// Adafruit Font https://rop.nl/truetype2gfx/

#include "AiEsp32RotaryEncoder.h"
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Fonts/FreeSans12pt7b.h>

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 32

#define BUZZER_PIN           25         
#define ROTARY_ENCODER_A_PIN 33
#define ROTARY_ENCODER_B_PIN 32
#define ROTARY_ENCODER_BUTTON_PIN 14

#define ROTARY_ENCODER_STEPS 4

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64

// Default voltage control values
#define VOLT_MIN      410       // min selectable voltage
#define VOLT_MAX      594       // max selectable voltage
#define VOLT_DEFAULT  545       // default start voltage
#define VOLT_STEP     1         // rotary encoder voltage change steps

// Default voltage control values
#define CURR_MIN      50        // min selectable current
#define CURR_MAX      635       // max selectable current
#define CURR_DEFAULT  580       // default start current
#define CURR_STEP     1         // rotary encoder current change steps

#define BEEP_ENABLE   true      // enable/disable buzzer

bool      beepEnable  = BEEP_ENABLE;
uint16_t DefaultVolt = VOLT_DEFAULT;
uint16_t DefaultCurr = CURR_DEFAULT;
uint16_t SetVoltage = VOLT_DEFAULT;
uint16_t SetCurrent = CURR_DEFAULT;

bool show_menu;

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
AiEsp32RotaryEncoder rotaryEncoder = AiEsp32RotaryEncoder(ROTARY_ENCODER_A_PIN, ROTARY_ENCODER_B_PIN, ROTARY_ENCODER_BUTTON_PIN, -1, ROTARY_ENCODER_STEPS);

String menu_items[] = 
{
  "Set Voltage online",
  "Set Current online", 
  "Default Voltage",
  "Default Current",
  "Back..."
  };
int menu_item = 0;
int currentMenu_item = 0;

void setForRotary(int value)
{

    currentMenu_item = value;
    switch (value)
    {
    case 0:
        rotaryEncoder.setBoundaries(0, ROTARY_ENCODER_STEPS  , true);
        rotaryEncoder.setEncoderValue(0);
        break;
    case 1: //"Set Voltage online"
        rotaryEncoder.setBoundaries(VOLT_MIN, VOLT_MAX, false); 
        rotaryEncoder.setEncoderValue(SetVoltage);
        break;
    case 2: //"Set Current online"
        rotaryEncoder.setBoundaries(CURR_MIN, CURR_MAX, false); 
        rotaryEncoder.setEncoderValue(SetCurrent);
        break;
    case 3: //"Set Default Voltage"
        rotaryEncoder.setBoundaries(VOLT_MIN, VOLT_MAX, false); 
        rotaryEncoder.setEncoderValue(DefaultVolt);
        break;
    case 4: //"Set Default Current"
        rotaryEncoder.setBoundaries(CURR_MIN, CURR_MAX, false); 
        rotaryEncoder.setEncoderValue(DefaultCurr);
        break;
    default:
        break;
    }
    showMenu();
}

void rotary_onButtonClick()
{
    static unsigned long lastTimePressed = 0;
    if (millis() - lastTimePressed < 200)
        return;
    lastTimePressed = millis();

    int selectedValue = rotaryEncoder.readEncoder();

    switch (currentMenu_item)
    {
    case 0: //"Setup Menu"
        menu_item = selectedValue + 1;
        setForRotary(menu_item);
        break;
    case 1: //"Set Voltage online"
        SetVoltageOnline();
        setForRotary(0);
        break;
    case 2: //"Set Current online"
        SetVoltageOnline();
        setForRotary(0);
        break;
    case 3: //"Set Default Voltage"
        SetVoltageOnline();
        setForRotary(0);
        break;
    case 4: //"Set Default Current"
        SetVoltageOnline();
        setForRotary(0);
        break;
    default:
        break;
    }
}

void IRAM_ATTR readEncoderISR()
{
    rotaryEncoder.readEncoder_ISR();
}

void setup()
{
  pinMode(BUZZER_PIN,   OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);

