#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
#include "HardwareSerial.h"
#include "SSD1306.h"
#include <CayenneLPP.h>
#include <TinyGPS++.h>                                  // Tiny GPS Plus Library

//---------------------------------------------------------
//setup gps
//---------------------------------------------------------
TinyGPSPlus gps;                                        // Create an Instance of the TinyGPS++ object called gps
HardwareSerial Serial2(2);
int gpstry = 0;
float lat, lon;
String lat1, lon1;

//---------------------------------------------------------
//setup display
//---------------------------------------------------------
SSD1306 display (0x3c, 4, 15);
int packet = 0;
String ttnstat = "Start";

//---------------------------------------------------------
//cayenne lpp integration
//---------------------------------------------------------
CayenneLPP lpp(51);
//#define LPP_GPS                 136     // 3 byte lon/lat 0.0001 °, 3 bytes alt 0.01m
//#define LPP_GPS_SIZE                 11

// LoRaWAN NwkSKey, network session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const PROGMEM u1_t NWKSKEY[16] = {  };

// LoRaWAN AppSKey, application session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const u1_t PROGMEM APPSKEY[16] = {  };

// LoRaWAN end-device address (DevAddr)
static const u4_t DEVADDR = 0x00000000 ; // <-- Change this address for every node!

// These callbacks are only used in over-the-air activation, so they are
// left empty here (we cannot leave them out completely unless
// DISABLE_JOIN is set in config.h, otherwise the linker will complain).
void os_getArtEui (u1_t* buf) { }
void os_getDevEui (u1_t* buf) { }
void os_getDevKey (u1_t* buf) { }

static uint8_t mydata[] = "Hello, world!";
static osjob_t sendjob;

// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 1;

// Pin mapping
// These settings should be set to the GPIO pins of the device
// you want to run the LMIC stack on.
//
// Pin mapping
const lmic_pinmap lmic_pins = {
    .nss = 18,
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 14,
    .dio = {26, 33, 32},
};

void onEvent (ev_t ev) {
    Serial.print(gps.time.value());
    Serial.print(": onevent : ");
    switch(ev) {
        case EV_SCAN_TIMEOUT:
            Serial.println(F("EV_SCAN_TIMEOUT"));
            ttnstat = "EV_SCAN_TIMEOUT";
            disp();
            break;
        case EV_BEACON_FOUND:
            Serial.println(F("EV_BEACON_FOUND"));
            ttnstat = "EV_BEACON_FOUND";
            disp();
            break;
        case EV_BEACON_MISSED:
            Serial.println(F("EV_BEACON_MISSED"));
            ttnstat = "EV_BEACON_MISSED";
            disp();
            break;
        case EV_BEACON_TRACKED:
            Serial.println(F("EV_BEACON_TRACKED"));
            ttnstat = "EV_BEACON_TRACKED";
            disp();
            break;
        case EV_JOINING:
            Serial.println(F("EV_JOINING"));
            ttnstat = "EV_JOINING";
            disp();
            break;
        case EV_JOINED:
            Serial.println(F("EV_JOINED"));
            ttnstat = "EV_JOINED";
            disp();
            // Disable link check validation (automatically enabled
            // during join, but not supported by TTN at this time).
            LMIC_setLinkCheckMode(0);
            break;
        case EV_RFU1:
            Serial.println(F("EV_RFU1"));
            ttnstat = "EV_RFU1";
            disp();
            break;
        case EV_JOIN_FAILED:
            Serial.println(F("EV_JOIN_FAILED"));
            ttnstat = "EV_JOIN_FAILED";
            disp();
            break;
        case EV_REJOIN_FAILED:
            Serial.println(F("EV_REJOIN_FAILED"));
            ttnstat = "EV_REJOIN_FAILED";
            disp();
            break;
        case EV_TXCOMPLETE:
            Serial.println(F("EV_TXCOMPLETE (includes waiting for RX windows)"));
            ttnstat = "EV_TXCOMPLETE";
            disp();
            if (LMIC.txrxFlags & TXRX_ACK)
              Serial.println(F("Received ack"));
            ttnstat = "Recieved ack";
            disp();       
            if (LMIC.dataLen) {
              Serial.println(F("Received "));
              Serial.println(LMIC.dataLen);
              Serial.println(F(" bytes of payload"));
            ttnstat = ("Status: Recieved " + String(LMIC.dataLen) + " bytes of payload");
            disp();
            }
            // Schedule next transmission
            os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
            break;
        case EV_LOST_TSYNC:
            Serial.println(F("EV_LOST_TSYNC"));
            ttnstat = "EV_LOST_TSYNC";
            disp();
            break;
        case EV_RESET:
            Serial.println(F("EV_RESET"));
            ttnstat = "EV_RESET";
            disp();
            break;
        case EV_RXCOMPLETE:
            // data received in ping slot
            Serial.println(F("EV_RXCOMPLETE"));
            ttnstat = "EV_RXCOMPLETE";
            disp();
            break;
        case EV_LINK_DEAD:
            Serial.println(F("EV_LINK_DEAD"));
            ttnstat = "EV_LINK_DEAD";
            disp();
            break;
        case EV_LINK_ALIVE:
            Serial.println(F("EV_LINK_ALIVE"));
            ttnstat = "EV_LINK_ALIVE";
            disp();
            break;
         default:
            Serial.println(F("Unknown event"));
            ttnstat = "Unknown event";
            disp();
            break;
    }
}
// ----------------------------------------------------
// This function prepares a message for the LoRaWAN network
// The message will be sent multiple times.
//---------------------------------------------------------
void do_send(osjob_t* j){
    // Check if there is not a current TX/RX job running
    if (LMIC.opmode & OP_TXRXPEND) {
     Serial.print(gps.time.value());  
     Serial.println(F(": OP_TXRXPEND"));
        ttnstat = "TXPEND - 10sec";
        disp();
        delay(1000);
    } else {
        // Prepare upstream data transmission at the next possible time.
        LMIC_setDrTxpow(DR_SF7,14);
        LMIC_setTxData2(1, lpp.getBuffer(), lpp.getSize(), 0);
      // // //   Serial.print(gps.time.value());        
        Serial.println(": Packet " + String(packet) + " queued");
        ttnstat = ("Packet " + String(packet) + " queued");
        disp();
        packet ++; 
    }
}

