/*
 * 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/app/application.hpp>
#include <graphene/app/plugin.hpp>
#include <graphene/app/api.hpp>

#include <graphene/net/core_messages.hpp>

#include <graphene/time/time.hpp>

#include <graphene/utilities/key_conversion.hpp>

#include <fc/rpc/api_connection.hpp>
#include <fc/rpc/websocket_api.hpp>

#include <boost/filesystem/path.hpp>

#include <iostream>

#include <fc/log/file_appender.hpp>
#include <fc/log/logger.hpp>
#include <fc/log/logger_config.hpp>

namespace graphene { namespace app {
using net::item_hash_t;
using net::item_id;
using net::message;
using net::block_message;
using net::trx_message;

using chain::block_header;
using chain::signed_block_header;
using chain::signed_block;
using chain::block_id_type;

using std::vector;

namespace bpo = boost::program_options;

namespace detail {

   class application_impl : public net::node_delegate
   {
   public:
      fc::optional<fc::temp_file> _lock_file;
      bool _is_block_producer = false;

      void reset_p2p_node(const fc::path& data_dir)
      { try {
         _p2p_network = std::make_shared<net::node>("Graphene Reference Implementation");

         _p2p_network->load_configuration(data_dir / "p2p");
         _p2p_network->set_node_delegate(this);

         if( _options->count("seed-node") )
         {
            auto seeds = _options->at("seed-node").as<vector<string>>();
            for( const string& ep : seeds )
            {
               fc::ip::endpoint node = fc::ip::endpoint::from_string(ep);
               ilog("Adding seed node ${ip}", ("ip", node));
               _p2p_network->add_node(node);
               _p2p_network->connect_to_endpoint(node);
            }
         }

         if( _options->count("p2p-endpoint") )
            _p2p_network->listen_on_endpoint(fc::ip::endpoint::from_string(_options->at("p2p-endpoint").as<string>()), true);
         else
            _p2p_network->listen_on_port(0, false);
         _p2p_network->listen_to_p2p_network();
         ilog("Configured p2p node to listen on ${ip}", ("ip", _p2p_network->get_actual_listening_endpoint()));

         _p2p_network->connect_to_p2p_network();
         _p2p_network->sync_from(net::item_id(net::core_message_type_enum::block_message_type,
                                              _chain_db->head_block_id()),
                                 std::vector<uint32_t>());
      } FC_CAPTURE_AND_RETHROW() }

      void reset_websocket_server()
      { try {
         if( !_options->count("rpc-endpoint") )
            return;

         _websocket_server = std::make_shared<fc::http::websocket_server>();

         _websocket_server->on_connection([&]( const fc::http::websocket_connection_ptr& c ){
            auto wsc = std::make_shared<fc::rpc::websocket_api_connection>(*c);
            auto login = std::make_shared<graphene::app::login_api>( std::ref(*_self) );
            auto db_api = std::make_shared<graphene::app::database_api>( std::ref(*_self->chain_database()) );
            wsc->register_api(fc::api<graphene::app::database_api>(db_api));
            wsc->register_api(fc::api<graphene::app::login_api>(login));
            c->set_session_data( wsc );
         });
         _websocket_server->listen( fc::ip::endpoint::from_string(_options->at("rpc-endpoint").as<string>()) );
         _websocket_server->start_accept();
      } FC_CAPTURE_AND_RETHROW() }


      void reset_websocket_tls_server()
      { try {
         if( !_options->count("rpc-tls-endpoint") )
            return;
         if( !_options->count("server-pem") )
            return;

         string password = _options->count("server-pem-password") ? _options->at("server-pem-password").as<string>() : "";
         _websocket_tls_server = std::make_shared<fc::http::websocket_tls_server>( _options->at("server-pem").as<string>(), password );

         _websocket_tls_server->on_connection([&]( const fc::http::websocket_connection_ptr& c ){
            auto wsc = std::make_shared<fc::rpc::websocket_api_connection>(*c);
            auto login = std::make_shared<graphene::app::login_api>( std::ref(*_self) );
            auto db_api = std::make_shared<graphene::app::database_api>( std::ref(*_self->chain_database()) );
            wsc->register_api(fc::api<graphene::app::database_api>(db_api));
            wsc->register_api(fc::api<graphene::app::login_api>(login));
            c->set_session_data( wsc );
         });
         _websocket_tls_server->listen( fc::ip::endpoint::from_string(_options->at("rpc-tls-endpoint").as<string>()) );
         _websocket_tls_server->start_accept();
      } FC_CAPTURE_AND_RETHROW() }

      application_impl(application* self)
         : _self(self),
           _chain_db(std::make_shared<chain::database>())
      {
      }

