#include <OneWire.h>
#include <Wire.h>
#include <DallasTemperature.h>
#include <LiquidCrystal_I2C.h>
#include <RTClib.h>
#include <SPI.h>
#include <SD.h>

// LCD, RTC e SD
constexpr uint8_t LCD_ADDR = 0x27;
constexpr uint8_t LCD_COLS = 20;
constexpr uint8_t LCD_ROWS = 4;
LiquidCrystal_I2C lcd(LCD_ADDR, LCD_COLS, LCD_ROWS);
RTC_DS3231 rtc;
constexpr uint8_t SD_CS_PIN = 10;

// Sensores em pinos separados
constexpr uint8_t SENSOR_PINS[4] = {2, 3, 4, 5};
OneWire oneWires[4] = {OneWire(SENSOR_PINS[0]), OneWire(SENSOR_PINS[1]), OneWire(SENSOR_PINS[2]), OneWire(SENSOR_PINS[3])};
DallasTemperature sensors[4] = {DallasTemperature(&oneWires[0]), DallasTemperature(&oneWires[1]), DallasTemperature(&oneWires[2]), DallasTemperature(&oneWires[3])};

File dataFile;

// Botões (pull-up interno)
constexpr uint8_t BTN_PROG = 7;
constexpr uint8_t BTN_UP   = 6;
constexpr uint8_t BTN_DOWN = 8;

// Menus
constexpr uint8_t MAIN_MENU_SIZE = 3;
const char* mainMenu[MAIN_MENU_SIZE] = {"Automatico", "Selecionar", "Historico"};
constexpr uint8_t SENSOR_MENU_SIZE = 5;
const char* sensorMenu[SENSOR_MENU_SIZE] = {"Ambiente", "Interno", "Externo", "Pastilha", "Sair"};

int mainMenuIndex = 0;
int sensorMenuIndex = 0;

void setup() {
  Serial.begin(9600);
  lcd.begin(LCD_COLS, LCD_ROWS);
  lcd.backlight();

  pinMode(BTN_PROG, INPUT_PULLUP);
  pinMode(BTN_UP,   INPUT_PULLUP);
  pinMode(BTN_DOWN, INPUT_PULLUP);

  for (auto& sensor : sensors) sensor.begin();

  if (!rtc.begin()) {
    lcd.clear(); lcd.print("Erro no RTC"); while (1);
  }
  if (!SD.begin(SD_CS_PIN)) {
    lcd.clear(); lcd.print("Erro no SD"); while (1);
  }

  // Splash
  lcd.clear();
  lcd.setCursor(5, 1); lcd.print("PeltierLab");
  lcd.setCursor(2, 2); lcd.print("Press any button");
  while (digitalRead(BTN_PROG) == HIGH &&
         digitalRead(BTN_UP)   == HIGH &&
         digitalRead(BTN_DOWN) == HIGH) {
    delay(10);
  }
  delay(300);
  showMainMenu();
}

void loop() {
  handleMainMenu();
}

// ——— Funções utilitárias ————————————————————————————————
bool buttonPressed() {
  return digitalRead(BTN_PROG) == LOW ||
         digitalRead(BTN_UP)   == LOW ||
         digitalRead(BTN_DOWN) == LOW;
}

void waitForButtonRelease() {
  while (buttonPressed()) delay(10);
}

void debounceDelay() {
  delay(200);
}

// ——— MENU PRINCIPAL ——————————————————————————————————————
void showMainMenu() {
  DateTime now = rtc.now();
  lcd.clear();
  for (uint8_t i = 0; i < MAIN_MENU_SIZE; i++) {
    lcd.setCursor(0, i);
    lcd.print((i == mainMenuIndex) ? ">" : " ");
    lcd.print(mainMenu[i]);
  }
  // Hora na última linha
  lcd.setCursor(14, 3);
  printTime(now.hour(), now.minute());
}

void handleMainMenu() {
  if (digitalRead(BTN_UP) == LOW) {
    mainMenuIndex = (mainMenuIndex > 0) ? mainMenuIndex - 1 : MAIN_MENU_SIZE - 1;
    debounceDelay();
    showMainMenu();
  }
  if (digitalRead(BTN_DOWN) == LOW) {
    mainMenuIndex = (mainMenuIndex < MAIN_MENU_SIZE - 1) ? mainMenuIndex + 1 : 0;
    debounceDelay();
    showMainMenu();
  }
  if (digitalRead(BTN_PROG) == LOW) {
    debounceDelay();
    switch (mainMenuIndex) {
      case 0: showAutomaticScreen(); break;
      case 1: showSensorSelection(); break;
      case 2: showHistory();         break;
    }
    showMainMenu();
  }
}

// ——— AUTOMATICO ——————————————————————————————————————
void showAutomaticScreen() {
  uint8_t screen = 0; // 0: Temperaturas, 1: Média+Hora+Data
  unsigned long lastSwitch = millis();
  const unsigned long interval = 1500;

  float temps[4], media = 0;
  DateTime now;
  char hora[6], data[11];

  while (true) {
    if (screen == 0) {
      media = 0;
      for (uint8_t i = 0; i < 4; i++) {
        sensors[i].requestTemperatures();
        temps[i] = sensors[i].getTempCByIndex(0);
        media += temps[i];
      }
      media /= 4.0;

      now = rtc.now();
      snprintf(hora, sizeof(hora), "%02d:%02d", now.hour(), now.minute());
      snprintf(data, sizeof(data), "%02d/%02d/%04d", now.day(), now.month(), now.year());

      lcd.clear();
      for (uint8_t i = 0; i < 4; i++) {
        lcd.setCursor(0, i);
        lcd.print(sensorMenu[i]);
        lcd.print(" : ");
        lcd.print(temps[i], 1);
        lcd.write(223); lcd.print("C");
      }
    } else {
      lcd.clear();
      lcd.setCursor(0, 0); lcd.print("Media  : "); lcd.print(media, 1); lcd.write(223); lcd.print("C");
      lcd.setCursor(0, 1); lcd.print("Hora   : "); lcd.print(hora);
      lcd.setCursor(0, 3); lcd.print("Data   : "); lcd.print(data);

