#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <Adafruit_FT6206.h>

#define TFT_CS    10
#define TFT_DC    A2
#define TFT_RST   A3
#define LED_GRN   A0
#define LED_RED   A1

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {{'1','2','3','A'},{'4','5','6','B'},{'7','8','9','C'},{'*','0','#','D'}};
byte rowPins[ROWS] = {9, 8, 7, 6}; 
byte colPins[COLS] = {5, 4, 3, 2}; 

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
LiquidCrystal_I2C lcd(0x27, 16, 2);
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
Adafruit_FT6206 ctp = Adafruit_FT6206();

enum State { MERCHANT_ENTRY, ID_PHASE, ACCOUNT_SEL, PIN_PHASE };
State currentState = MERCHANT_ENTRY;

// --- MULTI-USER DATA ---
int currentUser = 0; 
String userNames[] = {"Tapish Chahera", "Simran Chawla"};
String userBanks[2][5] = {
  {"SBI 4894", "PNB 7930", "HDFC 4689", "ICICI 1122", "AXIS 9901"}, 
  {"KOTAK 2210", "INDUS 5543", "YES 9090", "BOB 3321", "UCO 1199"}
};

const int totalBanks = 5;
int scrollIndex = 0;
String amount = "";
String selectedBank = "";
int pinTaps = 0;
int failMode = 0; 
float totalSales = 0;
bool sosActive = false;
unsigned long lastTouch = 0;

void setup() {
  pinMode(LED_GRN, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  lcd.init(); lcd.backlight();
  tft.begin(); tft.setRotation(0); 
  
  // FIX: Lower threshold from 40 to 10 for "Feather Touch" sensitivity
  ctp.begin(10); 
  
  resetSystem();
}

void resetSystem() {
  currentState = MERCHANT_ENTRY;
  amount = ""; pinTaps = 0; failMode = 0; selectedBank = ""; scrollIndex = 0;
  sosActive = false;
  
  digitalWrite(LED_GRN, LOW); digitalWrite(LED_RED, LOW);
  
  lcd.clear();
  lcd.print("Enter Amount:");
  lcd.setCursor(0, 1); lcd.print("Rs. ");

  // IDLE STATE: Dark Grey Outline
  tft.fillScreen(ILI9341_BLACK);
  tft.drawEllipse(120, 160, 50, 80, 0x5AEB); // Static Outline
  tft.drawEllipse(120, 160, 49, 79, 0x5AEB); // Thicker line
}

// --- OPTIMIZED ANIMATION FUNCTION ---
void scanFingerEffect(uint16_t color) {
  // Loop from center to outside
  for (int r = 0; r <= 50; r+=3) { // Step by 3 for faster animation
    // Use Integer Math (r * 1.6 is roughly r * 8 / 5)
    int ry = (r * 8) / 5; 
    
    // Draw concentric ovals
    tft.drawEllipse(120, 160, r, ry, color);
    tft.drawEllipse(120, 160, r+1, ry+1, color); // Double line for fill density
  }
}

void updateBankList() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(String(scrollIndex + 1) + "." + userBanks[currentUser][scrollIndex]);
  if (scrollIndex + 1 < totalBanks) {
    lcd.setCursor(0, 1);
    lcd.print(String(scrollIndex + 2) + "." + userBanks[currentUser][scrollIndex + 1]);
  }
}

void loop() {
  // 1. Handle Keypad Inputs
  KeyState kstate = keypad.getState();
  char key = keypad.getKey();
  
  if (kstate == HOLD) {
     char lastKey = keypad.key[0].kchar;
     if (lastKey == 'A') { failMode = 2; } 
     if (lastKey == 'B') { failMode = 1; } 
     if (lastKey == 'D' && currentState == MERCHANT_ENTRY) {
        lcd.clear(); lcd.print("TOTAL SALES:");
        lcd.setCursor(0,1); lcd.print("Rs. " + String(totalSales, 2));
        delay(3000); resetSystem();
     }
  }

  if (key == '*') sosActive = true;
  if (key == 'B' && currentState == MERCHANT_ENTRY) currentUser = !currentUser;

