/**
 *  @file
 *  @copyright defined in eos/LICENSE.txt
 */
#include <eosio/chain/contracts/eos_contract.hpp>
#include <eosio/chain/contracts/contract_table_objects.hpp>
#include <eosio/chain/contracts/chain_initializer.hpp>

#include <eosio/chain/chain_controller.hpp>
#include <eosio/chain/apply_context.hpp>
#include <eosio/chain/transaction.hpp>
#include <eosio/chain/exceptions.hpp>

#include <eosio/chain/account_object.hpp>
#include <eosio/chain/permission_object.hpp>
#include <eosio/chain/permission_link_object.hpp>
#include <eosio/chain/generated_transaction_object.hpp>
#include <eosio/chain/global_property_object.hpp>
#include <eosio/chain/contracts/types.hpp>
#include <eosio/chain/producer_object.hpp>

#include <eosio/chain/wasm_interface.hpp>
#include <eosio/chain/contracts/abi_serializer.hpp>

#include <eosio/chain/rate_limiting.hpp>

namespace eosio { namespace chain { namespace contracts {

void validate_authority_precondition( const apply_context& context, const authority& auth ) {
   for(const auto& a : auth.accounts) {
      context.db.get<account_object, by_name>(a.permission.actor);
      context.db.find<permission_object, by_owner>(boost::make_tuple(a.permission.actor, a.permission.permission));
   }
}

/**
 *  This method is called assuming precondition_system_newaccount succeeds a
 */
void apply_eosio_newaccount(apply_context& context) { 
   auto create = context.act.data_as<newaccount>();
   try {
   context.require_authorization(create.creator);
   context.require_write_lock( config::eosio_auth_scope );

   EOS_ASSERT( validate(create.owner), action_validate_exception, "Invalid owner authority");
   EOS_ASSERT( validate(create.active), action_validate_exception, "Invalid active authority");
   EOS_ASSERT( validate(create.recovery), action_validate_exception, "Invalid recovery authority");

   auto& db = context.mutable_db;

   EOS_ASSERT( create.name.to_string().size() <= 12, action_validate_exception, "account names can only be 12 chars long" );
   if( !context.privileged ) {
      EOS_ASSERT( name(create.name).to_string().find( "eosio." ) == std::string::npos, action_validate_exception, "only privileged accounts can have names that contain 'eosio.'" );
   }

   auto existing_account = db.find<account_object, by_name>(create.name);
   EOS_ASSERT(existing_account == nullptr, action_validate_exception,
              "Cannot create account named ${name}, as that name is already taken",
              ("name", create.name));

   for( const auto& auth : { create.owner, create.active, create.recovery } ){
      validate_authority_precondition( context, auth );
   }

   const auto& new_account = db.create<account_object>([&create, &context](account_object& a) {
      a.name = create.name;
      a.creation_date = context.controller.head_block_time();
   });

   auto create_permission = [owner=create.name, &db, &context](const permission_name& name, permission_object::id_type parent, authority &&auth) {
      return db.create<permission_object>([&](permission_object& p) {
         p.name = name;
         p.parent = parent;
         p.owner = owner;
         p.auth = std::move(auth);
      });
   };

   const auto& owner_permission = create_permission("owner", 0, std::move(create.owner));
   create_permission("active", owner_permission.id, std::move(create.active));

   db.create<bandwidth_usage_object>([&]( auto& bu ) { bu.owner = create.name; });

} FC_CAPTURE_AND_RETHROW( (create) ) }


void apply_eosio_setcode(apply_context& context) {
   auto& db = context.mutable_db;
   auto  act = context.act.data_as<setcode>();

   context.require_authorization(act.account);
   context.require_write_lock( config::eosio_auth_scope );

   FC_ASSERT( act.vmtype == 0 );
   FC_ASSERT( act.vmversion == 0 );

   auto code_id = fc::sha256::hash( act.code.data(), act.code.size() );

   wasm_interface::validate(act.code);

   const auto& account = db.get<account_object,by_name>(act.account);
//   wlog( "set code: ${size}", ("size",act.code.size()));
   db.modify( account, [&]( auto& a ) {
      /** TODO: consider whether a microsecond level local timestamp is sufficient to detect code version changes*/
      #warning TODO: update setcode message to include the hash, then validate it in validate 
      a.code_version = code_id;
      // Added resize(0) here to avoid bug in boost vector container
      a.code.resize( 0 );
      a.code.resize( act.code.size() );
      a.last_code_update = context.controller.head_block_time();
      memcpy( a.code.data(), act.code.data(), act.code.size() );

