#include "DleParser.h"

#include <fsfw/serviceinterface/ServiceInterface.h>

#include <cstdio>
#include <fstream>
#include <iostream>

DleParser::DleParser(SimpleRingBuffer& decodeRingBuf, DleEncoder& decoder, BufPair encodedBuf,
                     BufPair decodedBuf, UserHandler handler, void* args)
    : decodeRingBuf(decodeRingBuf),
      decoder(decoder),
      encodedBuf(encodedBuf),
      decodedBuf(decodedBuf),
      handler(handler),
      ctx(args) {
  if (handler == nullptr) {
#if FSFW_CPP_OSTREAM_ENABLED == 1
    sif::error << "DleParser::DleParser: Invalid user handler" << std::endl;
#else
    sif::printError("DleParser::DleParser: Invalid user handler\n");
#endif
  }
}

ReturnValue_t DleParser::passData(const uint8_t* data, size_t len) {
  if (data == nullptr or len == 0 or handler == nullptr) {
    return returnvalue::FAILED;
  }
  return decodeRingBuf.writeData(data , len);
//  std::string filename = std::string("/mnt/sd0/scex/transfer") + std::to_string(COUNTER++);
//  std::ofstream of(filename);
//  of.write(reinterpret_cast<const char*>(data), len);
//  size_t copyIntoRingBufFromHere = 0;
//  size_t copyAmount = len;
//  size_t startIdx = 0;
//  ReturnValue_t result = returnvalue::OK;
//  bool startFoundInThisPacket = false;
//  for (size_t idx = 0; idx < len; idx++) {
//    if (data[idx] == DleEncoder::STX_CHAR) {
//      if (not startFound and not startFoundInThisPacket) {
//        startIdx = idx;
//        copyIntoRingBufFromHere = idx;
//        copyAmount = len - idx;
//      } else {
//        // Maybe print warning, should not happen
//        decodeRingBuf.clear();
//        ErrorInfo info;
//        info.len = idx;
//        prepareErrorContext(ErrorTypes::CONSECUTIVE_STX_CHARS, info);
//        handler(ctx);
//        copyIntoRingBufFromHere = idx;
//        copyAmount = len - idx;
//      }
//      startFound = true;
//      startFoundInThisPacket = true;
//    } else if (data[idx] == DleEncoder::ETX_CHAR) {
//      if (startFoundInThisPacket) {
//        size_t readLen = 0;
//        size_t decodedLen = 0;
//        result = decoder.decode(data + startIdx, idx + 1 - startIdx, &readLen, decodedBuf.first,
//                                decodedBuf.second, &decodedLen);
//        if (result == returnvalue::OK) {
//          ctx.setType(ContextType::PACKET_FOUND);
//          ctx.decodedPacket.first = decodedBuf.first;
//          ctx.decodedPacket.second = decodedLen;
//          this->handler(ctx);
//        } else if (result == DleEncoder::STREAM_TOO_SHORT) {
//          ErrorInfo info;
//          info.res = result;
//          prepareErrorContext(ErrorTypes::DECODING_BUF_TOO_SMALL, info);
//          handler(ctx);
//        } else {
//          ErrorInfo info;
//          info.res = result;
//          prepareErrorContext(ErrorTypes::DECODING_BUF_TOO_SMALL, info);
//          handler(ctx);
//        }
//        decodeRingBuf.clear();
//        if ((idx + 1) < len) {
//          copyIntoRingBufFromHere = idx + 1;
//          copyAmount = len - idx - 1;
//        } else {
//          copyAmount = 0;
//        }
//      } else if (startFound) {
//        // ETX found but STX was found in another mini packet. Reconstruct the full packet
//        // to decode it
//        result = decodeRingBuf.writeData(data, idx + 1);
//        if (result != returnvalue::OK) {
//          ErrorInfo info;
//          info.res = result;
//          prepareErrorContext(ErrorTypes::RING_BUF_ERROR, info);
//          handler(ctx);
//        }
//        size_t fullEncodedLen = decodeRingBuf.getAvailableReadData();
//        if (fullEncodedLen > encodedBuf.second) {
//          ErrorInfo info;
//          info.len = fullEncodedLen;
//          prepareErrorContext(ErrorTypes::ENCODED_BUF_TOO_SMALL, info);
//          handler(ctx);
//          decodeRingBuf.clear();
//        } else {
//          size_t decodedLen = 0;
//          size_t readLen = 0;
//          decodeRingBuf.readData(encodedBuf.first, fullEncodedLen, true);
//          result = decoder.decode(encodedBuf.first, fullEncodedLen, &readLen, decodedBuf.first,
//                                  decodedBuf.second, &decodedLen);
//          if (result == returnvalue::OK) {
//            if (this->handler != nullptr) {
//              ctx.setType(ContextType::PACKET_FOUND);
//              ctx.decodedPacket.first = decodedBuf.first;
//              ctx.decodedPacket.second = decodedLen;
//              this->handler(ctx);
//            }
//          } else if (result == DleEncoder::STREAM_TOO_SHORT) {
//            ErrorInfo info;
//            info.res = result;
//            prepareErrorContext(ErrorTypes::DECODING_BUF_TOO_SMALL, info);
//            handler(ctx);
//          } else {
//            ErrorInfo info;
//            info.res = result;
//            prepareErrorContext(ErrorTypes::DECODE_ERROR, info);
//            handler(ctx);
//          }
//          decodeRingBuf.clear();
//          startFound = false;
//          startFoundInThisPacket = false;
//          if ((idx + 1) < len) {
//            copyIntoRingBufFromHere = idx + 1;
//            copyAmount = len - idx - 1;
//          } else {
//            copyAmount = 0;
//          }
//        }
//      } else {
//        // End data without preceeding STX
//        ErrorInfo info;
//        info.len = idx + 1;
//        prepareErrorContext(ErrorTypes::CONSECUTIVE_ETX_CHARS, info);
//        handler(ctx);
//        decodeRingBuf.clear();
//        if ((idx + 1) < len) {
//          copyIntoRingBufFromHere = idx + 1;
//          copyAmount = len - idx - 1;
//        } else {
//          copyAmount = 0;
//        }
//      }
//      startFoundInThisPacket = false;
//      startFound = false;
//    }
//  }
//  if (copyAmount > 0) {
//    result = decodeRingBuf.writeData(data + copyIntoRingBufFromHere, copyAmount);
//    if (result != returnvalue::OK) {
//      ErrorInfo info;
//      info.res = result;
//      prepareErrorContext(ErrorTypes::RING_BUF_ERROR, info);
//      handler(ctx);
//    }
//  }
}


