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

/* for feather m0 */
#define RFM95_CS 8
#define RFM95_RST 4
#define RFM95_INT 3

// Change to 434.0 or other frequency, must match RX's freq!
#define RF95_FREQ 915.0

// Lower bandwidth means longer distance but lower data rate
// Valid values are:
// 0-7800khz: 7.8
// 7801-10400khz: 10.4 
// 10401-15600 15.6 
// 15601-20800 20.8
// 20801-31250 31.25
// 31251-41700 41.7
// 41701-62500 62.5
// 62501-12500 125.0 DEFAULT
// 12501-250000 250.0
// >250000 500.0
#define RF95_BANDWIDTH 62.5

// Higher spread factor means longer distance
// Valid values are 6-12
#define RF95_SPREAD_FACTOR 12

// Higher TX power means longer distance
// Valid values are 5-23
#define RF95_TX_POWER 23

// Make sure you run setLowDatarate() when going for long distance

// Singleton instance of the radio driver
RH_RF95 rf95(RFM95_CS, RFM95_INT);

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(RFM95_RST, OUTPUT);
  // Start with the LED on low
  digitalWrite(LED_BUILTIN, LOW);

  while (!Serial);  // wait until serial console is open, remove if not tethered to computer
  Serial.begin(115200);
  delay(100);
  Serial.println("Feather LoRa RX Debug Demo!");

  // manual reset
  digitalWrite(RFM95_RST, LOW);
  delay(10);
  digitalWrite(RFM95_RST, HIGH);
  delay(10);

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

  // Defaults after init are 434.0MHz, modulation GFSK_Rb250Fd250, +13dbM
  if (!rf95.setFrequency(RF95_FREQ)) {
    Serial.println("setFrequency failed");
    while (1);
  }
  Serial.print("Set Freq to: ");
  Serial.println(RF95_FREQ);

  // Set the signal bandwidth
  rf95.setSignalBandwidth(RF95_BANDWIDTH);
  Serial.print("Set bandwidth to: ");
  Serial.println(RF95_BANDWIDTH);

  // Set the signal bandwidth
  rf95.setSpreadingFactor(RF95_SPREAD_FACTOR);
  Serial.print("Set spreading factor to: ");
  Serial.println(RF95_SPREAD_FACTOR);

  // Set low transmission rate
  rf95.setLowDatarate();
  Serial.println("Set low data rate");

  // The default transmitter power is 13dBm, using PA_BOOST.
  // If you are using RFM95/96/97/98 modules which uses the PA_BOOST transmitter pin, then
  // you can set transmitter powers from 5 to 23 dBm:
  rf95.setTxPower(RF95_TX_POWER, false);
  
  // Begin the user interaction piece
  Serial.println("Please enter your name: ");
}

int32_t packet_num = 0;
String serial_input = "";
String chat_name = "";
String chat_message = "";

void loop() {

  // We start in anonymous mode
  // When we enter a name we can start messaging in the chat
  if (chat_name == "") {
    if (Serial.available()) {
      // read the incoming byte:
      chat_name = Serial.readStringUntil('\0');
      String intro_message = chat_name + " has joined the chat!";

      Serial.println("Welcome " + chat_name);
      digitalWrite(LED_BUILTIN, HIGH);
      rf95.send((uint8_t *)reinterpret_cast<const uint8_t *>(&intro_message), RH_RF95_MAX_MESSAGE_LEN);
      rf95.waitPacketSent();
      digitalWrite(LED_BUILTIN, LOW);
    }
  } else {
    if (Serial.available()) {
      // read the incoming byte:
      digitalWrite(LED_BUILTIN, HIGH);
      chat_message = Serial.readStringUntil('\0');
      String send_message = chat_name + ": " + chat_message;

      Serial.println(send_message);
      rf95.send((uint8_t *)reinterpret_cast<const uint8_t *>(&send_message), RH_RF95_MAX_MESSAGE_LEN);
      rf95.waitPacketSent();
      digitalWrite(LED_BUILTIN, LOW);
    }
  }
  // Receiver code
  if (rf95.available()) {
    digitalWrite(LED_BUILTIN, HIGH);
    // Should be a message for us now
    uint8_t buf[RH_RF95_MAX_MESSAGE_LEN];
    uint8_t len = sizeof(buf);

    if (rf95.recv(buf, &len)) {
      // RH_RF95::printBuffer("Received: ", buf, len);
      Serial.println((char *)buf);
      // Serial.print("RSSI: ");
      // Serial.println(rf95.lastRssi(), DEC);
      digitalWrite(LED_BUILTIN, LOW);
    }
  }
}