   });

}

void apply_eosio_setabi(apply_context& context) {
   auto& db = context.mutable_db;
   auto  act = context.act.data_as<setabi>();

   context.require_authorization(act.account);

   // if system account append native abi
   if ( act.account == eosio::chain::config::system_account_name ) {
      act.abi = chain_initializer::eos_contract_abi(act.abi);
   }

   /// if an ABI is specified make sure it is well formed and doesn't
   /// reference any undefined types
   abi_serializer(act.abi).validate();
   // todo: figure out abi serialization location

   const auto& account = db.get<account_object,by_name>(act.account);
   db.modify( account, [&]( auto& a ) {
      a.set_abi( act.abi );
   });
}

void apply_eosio_updateauth(apply_context& context) {
   context.require_write_lock( config::eosio_auth_scope );

   auto update = context.act.data_as<updateauth>();
   EOS_ASSERT(!update.permission.empty(), action_validate_exception, "Cannot create authority with empty name");
   EOS_ASSERT(update.permission != update.parent, action_validate_exception,
              "Cannot set an authority as its own parent");
   EOS_ASSERT(validate(update.data), action_validate_exception,
              "Invalid authority: ${auth}", ("auth", update.data));
   if (update.permission == "active")
      EOS_ASSERT(update.parent == "owner", action_validate_exception, "Cannot change active authority's parent from owner", ("update.parent", update.parent) );
   if (update.permission == "owner")
      EOS_ASSERT(update.parent.empty(), action_validate_exception, "Cannot change owner authority's parent");

   auto& db = context.mutable_db;

   FC_ASSERT(context.act.authorization.size(), "updateauth can only have one action authorization");
   const auto& act_auth = context.act.authorization.front();
   // lazy evaluating loop
   auto permission_is_valid_for_update = [&](){
      if (act_auth.permission == config::owner_name || act_auth.permission == update.permission) {
         return true;
      }
      const permission_object *current = db.find<permission_object, by_owner>(boost::make_tuple(update.account, update.permission));
      // Permission doesn't exist yet, check parent permission
      if (current == nullptr) current = db.find<permission_object, by_owner>(boost::make_tuple(update.account, update.parent));
      // Ensure either the permission or parent's permission exists
      EOS_ASSERT(current != nullptr, permission_query_exception,
                 "Fail to retrieve permission for: {\"actor\": \"${actor}\", \"permission\": \"${permission}\" }",
                 ("actor", update.account)("permission", update.parent));

      while(current->name != config::owner_name) {
         if (current->name == act_auth.permission) {
            return true;
         }
         current = &db.get<permission_object>(current->parent);
      }

      return false;
   };

   FC_ASSERT(act_auth.actor == update.account && permission_is_valid_for_update(), "updateauth must carry a permission equal to or in the ancestery of permission it updates");

   db.get<account_object, by_name>(update.account);
   validate_authority_precondition(context, update.data);

   auto permission = db.find<permission_object, by_owner>(boost::make_tuple(update.account, update.permission));
   
   permission_object::id_type parent_id = 0;
   if(update.permission != "owner") {
      auto& parent = db.get<permission_object, by_owner>(boost::make_tuple(update.account, update.parent));
      parent_id = parent.id;
   }

   if (permission) {
      EOS_ASSERT(parent_id == permission->parent, action_validate_exception,
                 "Changing parent authority is not currently supported");
   
