text: // Copyright (c) 2014-2019, The Monero Project
  // Copyright (c)      2018, The Loki Project
  //
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  //
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  //
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
  //
  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include "bootstrap_serialization.h"
  #include "serialization/binary_utils.h" // dump_binary(), parse_binary()
  
  #include "bootstrap_file.h"
  
  #undef OXEN_DEFAULT_LOG_CATEGORY
  #define OXEN_DEFAULT_LOG_CATEGORY "bcutil"
  
  namespace po = boost::program_options;
  
  using namespace cryptonote;
  
  namespace
  {
    // This number was picked by taking the leading 4 bytes from this output:
    // echo Oxen bootstrap file | sha1sum
    const uint32_t blockchain_raw_magic = 0x28721586;
    const uint32_t header_size = 1024;
  
    std::string refresh_string = "\r                                    \r";
  }
  
  
  
  bool BootstrapFile::open_writer(const fs::path& file_path)
  {
    const auto dir_path = file_path.parent_path();
    if (!dir_path.empty())
    {
      if (fs::exists(dir_path))
      {
        if (!fs::is_directory(dir_path))
        {
          MFATAL("export directory path is a file: " << dir_path);
          return false;
        }
      }
      else
      {
        if (!fs::create_directory(dir_path))
        {
          MFATAL("Failed to create directory " << dir_path);
          return false;
        }
      }
    }
  
    m_raw_data_file = new std::ofstream();
  
    bool do_initialize_file = false;
    uint64_t num_blocks = 0;
  
    if (! fs::exists(file_path))
    {
      MDEBUG("creating file");
      do_initialize_file = true;
      num_blocks = 0;
    }
    else
    {
      num_blocks = count_blocks(file_path.string());
      MDEBUG("appending to existing file with height: " << num_blocks-1 << "  total blocks: " << num_blocks);
    }
    m_height = num_blocks;
  
    if (do_initialize_file)
      m_raw_data_file->open(file_path.string(), std::ios_base::binary | std::ios_base::out | std::ios::trunc);
    else
      m_raw_data_file->open(file_path.string(), std::ios_base::binary | std::ios_base::out | std::ios::app | std::ios::ate);
  
    if (m_raw_data_file->fail())
      return false;
  
    m_output_stream = new boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>>(m_buffer);
    if (m_output_stream == nullptr)
      return false;
  
    if (do_initialize_file)
      initialize_file();
  
    return true;
  }
  
  
  bool BootstrapFile::initialize_file()
  {
    const uint32_t file_magic = blockchain_raw_magic;
  
    std::string blob;
    try {
      blob = serialization::dump_binary(file_magic);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in serialization of file magic: "s + e.what());
    }
    *m_raw_data_file << blob;
  
    bootstrap::file_info bfi;
    bfi.major_version = 0;
    bfi.minor_version = 1;
    bfi.header_size = header_size;
  
    bootstrap::blocks_info bbi;
    bbi.block_first = 0;
    bbi.block_last = 0;
    bbi.block_last_pos = 0;
  
    buffer_type buffer2;
    boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>> output_stream_header(buffer2);
  
    uint32_t bd_size = 0;
  
    blobdata bd = t_serializable_object_to_blob(bfi);
    MDEBUG("bootstrap::file_info size: " << bd.size());
    bd_size = bd.size();
  
    try {
      blob = serialization::dump_binary(bd_size);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in serialization of bootstrap::file_info size: "s + e.what());
    }
    output_stream_header << blob;
    output_stream_header << bd;
  
    bd = t_serializable_object_to_blob(bbi);
    MDEBUG("bootstrap::blocks_info size: " << bd.size());
    bd_size = bd.size();
  
    try {
      blob = serialization::dump_binary(bd_size);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in serialization of bootstrap::blocks_info size: "s + e.what());
    }
    output_stream_header << blob;
    output_stream_header << bd;
  
    output_stream_header.flush();
    output_stream_header << std::string(header_size-buffer2.size(), 0); // fill in rest with null bytes
    output_stream_header.flush();
    std::copy(buffer2.begin(), buffer2.end(), std::ostreambuf_iterator<char>(*m_raw_data_file));
  
    return true;
  }
  
  void BootstrapFile::flush_chunk()
  {
    m_output_stream->flush();
  
