/**
 * @file       TinyGsmClientBG96.h
 * @author     Volodymyr Shymanskyy
 * @license    LGPL-3.0
 * @copyright  Copyright (c) 2016 Volodymyr Shymanskyy
 * @date       Apr 2018
 */

#ifndef TinyGsmClientBG96_h
#define TinyGsmClientBG96_h
//#pragma message("TinyGSM:  TinyGsmClientBG96")

//#define TINY_GSM_DEBUG Serial

#if !defined(TINY_GSM_RX_BUFFER)
  #define TINY_GSM_RX_BUFFER 64
#endif

#define TINY_GSM_MUX_COUNT 12

#include <TinyGsmCommon.h>

#define GSM_NL "\r\n"
static const char GSM_OK[] TINY_GSM_PROGMEM = "OK" GSM_NL;
static const char GSM_ERROR[] TINY_GSM_PROGMEM = "ERROR" GSM_NL;

enum SimStatus {
  SIM_ERROR = 0,
  SIM_READY = 1,
  SIM_LOCKED = 2,
};

enum RegStatus {
  REG_UNREGISTERED = 0,
  REG_SEARCHING    = 2,
  REG_DENIED       = 3,
  REG_OK_HOME      = 1,
  REG_OK_ROAMING   = 5,
  REG_UNKNOWN      = 4,
};


class TinyGsmBG96
{

public:

class GsmClient : public Client
{
  friend class TinyGsmBG96;
  typedef TinyGsmFifo<uint8_t, TINY_GSM_RX_BUFFER> RxFifo;

public:
  GsmClient() {}

  GsmClient(TinyGsmBG96& modem, uint8_t mux = 1) {
    init(&modem, mux);
  }

  virtual ~GsmClient(){}

  bool init(TinyGsmBG96* modem, uint8_t mux = 1) {
    this->at = modem;
    this->mux = mux;
    sock_available = 0;
    prev_check = 0;
    sock_connected = false;
    got_data = false;

    at->sockets[mux] = this;

    return true;
  }

public:
  virtual int connect(const char *host, uint16_t port, int timeout_s) {
    stop();
    TINY_GSM_YIELD();
    rx.clear();
    sock_connected = at->modemConnect(host, port, mux, false, timeout_s);
    return sock_connected;
  }

TINY_GSM_CLIENT_CONNECT_OVERLOADS()

  virtual void stop(uint32_t maxWaitMs) {
    TINY_GSM_CLIENT_DUMP_MODEM_BUFFER()
    at->sendAT(GF("+QICLOSE="), mux);
    sock_connected = false;
    at->waitResponse();
  }

  virtual void stop() { stop(15000L); }

TINY_GSM_CLIENT_WRITE()

TINY_GSM_CLIENT_AVAILABLE_WITH_BUFFER_CHECK()

TINY_GSM_CLIENT_READ_WITH_BUFFER_CHECK()

TINY_GSM_CLIENT_PEEK_FLUSH_CONNECTED()

  /*
   * Extended API
   */

  String remoteIP() TINY_GSM_ATTR_NOT_IMPLEMENTED;

private:
  TinyGsmBG96*    at;
  uint8_t         mux;
  uint16_t        sock_available;
  uint32_t        prev_check;
  bool            sock_connected;
  bool            got_data;
  RxFifo          rx;
};


// class GsmClientSecure : public GsmClient
// {
// public:
//   GsmClientSecure() {}
//
//   GsmClientSecure(TinyGsmBG96& modem, uint8_t mux = 1)
//     : GsmClient(modem, mux)
//   {}
//
//   virtual ~GsmClientSecure(){}
//
// public:
//   virtual int connect(const char *host, uint16_t port, int timeout_s) {
//     stop();
//     TINY_GSM_YIELD();
//     rx.clear();
//     sock_connected = at->modemConnect(host, port, mux, true, timeout_s);
//     return sock_connected;
//   }
// };


public:

  TinyGsmBG96(Stream& stream)
    : stream(stream)
  {
    memset(sockets, 0, sizeof(sockets));
  }
  virtual ~TinyGsmBG96() {}

  /*
   * Basic functions
   */

  bool begin(const char* pin = NULL) {
    return init(pin);
  }

  bool init(const char* pin = NULL) {
    DBG(GF("### TinyGSM Version:"), TINYGSM_VERSION);

    if (!testAT()) {
      return false;
    }

    sendAT(GF("&FZE0"));  // Factory + Reset + Echo Off
    if (waitResponse() != 1) {
      return false;
    }

    DBG(GF("### Modem:"), getModemName());

    int ret = getSimStatus();
    // if the sim isn't ready and a pin has been provided, try to unlock the sim
    if (ret != SIM_READY && pin != NULL && strlen(pin) > 0) {
      simUnlock(pin);
      return (getSimStatus() == SIM_READY);
    }
    // if the sim is ready, or it's locked but no pin has been provided, return
    // true
    else {
      return (ret == SIM_READY || ret == SIM_LOCKED);
    }
  }

  String getModemName() {
    return "Quectel BG96";
  }

TINY_GSM_MODEM_SET_BAUD_IPR()

TINY_GSM_MODEM_TEST_AT()

TINY_GSM_MODEM_MAINTAIN_CHECK_SOCKS()

  bool factoryDefault() {
    sendAT(GF("&FZE0&W"));  // Factory + Reset + Echo Off + Write
    waitResponse();
    sendAT(GF("+IPR=0"));   // Auto-baud
    waitResponse();
    sendAT(GF("&W"));       // Write configuration
    return waitResponse() == 1;
  }

TINY_GSM_MODEM_GET_INFO_ATI()

  bool hasSSL() {
    return false;  // TODO: For now
  }

  bool hasWifi() {
    return false;
  }

  bool hasGPRS() {
    return true;
  }

  /*
   * Power functions
   */

  bool restart() {
    if (!testAT()) {
      return false;
    }
    sendAT(GF("+CFUN=1,1"));
    if (waitResponse(60000L, GF("POWERED DOWN")) != 1) {
      return false;
    }
    delay(3000);
    return init();
  }

  bool poweroff() {
    sendAT(GF("+QPOWD=1"));
    waitResponse(300);  // returns OK first
    return waitResponse(300, GF("POWERED DOWN")) == 1;
  }

  bool radioOff() {
    sendAT(GF("+CFUN=0"));
    if (waitResponse(10000L) != 1) {
      return false;
    }
    delay(3000);
    return true;
  }

  /*
   * SIM card functions
   */

TINY_GSM_MODEM_SIM_UNLOCK_CPIN()

  String getSimCCID() {
    sendAT(GF("+QCCID"));
    if (waitResponse(GF(GSM_NL "+QCCID:")) != 1) {
      return "";
    }
    String res = stream.readStringUntil('\n');
    waitResponse();
    res.trim();
    return res;
  }

TINY_GSM_MODEM_GET_IMEI_GSN()

  SimStatus getSimStatus(unsigned long timeout_ms = 10000L) {
    for (unsigned long start = millis(); millis() - start < timeout_ms; ) {
      sendAT(GF("+CPIN?"));
      if (waitResponse(GF(GSM_NL "+CPIN:")) != 1) {
        delay(1000);
        continue;
      }
      int status = waitResponse(GF("READY"), GF("SIM PIN"), GF("SIM PUK"), GF("NOT INSERTED"));
      waitResponse();
      switch (status) {
        case 2:
        case 3:  return SIM_LOCKED;
        case 1:  return SIM_READY;
        default: return SIM_ERROR;
      }
    }
    return SIM_ERROR;
  }

TINY_GSM_MODEM_GET_REGISTRATION_XREG(CREG)

TINY_GSM_MODEM_GET_OPERATOR_COPS()