      // Grava log apenas na segunda tela
      char log[64];
      snprintf(log, sizeof(log), "%s %s; S1=%.2f; S2=%.2f; S3=%.2f; S4=%.2f; M=%.2f",
               data, hora, temps[0], temps[1], temps[2], temps[3], media);
      dataFile = SD.open("log.txt", FILE_WRITE);
      if (dataFile) { dataFile.println(log); dataFile.close(); }
    }

    lastSwitch = millis();
    while (millis() - lastSwitch < interval) {
      if (buttonPressed()) {
        waitForButtonRelease();
        showMainMenu();
        return;
      }
      delay(10);
    }
    screen = 1 - screen; // alterna entre 0 e 1
  }
}

// ——— SELEÇÃO DE SENSOR ————————————————————————————————
void showSensorSelection() {
  sensorMenuIndex = 0;
  int displayStart = 0;

  auto printSensorMenu = [&]() {
    lcd.clear();
    for (uint8_t i = 0; i < 4; i++) {
      int optionIdx = displayStart + i;
      if (optionIdx >= SENSOR_MENU_SIZE) break;
      lcd.setCursor(0, i);
      lcd.print((optionIdx == sensorMenuIndex) ? ">" : " ");
      lcd.print(sensorMenu[optionIdx]);
    }
  };

  printSensorMenu();

  while (true) {
    if (digitalRead(BTN_UP) == LOW) {
      sensorMenuIndex = (sensorMenuIndex > 0) ? sensorMenuIndex - 1 : SENSOR_MENU_SIZE - 1;
      if (sensorMenuIndex < displayStart) displayStart = sensorMenuIndex;
      if (sensorMenuIndex == SENSOR_MENU_SIZE - 1) displayStart = SENSOR_MENU_SIZE - 4 < 0 ? 0 : SENSOR_MENU_SIZE - 4;
      debounceDelay();
      printSensorMenu();
    }
    if (digitalRead(BTN_DOWN) == LOW) {
      sensorMenuIndex = (sensorMenuIndex < SENSOR_MENU_SIZE - 1) ? sensorMenuIndex + 1 : 0;
      if (sensorMenuIndex > displayStart + 3) displayStart = sensorMenuIndex - 3;
      if (sensorMenuIndex == 0) displayStart = 0;
      debounceDelay();
      printSensorMenu();
    }
    if (digitalRead(BTN_PROG) == LOW) {
      debounceDelay();
      if (strcmp(sensorMenu[sensorMenuIndex], "Sair") == 0) return;
      float temp = 0;
      if (sensorMenuIndex < 4) {
        sensors[sensorMenuIndex].requestTemperatures();
        temp = sensors[sensorMenuIndex].getTempCByIndex(0);
      }
      lcd.clear();
      lcd.setCursor(0, 0); lcd.print("Sensor: "); lcd.print(sensorMenu[sensorMenuIndex]);
      lcd.setCursor(0, 1); lcd.print("Temp  : "); lcd.print(temp, 1); lcd.write(223); lcd.print("C");
      delay(3000);
      printSensorMenu();
    }
  }
}

// ——— HISTÓRICO ————————————————————————————————————————
void showHistory() {
  String logs[4];
  int count = 0;
  File f = SD.open("log.txt");
  if (f) {
    int totalLines = 0;
    while (f.available()) { f.readStringUntil('\n'); totalLines++; }
    f.seek(0);
    int skip = totalLines > 4 ? totalLines - 4 : 0;
    for (int i = 0; i < skip; i++) f.readStringUntil('\n');
    while (f.available() && count < 4) logs[count++] = f.readStringUntil('\n');
    f.close();
  }

  int selected = 0, lastSelected = -1;
  while (true) {
    if (selected != lastSelected) {
      lcd.clear();
      lcd.setCursor(0, 0);
      for (int i = 0; i < count; i++) {
        lcd.setCursor(0, i + 1);
        lcd.print((i == selected) ? ">" : " ");
        lcd.print(logs[i].substring(0, 18));
      }
      lastSelected = selected;
    }
    if (digitalRead(BTN_UP) == LOW) {
      selected = (selected > 0) ? selected - 1 : count - 1;
      debounceDelay();
    }
    if (digitalRead(BTN_DOWN) == LOW) {
      selected = (selected < count - 1) ? selected + 1 : 0;
      debounceDelay();
    }
    if (digitalRead(BTN_PROG) == LOW) {
      debounceDelay();
      return;
    }
  }
}

// ——— Funções auxiliares ————————————————————————————————
void printTime(uint8_t hour, uint8_t minute) {
  if (hour < 10) lcd.print('0');
  lcd.print(hour);
  lcd.print(':');
  if (minute < 10) lcd.print('0');
  lcd.print(minute);
}