// 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 "serialization/json_utils.h" // dump_json()

#include "bootstrap_file.h"

#undef LOKI_DEFAULT_LOG_CATEGORY
#define LOKI_DEFAULT_LOG_CATEGORY "bcutil"

namespace po = boost::program_options;

using namespace cryptonote;
using namespace epee;

namespace
{
  // This number was picked by taking the leading 4 bytes from this output:
  // echo Loki 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 boost::filesystem::path& file_path)
{
  const boost::filesystem::path dir_path = file_path.parent_path();
  if (!dir_path.empty())
  {
    if (boost::filesystem::exists(dir_path))
    {
      if (!boost::filesystem::is_directory(dir_path))
      {
        MFATAL("export directory path is a file: " << dir_path);
        return false;
      }
    }
    else
    {
      if (!boost::filesystem::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 (! boost::filesystem::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;
  if (! ::serialization::dump_binary(file_magic, blob))
  {
    throw std::runtime_error("Error in serialization of file magic");
  }
  *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();

  if (! ::serialization::dump_binary(bd_size, blob))
  {
    throw std::runtime_error("Error in serialization of bootstrap::file_info size");
  }
  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();

  if (! ::serialization::dump_binary(bd_size, blob))
  {
    throw std::runtime_error("Error in serialization of bootstrap::blocks_info size");
  }
  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;
  if (! ::serialization::dump_binary(chunk_size, blob))
  {
    throw std::runtime_error("Error in serialization of chunk size");
  }
  *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 = boost::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, boost::filesystem::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 << ENDL;

  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(std::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));

  if (! ::serialization::parse_binary(str1, file_magic))
    throw std::runtime_error("Error in deserialization of file_magic");

  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");
  if (! ::serialization::parse_binary(str1, buflen_file_info))
    throw std::runtime_error("Error in deserialization of buflen_file_info");
  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;
  if (! ::serialization::parse_binary(str1, bfi))
    throw std::runtime_error("Error in deserialization of bootstrap::file_info");
  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(std::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));
    if (! ::serialization::parse_binary(str1, chunk_size))
      throw std::runtime_error("Error in deserialization of chunk_size");
    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 std::string& 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 std::string& import_file_path, std::streampos &start_pos, uint64_t& seek_height)
{
  boost::filesystem::path raw_file_path(import_file_path);
  boost::system::error_code ec;
  if (!boost::filesystem::exists(raw_file_path, ec))
  {
    MFATAL("bootstrap file not found: " << raw_file_path);
    throw std::runtime_error("Aborting");
  }
  std::ifstream import_file;
  import_file.open(import_file_path, std::ios_base::binary | std::ifstream::in);

  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 << ENDL;
  std::cout << "Done scanning bootstrap file" << ENDL;
  std::cout << "Full header length: " << full_header_size << " bytes" << ENDL;
  std::cout << "Scanned for blocks: " << bytes_read << " bytes" << ENDL;
  std::cout << "Total:              " << full_header_size + bytes_read << " bytes" << ENDL;
  std::cout << "Number of blocks: " << h << ENDL;
  std::cout << 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;
}
