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

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin definīcijas
const int startButton = 2;
const int modePinSweep = 3; 
const int modePinPhase = 4; 
const int btnUp = 5;      
const int btnDown = 6;    
const int modeAudioPin = 7; // Audio režīma slēdzis (5V = Ieslēgts)   
const int potPin = A0;      // Manuālais potenciometrs frekvencei
const int batteryPin = A1;  // Akumulatora sprieguma mērīšana
const int audioPin = A2;    // MCP6002 audio ieeja (2.5V viduspunkts)
const int contactPin = A3;  // Kontakta kontrole ar ādu (100mV slieksnis)
const int zapperOut = 9;    // Timer1 OC1A izeja uz CD4093 un MOSFET
const int buzzerLed = 10;   // Pīkstulis un LED indikācija

// Projekta parametri
int mode = 1; 
bool isRunning = false;
unsigned long startTime;
const unsigned long totalTimer = 420000; // 7 minūtes
const unsigned long sweepCycle = 120000; // 2 minūtes
const unsigned long phaseInterval = 2000;

// Mainīgie
float batteryVoltage = 0.0;
unsigned long lastLcdUpdate = 0;
bool phaseInverted = false;
unsigned long lastPhaseFlip = 0;
float currentDuty = 0.5;
long fineTuneOffset = 0; 
int lastPotVal = 0;
unsigned long btnPressTime = 0;
int stepSize = 1;

// Audio un kontakta papildus mainīgie
unsigned long lastBuzzerMillis = 0;
bool contactOk = true;

void setup() {
  pinMode(startButton, INPUT); 
  pinMode(modePinSweep, INPUT); 
  pinMode(modePinPhase, INPUT); 
  pinMode(modeAudioPin, INPUT); 
  pinMode(btnUp, INPUT);    
  pinMode(btnDown, INPUT);  
  pinMode(zapperOut, OUTPUT);
  pinMode(buzzerLed, OUTPUT);
  
  digitalWrite(zapperOut, LOW);
  
  TCCR1A = 0; 
  TCCR1B = 0;

  lcd.init();
  lcd.backlight();
  lcd.print("ZAPPER V10.0 PWM");
  delay(1000);
  lcd.clear();
}

void setHardwareSignal(float frequency, float duty, bool inverted) {
  if (frequency < 10) frequency = 10; 
  unsigned long topValue = (16000000UL / (1 * (unsigned long)frequency)) - 1;
  if (topValue > 65535) topValue = 65535;

  ICR1 = topValue;
  OCR1A = (unsigned int)(topValue * duty);

  TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10); 
  if (inverted) {
    TCCR1A = _BV(COM1A1) | _BV(COM1A0) | _BV(WGM11); 
  } else {
    TCCR1A = _BV(COM1A1) | _BV(WGM11); 
  }
}

void stopHardwareSignal() {
  TCCR1A = 0; 
  TCCR1B = 0;
  digitalWrite(zapperOut, LOW);
}

void updateBattery() {
  int raw = analogRead(batteryPin);
  batteryVoltage = (raw / 1023.0) * 5.0 * 2.0;
}

void readMode() {
  // Ja uz D7 ir 5V, piespiedu kārtā ieslēdzam AUDIO režīmu (Mode 5)
  if (digitalRead(modeAudioPin) == HIGH) {
    mode = 5;
    return;
  }

  bool s1 = digitalRead(modePinSweep);
  bool s2 = digitalRead(modePinPhase);
  if (s1 && s2) mode = 4;
  else if (s1)  mode = 2;
  else if (s2)  mode = 3;
  else          mode = 1;
}

void handleFineTune() {
  bool up = digitalRead(btnUp);
  bool down = digitalRead(btnDown);
  if (up || down) {
    if (btnPressTime == 0) btnPressTime = millis();
    unsigned long duration = millis() - btnPressTime;
    
    if (duration > 3000) stepSize = 100;
    else if (duration > 1000) stepSize = 10;
    else stepSize = 1;
    
    if (up) fineTuneOffset += stepSize;
    if (down) fineTuneOffset -= stepSize;
    delay(100); 
  } else {
    btnPressTime = 0;
    stepSize = 1;
  }
}

void stopZapper() {
  isRunning = false;
  stopHardwareSignal();
  digitalWrite(buzzerLed, LOW);
  lcd.clear();
  lcd.print(" CYCLE FINISHED ");
  digitalWrite(buzzerLed, HIGH); delay(1000); digitalWrite(buzzerLed, LOW);
  delay(1000);
  lcd.clear();
}

void startZapper() {
  lcd.clear();
  isRunning = true;
  startTime = millis();
  lastPhaseFlip = millis();
  lastBuzzerMillis = millis();
  digitalWrite(buzzerLed, HIGH); delay(200); digitalWrite(buzzerLed, LOW);
}

void runZapper() {
  unsigned long currentTime = millis();
  unsigned long elapsed = currentTime - startTime;

  if (elapsed >= totalTimer) { stopZapper(); return; }
  if (elapsed > 1000 && digitalRead(startButton) == HIGH) { stopZapper(); delay(500); return; }

  readMode(); 

  // PĀRBAUDĀM KONTAKTU UZ A3 (20 atbilst ~100mV slieksnim)
  int contactVal = analogRead(contactPin);
  if (contactVal >= 20) {
    contactOk = true;
  } else {
    contactOk = false;
  }