//---------------------------------------------------------
// Display
//---------------------------------------------------------
void disp() {
    display.clear();
    display.drawString (0, 1, "TTGO gps v02");
    display.drawString (0, 10, "GPS Satelites: " + String (gps.satellites.value()));
    display.drawString (0, 20, "Lattitude:   " + String (gps.location.lat(), 6));
    display.drawString (0, 30, "Longitude: " + String (gps.location.lng(), 6));
    display.drawString (0, 40, "Data: " + String ((char*)lpp.getBuffer()));
    display.drawString (0, 50, "Status: " + (ttnstat));
    display.display ();
    
}
void setup() {
    Serial.begin(115200);
    Serial.println(F("Starting"));

  //serial gps
    Serial2.begin(9600,SERIAL_8N1,23,17);      
    Serial.println("void setup");
  //setup oled  
    pinMode(16,OUTPUT);
    digitalWrite(16, LOW);    // set GPIO16 low to reset OLED
    delay(500); 
    digitalWrite(16, HIGH); // while OLED is running, must set GPIO16 in high
    SPI.begin (SCK, MISO, MOSI, SS);
    display.init ();
    display.flipScreenVertically ();
    display.setFont (ArialMT_Plain_10);
    disp();

    #ifdef VCC_ENABLE
    // For Pinoccio Scout boards
    pinMode(VCC_ENABLE, OUTPUT);
    digitalWrite(VCC_ENABLE, HIGH);
    delay(1000);
    #endif

    // LMIC init
    os_init();
    // Reset the MAC state. Session and pending data transfers will be discarded.
    LMIC_reset();

    // Set static session parameters. Instead of dynamically establishing a session
    // by joining the network, precomputed session parameters are be provided.
    #ifdef PROGMEM
    // On AVR, these values are stored in flash and only copied to RAM
    // once. Copy them to a temporary buffer here, LMIC_setSession will
    // copy them into a buffer of its own again.
    uint8_t appskey[sizeof(APPSKEY)];
    uint8_t nwkskey[sizeof(NWKSKEY)];
    memcpy_P(appskey, APPSKEY, sizeof(APPSKEY));
    memcpy_P(nwkskey, NWKSKEY, sizeof(NWKSKEY));
    LMIC_setSession (0x1, DEVADDR, nwkskey, appskey);
    #else
    // If not running an AVR with PROGMEM, just use the arrays directly
    LMIC_setSession (0x1, DEVADDR, NWKSKEY, APPSKEY);
    #endif

