#include <WiFi.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

const char *ssid = "ESP32-Receiver";
const char *password = "password";

WiFiServer server(80);
Adafruit_SSD1306 display(128, 64, &Wire, -1);

void setup()
{
  Serial.begin(115200);

    WiFi.softAP(ssid, password);

      server.begin();

        if (!display.begin(SSD1306_I2C, 0x3C))
          {
              Serial.println(F("SSD1306 allocation failed"));
                  for (;;)
                        ;
                          }

                            display.display();
                              delay(2000);
                                display.clearDisplay();
                                }

                                void loop()
                                {
                                  WiFiClient client = server.available();

                                    if (client)
                                      {
                                          String request = client.readStringUntil('\r');
                                              client.flush();

                                                  int pos = request.indexOf("GET /");
                                                      if (pos != -1)
                                                          {
                                                                tampilkanData();
                                                                    }
                                                                      }
                                                                      }

                                                                      void tampilkanData()
                                                                      {
                                                                        int jarak = bacaData();
                                                                          display.clearDisplay();
                                                                            display.setTextSize(2);
                                                                              display.setTextColor(SSD1306_WHITE);
                                                                                display.setCursor(0, 0);
                                                                                  display.print("Jarak: ");
                                                                                    display.print(jarak);
                                                                                      display.print(" cm");
                                                                                        display.display();
                                                                                        }

                                                                                        int bacaData()
                                                                                        {
                                                                                          WiFiClient client = server.available();
                                                                                            if (client)
                                                                                              {
                                                                                                  client.print(String("GET /") + " HTTP/1.1\r\n" +
                                                                                                                   "Host: " + WiFi.localIP().toString() + "\r\n" +
                                                                                                                                    "Connection: close\r\n\r\n");
                                                                                                                                        while (!client.available())
                                                                                                                                            {
                                                                                                                                                  delay(1);
                                                                                                                                                      }
                                                                                                                                                          String response = client.readStringUntil('\r');
                                                                                                                                                              int jarak = response.toInt();
                                                                                                                                                                  client.stop();
                                                                                                                                                                      return jarak;
                                                                                                                                                                        }
                                                                                                                                                                          return -1;
                                                                                                                                                                          }