/*
 * Copyright (c) 2015, Cryptonomex, Inc.
 * All rights reserved.
 *
 * This source code is provided for evaluation in private test networks only, until September 8, 2015. After this date, this license expires and
 * the code may not be used, modified or distributed for any purpose. Redistribution and use in source and binary forms, with or without modification,
 * are permitted until September 8, 2015, provided that the following conditions are met:
 *
 * 1. The code and/or derivative works are used only for private test networks consisting of no more than 10 P2P nodes.
 *
 * 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 <graphene/chain/database.hpp>

#include <graphene/chain/operation_history_object.hpp>
#include <graphene/chain/protocol/fee_schedule.hpp>

#include <fc/io/fstream.hpp>

#include <fstream>
#include <functional>
#include <iostream>

namespace graphene { namespace chain {

database::database()
{
   initialize_indexes();
   initialize_evaluators();
}

database::~database()
{
   clear_pending();
}

void database::reindex(fc::path data_dir, const genesis_state_type& initial_allocation)
{ try {
   ilog( "reindexing blockchain" );
   wipe(data_dir, false);
   open(data_dir, [&initial_allocation]{return initial_allocation;});

   auto start = fc::time_point::now();
   auto last_block = _block_id_to_block.last();
   if( !last_block ) {
      elog( "!no last block" );
      edump((last_block));
      return;
   }

   const auto last_block_num = last_block->block_num();

   ilog( "Replaying blocks..." );
   _undo_db.disable();
   for( uint32_t i = 1; i <= last_block_num; ++i )
   {
      if( i % 2000 == 0 ) std::cerr << "   " << double(i*100)/last_block_num << "%   "<<i << " of " <<last_block_num<<"   \n";
      fc::optional< signed_block > block = _block_id_to_block.fetch_by_number(i);
      if( !block.valid() )
      {
         wlog( "Reindexing terminated due to gap:  Block ${i} does not exist!", ("i", i) );
         uint32_t dropped_count = 0;
         while( true )
         {
            fc::optional< block_id_type > last_id = _block_id_to_block.last_id();
            // this can trigger if we attempt to e.g. read a file that has block #2 but no block #1
            if( !last_id.valid() )
               break;
            // we've caught up to the gap
            if( block_header::num_from_id( *last_id ) <= i )
               break;
            _block_id_to_block.remove( *last_id );
            dropped_count++;
         }
         wlog( "Dropped ${n} blocks from after the gap", ("n", dropped_count) );
         break;
      }
      apply_block(*block, skip_witness_signature |
                          skip_transaction_signatures |
                          skip_transaction_dupe_check |
                          skip_tapos_check |
                          skip_witness_schedule_check |
                          skip_authority_check);
   }
   _undo_db.enable();
   auto end = fc::time_point::now();
   ilog( "Done reindexing, elapsed time: ${t} sec", ("t",double((end-start).count())/1000000.0 ) );
} FC_CAPTURE_AND_RETHROW( (data_dir) ) }

void database::wipe(const fc::path& data_dir, bool include_blocks)
{
   ilog("Wiping database", ("include_blocks", include_blocks));
   close();
   object_database::wipe(data_dir);
   if( include_blocks )
      fc::remove_all( data_dir / "database" );
}

void database::open(
   const fc::path& data_dir,
   std::function<genesis_state_type()> genesis_loader)
{
   try
   {
      auto is_new = [&]() -> bool
      {
         // directory doesn't exist
         if( !fc::exists( data_dir ) )
            return true;
         // if directory exists but is empty, return true; else false.
         return ( fc::directory_iterator( data_dir ) == fc::directory_iterator() );
      };

      auto is_outdated = [&]() -> bool
      {
         if( !fc::exists( data_dir / "db_version" ) )
            return true;
         std::string version_str;
         fc::read_file_contents( data_dir / "db_version", version_str );
         return (version_str != GRAPHENE_CURRENT_DB_VERSION);
      };

      if( (!is_new()) && is_outdated() )
      {
         ilog( "Old database version detected, reindex is required" );
         wipe( data_dir, false );
         fc::remove_all( data_dir / "db_version" );
      }

      object_database::open(data_dir);

      _block_id_to_block.open(data_dir / "database" / "block_num_to_block");

      if( !find(global_property_id_type()) )
         init_genesis(genesis_loader());

      fc::optional<signed_block> last_block = _block_id_to_block.last();
      if( last_block.valid() )
      {
         _fork_db.start_block( *last_block );
         idump((last_block->id())(last_block->block_num()));
         if( last_block->id() != head_block_id() )
         {
              FC_ASSERT( head_block_num() == 0, "last block ID does not match current chain state" );
         }
      }

      // doing this down here helps ensure that DB will be wiped
      // if any of the above steps were interrupted on a previous run
      if( !fc::exists( data_dir / "db_version" ) )
      {
         std::ofstream db_version(
            (data_dir / "db_version").generic_string().c_str(),
            std::ios::out | std::ios::binary | std::ios::trunc );
         std::string version_string = GRAPHENE_CURRENT_DB_VERSION;
         db_version.write( version_string.c_str(), version_string.size() );
         db_version.close();
      }

      //idump((head_block_id())(head_block_num()));
   }
   FC_CAPTURE_LOG_AND_RETHROW( (data_dir) )
}

void database::close(bool rewind)
{
   // TODO:  Save pending tx's on close()
   clear_pending();

   // pop all of the blocks that we can given our undo history, this should
   // throw when there is no more undo history to pop
   if( rewind )
   {
      try
      {
         while( true )
         {
         //   elog("pop");
            block_id_type popped_block_id = head_block_id();
            pop_block();
            _fork_db.remove(popped_block_id); // doesn't throw on missing
            try
            {
               _block_id_to_block.remove(popped_block_id);
            }
            catch (const fc::key_not_found_exception&)
            {
            }
         }
      }
      catch (...)
      {
      }
   }

   // Since pop_block() will move tx's in the popped blocks into pending,
   // we have to clear_pending() after we're done popping to get a clean
   // DB state (issue #336).
   clear_pending();

   object_database::flush();
   object_database::close();

   if( _block_id_to_block.is_open() )
      _block_id_to_block.close();

   _fork_db.reset();
}

} }