  Serial.begin(115200);
  display.begin(SSD1306_EXTERNALVCC, 0x3C); 
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(12, 0);
  display.println("FLATPACK2");
  display.setTextSize(1);
  display.setCursor(10, 20);
  display.println("Rectifier 48/2000HE");
  display.display();
  delay(1000);

  // Core encoder
  rotaryEncoder.begin();
  rotaryEncoder.setup(readEncoderISR);
  rotaryEncoder.setAcceleration(150);
  rotaryEncoder.correctionOffset = 2; //try with zero or ROTARY_ENCODER_STEPS/2
  rotaryEncoder.isButtonPulldown = false;
  rotaryEncoder.areEncoderPinsPulldownforEsp32 = true;
  //setForRotary(0);
}


void loop()
{
if (!show_menu ) {
  MainScreen();
  if (rotaryEncoder.isEncoderButtonClicked()){
  show_menu = true; setForRotary(0);  
  }
}
else {
  if (rotaryEncoder.encoderChanged())
  {
    showMenu();
  }
  if (rotaryEncoder.isEncoderButtonClicked())
  { 
    rotary_onButtonClick();
  }
}
}

void MainScreen(){
  float U=54.5;
  float A=5.0;display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(12, 0);
  display.print(F("SET: "));
  display.print((float)SetVoltage/10, 1);display.print(F("V "));
  display.print((float)SetCurrent/10, 1);display.print(F("A"));
  display.setFont(&FreeSans12pt7b);
  display.setTextSize(1);
  display.setCursor(0, 30);
  display.print(U, 1);display.print(F("V "));display.print(A, 1);display.print(F("A"));
  display.setFont();
  display.display();
}

void showMenu()
{
  beep();
  int selectedValue = rotaryEncoder.readEncoder();
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(30, 0);
  uint8_t arrow = 1;
  switch (currentMenu_item){
      case 0: //"Select device"
          uint8_t selected;
          uint8_t lastselected;
          display.println("Setup Menu");
          selected = selectedValue;
          arrow = constrain(arrow + selected - lastselected, 0, 2);
          lastselected = selected;
          display.setCursor(0, (8 * arrow)+5);
          display.print(">"); 
          for (uint8_t i=1; i<3; i++) {
            uint8_t drawnumber = selected + i - arrow;
            if (drawnumber < sizeof(menu_items))
            display.setCursor(12, (8 * i)+5 );
            display.print(menu_items[selected + i - arrow]); 
          }
          break;
      case 1: //"Set Voltage online"
          display.setCursor(10, 0);
          display.println("Set Voltage online");
          display.setCursor(0, 12);
          display.setTextSize(2);
          display.print(">");
          display.setCursor(20, 12);
          display.print((float)selectedValue/10,1);
          display.print(" V");
          SetVoltage = selectedValue;
          break;
      case 2: //"Set Current online"
          display.setCursor(10, 0);
          display.println("Set Current online");
          display.setCursor(0, 12);
          display.setTextSize(2);
          display.print(">");
          display.setCursor(20, 12);
          display.print((float)selectedValue/10,1);
          display.print(" A");
          SetCurrent = selectedValue;
          break;
      case 3: 
          display.setCursor(10, 0);
          display.println("Set Default Voltage");
          display.setCursor(0, 12);
          display.setTextSize(2);
          display.print(">");
          display.setCursor(20, 12);
          display.print((float)selectedValue/10,1);
          display.print(" V");
          DefaultVolt = selectedValue;
          break;
      case 4: 
          display.setCursor(10, 0);
          display.println("Set Default Current");
          display.setCursor(0, 12);
          display.setTextSize(2);
          display.print(">");
          display.setCursor(20, 12);
          display.print((float)selectedValue/10,1);
          display.print(" A");
          DefaultCurr = selectedValue;
          break;
      case 5: 
          currentMenu_item = 0;
          show_menu = false;
          break;
      default:
          break;
    }
  display.display();
}


void SetVoltageOnline()
{ 

}

// creates a short beep on the buzzer
void beep(){
  if (beepEnable) {
    for (uint8_t i=0; i<255; i++) {
      digitalWrite(BUZZER_PIN, HIGH);
      delayMicroseconds(125);
      digitalWrite(BUZZER_PIN, LOW);
      delayMicroseconds(125);
    }
  }
}