#include <Arduino.h>
#include "DHT.h"
#include <WiFi.h>
#include <PubSubClient.h>

// =============================
// CONFIGURACIÓN DE PINES
// =============================
#define DHTPIN 25         
#define DHTTYPE DHT22
#define SOIL_PIN 34       
#define RELAY_PIN 0       
#define LED_PIN 33         
#define PIN_BUTTON_MANUAL 26 

// =============================
// OBJETOS Y VARIABLES
// =============================
DHT dht(DHTPIN, DHTTYPE);

// Estado del sistema
bool lastButtonManual = HIGH;

// Umbrales de humedad suelo (% C.C.)
const float HUM_ON = 60.0;  // umbral mínimo de humedad (%)
const float HUM_OFF = 80.0; // máximo de humedad (%)

// Seguridad: tiempo máximo de riego (30 min = 1800000 ms)
const unsigned long MAX_RIEGO_MS = 1800000;

// Variables de estado
float soilHumidity = 70.0;   
float temp = 18.0;           
float humAmb = 50.0;         
bool bombaEncendida = false;
bool controlManual = false;  
long tiempoInicioRiego = 0;

// =============================
// VARIABLES DE CONTROL DE VOLUMEN
// =============================
const float volumenObjetivo_L = 2667.0;   // 2.667 m3 = 2667 litros
const float caudalTotal_Lps = 20.0 / 60.0; // 20 L/min = 0.333 L/s
float volumenAcumulado = 0.0;

unsigned long tiempoAnteriorVol = 0;
const unsigned long intervaloVol = 1000; // 1s

// =============================
// CONFIGURACIÓN WIFI Y MQTT
// =============================
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";

WiFiClient espClient;
PubSubClient client(espClient);

// =============================
// PROTOTIPOS DE FUNCIONES
// =============================
void setupWifi();
void reconnect();
void callback(char* topic, byte* message, unsigned int length);
void publishEstado();
void controlVolumen(unsigned long now);

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

  pinMode(RELAY_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(PIN_BUTTON_MANUAL, INPUT_PULLUP);

  digitalWrite(RELAY_PIN, LOW);
  digitalWrite(LED_PIN, LOW);

  Serial.println("===== Sistema de Riego Automático ESP32 =====");

  setupWifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  tiempoAnteriorVol = millis();
}

// =============================
// FUNCIONES DE WIFI
// =============================
void setupWifi() {
  delay(10);
  Serial.println();
  Serial.print("Conectando a ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

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

  Serial.println("\n✅ WiFi conectado");
  Serial.print("IP: ");
  Serial.println(WiFi.localIP());
}

// =============================
// FUNCIONES DEL SISTEMA DE RIEGO
// =============================
void encenderBomba(unsigned long now) {
  digitalWrite(RELAY_PIN, HIGH);
  digitalWrite(LED_PIN, HIGH);
  bombaEncendida = true;
  tiempoInicioRiego = now;

  tiempoAnteriorVol = now;
  Serial.println("[RIEGO] 💧 Bomba ENCENDIDA");
}

void apagarBomba() {
  digitalWrite(RELAY_PIN, LOW);
  digitalWrite(LED_PIN, LOW);
  bombaEncendida = false;
  Serial.println("[RIEGO] ✅ Bomba APAGADA");
}

void checkManualButton(unsigned long now) {
  bool buttonState = digitalRead(PIN_BUTTON_MANUAL);
  if (buttonState == LOW && lastButtonManual == HIGH) {
    if (!controlManual) {
      controlManual = true;
      encenderBomba(now);
      Serial.println("[MANUAL] Bomba encendida con botón.");
    } else {
      controlManual = false;
      apagarBomba();
      Serial.println("[MANUAL] Bomba apagada, vuelve automático.");
    }
    delay(100);
  }
  lastButtonManual = buttonState;
}

void controlRiego(unsigned long now) {
  if (!bombaEncendida && soilHumidity <= HUM_ON) {
    encenderBomba(now);
  } else if (bombaEncendida && soilHumidity >= HUM_OFF) {
    apagarBomba();
  }

  if (bombaEncendida && (now - tiempoInicioRiego >= MAX_RIEGO_MS)) {
    Serial.println("[ALERTA] Tiempo máximo alcanzado → Bomba apagada.");
    apagarBomba();
  }

  if (temp < 9.0 || temp > 20.0) {
    Serial.print("[ALERTA] Temp fuera de rango: ");
    Serial.println(temp);
  }
}

