/**
 * @file FlowControlProtocol.cpp
 * FlowControlProtocol class implementation
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "FlowControlProtocol.h"

#include <chrono>
#include <cstdio>
#include <ctime>
#include <thread>
#include <string>
#include <random>
#include <iostream>
#include <cinttypes>

#include "FlowController.h"
#include "core/Core.h"
#include "utils/gsl.h"

namespace org {
namespace apache {
namespace nifi {
namespace minifi {

int FlowControlProtocol::connectServer(const char *host, uint16_t port) {
  return 0;
}

int FlowControlProtocol::sendData(uint8_t *buf, int buflen) {
  return 0;
}

int FlowControlProtocol::selectClient(int msec) {
  fd_set fds;
  struct timeval tv{};
  int retval;
  int fd = _socket;

  FD_ZERO(&fds);
  FD_SET(fd, &fds);

  tv.tv_sec = msec / 1000;
  tv.tv_usec = (msec % 1000) * 1000;

  if (msec > 0)
    retval = select(fd + 1, &fds, nullptr, nullptr, &tv);
  else
    retval = select(fd + 1, &fds, nullptr, nullptr, nullptr);

  if (retval <= 0)
    return retval;
  if (FD_ISSET(fd, &fds))
    return retval;
  else
    return 0;
}

int FlowControlProtocol::readData(uint8_t *buf, int buflen) {
  int sendSize = buflen;

  while (buflen) {
    int status;
    status = selectClient(MAX_READ_TIMEOUT);
    if (status <= 0) {
      return status;
    }
#ifndef __MACH__
    status = read(_socket, buf, buflen);
#else
    status = recv(_socket, buf, buflen, 0);
#endif
    if (status <= 0) {
      return status;
    }
    buflen -= status;
    buf += status;
  }

  return sendSize;
}

int FlowControlProtocol::readHdr(FlowControlProtocolHeader *hdr) {
  uint8_t buffer[sizeof(FlowControlProtocolHeader)];

  uint8_t *data = buffer;

  int status = readData(buffer, sizeof(FlowControlProtocolHeader));
  if (status <= 0)
    return status;

  uint32_t value;
  data = this->decode(data, value);
  hdr->msgType = value;

  data = this->decode(data, value);
  hdr->seqNumber = value;

  data = this->decode(data, value);
  hdr->status = value;

  data = this->decode(data, value);
  hdr->payloadLen = value;

  return sizeof(FlowControlProtocolHeader);
}

void FlowControlProtocol::start() {
  if (_reportInterval <= 0)
    return;
  if (running_)
    return;
  running_ = true;
  logger_->log_trace("FlowControl Protocol Start");
  _thread = std::thread(run, this);
  _thread.detach();
}

void FlowControlProtocol::stop() {
  if (!running_)
    return;
  running_ = false;
  logger_->log_info("FlowControl Protocol Stop");
}

void FlowControlProtocol::run(FlowControlProtocol *protocol) {
  while (protocol->running_) {
    std::this_thread::sleep_for(std::chrono::milliseconds(protocol->_reportInterval));
    if (!protocol->_registered) {
      // if it is not register yet
      protocol->sendRegisterReq();
    } else {
      protocol->sendReportReq();
    }
  }
}

int FlowControlProtocol::sendRegisterReq() {
  if (_registered) {
    logger_->log_debug("Already registered");
    return -1;
  }

  uint16_t port = this->_serverPort;

  if (this->_socket <= 0)
    this->_socket = connectServer(_serverName.c_str(), port);

  if (this->_socket <= 0)
    return -1;

  // Calculate the total payload msg size
  const auto payloadSize = FlowControlMsgIDEncodingLen(FLOW_SERIAL_NUMBER, 0) + FlowControlMsgIDEncodingLen(FLOW_YML_NAME, gsl::narrow<int>(this->_controller->getName().size() + 1));
  const size_t size = sizeof(FlowControlProtocolHeader) + payloadSize;

  std::vector<uint8_t> buffer;
  buffer.resize(size);
  uint8_t *data = buffer.data();