      // TODO/QUESTION: If we are updating an existing permission, should we check if the message declared
      // permission satisfies the permission we want to modify?
      db.modify(*permission, [&update, &parent_id, &context](permission_object& po) {
         po.auth = update.data;
         po.parent = parent_id;
         po.last_updated = context.controller.head_block_time();
         po.delay = time_point_sec(update.delay.convert_to<uint64_t>());
      });
   }  else {
      // TODO/QUESTION: If we are creating a new permission, should we check if the message declared
      // permission satisfies the parent permission?
      db.create<permission_object>([&update, &parent_id, &context](permission_object& po) {
         po.name = update.permission;
         po.owner = update.account;
         po.auth = update.data;
         po.parent = parent_id;
         po.last_updated = context.controller.head_block_time();
         po.delay = time_point_sec(update.delay.convert_to<uint64_t>());
      });
   }
}

void apply_eosio_deleteauth(apply_context& context) {
   auto remove = context.act.data_as<deleteauth>();
   EOS_ASSERT(remove.permission != "active", action_validate_exception, "Cannot delete active authority");
   EOS_ASSERT(remove.permission != "owner", action_validate_exception, "Cannot delete owner authority");

   auto& db = context.mutable_db;
   context.require_authorization(remove.account);
   const auto& permission = db.get<permission_object, by_owner>(boost::make_tuple(remove.account, remove.permission));

   { // Check for children
      const auto& index = db.get_index<permission_index, by_parent>();
      auto range = index.equal_range(permission.id);
      EOS_ASSERT(range.first == range.second, action_validate_exception,
                 "Cannot delete an authority which has children. Delete the children first");
   }

   { // Check for links to this permission
      const auto& index = db.get_index<permission_link_index, by_permission_name>();
      auto range = index.equal_range(boost::make_tuple(remove.account, remove.permission));
      EOS_ASSERT(range.first == range.second, action_validate_exception,
                 "Cannot delete a linked authority. Unlink the authority first");
   }

   db.remove(permission);
}

void apply_eosio_linkauth(apply_context& context) {
   auto requirement = context.act.data_as<linkauth>();
   EOS_ASSERT(!requirement.requirement.empty(), action_validate_exception, "Required permission cannot be empty");

   context.require_authorization(requirement.account);
   
   auto& db = context.mutable_db;
   db.get<account_object, by_name>(requirement.account);
   db.get<account_object, by_name>(requirement.code);
   db.get<permission_object, by_name>(requirement.requirement);
   
   auto link_key = boost::make_tuple(requirement.account, requirement.code, requirement.type);
   auto link = db.find<permission_link_object, by_action_name>(link_key);
   
   if (link) {
      EOS_ASSERT(link->required_permission != requirement.requirement, action_validate_exception,
                 "Attempting to update required authority, but new requirement is same as old");
      db.modify(*link, [requirement = requirement.requirement](permission_link_object& link) {
          link.required_permission = requirement;
      });
   } else {
      db.create<permission_link_object>([&requirement](permission_link_object& link) {
         link.account = requirement.account;
         link.code = requirement.code;
         link.message_type = requirement.type;
         link.required_permission = requirement.requirement;
      });
   }
}

void apply_eosio_unlinkauth(apply_context& context) {
   auto& db = context.mutable_db;
   auto unlink = context.act.data_as<unlinkauth>();

   context.require_authorization(unlink.account);

   auto link_key = boost::make_tuple(unlink.account, unlink.code, unlink.type);
   auto link = db.find<permission_link_object, by_action_name>(link_key);
   EOS_ASSERT(link != nullptr, action_validate_exception, "Attempting to unlink authority, but no link found");
   db.remove(*link);
}


void apply_eosio_onerror(apply_context& context) {
   assert(context.trx_meta.sender);
   context.require_recipient(*context.trx_meta.sender);
}

static const abi_serializer& get_abi_serializer() {
   static optional<abi_serializer> _abi_serializer;
   if (!_abi_serializer) {
      _abi_serializer.emplace(chain_initializer::eos_contract_abi(abi_def()));
   }

   return *_abi_serializer;
}

static optional<variant> get_pending_recovery(apply_context& context, account_name account ) {
   const uint64_t id = account;
   const auto table = N(recovery);
   const auto iter = context.db_find_i64(config::system_account_name, account, table, id);
   if (iter != -1) {
      const auto buffer_size = context.db_get_i64(iter, nullptr, 0);
      bytes value(buffer_size);

      const auto written_size = context.db_get_i64(iter, value.data(), buffer_size);
      assert(written_size == buffer_size);

      return get_abi_serializer().binary_to_variant("pending_recovery", value);
   }

   return optional<variant_object>();
}

static auto get_account_creation(const apply_context& context, const account_name& account) {
   auto const& accnt = context.db.get<account_object, by_name>(account);
   return (time_point)accnt.creation_date;
};

static auto get_permission_last_used(const apply_context& context, const account_name& account, const permission_name& permission) {
   auto const* perm = context.db.find<permission_usage_object, by_account_permission>(boost::make_tuple(account, permission));
   if (perm) {
      return optional<time_point>(perm->last_used);
   }

   return optional<time_point>();
};

void apply_eosio_postrecovery(apply_context& context) {
   context.require_write_lock( config::eosio_auth_scope );

