//First Device (nano)

#include <SPI.h>
#include <RH_RF95.h>

#define RFM95_CS   10
#define RFM95_RST  9
#define RFM95_INT  2
#define BUTTON_PIN 5
#define LED_PIN    6

#define RF95_FREQ  433.0

RH_RF95 rf95(RFM95_CS, RFM95_INT);

bool ledState = false;

void setup() {
  Serial.begin(9600);
  while (!Serial);

  pinMode(RFM95_RST, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(RFM95_RST, HIGH);

  Serial.println("Initializing LoRa...");

  digitalWrite(RFM95_RST, LOW);
  delay(10);
  digitalWrite(RFM95_RST, HIGH);
  delay(100);

  if (!rf95.init()) {
    Serial.println("LoRa init failed. Check your connections.");
    while (1);
  }
  Serial.println("LoRa radio init OK!");

  if (!rf95.setFrequency(RF95_FREQ)) {
    Serial.println("setFrequency failed");
    while (1);
  }
  Serial.print("Set Freq to: "); Serial.println(RF95_FREQ);

  rf95.setTxPower(13, false);
}

void loop() {
  static bool lastButtonState = HIGH;
  bool buttonState = digitalRead(BUTTON_PIN);

  if (buttonState == LOW && lastButtonState == HIGH) {
    Serial.println("Button pressed, sending message to toggle LED on second device");
    sendMessage("TOGGLE_LED");
  }

  lastButtonState = buttonState;

  if (rf95.available()) {
    uint8_t buf[RH_RF95_MAX_MESSAGE_LEN];
    uint8_t len = sizeof(buf);

    if (rf95.recv(buf, &len)) {
      Serial.print("Received: ");
      Serial.println((char*)buf);
      checkRSSI();

      if (strncmp((char*)buf, "TOGGLE_LED", len) == 0) {
        ledState = !ledState;
        digitalWrite(LED_PIN, ledState ? HIGH : LOW);
        Serial.print("LED state: ");
        Serial.println(ledState ? "ON" : "OFF");
      }
    }
  }

  delay(10);  // Small delay to debounce button
}

void sendMessage(const char* message) {
  uint8_t retries = 5;
  while (retries--) {
    rf95.send((uint8_t*)message, strlen(message));
    rf95.waitPacketSent();
    Serial.println("Message sent");
    checkRSSI();  // Print RSSI after sending message
    delay(1000);  // Wait for response
  }
}

void checkRSSI() {
  int8_t rssi = rf95.lastRssi();
  Serial.print("RSSI: ");
  Serial.println(rssi);
}