  /*
   * Generic network functions
   */

TINY_GSM_MODEM_GET_CSQ()

  bool isNetworkConnected() {
    RegStatus s = getRegistrationStatus();
    return (s == REG_OK_HOME || s == REG_OK_ROAMING);
  }

TINY_GSM_MODEM_WAIT_FOR_NETWORK()

  /*
   * GPRS functions
   */

  bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) {
    gprsDisconnect();

    //Configure the TCPIP Context
    sendAT(GF("+QICSGP=1,1,\""), apn, GF("\",\""), user, GF("\",\""), pwd, GF("\""));
    if (waitResponse() != 1) {
      return false;
    }

    //Activate GPRS/CSD Context
    sendAT(GF("+QIACT=1"));
    if (waitResponse(150000L) != 1) {
      return false;
    }

    //Attach to Packet Domain service - is this necessary?
    sendAT(GF("+CGATT=1"));
    if (waitResponse(60000L) != 1) {
      return false;
    }

    return true;
  }

  bool gprsDisconnect() {
    sendAT(GF("+QIDEACT=1"));  // Deactivate the bearer context
    if (waitResponse(40000L) != 1)
      return false;

    return true;
  }

TINY_GSM_MODEM_GET_GPRS_IP_CONNECTED()

  /*
   * IP Address functions
   */

  String getLocalIP() {
    sendAT(GF("+QILOCIP"));
    stream.readStringUntil('\n');
    String res = stream.readStringUntil('\n');
    if (waitResponse() != 1) {
      return "";
    }
    return res;
  }

  IPAddress localIP() {
    return TinyGsmIpFromString(getLocalIP());
  }

  /*
   * Phone Call functions
   */

  bool setGsmBusy(bool busy = true) TINY_GSM_ATTR_NOT_AVAILABLE;

  bool callAnswer() {
    sendAT(GF("A"));
    return waitResponse() == 1;
  }

  // Returns true on pick-up, false on error/busy
  bool callNumber(const String& number) TINY_GSM_ATTR_NOT_IMPLEMENTED;

  bool callHangup() {
    sendAT(GF("H"));
    return waitResponse() == 1;
  }

  // 0-9,*,#,A,B,C,D
  bool dtmfSend(char cmd, int duration_ms = 100) { // TODO: check
    duration_ms = constrain(duration_ms, 100, 1000);

    sendAT(GF("+VTD="), duration_ms / 100); // VTD accepts in 1/10 of a second
    waitResponse();

    sendAT(GF("+VTS="), cmd);
    return waitResponse(10000L) == 1;
  }

  /*
   * Messaging functions
   */

  String sendUSSD(const String& code) TINY_GSM_ATTR_NOT_IMPLEMENTED;

  bool sendSMS(const String& number, const String& text) {
    sendAT(GF("+CMGF=1"));
    waitResponse();
    //Set GSM 7 bit default alphabet (3GPP TS 23.038)
    sendAT(GF("+CSCS=\"GSM\""));
    waitResponse();
    sendAT(GF("+CMGS=\""), number, GF("\""));
    if (waitResponse(GF(">")) != 1) {
      return false;
    }
    stream.print(text);
    stream.write((char)0x1A);
    stream.flush();
    return waitResponse(60000L) == 1;
  }

  bool sendSMS_UTF16(const String& number, const void* text, size_t len) {
    sendAT(GF("+CMGF=1"));
    waitResponse();
    sendAT(GF("+CSCS=\"HEX\""));
    waitResponse();
    sendAT(GF("+CSMP=17,167,0,8"));
    waitResponse();

    sendAT(GF("+CMGS=\""), number, GF("\""));
    if (waitResponse(GF(">")) != 1) {
      return false;
    }

    uint16_t* t = (uint16_t*)text;
    for (size_t i=0; i<len; i++) {
      uint8_t c = t[i] >> 8;
      if (c < 0x10) { stream.print('0'); }
      stream.print(c, HEX);
      c = t[i] & 0xFF;
      if (c < 0x10) { stream.print('0'); }
      stream.print(c, HEX);
    }
    stream.write((char)0x1A);
    stream.flush();
    return waitResponse(60000L) == 1;
  }