    #if defined(CFG_eu868)
    // Set up the channels used by the Things Network, which corresponds
    // to the defaults of most gateways. Without this, only three base
    // channels from the LoRaWAN specification are used, which certainly
    // works, so it is good for debugging, but can overload those
    // frequencies, so be sure to configure the full frequency range of
    // your network here (unless your network autoconfigures them).
    // Setting up channels should happen after LMIC_setSession, as that
    // configures the minimal channel set.
    // NA-US channels 0-71 are configured automatically
    LMIC_setupChannel(0, 868100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(1, 868300000, DR_RANGE_MAP(DR_SF12, DR_SF7B), BAND_CENTI);      // g-band
    LMIC_setupChannel(2, 868500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(3, 867100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(4, 867300000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(5, 867500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(6, 867700000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(7, 867900000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(8, 868800000, DR_RANGE_MAP(DR_FSK,  DR_FSK),  BAND_MILLI);      // g2-band
    // TTN defines an additional channel at 869.525Mhz using SF9 for class B
    // devices' ping slots. LMIC does not have an easy way to define set this
    // frequency and support for class B is spotty and untested, so this
    // frequency is not configured here.
    #elif defined(CFG_us915)
    // NA-US channels 0-71 are configured automatically
    // but only one group of 8 should (a subband) should be active
    // TTN recommends the second sub band, 1 in a zero based count.
    // https://github.com/TheThingsNetwork/gateway-conf/blob/master/US-global_conf.json
    LMIC_selectSubBand(1);
    #endif

    // Disable link check validation
    LMIC_setLinkCheckMode(0);

    // TTN uses SF9 for its RX2 window.
    LMIC.dn2Dr = DR_SF9;

    // Set data rate and transmit power for uplink (note: txpow seems to be ignored by the library)
    LMIC_setDrTxpow(DR_SF7,14);

    // Start job
    do_send(&sendjob);
}

void loop() {
//  Serial.print(gps.time.value());  
Serial.println(": loop1loop");

//cayenne loop part
lpp.reset();

while (Serial2.available() > 0)
  gps.encode(Serial2.read());
  Serial.print(gps.time.value());  
  Serial.println(": loop2serialreadgps");
if (millis() > 5000 && gps.charsProcessed() < 10)
  {
  Serial.println("ERROR: not getting any GPS data!");
  // dump the stream to Serial
  Serial.println("GPS stream dump:");
  while (true) // infinite loop
    if (Serial2.available() > 0) // any data coming in?
      Serial.write(Serial2.read());
  }

if (gps.location.isValid())
  {
    lpp.reset(); //empty lpp buffer
    lat1 = String(gps.location.lat(), 6);
    lon1 = String(gps.location.lng(), 6);
    lat = lat1.toFloat();
    lon = lon1.toFloat();
    Serial.print(gps.time.value());  
    Serial.println(": loop3gpslocupd");
    Serial.println("gps update sending");
    Serial.print("LAT="); Serial.println(lat1);
    Serial.print("LNG="); Serial.println(lon1);
    Serial.print("ALT="); Serial.println((gps.altitude.value()) / 100);
    //addgps data to buffer
    //lpp.addTemperature(1, 22.5); //dummy data
    //lpp.addBarometricPressure(2, 1073.21); //dummy data
    lpp.addGPS(3, (lat), (lon), ((gps.altitude.value()) / 100));
    //lpp.addGPS(3, 52.240600, 4.433500, 12); //dummy data
    do_send(&sendjob);        // Put job in run queue(send mydata buffer)
  }
  os_runloop_once();      // Let the server run its jobs
  Serial.print(gps.time.value());  
  Serial.println(": loop4osrunloop");
  delay(1000);         // Wait a second. Note: actual wait time is longer
}
//---------------------------------------------------------