  // Ja kontakta nav, signālu atslēdzam un reizi sekundē pīkstam
  if (!contactOk) {
    stopHardwareSignal();
    if (currentTime - lastBuzzerMillis >= 1000) {
      lastBuzzerMillis = currentTime;
      digitalWrite(buzzerLed, HIGH); delay(50); digitalWrite(buzzerLed, LOW);
    }
    
    if (currentTime - lastLcdUpdate > 300) {
      lastLcdUpdate = currentTime;
      lcd.setCursor(0, 0); lcd.print("NO CONTACT!     ");
      lcd.setCursor(0, 1); lcd.print("CHECK ELECTRODES");
    }
    return; 
  }

  // Ja kontakts ir, lasām potenciometru pārējiem režīmiem
  int potVal = analogRead(potPin);
  if (abs(potVal - lastPotVal) > 12 && mode != 5) { fineTuneOffset = 0; lastPotVal = potVal; }
  if (mode != 2 && mode != 5) handleFineTune();

  float freq;
  
  if (mode == 5) {
    // AUDIO REŽĪMS: Fiksēta 33.33 kHz nesošā frekvence
    freq = 33333.33; 
    
    // Lasām audio signālu no pareizās ieejas - A2
    int audioVal = analogRead(audioPin); 
    
    // PWM modulācija ap 2.5V viduspunktu (ADC vērtība ~512)
    float audioSignal = (audioVal - 512) / 512.0; 
    currentDuty = 0.5 + (audioSignal * 0.4); // Modulācijas dziļums (10% līdz 90%)
    phaseInverted = false;
  }
  else if (mode == 2) { 
    unsigned long sweepMillis = currentTime % sweepCycle;
    float sweepPos = (sweepMillis < (sweepCycle / 2)) ? 
                     ((float)sweepMillis / (sweepCycle / 2.0)) : 
                     (1.0 - ((float)(sweepMillis - (sweepCycle / 2.0)) / (sweepCycle / 2.0)));
    freq = 10.0 + (39990.0 * (sweepPos * sweepPos)); 
    currentDuty = 0.5;
    phaseInverted = false;
  } 
  else {
    float normPot = potVal / 1023.0; 
    freq = 14.0 + (39986.0 * (normPot * normPot)) + (float)fineTuneOffset;
    
    if (mode == 3) { 
      if (currentTime - lastPhaseFlip >= phaseInterval) {
        phaseInverted = !phaseInverted;
        lastPhaseFlip = currentTime;
      }
      currentDuty = 0.5;
    } 
    else if (mode == 4) { 
      unsigned long dcMillis = currentTime % 4000;
      if (dcMillis < 2000) currentDuty = 0.1 + (0.8 * (dcMillis / 2000.0));
      else currentDuty = 0.9 - (0.8 * ((dcMillis - 2000) / 2000.0));
      phaseInverted = false;
    } else {
      currentDuty = 0.5;
      phaseInverted = false;
    }
  }

  // Padedzam signālu uz taimeri (izeja D9)
  setHardwareSignal(freq, currentDuty, phaseInverted);

  // LCD informācijas atjaunošana darbības laikā
  if (currentTime - lastLcdUpdate > 300) {
    lastLcdUpdate = currentTime;
    updateBattery();
    lcd.setCursor(0, 0);
    switch(mode) {
      case 1: lcd.print("MANUAL   "); break;
      case 2: lcd.print("SWEEP    "); break;
      case 3: lcd.print("PHASE180 "); break;
      case 4: lcd.print("DUTY MOD "); break;
      case 5: lcd.print("AUDIO PWM"); break; 
    }
    unsigned long rem = (totalTimer - elapsed) / 1000;
    lcd.setCursor(11, 0);
    lcd.print(rem/60); lcd.print(":"); 
    if(rem%60 < 10) lcd.print("0"); lcd.print(rem%60);
    
    lcd.setCursor(0, 1);
    if (mode == 5) {
      lcd.print("33.33kHz MOD ");
    } else {
      if (freq >= 1000) { lcd.print(freq/1000.0, 2); lcd.print("kHz "); } 
      else { lcd.print((int)freq); lcd.print("Hz  "); }
    }
    lcd.setCursor(11, 1);
    lcd.print(batteryVoltage, 1); lcd.print("V ");
  }
}

void loop() {
  if (!isRunning) {
    updateBattery(); 
    readMode();
    if (mode != 5) handleFineTune();

    lcd.setCursor(0, 0);
    lcd.print("READY: ");
    switch(mode) {
      case 1: lcd.print("MANUAL   "); break;
      case 2: lcd.print("SWEEP    "); break;
      case 3: lcd.print("PHASE    "); break;
      case 4: lcd.print("DUTY CYC "); break; // Salabots šeit (pielikts break un sakārtotas iekavas)
      case 5: lcd.print("AUDIO PWM"); break; 
    }

    lcd.setCursor(0, 1);
    lcd.print("BAT:"); lcd.print(batteryVoltage, 1); lcd.print("V  START? ");

    if (digitalRead(startButton) == HIGH && batteryVoltage >= 3.2) {
      startZapper();
      delay(300); 
    }
  } else {
    runZapper();
  }
}