    uint32_t chunk_size = m_buffer.size();
    // MTRACE("chunk_size " << chunk_size);
    if (chunk_size > BUFFER_SIZE)
    {
      MWARNING("WARNING: chunk_size " << chunk_size << " > BUFFER_SIZE " << BUFFER_SIZE);
    }
  
    std::string blob;
    try {
      blob = serialization::dump_binary(chunk_size);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in serialization of chunk size: "s + e.what());
    }
    *m_raw_data_file << blob;
  
    if (m_max_chunk < chunk_size)
    {
      m_max_chunk = chunk_size;
    }
    long pos_before = m_raw_data_file->tellp();
    std::copy(m_buffer.begin(), m_buffer.end(), std::ostreambuf_iterator<char>(*m_raw_data_file));
    m_raw_data_file->flush();
    long pos_after = m_raw_data_file->tellp();
    long num_chars_written = pos_after - pos_before;
    if (static_cast<unsigned long>(num_chars_written) != chunk_size)
    {
      MFATAL("Error writing chunk:  height: " << m_cur_height << "  chunk_size: " << chunk_size << "  num chars written: " << num_chars_written);
      throw std::runtime_error("Error writing chunk");
    }
  
    m_buffer.clear();
    delete m_output_stream;
    m_output_stream = new boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>>(m_buffer);
    MDEBUG("flushed chunk:  chunk_size: " << chunk_size);
  }
  
  void BootstrapFile::write_block(block& block)
  {
    bootstrap::block_package bp;
    bp.block = block;
  
    std::vector<transaction> txs;
  
    uint64_t block_height = var::get<txin_gen>(block.miner_tx.vin.front()).height;
  
  
    // now add all regular transactions
    for (const auto& tx_id : block.tx_hashes)
    {
      if (tx_id == crypto::null_hash)
      {
        throw std::runtime_error("Aborting: tx == null_hash");
      }
      transaction tx = m_blockchain_storage->get_db().get_tx(tx_id);
  
      txs.push_back(tx);
    }
  
    // these non-coinbase txs will be serialized using this structure
    bp.txs = txs;
  
    // These three attributes are currently necessary for a fast import that adds blocks without verification.
    bool include_extra_block_data = true;
    if (include_extra_block_data)
    {
      size_t block_weight = m_blockchain_storage->get_db().get_block_weight(block_height);
      difficulty_type cumulative_difficulty = m_blockchain_storage->get_db().get_block_cumulative_difficulty(block_height);
      uint64_t coins_generated = m_blockchain_storage->get_db().get_block_already_generated_coins(block_height);
  
      bp.block_weight = block_weight;
      bp.cumulative_difficulty = cumulative_difficulty;
      bp.coins_generated = coins_generated;
    }
  
    blobdata bd = t_serializable_object_to_blob(bp);
    m_output_stream->write((const char*)bd.data(), bd.size());
  }
  
  bool BootstrapFile::close()
  {
    if (m_raw_data_file->fail())
      return false;
  
    m_raw_data_file->flush();
    delete m_output_stream;
    delete m_raw_data_file;
    return true;
  }
  
  
  bool BootstrapFile::store_blockchain_raw(Blockchain* _blockchain_storage, tx_memory_pool* _tx_pool, fs::path& output_file, uint64_t requested_block_stop)
  {
    uint64_t num_blocks_written = 0;
    m_max_chunk = 0;
    m_blockchain_storage = _blockchain_storage;
    m_tx_pool = _tx_pool;
    uint64_t progress_interval = 100;
    MINFO("Storing blocks raw data...");
    if (!BootstrapFile::open_writer(output_file))
    {
      MFATAL("failed to open raw file for write");
      return false;
    }
    block b;
  