  // encode the HDR
  FlowControlProtocolHeader hdr;
  hdr.msgType = REGISTER_REQ;
  hdr.payloadLen = payloadSize;
  hdr.seqNumber = this->_seqNumber;
  hdr.status = RESP_SUCCESS;
  data = this->encode(data, hdr.msgType);
  data = this->encode(data, hdr.seqNumber);
  data = this->encode(data, hdr.status);
  data = this->encode(data, hdr.payloadLen);

  // encode the serial number
  data = this->encode(data, FLOW_SERIAL_NUMBER);
  data = this->encode(data, this->_serialNumber, 8);

  // encode the YAML name
  data = this->encode(data, FLOW_YML_NAME);
  data = this->encode(data, this->_controller->getName());

  // send it
  int status = sendData(buffer.data(), size);
  buffer.clear();
  if (status <= 0) {
    close(_socket);
    _socket = 0;
    logger_->log_error("Flow Control Protocol Send Register Req failed");
    return -1;
  }

  // Looking for register respond
  status = readHdr(&hdr);

  if (status <= 0) {
    close(_socket);
    _socket = 0;
    logger_->log_error("Flow Control Protocol Read Register Resp header failed");
    return -1;
  }
  logger_->log_debug("Flow Control Protocol receive MsgType %s", FlowControlMsgTypeToStr((FlowControlMsgType) hdr.msgType));
  logger_->log_debug("Flow Control Protocol receive Seq Num %" PRIu32, hdr.seqNumber);
  logger_->log_debug("Flow Control Protocol receive Resp Code %s", FlowControlRespCodeToStr((FlowControlRespCode) hdr.status));
  logger_->log_debug("Flow Control Protocol receive Payload len %" PRIu32, hdr.payloadLen);

  if (hdr.status == RESP_SUCCESS && hdr.seqNumber == this->_seqNumber) {
    this->_registered = true;
    this->_seqNumber++;
    logger_->log_trace("Flow Control Protocol Register success");
    std::vector<uint8_t> payload;
    payload.resize(hdr.payloadLen);
    uint8_t *payloadPtr = payload.data();
    status = readData(payload.data(), hdr.payloadLen);
    if (status <= 0) {
      logger_->log_warn("Flow Control Protocol Register Read Payload fail");
      close(_socket);
      _socket = 0;
      return -1;
    }
    while (payloadPtr < (payload.data() + hdr.payloadLen)) {
      uint32_t msgID;
      payloadPtr = this->decode(payloadPtr, msgID);
      if (((FlowControlMsgID) msgID) == REPORT_INTERVAL) {
        // Fixed 4 bytes
        uint32_t reportInterval;
        payloadPtr = this->decode(payloadPtr, reportInterval);
        logger_->log_debug("Flow Control Protocol receive report interval %" PRIu32 " ms", reportInterval);
        this->_reportInterval = reportInterval;
      } else {
        break;
      }
    }
    close(_socket);
    _socket = 0;
    return 0;
  } else {
    logger_->log_warn("Flow Control Protocol Register fail");
    close(_socket);
    _socket = 0;
    return -1;
  }
}

int FlowControlProtocol::sendReportReq() {
  uint16_t port = this->_serverPort;

  if (this->_socket <= 0)
    this->_socket = connectServer(_serverName.c_str(), port);

  if (this->_socket <= 0)
    return -1;

  // Calculate the total payload msg size
  uint32_t payloadSize = FlowControlMsgIDEncodingLen(FLOW_YML_NAME, gsl::narrow<int>(this->_controller->getName().size() + 1));
  const size_t size = sizeof(FlowControlProtocolHeader) + payloadSize;

  std::vector<uint8_t> buffer;
  buffer.resize(size);
  auto* data = buffer.data();

  // encode the HDR
  FlowControlProtocolHeader hdr;
  hdr.msgType = REPORT_REQ;
  hdr.payloadLen = payloadSize;
  hdr.seqNumber = this->_seqNumber;
  hdr.status = RESP_SUCCESS;
  data = this->encode(data, hdr.msgType);
  data = this->encode(data, hdr.seqNumber);
  data = this->encode(data, hdr.status);
  data = this->encode(data, hdr.payloadLen);