ReturnValue_t DleParser::parseRingBuf(size_t& readSize) {
  size_t availableData = decodeRingBuf.getAvailableReadData();
  if (availableData > encodedBuf.second) {
    ErrorInfo info;
    info.len = decodeRingBuf.getAvailableReadData();
     prepareErrorContext(ErrorTypes::DECODING_BUF_TOO_SMALL, info);
     handler(ctx);
  }
  ReturnValue_t result = decodeRingBuf.readData(encodedBuf.first, availableData);
  if(result != returnvalue::OK) {
    ErrorInfo info;
    info.res = result;
    prepareErrorContext(ErrorTypes::RING_BUF_ERROR, info);
  }
  bool stxFound = false;
  size_t stxIdx = 0;
  for (size_t vectorIdx = 0; vectorIdx < availableData; vectorIdx++) {
    // handle STX char
    if (encodedBuf.first[vectorIdx] == DleEncoder::STX_CHAR) {
      if (not stxFound) {
        stxFound = true;
        stxIdx = vectorIdx;
      } else {
        // might be lost packet, so we should advance the read pointer
        // without skipping the STX
        readSize = vectorIdx;
        return POSSIBLE_PACKET_LOSS;
      }
    }
    // handle ETX char
    if (encodedBuf.first[vectorIdx] == DleEncoder::ETX_CHAR) {
      if (stxFound) {
        // This is propably a packet, so we decode it.
        size_t decodedLen = 0;
        size_t dummy = 0;
        readSize = vectorIdx;
        ReturnValue_t result = decoder.decode(&encodedBuf.first[stxIdx], availableData - stxIdx,
                                                  &dummy, decodedBuf.first, decodedBuf.second, &decodedLen);
        if (result == returnvalue::OK) {
          ctx.setType(ContextType::PACKET_FOUND);
          ctx.decodedPacket.first = decodedBuf.first;
          ctx.decodedPacket.second = decodedLen;
          this->handler(ctx);
          return returnvalue::OK;
        } else {
          // invalid packet, skip.
          readSize = ++vectorIdx;
          return POSSIBLE_PACKET_LOSS;
        }
      } else {
        // might be lost packet, so we should advance the read pointer
        readSize = ++vectorIdx;
        return POSSIBLE_PACKET_LOSS;
      }
    }
  }
  return returnvalue::OK;
}


