#include <WiFi.h>
#include <HTTPClient.h>
#include <DHT.h>

/* ====== CONFIG ====== */
const char* WIFI_SSID   = "";
const char* WIFI_PASS   = "";

const String BOT_TOKEN  = "";
const String CHAT_ID    = "";  

// Pines
const int PIN_BOTON = 38;  // botón a GND con INPUT_PULLUP
const int PIN_DHT   = 36;  // DHT11 DATA
const int PIN_LED   = 37;  // LED externo

#define DHTTYPE DHT11
DHT dht(PIN_DHT, DHTTYPE);

// Umbrales (ajusta a gusto)
float T_MIN = 15.0, T_MAX = 30.0;   // °C
float H_MIN = 20.0, H_MAX = 90.0;   // %HR

// Timings
const unsigned long DEBOUNCE_MS   = 50;
const unsigned long COOLDOWN_BTN  = 3000;
const unsigned long COOLDOWN_DHT  = 60000;
const unsigned long DHT_SAMPLE_MS = 5000;

/* ====== UTILS ====== */
String urlencode(const String &s) {
  String o; o.reserve(s.length()*3);
  for (uint16_t i=0;i<s.length();i++){
    uint8_t c = (uint8_t)s[i];
    if (c==' ') o+="%20";
    else if (c=='\n') o+="%0A";
    else if ((c>='0'&&c<='9')||(c>='A'&&c<='Z')||(c>='a'&&c<='z')||c=='-'||c=='_'||c=='.'||c=='~') o+=(char)c;
    else { char buf[4]; snprintf(buf,sizeof(buf),"%%%02X",c); o+=buf; }
  }
  return o;
}

bool sendMessage(const String &text) {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("[sendMessage] WiFi NO conectado");
    return false;
  }
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + BOT_TOKEN +
               "/sendMessage?chat_id=" + CHAT_ID +
               "&text=" + urlencode(text);
  Serial.print("[sendMessage] URL: ");
  Serial.println(url);
  http.begin(url);
  int code = http.GET();
  Serial.printf("[sendMessage] HTTP %d\n", code);
  http.end();
  return (code == 200);
}

/* ====== TELEGRAM getUpdates (parsing simple) ====== */
long lastUpdateId = 0;

void pollTelegram() {
  if (WiFi.status() != WL_CONNECTED) return;
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + BOT_TOKEN + "/getUpdates?timeout=0";
  if (lastUpdateId) url += "&offset=" + String(lastUpdateId + 1);
  http.begin(url);
  int code = http.GET();
  if (code != 200) { Serial.printf("[getUpdates] HTTP %d\n", code); http.end(); return; }
  String res = http.getString();
  http.end();

  int pos = 0;
  while (true) {
    int u1 = res.indexOf("\"update_id\":", pos); if (u1 < 0) break;
    int u2 = res.indexOf(",", u1); if (u2 < 0) break;
    lastUpdateId = res.substring(u1 + 12, u2).toInt();

    int c1 = res.indexOf("\"chat\":{\"id\":", u2); if (c1 < 0) { pos = u2; continue; }
    c1 += 13;
    int c2 = res.indexOf(",", c1); if (c2 < 0) break;
    String chatIdRx = res.substring(c1, c2); chatIdRx.trim();

    int t1 = res.indexOf("\"text\":\"", c2); if (t1 < 0) { pos = c2; continue; }
    t1 += 8;
    int t2 = res.indexOf("\"", t1); if (t2 < 0) break;
    String text = res.substring(t1, t2);

    Serial.printf("[RX] chat:%s txt:%s\n", chatIdRx.c_str(), text.c_str());

    // Solo acepta comandos del chat autorizado
    if (chatIdRx != CHAT_ID) { pos = t2; continue; }

    if (text == "/led_on") {
      digitalWrite(PIN_LED, HIGH);
      sendMessage("💡 LED: ON");
    } else if (text == "/led_off") {
      digitalWrite(PIN_LED, LOW);
      sendMessage("💡 LED: OFF");
    } else if (text == "/status") {
      float h = dht.readHumidity();
      float t = dht.readTemperature(); // °C
      String s = "ℹ️ Estado:\nLED: ";
      s += (digitalRead(PIN_LED) ? "ON" : "OFF");
      if (isnan(h) || isnan(t)) s += "\nDHT11: sin lectura";
      else s += "\nTemp: " + String(t,1) + "°C\nHum: " + String(h,0) + "%";
      sendMessage(s);
    } else {
      sendMessage("Comandos: /led_on /led_off /status");
    }

    pos = t2;
  }
}

/* ====== BOTÓN (antirrebote) ====== */
unsigned long lastBtnChange = 0, lastBtnAlert = 0;
int lastBtnStable = HIGH;

