#include <Wire.h>
#include <TinyGPSPlus.h>
#include <HardwareSerial.h>
#include <SPI.h>
#include <LoRa.h>
#include <Adafruit_BMP280.h>

// -------------------- BMP280 --------------------
#define I2C_SDA D2
#define I2C_SCL D3
Adafruit_BMP280 bmp;
bool bmp_ready = false;

// -------------------- GPS --------------------
#define GPS_RX D7
#define GPS_TX D6
HardwareSerial GPSserial(1);
TinyGPSPlus gps;

// -------------------- LoRa SPI remapped --------------------
#define LORA_SCK  D8
#define LORA_MISO D9
#define LORA_MOSI D10
#define LORA_CS   D1
#define LORA_RST  D5
#define LORA_IRQ  -1
SPIClass SPI_LORA(FSPI);

// -------------------- Timing --------------------
unsigned long lastSendTime = 0;
const unsigned long interval = 2000;  // 2 seconds

void setup() {
  Serial.begin(115200);
  delay(1000);
  Serial.println("🔧 Initializing LoRa + BMP280 + GPS...");

  // GPS UART
  GPSserial.begin(9600, SERIAL_8N1, GPS_RX, GPS_TX);

  // BMP280 I2C
  Wire.begin(I2C_SDA, I2C_SCL);
  if (bmp.begin(0x76)) {
    bmp_ready = true;
    Serial.println("✅ BMP280 initialized (0x76).");
  } else if (bmp.begin(0x77)) {
    bmp_ready = true;
    Serial.println("✅ BMP280 initialized (0x77).");
  } else {
    Serial.println("⚠️ BMP280 not found. Skipping temperature.");
  }

  // LoRa SPI
  SPI_LORA.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_CS);
  LoRa.setSPI(SPI_LORA);
  LoRa.setPins(LORA_CS, LORA_RST, LORA_IRQ);
  if (!LoRa.begin(433E6)) {
    Serial.println("❌ LoRa init failed.");
    while (true);
  }

  LoRa.setTxPower(20);
  LoRa.setSpreadingFactor(12);
  LoRa.setSignalBandwidth(125E3);
  LoRa.enableCrc();
  Serial.println("✅ LoRa initialized.");
}

void loop() {
  while (GPSserial.available()) {
    gps.encode(GPSserial.read());
  }

  unsigned long now = millis();
  if (now - lastSendTime >= interval) {
    lastSendTime = now;

    if (gps.location.isValid()) {
      String msg = "Lat=" + String(gps.location.lat(), 6);
      msg += ",Lng=" + String(gps.location.lng(), 6);
      msg += ",Sat=" + String(gps.satellites.value());
      msg += ",Alt=" + String(gps.altitude.meters(), 1);

      if (bmp_ready) {
        float temp = bmp.readTemperature();
        msg += ",T=" + String(temp, 2) + "C";
      } else {
        msg += ",T=N/A";
      }

      Serial.println("📤 Sending: " + msg);
      LoRa.beginPacket();
      LoRa.print(msg);
      LoRa.endPacket();
    } else {
      Serial.println("⚠️ GPS not fixed yet...");
    }
  }
}