  /*
   * Location functions
   */

  String getGsmLocation() TINY_GSM_ATTR_NOT_AVAILABLE;

  /*
   * Battery & temperature functions
   */

  // Use: float vBatt = modem.getBattVoltage() / 1000.0;
  uint16_t getBattVoltage() {
    sendAT(GF("+CBC"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return 0;
    }
    streamSkipUntil(','); // Skip battery charge status
    streamSkipUntil(','); // Skip battery charge level
    // return voltage in mV
    uint16_t res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  int8_t getBattPercent() {
    sendAT(GF("+CBC"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    streamSkipUntil(','); // Skip battery charge status
    // Read battery charge level
    int res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  uint8_t getBattChargeState() {
    sendAT(GF("+CBC?"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    // Read battery charge status
    int res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  bool getBattStats(uint8_t &chargeState, int8_t &percent, uint16_t &milliVolts) {
    sendAT(GF("+CBC?"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    chargeState = stream.readStringUntil(',').toInt();
    percent = stream.readStringUntil(',').toInt();
    milliVolts = stream.readStringUntil('\n').toInt();
    // Wait for final OK
    waitResponse();
    return true;
  }

  float getTemperature() TINY_GSM_ATTR_NOT_AVAILABLE;

  /*
   * Client related functions
   */

protected:

 bool modemConnect(const char* host, uint16_t port, uint8_t mux,
                   bool ssl = false, int timeout_s = 20) {
   if (ssl) {
     DBG("SSL not yet supported on this module!");
   }
   int rsp;
   uint32_t timeout_ms = ((uint32_t)timeout_s) * 1000;

    // <PDPcontextID>(1-16), <connectID>(0-11),"TCP/UDP/TCP LISTENER/UDP SERVICE",
    // "<IP_address>/<domain_name>",<remote_port>,<local_port>,<access_mode>(0-2 0=buffer)
    sendAT(GF("+QIOPEN=1,"), mux, ',', GF("\"TCP"), GF("\",\""), host, GF("\","), port, GF(",0,0"));
    rsp = waitResponse();

    if (waitResponse(timeout_ms, GF(GSM_NL "+QIOPEN:")) != 1) {
      return false;
    }

    if (stream.readStringUntil(',').toInt() != mux) {
      return false;
    }
    // Read status
    rsp = stream.readStringUntil('\n').toInt();

    return (0 == rsp);
  }

  int16_t modemSend(const void* buff, size_t len, uint8_t mux) {
    sendAT(GF("+QISEND="), mux, ',', (uint16_t)len);
    if (waitResponse(GF(">")) != 1) {
      return 0;
    }
    stream.write((uint8_t*)buff, len);
    stream.flush();
    if (waitResponse(GF(GSM_NL "SEND OK")) != 1) {
      return 0;
    }
    // TODO: Wait for ACK? AT+QISEND=id,0
    return len;
  }

  size_t modemRead(size_t size, uint8_t mux) {
    sendAT(GF("+QIRD="), mux, ',', (uint16_t)size);
    if (waitResponse(GF("+QIRD:")) != 1) {
      return 0;
    }
    int len = stream.readStringUntil('\n').toInt();

    for (int i=0; i<len; i++) {
      TINY_GSM_MODEM_STREAM_TO_MUX_FIFO_WITH_DOUBLE_TIMEOUT
    }
    waitResponse();
    DBG("### READ:", len, "from", mux);
    sockets[mux]->sock_available = modemGetAvailable(mux);
    return len;
  }

  size_t modemGetAvailable(uint8_t mux) {
    sendAT(GF("+QIRD="), mux, GF(",0"));
    size_t result = 0;
    if (waitResponse(GF("+QIRD:")) == 1) {
      streamSkipUntil(','); // Skip total received
      streamSkipUntil(','); // Skip have read
      result = stream.readStringUntil('\n').toInt();
      if (result) {
        DBG("### DATA AVAILABLE:", result, "on", mux);
      }
      waitResponse();
    }
    if (!result) {
      sockets[mux]->sock_connected = modemGetConnected(mux);
    }
    return result;
  }

