#include <Arduino.h>
#include <WiFi.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
#include <LiquidCrystal.h>

// PINES
#define MQ135_PIN 34
#define FAN_PWM_PIN 25
#define RELAY_PIN 26
#define LED_GREEN 12
#define LED_YELLOW 13
#define LED_RED 14
#define BUTTON_PIN 27
#define LCD_RS 15
#define LCD_EN 2
#define LCD_D4 19
#define LCD_D5 18
#define LCD_D6 5
#define LCD_D7 4

// PWM
#define PWM_CHANNEL 0
#define PWM_FREQUENCY 25000
#define PWM_RESOLUTION 8

// UMBRALES
#define HUMIDITY_THRESHOLD_LOW 60
#define HUMIDITY_THRESHOLD_HIGH 75
#define TEMP_THRESHOLD 28
#define AIR_QUALITY_THRESHOLD 400
#define AUTO_OFF_DELAY 300000
#define SENSOR_READ_INTERVAL 2000

// OBJETOS
Adafruit_BME280 bme;
LiquidCrystal lcd(LCD_RS, LCD_EN, LCD_D4, LCD_D5, LCD_D6, LCD_D7);

// VARIABLES GLOBALES
enum Mode { AUTO, MANUAL };
enum FanSpeed { FAN_OFF, FAN_LOW, FAN_MEDIUM, FAN_HIGH };
Mode currentMode = AUTO;
FanSpeed currentSpeed = FAN_OFF;
FanSpeed manualSpeed = FAN_OFF;
float humidity = 0;
float temperature = 0;
int airQuality = 0;
// ... (resto de variables globales)
bool buttonPressed = false;
bool lastButtonState = false;
unsigned long lastSensorRead = 0;
unsigned long fanStartTime = 0;
unsigned long lastButtonPress = 0;
const unsigned long debounceDelay = 200;
bool errorState = false;
unsigned long lastErrorBlink = 0;
bool errorLedState = false;

void setup() {
  Serial.begin(115200);
  lcd.begin(16, 2);
  lcd.print("Extractor Bano");
  lcd.setCursor(0, 1);
  lcd.print("Iniciando...");

  if (!bme.begin(0x76)) {
    Serial.println("Error BME280");
    lcd.clear();
    lcd.print("ERROR SENSOR");
    while (1) delay(10);
  }

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(MQ135_PIN, INPUT);

  digitalWrite(RELAY_PIN, LOW);
  turnOffAllLEDs();

  ledcSetup(PWM_CHANNEL, PWM_FREQUENCY, PWM_RESOLUTION);
  ledcAttachPin(FAN_PWM_PIN, PWM_CHANNEL);
  ledcWrite(PWM_CHANNEL, 0);

  delay(2000);
  lcd.clear();
  updateDisplay();
}

void loop() {
  checkButton();
  if (millis() - lastSensorRead >= SENSOR_READ_INTERVAL) {
    readSensors();
    lastSensorRead = millis();
  }
  if (currentMode == AUTO) processAutoMode();
  else processManualMode();
  controlFan();
  updateLEDs();
  updateDisplay();
  if (errorState) handleErrorState();
  delay(100);
}

void readSensors() {
  float newHumidity = bme.readHumidity();
  float newTemperature = bme.readTemperature();
  if (isnan(newHumidity) || isnan(newTemperature)) {
    errorState = true;
    return;
  } else {
    errorState = false;
    humidity = newHumidity;
    temperature = newTemperature;
  }
  airQuality = analogRead(MQ135_PIN);
}

void checkButton() {
  bool buttonState = !digitalRead(BUTTON_PIN);
  if (buttonState && !lastButtonState && (millis() - lastButtonPress > debounceDelay)) {
    buttonPressed = true;
    lastButtonPress = millis();
    toggleMode();
  }
  lastButtonState = buttonState;
}