/* ====== DHT (umbrales) ====== */
unsigned long lastDhtSample = 0, lastDhtAlert = 0;

/* ====== SETUP / LOOP ====== */
void setup() {
  Serial.begin(115200);
  Serial.println();
  Serial.println("===== ARRANCANDO ESP32 TELEGRAM =====");
  Serial.printf("PIN_BOTON=%d  PIN_LED=%d  PIN_DHT=%d\n", PIN_BOTON, PIN_LED, PIN_DHT);

  pinMode(PIN_BOTON, INPUT_PULLUP);
  pinMode(PIN_LED, OUTPUT);
  digitalWrite(PIN_LED, LOW);

  dht.begin();
  Serial.println("DHT inicializado");

  WiFi.begin(WIFI_SSID, WIFI_PASS);
  Serial.print("Conectando a WiFi");
  while (WiFi.status() != WL_CONNECTED) { delay(300); Serial.print("."); }
  Serial.println("\nWiFi conectado");
  Serial.print("IP: ");
  Serial.println(WiFi.localIP());

  bool ok = sendMessage("ESP32 listo ✅\nComandos: /led_on /led_off /status");
  Serial.printf("Mensaje de arranque enviado: %s\n", ok ? "OK" : "ERROR");
}

void loop() {
  unsigned long now = millis();

  // DEBUG: estado crudo del botón cada 200 ms
  static unsigned long lastBtnDebug = 0;
  if (now - lastBtnDebug > 200) {
    lastBtnDebug = now;
    int raw = digitalRead(PIN_BOTON);
    Serial.printf("[BTN] raw=%d stable=%d\n", raw, lastBtnStable);
  }

  // (1) Botón → Telegram
  int val = digitalRead(PIN_BOTON);
  if (val != lastBtnStable && (now - lastBtnChange) > DEBOUNCE_MS) {
    lastBtnChange = now;
    lastBtnStable = val;
    Serial.printf("[BTN] cambio detectado, val=%d\n", val);
    if (val == LOW && (now - lastBtnAlert) > COOLDOWN_BTN) {
      lastBtnAlert = now;
      Serial.println("[BTN] Botón presionado → enviando mensaje");
      bool ok = sendMessage("🔘 Botón presionado");
      Serial.printf("[BTN] sendMessage = %s\n", ok ? "OK" : "ERROR");
    }
  }

  // (2) DHT11 → umbrales
  if (now - lastDhtSample > DHT_SAMPLE_MS) {
    lastDhtSample = now;
    float h = dht.readHumidity();
    float t = dht.readTemperature(); // °C
    if (!isnan(h) && !isnan(t)) {
      bool fuera = (t < T_MIN || t > T_MAX || h < H_MIN || h > H_MAX);
      Serial.printf("DHT11: T=%.1fC H=%.0f%% %s\n", t, h, fuera ? "(fuera)" : "");
      if (fuera && (now - lastDhtAlert) > COOLDOWN_DHT) {
        lastDhtAlert = now;
        String msg = "⚠️ Umbral DHT11\nTemp: " + String(t,1) + "°C (" +
                     String(T_MIN,0) + "-" + String(T_MAX,0) + ")\nHum: " +
                     String(h,0) + "% (" + String(H_MIN,0) + "-" + String(H_MAX,0) + ")";
        bool ok = sendMessage(msg);
        Serial.printf("[DHT] sendMessage = %s\n", ok ? "OK" : "ERROR");
      }
    } else {
      Serial.println("DHT11: lectura fallida");
    }
  }

  // (3) Telegram → control LED
  static unsigned long lastPoll = 0;
  if (now - lastPoll > 1500) { lastPoll = now; pollTelegram(); }
}