  bool modemGetConnected(uint8_t mux) {
    sendAT(GF("+QISTATE=1,"), mux);
    //+QISTATE: 0,"TCP","151.139.237.11",80,5087,4,1,0,0,"uart1"

    if (waitResponse(GF("+QISTATE:")))
      return false;

    streamSkipUntil(','); // Skip mux
    streamSkipUntil(','); // Skip socket type
    streamSkipUntil(','); // Skip remote ip
    streamSkipUntil(','); // Skip remote port
    streamSkipUntil(','); // Skip local port
    int res = stream.readStringUntil(',').toInt(); // socket state

    waitResponse();

    // 0 Initial, 1 Opening, 2 Connected, 3 Listening, 4 Closing
    return 2 == res;
  }

public:

  /*
   Utilities
   */

TINY_GSM_MODEM_STREAM_UTILITIES()

  // TODO: Optimize this!
  uint8_t waitResponse(uint32_t timeout_ms, String& data,
                       GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    /*String r1s(r1); r1s.trim();
    String r2s(r2); r2s.trim();
    String r3s(r3); r3s.trim();
    String r4s(r4); r4s.trim();
    String r5s(r5); r5s.trim();
    DBG("### ..:", r1s, ",", r2s, ",", r3s, ",", r4s, ",", r5s);*/
    data.reserve(64);
    int index = 0;
    unsigned long startMillis = millis();
    do {
      TINY_GSM_YIELD();
      while (stream.available() > 0) {
        TINY_GSM_YIELD();
        int a = stream.read();
        if (a <= 0) continue; // Skip 0x00 bytes, just in case
        data += (char)a;
        if (r1 && data.endsWith(r1)) {
          index = 1;
          goto finish;
        } else if (r2 && data.endsWith(r2)) {
          index = 2;
          goto finish;
        } else if (r3 && data.endsWith(r3)) {
          index = 3;
          goto finish;
        } else if (r4 && data.endsWith(r4)) {
          index = 4;
          goto finish;
        } else if (r5 && data.endsWith(r5)) {
          index = 5;
          goto finish;
        } else if (data.endsWith(GF(GSM_NL "+QIURC:"))) {
          stream.readStringUntil('\"');
          String urc = stream.readStringUntil('\"');
          stream.readStringUntil(',');
          if (urc == "recv") {
            int mux = stream.readStringUntil('\n').toInt();
            DBG("### URC RECV:", mux);
            if (mux >= 0 && mux < TINY_GSM_MUX_COUNT && sockets[mux]) {
              sockets[mux]->got_data = true;
            }
          } else if (urc == "closed") {
            int mux = stream.readStringUntil('\n').toInt();
            DBG("### URC CLOSE:", mux);
            if (mux >= 0 && mux < TINY_GSM_MUX_COUNT && sockets[mux]) {
              sockets[mux]->sock_connected = false;
            }
          } else {
            stream.readStringUntil('\n');
          }
          data = "";
        }
      }
    } while (millis() - startMillis < timeout_ms);
finish:
    if (!index) {
      data.trim();
      if (data.length()) {
        DBG("### Unhandled:", data);
      }
      data = "";
    }
    //data.replace(GSM_NL, "/");
    //DBG('<', index, '>', data);
    return index;
  }

  uint8_t waitResponse(uint32_t timeout_ms,
                       GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    String data;
    return waitResponse(timeout_ms, data, r1, r2, r3, r4, r5);
  }

  uint8_t waitResponse(GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    return waitResponse(1000, r1, r2, r3, r4, r5);
  }

public:
  Stream&       stream;

protected:
  GsmClient*    sockets[TINY_GSM_MUX_COUNT];
};

#endif