  // encode the YAML name
  data = this->encode(data, FLOW_YML_NAME);
  data = this->encode(data, this->_controller->getName());

  // send it
  int status = sendData(buffer.data(), size);
  buffer.clear();
  if (status <= 0) {
    close(_socket);
    _socket = 0;
    logger_->log_error("Flow Control Protocol Send Report Req failed");
    return -1;
  }

  // Looking for report respond
  status = readHdr(&hdr);

  if (status <= 0) {
    close(_socket);
    _socket = 0;
    logger_->log_error("Flow Control Protocol Read Report Resp header failed");
    return -1;
  }
  logger_->log_debug("Flow Control Protocol receive MsgType %s", FlowControlMsgTypeToStr((FlowControlMsgType) hdr.msgType));
  logger_->log_debug("Flow Control Protocol receive Seq Num %" PRIu32, hdr.seqNumber);
  logger_->log_debug("Flow Control Protocol receive Resp Code %s", FlowControlRespCodeToStr((FlowControlRespCode) hdr.status));
  logger_->log_debug("Flow Control Protocol receive Payload len %" PRIu32, hdr.payloadLen);

  if (hdr.status == RESP_SUCCESS && hdr.seqNumber == this->_seqNumber) {
    this->_seqNumber++;
    std::vector<uint8_t> payload;
    payload.resize(hdr.payloadLen);
    uint8_t *payloadPtr = payload.data();
    status = readData(payload.data(), hdr.payloadLen);
    if (status <= 0) {
      logger_->log_warn("Flow Control Protocol Report Resp Read Payload fail");
      close(_socket);
      _socket = 0;
      return -1;
    }
    std::string processor;
    std::string propertyName;
    std::string propertyValue;
    while (payloadPtr < (payload.data() + hdr.payloadLen)) {
      uint32_t msgID;
      payloadPtr = this->decode(payloadPtr, msgID);
      if (((FlowControlMsgID) msgID) == PROCESSOR_NAME) {
        uint32_t len;
        payloadPtr = this->decode(payloadPtr, len);
        processor = (const char *) payloadPtr;
        payloadPtr += len;
        logger_->log_debug("Flow Control Protocol receive report resp processor %s", processor);
      } else if (((FlowControlMsgID) msgID) == PROPERTY_NAME) {
        uint32_t len;
        payloadPtr = this->decode(payloadPtr, len);
        propertyName = (const char *) payloadPtr;
        payloadPtr += len;
        logger_->log_debug("Flow Control Protocol receive report resp property name %s", propertyName);
      } else if (((FlowControlMsgID) msgID) == PROPERTY_VALUE) {
        uint32_t len;
        payloadPtr = this->decode(payloadPtr, len);
        propertyValue = (const char *) payloadPtr;
        payloadPtr += len;
        logger_->log_debug("Flow Control Protocol receive report resp property value %s", propertyValue);
        this->_controller->updatePropertyValue(processor, propertyName, propertyValue);
      } else {
        break;
      }
    }
    close(_socket);
    _socket = 0;
    return 0;
  } else if (hdr.status == RESP_TRIGGER_REGISTER && hdr.seqNumber == this->_seqNumber) {
    logger_->log_trace("Flow Control Protocol trigger reregister");
    this->_registered = false;
    this->_seqNumber++;
    close(_socket);
    _socket = 0;
    return 0;
  } else if (hdr.status == RESP_STOP_FLOW_CONTROLLER && hdr.seqNumber == this->_seqNumber) {
    logger_->log_trace("Flow Control Protocol stop flow controller");
    this->_controller->stop(true);
    this->_seqNumber++;
    close(_socket);
    _socket = 0;
    return 0;
  } else if (hdr.status == RESP_START_FLOW_CONTROLLER && hdr.seqNumber == this->_seqNumber) {
    logger_->log_trace("Flow Control Protocol start flow controller");
    this->_controller->start();
    this->_seqNumber++;
    close(_socket);
    _socket = 0;
    return 0;
  } else {
    logger_->log_trace("Flow Control Protocol Report fail");
    close(_socket);
    _socket = 0;
    return -1;
  }
}

}  // namespace minifi
}  // namespace nifi
}  // namespace apache
}  // namespace org