      ~application_impl()
      {
         fc::remove_all(_data_dir / "blockchain/dblock");
      }

      void startup()
      { try {
         bool clean = !fc::exists(_data_dir / "blockchain/dblock");
         fc::create_directories(_data_dir / "blockchain/dblock");

         auto nathan_key = fc::ecc::private_key::regenerate(fc::sha256::hash(string("nathan")));
         genesis_state_type initial_state;
         fc::reflector<fee_schedule_type>::visit(
                  fee_schedule_type::fee_set_visitor{initial_state.initial_parameters.current_fees, 0});
         secret_hash_type::encoder enc;
         fc::raw::pack(enc, nathan_key);
         fc::raw::pack(enc, secret_hash_type());
         auto secret = secret_hash_type::hash(enc.result());
         for( int i = 0; i < 10; ++i )
         {
            auto name = "init"+fc::to_string(i);
            initial_state.initial_accounts.emplace_back(name,
                                                        nathan_key.get_public_key(),
                                                        nathan_key.get_public_key(),
                                                        true);
            initial_state.initial_committee_candidates.push_back({name});
            initial_state.initial_witness_candidates.push_back({name, nathan_key.get_public_key(), secret});
         }

         initial_state.initial_accounts.emplace_back("nathan", nathan_key.get_public_key());
         initial_state.initial_balances.push_back({nathan_key.get_public_key(),
                                                   GRAPHENE_SYMBOL,
                                                   GRAPHENE_MAX_SHARE_SUPPLY});
         if( _options->count("genesis-json") )
            initial_state = fc::json::from_file(_options->at("genesis-json").as<boost::filesystem::path>())
                  .as<genesis_state_type>();
         else
            dlog("Allocating all stake to ${key}", ("key", utilities::key_to_wif(nathan_key)));

         if( _options->count("resync-blockchain") )
            _chain_db->wipe(_data_dir / "blockchain", true);

         if( _options->count("replay-blockchain") )
         {
            ilog("Replaying blockchain on user request.");
            _chain_db->reindex(_data_dir/"blockchain", initial_state);
         } else if( clean )
            _chain_db->open(_data_dir / "blockchain", initial_state);
         else {
            wlog("Detected unclean shutdown. Replaying blockchain...");
            _chain_db->reindex(_data_dir / "blockchain", initial_state);
         }

         reset_p2p_node(_data_dir);
         reset_websocket_server();
         reset_websocket_tls_server();
      } FC_CAPTURE_AND_RETHROW() }

      /**
       * If delegate has the item, the network has no need to fetch it.
       */
      virtual bool has_item( const net::item_id& id ) override
      {
         try
         {
            if( id.item_type == graphene::net::block_message_type )
               return _chain_db->is_known_block(id.item_hash);
            else
               return _chain_db->is_known_transaction(id.item_hash);
         }
         FC_CAPTURE_AND_RETHROW( (id) )
      }

      /**
       * @brief allows the application to validate an item prior to broadcasting to peers.
       *
       * @param sync_mode true if the message was fetched through the sync process, false during normal operation
       * @returns true if this message caused the blockchain to switch forks, false if it did not
       *
       * @throws exception if error validating the item, otherwise the item is safe to broadcast on.
       */
      virtual bool handle_block( const graphene::net::block_message& blk_msg, bool sync_mode ) override
      { try {
         ilog("Got block #${n} from network", ("n", blk_msg.block.block_num()));
         try {
            return _chain_db->push_block( blk_msg.block, _is_block_producer? database::skip_nothing : database::skip_transaction_signatures );
         } catch( const fc::exception& e ) {
            elog("Error when pushing block:\n${e}", ("e", e.to_detail_string()));
            throw;
         }
      } FC_CAPTURE_AND_RETHROW( (blk_msg)(sync_mode) ) }

      virtual bool handle_transaction( const graphene::net::trx_message& trx_msg, bool sync_mode ) override
      { try {
         ilog("Got transaction from network");
         _chain_db->push_transaction( trx_msg.trx );
         return false;
      } FC_CAPTURE_AND_RETHROW( (trx_msg)(sync_mode) ) }

