// -------- WIFI --------
#include <WiFi.h>

// -------- FIREBASE --------
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h"
#include "addons/RTDBHelper.h"

// -------- WIFI --------
const char* ssid = "MiCho";
const char* password = "Hello1234";

// -------- FIREBASE CONFIG --------
#define API_KEY "AIzaSyDpefz07KOuYyj0mZ1YtvJkm5g3z5HU0-I"
#define DATABASE_URL "https://smart-piggy-effc6-default-rtdb.asia-southeast1.firebasedatabase.app/"

FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;

// -------- PIN SETUP --------
#define BUTTON_PIN D8
#define LED_PIN D2

// -------- TIMING --------
const unsigned long debounceDelay = 50;
const unsigned long longPressTime = 1000;
const unsigned long doublePressGap = 400;

// -------- FIREBASE TIMING --------
unsigned long lastFirebaseRead = 0;
const unsigned long firebaseInterval = 2000;

// -------- STATE --------
int totalAmount = 0;
int goal = 0;
int lastGoal = -1;

// -------- BUTTON STATE --------
bool buttonState = LOW;
bool lastButtonReading = LOW;

unsigned long lastDebounceTime = 0;
unsigned long pressStartTime = 0;
unsigned long lastReleaseTime = 0;

int pressCount = 0;

// -------- SETUP --------
void setup() {
  Serial.begin(115200);

  pinMode(BUTTON_PIN, INPUT_PULLDOWN);
  pinMode(LED_PIN, OUTPUT);

  digitalWrite(LED_PIN, LOW);

  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi Connected!");
  Serial.println(WiFi.localIP());

  config.api_key = API_KEY;
  config.database_url = DATABASE_URL;
  config.token_status_callback = tokenStatusCallback;

  Firebase.signUp(&config, &auth, "", "");
  Firebase.begin(&config, &auth);
  Firebase.reconnectWiFi(true);

  Serial.println("Firebase ready");
}

// -------- LOOP --------
void loop() {

  // -------- READ GOAL (ONLY IF CHANGED) --------
  if (Firebase.ready() && millis() - lastFirebaseRead > firebaseInterval) {
    lastFirebaseRead = millis();

    if (Firebase.RTDB.get(&fbdo, "/piggy/goal")) {

      int newGoal = 0;
      String type = fbdo.dataType();

      if (type == "int") newGoal = fbdo.intData();
      else if (type == "float") newGoal = (int)fbdo.floatData();
      else if (type == "double") newGoal = (int)fbdo.doubleData();
      else if (type == "string") newGoal = fbdo.stringData().toInt();

      if (newGoal != lastGoal) {
        goal = newGoal;
        lastGoal = newGoal;

        Serial.print("Goal updated: ");
        Serial.println(goal);
      }
    }
  }

  // -------- BUTTON LOGIC --------
  int reading = digitalRead(BUTTON_PIN);

  if (reading != lastButtonReading) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {

    if (reading != buttonState) {
      buttonState = reading;

      if (buttonState == HIGH) {
        pressStartTime = millis();
      }
      else {
        unsigned long pressDuration = millis() - pressStartTime;

        if (pressDuration >= longPressTime) {
          handleLongPress();
          pressCount = 0;
        } 
        else {
          pressCount++;
          lastReleaseTime = millis();
        }
      }
    }
  }

  if (pressCount > 0 && (millis() - lastReleaseTime) > doublePressGap) {

    if (pressCount == 1) {
      handleSinglePress();
    }
    else if (pressCount == 2) {
      handleDoublePress();
    }

    pressCount = 0;
  }

  lastButtonReading = reading;
}

// -------- BUTTON ACTIONS --------

void handleSinglePress() {
  addAmount(1);
  blinkLED(1);
}

void handleDoublePress() {
  addAmount(2);
  blinkLED(2);
}

void handleLongPress() {
  addAmount(5);

  digitalWrite(LED_PIN, HIGH);
  delay(400);
  digitalWrite(LED_PIN, LOW);
}

// -------- FIREBASE WRITE (SAFE: NO OVERWRITE) --------

void sendToFirebase(int total, int percentage, int lastCoin) {

  if (Firebase.ready()) {

    Firebase.RTDB.setInt(&fbdo, "/piggy/total", total);
    Firebase.RTDB.setInt(&fbdo, "/piggy/percentage", percentage);
    Firebase.RTDB.setInt(&fbdo, "/piggy/lastCoin", lastCoin);
    Firebase.RTDB.setInt(&fbdo, "/piggy/goal", goal); // keep goal synced

    Serial.println("Data updated (safe write)");
  }
}

// -------- CORE LOGIC --------

void addAmount(int value) {

  totalAmount += value;

  int percentage = 0;

  if (goal > 0) {
    percentage = (totalAmount * 100) / goal;
  }

  Serial.print("Added: ");
  Serial.print(value);
  Serial.print(" | Total: ");
  Serial.print(totalAmount);
  Serial.print(" | ");
  Serial.print(percentage);
  Serial.println("%");

  sendToFirebase(totalAmount, percentage, value);
}

// -------- LED --------

void blinkLED(int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(LED_PIN, HIGH);
    delay(120);
    digitalWrite(LED_PIN, LOW);
    delay(120);
  }
}