ESP32 OTA V2 Over-The-Air

#include <WiFi.h>
#include <WebServer.h>
#include <Update.h>

const char* ssid = "Ateca";
const char* password = "q1w2e3r4t5";

WebServer server(80);

// Cambiamos el diseño HTML para comprobar visualmente la actualización
const char* indexHTML = 
  "<!DOCTYPE html><html><head><meta charset='utf-8'><title>ESP32 OTA V2</title>"
  "<style>body{font-family:Arial;text-align:center;margin-top:50px;background:#e3f2fd;}"
  "div{display:inline-block;padding:25px;background:#fff;border-radius:12px;box-shadow:0 4px 12px rgba(0,0,0,0.15);}"
  "h2{color:#0d47a1;}p{color:#2e7d32;font-weight:bold;}"
  "input[type=file]{margin:20px 0;}input[type=submit]{padding:10px 20px;background:#0288d1;color:#fff;border:none;border-radius:5px;cursor:pointer;}</style></head>"
  "<body><div><h2>ESP32 OTA Portal - Versión 2.0 🚀</h2>"
  "<p>¡Felicidades! Esta versión fue cargada por WiFi sin cables.</p>"
  "<form method='POST' action='/update' enctype='multipart/form-data'>"
  "<input type='file' name='update' accept='.bin'><br>"
  "<input type='submit' value='Actualizar Firmware'>"
  "</form></div></body></html>";

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println("\n--- Firmware V2 Ejecutándose ---");
  Serial.print("IP: ");
  Serial.println(WiFi.localIP());

  server.on("/", HTTP_GET, []() {
    server.send(200, "text/html", indexHTML);
  });

  server.on("/update", HTTP_POST, []() {
    server.sendHeader("Connection", "close");
    server.send(200, "text/html", "<h2>Actualizando a nueva versión... Reiniciando</h2>");
    delay(1000);
    ESP.restart();
  }, []() {
    HTTPUpload& upload = server.upload();
    if (upload.status == UPLOAD_FILE_START) {
      Serial.printf("Actualización iniciada: %s\n", upload.filename.c_str());
      if (!Update.begin(UPDATE_SIZE_UNKNOWN)) {
        Update.printError(Serial);
      }
    } else if (upload.status == UPLOAD_FILE_WRITE) {
      if (Update.write(upload.buf, upload.currentSize) != upload.currentSize) {
        Update.printError(Serial);
      }
    } else if (upload.status == UPLOAD_FILE_END) {
      if (Update.end(true)) {
        Serial.printf("Éxito: %u bytes escritos.\n", upload.totalSize);
      } else {
        Update.printError(Serial);
      }
    }
  });

  server.begin();
}

void loop() {
  server.handleClient();
}