd.print(" mm  "); 
    }
      if(digitalRead(button) == LOW){
        lcd.setCursor(0,0);
        lcd.clear();
        delay(500);
        lcd.setCursor(0,0);
        lcd.print("stock = ");
        lcd.setCursor(8, 0);
        lcd.print(stockValue,1);
        lcd.print(" mm "); 
        stockSet = true;
        lcd.setCursor(0,1);
        lcd.print("angle = 90");
            lcd.print("\xDF");
        lcd.print("   |");
        return stockValue;
    }      
}


void setAngle(){
    long newPosition = myEnc.read();
    
    if (newPosition != oldPosition) {
        oldPosition = newPosition;
        encoderValue = newPosition/4;
        angleValue = encoderValue/2 - stockValue + 110;
        printAngle(angleValue);
    }
    if (digitalRead(button)==LOW){
        lcd.clear();
        delay(500);
        lcd.setCursor(0,1);
        lcd.print("angle = ");
        lcd.setCursor(8, 1);
        lcd.print(angleValue,1);
        angleSet = true;
        return angleValue;
    }
}

void printAngle(float angleValue){
    lcd.createChar(7, customBackslash);
    if (angleValue < 90){
        lcd.setCursor(8,1);
        lcd.print(angleValue,1);
        lcd.print("\xDF");
        lcd.setCursor(14,1);
        lcd.write(byte(7)); //print our custom char backslash
    }
    else if (angleValue == 90){
        lcd.setCursor(8,1);
        lcd.print(angleValue,1);
        lcd.print("\xDF");
        lcd.print("      ");
        lcd.setCursor(14,1);
        lcd.print("|");
    }
    else {
        lcd.setCursor(8,1);
        float angleTemp = angleValue*-1+180;
        lcd.print(angleTemp,1);
        lcd.print("\xDF");
        lcd.print("      ");
        lcd.setCursor(14,1);
        lcd.print("/");
    }
    return;
}




void calculate(float stockValue, float angleValue){
    if(angleValue==0){
        angleValue = 90;
    }
    lcd.clear();
    lcd.setCursor(0,0);
    float offset =  (stockValue-14) / tan(angleValue*PI/180) ;
    if (offset > -0.1 && offset< 0.1){
        lcd.print("offset = 0.0 mm ");
    }
    else{
        lcd.clear();
        lcd.print("offset = ");
        lcd.print(offset,1);
        lcd.print(" mm");
    }
    while(digitalRead(button)==HIGH){
    }
    
    resetFunc();
}