    // block_start, block_stop use 0-based height. m_height uses 1-based height. So to resume export
    // from last exported block, block_start doesn't need to add 1 here, as it's already at the next
    // height.
    uint64_t block_start = m_height;
    uint64_t block_stop = 0;
    MINFO("source blockchain height: " <<  m_blockchain_storage->get_current_blockchain_height()-1);
    if ((requested_block_stop > 0) && (requested_block_stop < m_blockchain_storage->get_current_blockchain_height()))
    {
      MINFO("Using requested block height: " << requested_block_stop);
      block_stop = requested_block_stop;
    }
    else
    {
      block_stop = m_blockchain_storage->get_current_blockchain_height() - 1;
      MINFO("Using block height of source blockchain: " << block_stop);
    }
    for (m_cur_height = block_start; m_cur_height <= block_stop; ++m_cur_height)
    {
      // this method's height refers to 0-based height (genesis block = height 0)
      crypto::hash hash = m_blockchain_storage->get_block_id_by_height(m_cur_height);
      m_blockchain_storage->get_block_by_hash(hash, b);
      write_block(b);
      if (m_cur_height % NUM_BLOCKS_PER_CHUNK == 0) {
        flush_chunk();
        num_blocks_written += NUM_BLOCKS_PER_CHUNK;
      }
      if (m_cur_height % progress_interval == 0) {
        std::cout << refresh_string;
        std::cout << "block " << m_cur_height << "/" << block_stop << "\r" << std::flush;
      }
    }
    // NOTE: use of NUM_BLOCKS_PER_CHUNK is a placeholder in case multi-block chunks are later supported.
    if (m_cur_height % NUM_BLOCKS_PER_CHUNK != 0)
    {
      flush_chunk();
    }
    // print message for last block, which may not have been printed yet due to progress_interval
    std::cout << refresh_string;
    std::cout << "block " << m_cur_height-1 << "/" << block_stop << "\n";
  
    MINFO("Number of blocks exported: " << num_blocks_written);
    if (num_blocks_written > 0)
      MINFO("Largest chunk: " << m_max_chunk << " bytes");
  
    return BootstrapFile::close();
  }
  
  uint64_t BootstrapFile::seek_to_first_chunk(fs::ifstream& import_file)
  {
    uint32_t file_magic;
  
    std::string str1;
    char buf1[2048];
    import_file.read(buf1, sizeof(file_magic));
    if (! import_file)
      throw std::runtime_error("Error reading expected number of bytes");
    str1.assign(buf1, sizeof(file_magic));
  
    try {
      serialization::parse_binary(str1, file_magic);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in deserialization of file_magic: "s + e.what());
    }
  
    if (file_magic != blockchain_raw_magic)
    {
      MFATAL("bootstrap file not recognized");
      throw std::runtime_error("Aborting");
    }
    else
      MINFO("bootstrap file recognized");
  
    uint32_t buflen_file_info;
  
    import_file.read(buf1, sizeof(buflen_file_info));
    str1.assign(buf1, sizeof(buflen_file_info));
    if (! import_file)
      throw std::runtime_error("Error reading expected number of bytes");
    try {
      serialization::parse_binary(str1, buflen_file_info);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in deserialization of buflen_file_info: "s + e.what());
    }
    MINFO("bootstrap::file_info size: " << buflen_file_info);
  
    if (buflen_file_info > sizeof(buf1))
      throw std::runtime_error("Error: bootstrap::file_info size exceeds buffer size");
    import_file.read(buf1, buflen_file_info);
    if (! import_file)
      throw std::runtime_error("Error reading expected number of bytes");
    str1.assign(buf1, buflen_file_info);
    bootstrap::file_info bfi;
    try {
      serialization::parse_binary(str1, bfi);
    } catch (const std::exception& e) {
      throw std::runtime_error("Error in deserialization of bootstrap::file_info: "s + e.what());
    }
    MINFO("bootstrap file v" << unsigned(bfi.major_version) << "." << unsigned(bfi.minor_version));
    MINFO("bootstrap magic size: " << sizeof(file_magic));
    MINFO("bootstrap header size: " << bfi.header_size);
  
    uint64_t full_header_size = sizeof(file_magic) + bfi.header_size;
    import_file.seekg(full_header_size);
  
    return full_header_size;
  }
  
  uint64_t BootstrapFile::count_bytes(fs::ifstream& import_file, uint64_t blocks, uint64_t& h, bool& quit)
  {
    uint64_t bytes_read = 0;
    uint32_t chunk_size;
    char buf1[sizeof(chunk_size)];
    std::string str1;
    h = 0;
    while (1)
    {
      import_file.read(buf1, sizeof(chunk_size));
      if (!import_file) {
        std::cout << refresh_string;
        MDEBUG("End of file reached");
        quit = true;
        break;
      }
      bytes_read += sizeof(chunk_size);
      str1.assign(buf1, sizeof(chunk_size));
      try {
        serialization::parse_binary(str1, chunk_size);
      } catch (const std::exception& e) {
        throw std::runtime_error("Error in deserialization of chunk_size: "s + e.what());
      }
      MDEBUG("chunk_size: " << chunk_size);
  