void processAutoMode() {
  FanSpeed requiredSpeed = FAN_OFF;
  if (humidity >= HUMIDITY_THRESHOLD_HIGH) requiredSpeed = FAN_HIGH;
  else if (humidity >= HUMIDITY_THRESHOLD_LOW) requiredSpeed = FAN_MEDIUM;
  if (temperature >= TEMP_THRESHOLD) requiredSpeed = max(requiredSpeed, FAN_MEDIUM);
  if (airQuality >= AIR_QUALITY_THRESHOLD) requiredSpeed = max(requiredSpeed, FAN_LOW);
  if (requiredSpeed != currentSpeed) {
    if (requiredSpeed != FAN_OFF && currentSpeed == FAN_OFF) fanStartTime = millis();
    currentSpeed = requiredSpeed;
  }
  if (currentSpeed != FAN_OFF && (millis() - fanStartTime >= AUTO_OFF_DELAY) &&
      humidity < HUMIDITY_THRESHOLD_LOW && temperature < TEMP_THRESHOLD &&
      airQuality < AIR_QUALITY_THRESHOLD) {
    currentSpeed = FAN_OFF;
  }
}

void processManualMode() {
  if (buttonPressed) {
    buttonPressed = false;
    switch (manualSpeed) {
      case FAN_OFF: manualSpeed = FAN_LOW; break;
      case FAN_LOW: manualSpeed = FAN_MEDIUM; break;
      case FAN_MEDIUM: manualSpeed = FAN_HIGH; break;
      case FAN_HIGH: manualSpeed = FAN_OFF; break;
    }
    currentSpeed = manualSpeed;
    if (currentSpeed != FAN_OFF) fanStartTime = millis();
  }
}

void controlFan() {
  int pwmValue = 0;
  bool relayState = false;
  switch (currentSpeed) {
    case FAN_LOW: pwmValue = 85; relayState = true; break;
    case FAN_MEDIUM: pwmValue = 170; relayState = true; break;
    case FAN_HIGH: pwmValue = 255; relayState = true; break;
    default: pwmValue = 0; relayState = false; break;
  }
  digitalWrite(RELAY_PIN, relayState);
  ledcWrite(PWM_CHANNEL, pwmValue);
}

void updateLEDs() {
  if (errorState) return;
  turnOffAllLEDs();
  switch (currentSpeed) {
    case FAN_LOW: digitalWrite(LED_GREEN, HIGH); break;
    case FAN_MEDIUM: digitalWrite(LED_YELLOW, HIGH); break;
    case FAN_HIGH: digitalWrite(LED_RED, HIGH); break;
    default: break;
  }
}

void turnOffAllLEDs() {
  digitalWrite(LED_GREEN, LOW);
  digitalWrite(LED_YELLOW, LOW);
  digitalWrite(LED_RED, LOW);
}

void handleErrorState() {
  if (millis() - lastErrorBlink >= 500) {
    errorLedState = !errorLedState;
    digitalWrite(LED_GREEN, errorLedState);
    digitalWrite(LED_YELLOW, errorLedState);
    digitalWrite(LED_RED, errorLedState);
    lastErrorBlink = millis();
  }
  currentSpeed = FAN_OFF;
}

void updateDisplay() {
  static unsigned long lastDisplayUpdate = 0;
  if (millis() - lastDisplayUpdate < 1000) return;
  lastDisplayUpdate = millis();
  lcd.clear();
  lcd.setCursor(0, 0);
  if (currentMode == AUTO) lcd.print("Modo: AUTO ");
  else lcd.print("Modo: MANUAL ");
  switch (currentSpeed) {
    case FAN_OFF: lcd.print("OFF"); break;
    case FAN_LOW: lcd.print("BAJA"); break;
    case FAN_MEDIUM: lcd.print("MEDIA"); break;
    case FAN_HIGH: lcd.print("ALTA"); break;
  }
  lcd.setCursor(0, 1);
  if (errorState) {
    lcd.print("ERROR SENSORES");
  } else {
    char buffer[17];
    snprintf(buffer, sizeof(buffer), "H:%d%% T:%dC A:%d", (int)humidity, (int)temperature, airQuality);
    lcd.print(buffer);
  }
}

void toggleMode() {
  if (currentMode == AUTO) {
    currentMode = MANUAL;
    manualSpeed = FAN_OFF;
    currentSpeed = FAN_OFF;
  } else {
    currentMode = AUTO;
  }
}