void DleParser::defaultFoundPacketHandler(uint8_t* packet, size_t len, void* args) {
#if FSFW_VERBOSE_LEVEL >= 1
#if FSFW_CPP_OSTREAM_ENABLED == 1
  sif::info << "DleParserBase::handleFoundPacket: Detected DLE packet with " << len << " bytes"
            << std::endl;
#else
  sif::printInfo("DleParserBase::handleFoundPacket: Detected DLE packet with %d bytes\n", len);
#endif
#endif
}

void DleParser::defaultErrorHandler(ErrorTypes err, ErrorInfo ctx) {
  switch (err) {
    case (ErrorTypes::NONE): {
      errorPrinter("No error");
      break;
    }
    case (ErrorTypes::DECODE_ERROR): {
      errorPrinter("Decode Error");
      break;
    }
    case (ErrorTypes::RING_BUF_ERROR): {
      errorPrinter("Ring Buffer Error");
      break;
    }
    case (ErrorTypes::ENCODED_BUF_TOO_SMALL):
    case (ErrorTypes::DECODING_BUF_TOO_SMALL): {
      char opt[64];
      snprintf(opt, sizeof(opt), ": Too small for packet with length %zu", ctx.len);
      if (err == ErrorTypes::ENCODED_BUF_TOO_SMALL) {
        errorPrinter("Encoded buf too small", opt);
      } else {
        errorPrinter("Decoding buf too small", opt);
      }
      break;
    }
    case (ErrorTypes::CONSECUTIVE_STX_CHARS): {
      errorPrinter("Consecutive STX chars detected");
      break;
    }
    case (ErrorTypes::CONSECUTIVE_ETX_CHARS): {
      errorPrinter("Consecutive ETX chars detected");
      break;
    }
  }
}

void DleParser::errorPrinter(const char* str, const char* opt) {
  if (opt == nullptr) {
    opt = "";
  }
#if FSFW_VERBOSE_LEVEL >= 1
#if FSFW_CPP_OSTREAM_ENABLED == 1
  sif::info << "DleParserBase::handleParseError: " << str << opt << std::endl;
#else
  sif::printInfo("DleParserBase::handleParseError: %s%s\n", str, opt);
#endif
#endif
}

void DleParser::prepareErrorContext(ErrorTypes err, ErrorInfo info) {
  ctx.setType(ContextType::ERROR);
  ctx.error.first = err;
  ctx.error.second = info;
}

ReturnValue_t DleParser::confirmBytesRead(size_t bytesRead) {
  return decodeRingBuf.deleteData(bytesRead);
}

void DleParser::reset() {
  startFound = false;
  decodeRingBuf.clear();
}