      /**
       * Assuming all data elements are ordered in some way, this method should
       * return up to limit ids that occur *after* the last ID in synopsis that
       * we recognize.
       *
       * On return, remaining_item_count will be set to the number of items
       * in our blockchain after the last item returned in the result,
       * or 0 if the result contains the last item in the blockchain
       */
      virtual std::vector<item_hash_t> get_item_ids(uint32_t item_type,
                                                    const std::vector<item_hash_t>& blockchain_synopsis,
                                                    uint32_t& remaining_item_count,
                                                    uint32_t limit) override
      { try {
         FC_ASSERT( item_type == graphene::net::block_message_type );
         vector<block_id_type>  result;
         remaining_item_count = 0;
         if( _chain_db->head_block_num() == 0 )
            return result;

         result.reserve(limit);
         block_id_type last_known_block_id;
         auto itr = blockchain_synopsis.rbegin();
         while( itr != blockchain_synopsis.rend() )
         {
            if( _chain_db->is_known_block(*itr) || *itr == block_id_type() )
            {
               last_known_block_id = *itr;
               break;
            }
            ++itr;
         }

         for( auto num = block_header::num_from_id(last_known_block_id);
              num <= _chain_db->head_block_num() && result.size() < limit;
              ++num )
            if( num > 0 )
               result.push_back(_chain_db->get_block_id_for_num(num));

         if( block_header::num_from_id(result.back()) < _chain_db->head_block_num() )
            remaining_item_count = _chain_db->head_block_num() - block_header::num_from_id(result.back());

         return result;
      } FC_CAPTURE_AND_RETHROW( (blockchain_synopsis)(remaining_item_count)(limit) ) }

      /**
       * Given the hash of the requested data, fetch the body.
       */
      virtual message get_item( const item_id& id ) override
      { try {
         ilog("Request for item ${id}", ("id", id));
         if( id.item_type == graphene::net::block_message_type )
         {
            auto opt_block = _chain_db->fetch_block_by_id( id.item_hash );
            if( !opt_block )
               elog("Couldn't find block ${id} -- corresponding ID in our chain is ${id2}",
                    ("id", id.item_hash)("id2", _chain_db->get_block_id_for_num(block_header::num_from_id(id.item_hash))));
            FC_ASSERT( opt_block.valid() );
            ilog("Serving up block #${num}", ("num", opt_block->block_num()));
            return block_message( std::move(*opt_block) );
         }
         return trx_message( _chain_db->get_recent_transaction( id.item_hash ) );
      } FC_CAPTURE_AND_RETHROW( (id) ) }

      virtual fc::sha256 get_chain_id()const override
      {
         return _chain_db->get_global_properties().chain_id;
      }

      /**
       * Returns a synopsis of the blockchain used for syncing.
       * This consists of a list of selected item hashes from our current preferred
       * blockchain, exponentially falling off into the past.  Horrible explanation.
       *
       * If the blockchain is empty, it will return the empty list.
       * If the blockchain has one block, it will return a list containing just that block.
       * If it contains more than one block:
       *   the first element in the list will be the hash of the genesis block
       *   the second element will be the hash of an item at the half way point in the blockchain
       *   the third will be ~3/4 of the way through the block chain
       *   the fourth will be at ~7/8...
       *     &c.
       *   the last item in the list will be the hash of the most recent block on our preferred chain
       */
      virtual std::vector<item_hash_t> get_blockchain_synopsis( uint32_t item_type,
                                                                const graphene::net::item_hash_t& reference_point,
                                                                uint32_t number_of_blocks_after_reference_point ) override
      { try {
         std::vector<item_hash_t> result;
         result.reserve(30);
         auto head_block_num = _chain_db->head_block_num();
         result.push_back( _chain_db->head_block_id() );
         auto current = 1;
         while( current < head_block_num )
         {
            result.push_back( _chain_db->get_block_id_for_num( head_block_num - current ) );
            current = current*2;
         }
         std::reverse( result.begin(), result.end() );
         idump((reference_point)(number_of_blocks_after_reference_point)(result));
         return result;
      } FC_CAPTURE_AND_RETHROW( (reference_point)(number_of_blocks_after_reference_point) ) }

      /**
       * Call this after the call to handle_message succeeds.
       *
       * @param item_type the type of the item we're synchronizing, will be the same as item passed to the sync_from() call
       * @param item_count the number of items known to the node that haven't been sent to handle_item() yet.
       *                   After `item_count` more calls to handle_item(), the node will be in sync
       */
      virtual void     sync_status( uint32_t item_type, uint32_t item_count ) override
      {
         // any status reports to GUI go here
      }

      /**
       * Call any time the number of connected peers changes.
       */
      virtual void     connection_count_changed( uint32_t c ) override
      {
        // any status reports to GUI go here
      }

      virtual uint32_t get_block_number(const item_hash_t& block_id) override
      { try {
         return block_header::num_from_id(block_id);
      } FC_CAPTURE_AND_RETHROW( (block_id) ) }