  if (currentState == MERCHANT_ENTRY) {
    if (key >= '0' && key <= '9') {
      amount += key;
      lcd.setCursor(4, 1); lcd.print(amount);
    } 
    else if (key == 'A') { 
      amount = "";
      lcd.setCursor(4, 1); lcd.print("            ");
    }
    else if (key == '#') {
      if (amount.toFloat() > 2000) {
        lcd.clear(); lcd.print("LIMIT EXCEEDED!");
        lcd.setCursor(0,1); lcd.print("Max Rs. 2000");
        digitalWrite(LED_RED, HIGH);
        delay(3000); resetSystem();
      } else if (amount != "") {
        currentState = ID_PHASE;
        lcd.clear(); lcd.print("Place Finger on");
        lcd.setCursor(0, 1); lcd.print("Scanner...");
        
        tft.fillScreen(ILI9341_BLACK);
        tft.drawEllipse(120, 160, 50, 80, ILI9341_CYAN);
        tft.drawEllipse(120, 160, 49, 79, ILI9341_CYAN);
      }
    }
  }

  else if (currentState == ACCOUNT_SEL) {
    if (key == 'D' && scrollIndex < totalBanks - 2) { scrollIndex++; updateBankList(); }
    if (key == 'C' && scrollIndex > 0) { scrollIndex--; updateBankList(); }
    
    if (key >= '1' && key <= '9') {
      int choice = (key - '0') - 1;
      if (choice < totalBanks) {
        selectedBank = userBanks[currentUser][choice]; 
        currentState = PIN_PHASE;
        lcd.clear(); lcd.print("Selected: " + selectedBank.substring(0,6));
        lcd.setCursor(0, 1); lcd.print("Tap Pattern Now");
        
        tft.fillScreen(ILI9341_BLACK);
        tft.drawEllipse(120, 160, 50, 80, ILI9341_YELLOW);
        tft.drawEllipse(120, 160, 49, 79, ILI9341_YELLOW);
      }
    }
  }

  // --- 2. FIXED TOUCH LOGIC ---
  if (ctp.touched()) {
    // CRITICAL FIX: Always retrieve the point to clear the interrupt/register
    TS_Point p = ctp.getPoint(); 
    
    // Only process if enough time has passed (Debounce)
    if (millis() - lastTouch > 250) { // Fast 250ms debounce
      lastTouch = millis();
      
      // LOGIC: Check state
      if (currentState == ID_PHASE) {
        scanFingerEffect(ILI9341_CYAN); 
        
        if (failMode == 2) {
          lcd.clear(); lcd.print("ACCESS DENIED");
          lcd.setCursor(0,1); lcd.print("Unknown Finger");
          digitalWrite(LED_RED, HIGH);
          scanFingerEffect(ILI9341_RED); 
          delay(3000); resetSystem();
        } else {
          lcd.clear(); lcd.print("WELCOME:");
          lcd.setCursor(0, 1); lcd.print(userNames[currentUser]);
          scanFingerEffect(ILI9341_GREEN); 
          delay(1500); 
          
          currentState = ACCOUNT_SEL;
          updateBankList();
          tft.fillScreen(ILI9341_BLACK);
          tft.drawEllipse(120, 160, 50, 80, ILI9341_WHITE);
        }
      } 
      else if (currentState == PIN_PHASE) {
        pinTaps++;
        if (pinTaps == 1) { lcd.setCursor(0, 1); lcd.print("                "); }
        lcd.setCursor(0, 1); lcd.print("PIN: ");
        for(int i=0; i<pinTaps; i++) lcd.print("*");
        
        scanFingerEffect(ILI9341_WHITE); 
        tft.fillScreen(ILI9341_BLACK);
        tft.drawEllipse(120, 160, 50, 80, ILI9341_YELLOW); 

        if (pinTaps == 4) {
          lcd.clear();
          if (failMode == 1) {
            lcd.print("TXN FAILED");
            lcd.setCursor(0,1); lcd.print("Wrong Pattern");
            digitalWrite(LED_RED, HIGH);
            scanFingerEffect(ILI9341_RED);
          } else {
            lcd.print("PAYMENT SUCCESS");
            totalSales += amount.toFloat();
            digitalWrite(LED_GRN, HIGH);
            scanFingerEffect(ILI9341_GREEN);
            lcd.setCursor(0,1); 
            if (sosActive) lcd.print("SOS ALERT SENT!");
            else lcd.print("Ref: " + String(random(1000,9999)));
          }
          delay(4000); resetSystem();
        }
      }
    }
  }
}