#include <Keypad.h>
#include <EEPROM.h>
#include "HD44780_LCD_PCF8574.h"

// I2C LCD at address 0x27, 16 columns x 2 rows
HD44780LCD lcd(2, 16, 0x27, &Wire);

// Relay configuration
const int relayPins[] = {3, 4, 5, 6, 7, 8, 9, 10}; // Relay pins connected to digital pins
int activeRelay = -1;       // Relay currently selected by keypad
int pttRelay = -1;          // Relay activated when PTT is HIGH
const int pttPin = 2;       // Pin for PTT control (HIGH activates pttRelay)
const int EEPROM_ACTIVE_RELAY_ADDR = 0; // EEPROM address to store activeRelay
const int EEPROM_PTT_RELAY_ADDR = 1;    // EEPROM address to store pttRelay

bool pttSelectMode = false; // Flag for PTT selection mode

// Keypad configuration
const byte ROWS = 4; // Four rows
const byte COLS = 3; // Three columns
char keys[ROWS][COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};
byte rowPins[ROWS] = {A0, A1, A2, 13}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {A3, 11, 12};     // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  // Initialize LCD without cursor
  lcd.PCF8574_LCDInit(lcd.LCDCursorTypeOff);
  lcd.PCF8574_LCDClearScreen();
  lcd.PCF8574_LCDBackLightSet(true);
  lcd.PCF8574_LCDGOTO(lcd.LCDLineNumberOne, 0);
  lcd.PCF8574_LCDSendString("<Select Antenna>");
  delay(2000);

  // Set relay pins as output and turn them off
  for (int i = 0; i < 8; i++) {
    pinMode(relayPins[i], OUTPUT);
    digitalWrite(relayPins[i], LOW);
  }
  pinMode(pttPin, INPUT); // Set PTT pin as input

  // Load settings from EEPROM
  activeRelay = EEPROM.read(EEPROM_ACTIVE_RELAY_ADDR);
  pttRelay = EEPROM.read(EEPROM_PTT_RELAY_ADDR);
  if (activeRelay >= 0 && activeRelay <= 7) {
    activateRelay(activeRelay);
    lcdPrint(String("Antenna ") + (activeRelay + 1) + " On");
  } else {
    activeRelay = -1; // No saved relay is active
    lcdPrint("All Antennas Off");
  }
}

void loop() {
  // Check if PTT pin is HIGH or LOW
  if (digitalRead(pttPin) == HIGH && pttRelay != -1) {
    // PTT mode is on, activate the PTT antenna
    activateRelay(pttRelay);
    lcdPrint(String("TRANSMIT BY: ") + (pttRelay + 1));
  } else if (digitalRead(pttPin) == LOW) {
    // PTT mode is off, return to last keypad-selected antenna
    if (activeRelay != -1) {
      activateRelay(activeRelay);
      lcdPrint(String("Antenna ") + (activeRelay + 1) + " On");
    } else {
      turnOffAllRelays();
      lcdPrint("All Antennas Off");
    }
  }

  // Check keypad input
  char key = keypad.getKey();
  if (key) {
    if (pttSelectMode) {
      waitForPttSelection();  // Enter PTT selection mode
    } else {
      // Normal antenna selection mode
      if (key >= '1' && key <= '8') {
        int relayIndex = key - '1'; // Convert '1' to 0, ..., '8' to 7
        activeRelay = relayIndex;   // Update activeRelay to store the last selection
        if (EEPROM.read(EEPROM_ACTIVE_RELAY_ADDR) != activeRelay) {
          EEPROM.write(EEPROM_ACTIVE_RELAY_ADDR, activeRelay); // Save to EEPROM only if different
        }
        activateRelay(activeRelay);
        lcdPrint(String("Antenna ") + (relayIndex + 1) + " On");
      } else if (key == '0') {
        activeRelay = -1;           // Reset active relay variable
        if (EEPROM.read(EEPROM_ACTIVE_RELAY_ADDR) != activeRelay) {
          EEPROM.write(EEPROM_ACTIVE_RELAY_ADDR, activeRelay); // Save only if changed
        }
        turnOffAllRelays();         // Turn off all relays
        lcdPrint("All Antennas Off");
      } else if (key == '*') {
        // Enter PTT antenna selection mode
        pttSelectMode = true;
        lcdPrint("Select PTT Ant:");
        waitForPttSelection();  // Start waiting for PTT antenna selection
      }
    }
  }
}

void waitForPttSelection() {
  int tempPttRelay = -1;  // Temporary variable to hold the selected antenna number

  while (true) {
    char pttKey = keypad.getKey();

    if (pttKey) {
      if (pttKey >= '1' && pttKey <= '8') {
        // Set the temporary relay selection and display confirmation prompt
        tempPttRelay = pttKey - '1';
        lcdPrint(String("Set PTT Ant. ") + (tempPttRelay + 1) + ", Press # to Confirm");

      } else if (pttKey == '0') {
        // Option to clear the PTT antenna
        lcdPrint("Clear PTT Antenna, Press # to Confirm");
        tempPttRelay = -1;  // Indicate clearing the PTT relay

      } else if (pttKey == '#') {
        // Confirm the PTT relay selection or clearing
        pttRelay = tempPttRelay;
        if (EEPROM.read(EEPROM_PTT_RELAY_ADDR) != pttRelay) {
          EEPROM.write(EEPROM_PTT_RELAY_ADDR, pttRelay); // Save only if changed
        }
        if (pttRelay == -1) {
          lcdPrint("PTT Antenna Cleared");
        } else {
          lcdPrint(String("PTT Antenna ") + (pttRelay + 1) + " Saved");
        }
        pttSelectMode = false;  // Exit PTT selection mode
        break;

      } else {
        lcdPrint("Invalid Input, Press 1-8 or 0 to Clear");
      }
    }
  }
}

void lcdPrint(const String &text) {
  lcd.PCF8574_LCDClearScreen();
  lcd.PCF8574_LCDGOTO(lcd.LCDLineNumberOne, 0);
  lcd.PCF8574_LCDSendString("    4L7ZS ");
  lcd.PCF8574_LCDGOTO(lcd.LCDLineNumberTwo, 0);
  lcd.PCF8574_LCDSendString(text.c_str());
}

void activateRelay(int relayIndex) {
  turnOffAllRelays();               // Ensure only one relay is active
  digitalWrite(relayPins[relayIndex], HIGH);
}

void turnOffAllRelays() {
  for (int i = 0; i < 8; i++) {
    digitalWrite(relayPins[i], LOW);
  }
}