      /**
       * Returns the time a block was produced (if block_id = 0, returns genesis time).
       * If we don't know about the block, returns time_point_sec::min()
       */
      virtual fc::time_point_sec get_block_time(const item_hash_t& block_id) override
      { try {
         auto opt_block = _chain_db->fetch_block_by_id( block_id );
         if( opt_block.valid() ) return opt_block->timestamp;
         return fc::time_point_sec::min();
      } FC_CAPTURE_AND_RETHROW( (block_id) ) }

      /** returns graphene::time::now() */
      virtual fc::time_point_sec get_blockchain_now() override
      {
         return graphene::time::now();
      }

      virtual item_hash_t get_head_block_id() const override
      {
         return _chain_db->head_block_id();
      }

      virtual uint32_t estimate_last_known_fork_from_git_revision_timestamp(uint32_t unix_timestamp) const override
      {
         return 0; // there are no forks in graphene
      }

      virtual void error_encountered(const std::string& message, const fc::oexception& error) override
      {
         // notify GUI or something cool
      }

      application* _self;

      fc::path _data_dir;
      const bpo::variables_map* _options = nullptr;

      std::shared_ptr<graphene::chain::database>            _chain_db;
      std::shared_ptr<graphene::net::node>                  _p2p_network;
      std::shared_ptr<fc::http::websocket_server>      _websocket_server;
      std::shared_ptr<fc::http::websocket_tls_server>  _websocket_tls_server;

      std::map<string, std::shared_ptr<abstract_plugin>> _plugins;
   };

}

application::application()
   : my(new detail::application_impl(this))
{}

application::~application()
{
   if( my->_p2p_network )
   {
      //ilog("Closing p2p node");
      my->_p2p_network->close();
      my->_p2p_network.reset();
   }
   if( my->_chain_db )
   {
      //ilog("Closing chain database");
      my->_chain_db->close();
   }
}

void application::set_program_options(boost::program_options::options_description& command_line_options,
                                      boost::program_options::options_description& configuration_file_options) const
{
   configuration_file_options.add_options()
         ("p2p-endpoint", bpo::value<string>(), "Endpoint for P2P node to listen on")
         ("seed-node,s", bpo::value<vector<string>>()->composing(), "P2P nodes to connect to on startup (may specify multiple times)")
         ("rpc-endpoint", bpo::value<string>()->implicit_value("127.0.0.1:8090"), "Endpoint for websocket RPC to listen on")
         ("rpc-tls-endpoint", bpo::value<string>()->implicit_value("127.0.0.1:8089"), "Endpoint for TLS websocket RPC to listen on")
         ("server-pem,p", bpo::value<string>()->implicit_value("server.pem"), "The TLS certificate file for this server")
         ("server-pem-password,P", bpo::value<string>()->implicit_value(""), "Password for this certificate")
         ("genesis-json", bpo::value<boost::filesystem::path>(), "File to read Genesis State from")
         ;
   command_line_options.add(configuration_file_options);
   command_line_options.add_options()
         ("replay-blockchain", "Rebuild object graph by replaying all blocks")
         ("resync-blockchain", "Delete all blocks and re-sync with network from scratch")
         ;
   command_line_options.add(_cli_options);
   configuration_file_options.add(_cfg_options);
}

void application::initialize(const fc::path& data_dir, const boost::program_options::variables_map& options)
{
   my->_data_dir = data_dir;
   my->_options = &options;
}

void application::startup()
{
   my->startup();
}

std::shared_ptr<abstract_plugin> application::get_plugin(const string& name) const
{
   return my->_plugins[name];
}

net::node_ptr application::p2p_node()
{
   return my->_p2p_network;
}

std::shared_ptr<chain::database> application::chain_database() const
{
   return my->_chain_db;
}

void application::set_block_production(bool producing_blocks)
{
   my->_is_block_producer = producing_blocks;
}

void graphene::app::application::add_plugin(const string& name, std::shared_ptr<graphene::app::abstract_plugin> p)
{
   my->_plugins[name] = p;
}

void application::shutdown_plugins()
{
   for( auto& entry : my->_plugins )
      entry.second->plugin_shutdown();
   return;
}

void application::initialize_plugins( const boost::program_options::variables_map& options )
{
   for( auto& entry : my->_plugins )
      entry.second->plugin_initialize( options );
   return;
}

void application::startup_plugins()
{
   for( auto& entry : my->_plugins )
      entry.second->plugin_startup();
   return;
}

// namespace detail
} }