      if (chunk_size > BUFFER_SIZE)
      {
        std::cout << refresh_string;
        MWARNING("WARNING: chunk_size " << chunk_size << " > BUFFER_SIZE " << BUFFER_SIZE
            << "  height: " << h-1 << ", offset " << bytes_read);
        throw std::runtime_error("Aborting: chunk size exceeds buffer size");
      }
      if (chunk_size > CHUNK_SIZE_WARNING_THRESHOLD)
      {
        std::cout << refresh_string;
        MDEBUG("NOTE: chunk_size " << chunk_size << " > " << CHUNK_SIZE_WARNING_THRESHOLD << " << height: "
            << h-1 << ", offset " << bytes_read);
      }
      else if (chunk_size <= 0) {
        std::cout << refresh_string;
        MDEBUG("ERROR: chunk_size " << chunk_size << " <= 0" << "  height: " << h-1 << ", offset " << bytes_read);
        throw std::runtime_error("Aborting");
      }
      // skip to next expected block size value
      import_file.seekg(chunk_size, std::ios_base::cur);
      if (! import_file) {
        std::cout << refresh_string;
        MFATAL("ERROR: unexpected end of file: bytes read before error: "
            << import_file.gcount() << " of chunk_size " << chunk_size);
        throw std::runtime_error("Aborting");
      }
      bytes_read += chunk_size;
      h += NUM_BLOCKS_PER_CHUNK;
      if (h >= blocks)
        break;
    }
    return bytes_read;
  }
  
  uint64_t BootstrapFile::count_blocks(const fs::path& import_file_path)
  {
    std::streampos dummy_pos;
    uint64_t dummy_height = 0;
    return count_blocks(import_file_path, dummy_pos, dummy_height);
  }
  
  // If seek_height is non-zero on entry, return a stream position <= this height when finished.
  // And return the actual height corresponding to this position. Allows the caller to locate its
  // starting position without having to reread the entire file again.
  uint64_t BootstrapFile::count_blocks(const fs::path& import_file_path, std::streampos &start_pos, uint64_t& seek_height)
  {
    if (std::error_code ec; !fs::exists(import_file_path, ec))
    {
      MFATAL("bootstrap file not found: " << import_file_path);
      throw std::runtime_error("Aborting");
    }
    fs::ifstream import_file{import_file_path, std::ios::binary};
  
    uint64_t start_height = seek_height;
    uint64_t h = 0;
    if (import_file.fail())
    {
      MFATAL("import_file.open() fail");
      throw std::runtime_error("Aborting");
    }
  
    uint64_t full_header_size; // 4 byte magic + length of header structures
    full_header_size = seek_to_first_chunk(import_file);
  
    MINFO("Scanning blockchain from bootstrap file...");
    bool quit = false;
    uint64_t bytes_read = 0, blocks;
    int progress_interval = 10;
  
    while (! quit)
    {
      if (start_height && h + progress_interval >= start_height - 1)
      {
        start_height = 0;
        start_pos = import_file.tellg();
        seek_height = h;
      }
      bytes_read += count_bytes(import_file, progress_interval, blocks, quit);
      h += blocks;
      std::cout << "\r" << "block height: " << h-1 <<
        "    \r" <<
        std::flush;
  
      // std::cout << refresh_string;
      MDEBUG("Number bytes scanned: " << bytes_read);
    }
  
    import_file.close();
  
    std::cout << "\nDone scanning bootstrap file";
    std::cout << "\nFull header length: " << full_header_size << " bytes";
    std::cout << "\nScanned for blocks: " << bytes_read << " bytes";
    std::cout << "\nTotal:              " << full_header_size + bytes_read << " bytes";
    std::cout << "\nNumber of blocks: " << h;
    std::cout << std::endl;
  
    // NOTE: h is the number of blocks.
    // Note that a block's stored height is zero-based, but parts of the code use
    // one-based height.
    return h;
  }
  