// =============================
// CONTROL DE VOLUMEN POR EVENTO
// =============================
void controlVolumen(unsigned long now) {
  if (bombaEncendida && (now - tiempoAnteriorVol >= intervaloVol)) {
    unsigned long delta = now - tiempoAnteriorVol;
    volumenAcumulado += caudalTotal_Lps*(delta/1000.0);
    tiempoAnteriorVol = now;

    Serial.print("[VOLUMEN] Acumulado: ");
    Serial.print(volumenAcumulado);
    Serial.println(" L");

    if (volumenAcumulado >= volumenObjetivo_L) {
      Serial.println("[RIEGO] ✅ Volumen objetivo alcanzado (2.667 m3). Apagando bomba y reiniciando contador...");
      apagarBomba();
      volumenAcumulado = 0.0;
    }
  }
}

void logEstado() {
  unsigned long timestamp = millis() / 1000;
  Serial.print("[LOG][");
  Serial.print(timestamp);
  Serial.print("s] Temp=");
  Serial.print(temp);
  Serial.print("°C | HumAmb=");
  Serial.print(humAmb);
  Serial.print("% | HumSuelo=");
  Serial.print(soilHumidity);
  Serial.print(" | Volumen=");
  Serial.print(volumenAcumulado);
  Serial.println(" L");
  Serial.print("% | Bomba=");
  Serial.println(bombaEncendida ? "ON" : "OFF");
}

void leerSensores() {
  humAmb = dht.readHumidity();
  temp = dht.readTemperature();

  if (isnan(humAmb) || isnan(temp)) {
    Serial.println("[ERROR] Fallo DHT22");
  }

  int rawValue = analogRead(SOIL_PIN);
  soilHumidity = map(rawValue, 0, 4095, 100, 0);

  logEstado();
}

// =============================
// FUNCIONES DE MQTT
// =============================
void callback(char* topic, byte* message, unsigned int length) {
  String msg;
  for (unsigned int i = 0; i < length; i++) {
    msg += (char)message[i];
  }

  Serial.print("[MQTT] Mensaje en ");
  Serial.print(topic);
  Serial.print(": ");
  Serial.println(msg);

  if (String(topic) == "riego/control") {
    if (msg == "ON") {
      encenderBomba(millis());
      controlManual = true;
      Serial.println("[MQTT] Bomba encendida remotamente");
    } else if (msg == "OFF") {
      apagarBomba();
      controlManual = false;
      Serial.println("[MQTT] Bomba apagada remotamente");
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("[MQTT] Intentando conexión...");
    if (client.connect("ESP32RiegoClient")) {
      Serial.println("Conectado ✅");
      client.subscribe("riego/control"); // Suscripción a control remoto
    } else {
      Serial.print("Error, rc=");
      Serial.print(client.state());
      Serial.println(" Reintentando en 5s...");
      delay(5000);
    }
  }
}

void publishEstado() {
  String payload = "{";
  payload += "\"temp\":" + String(temp) + ",";
  payload += "\"humAmb\":" + String(humAmb) + ",";
  payload += "\"humSuelo\":" + String(soilHumidity)+","; 
  payload += "\"volumen\":" + String(volumenAcumulado);
  payload += "}";

  client.publish("riego/estado", payload.c_str(), true);
  Serial.println("[MQTT] Estado publicado: " + payload);
}

// =============================
// LOOP PRINCIPAL
// =============================
void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  unsigned long now = millis();
  checkManualButton(now);

  if (!controlManual) {
    leerSensores();
    controlRiego(now);
  }
  
  controlVolumen(now);

  static unsigned long lastPublish = 0;
  if (millis() - lastPublish > 5000) {
    publishEstado();
    lastPublish = millis();
  }
}