   FC_ASSERT(context.act.authorization.size() == 1, "Recovery Message must have exactly one authorization");

   auto recover_act = context.act.data_as<postrecovery>();
   const auto &auth = context.act.authorization.front();
   const auto& account = recover_act.account;
   context.require_write_lock(account);

   FC_ASSERT(!get_pending_recovery(context, account), "Account ${account} already has a pending recovery request!", ("account",account));

   fc::microseconds delay_lock;
   auto now = context.controller.head_block_time();
   if (auth.actor == account && auth.permission == N(active)) {
      // process owner recovery from active
      delay_lock = fc::days(30);
   } else {
      // process lost password

      auto owner_last_used = get_permission_last_used(context, account, N(owner));
      auto active_last_used = get_permission_last_used(context, account, N(active));

      if (!owner_last_used || !active_last_used) {
         auto account_creation = get_account_creation(context, account);
         if (!owner_last_used) {
            owner_last_used.emplace(account_creation);
         }

         if (!active_last_used) {
            active_last_used.emplace(account_creation);
         }
      }

      FC_ASSERT(*owner_last_used <= now - fc::days(30), "Account ${account} has had owner key activity recently and cannot be recovered yet!", ("account",account));
      FC_ASSERT(*active_last_used <= now - fc::days(30), "Account ${account} has had active key activity recently and cannot be recovered yet!", ("account",account));

      delay_lock = fc::days(7);
   }

   variant update;
   fc::to_variant( updateauth {
      .account = account,
      .permission = N(owner),
      .parent = 0,
      .data = recover_act.data
   }, update);

   uint32_t request_id = context.get_next_sender_id();

   auto record_data = mutable_variant_object()
      ("account", account)
      ("request_id", request_id)
      ("update", update)
      ("memo", recover_act.memo);

   deferred_transaction dtrx;
   dtrx.sender = config::system_account_name;
   dtrx.sender_id = request_id;
   dtrx.region = 0;
   dtrx.execute_after = context.controller.head_block_time() + delay_lock;
   dtrx.set_reference_block(context.controller.head_block_id());
   dtrx.expiration = dtrx.execute_after + fc::seconds(60);
   dtrx.actions.emplace_back(vector<permission_level>{{account,config::active_name}},
                             passrecovery { account });

   context.execute_deferred(std::move(dtrx));


   auto data = get_abi_serializer().variant_to_binary("pending_recovery", record_data);
   const uint64_t id = account;
   const uint64_t table = N(recovery);
   const auto payer = account;
   const auto iter = context.db_find_i64(config::system_account_name, account, table, id);
   if (iter == -1) {
      context.db_store_i64(account, table, payer, id, (const char*)data.data(), data.size());
   } else {
      context.db_update_i64(iter, payer, (const char*)data.data(), data.size());
   }

   context.console_append_formatted("Recovery Started for account ${account} : ${memo}\n", mutable_variant_object()("account", account)("memo", recover_act.memo));
}

static void remove_pending_recovery(apply_context& context, const account_name& account) {
   const auto iter = context.db_find_i64(config::system_account_name, account, N(recovery), account);
   if (iter != -1) {
      context.db_remove_i64(iter);
   }
}

void apply_eosio_passrecovery(apply_context& context) {
   auto pass_act = context.act.data_as<passrecovery>();
   const auto& account = pass_act.account;

   // ensure this is only processed if it is a deferred transaction from the system account
   FC_ASSERT(context.trx_meta.sender && *context.trx_meta.sender == config::system_account_name);
   context.require_authorization(account);

   auto maybe_recovery = get_pending_recovery(context, account);
   FC_ASSERT(maybe_recovery, "No pending recovery found for account ${account}", ("account", account));
   auto recovery = *maybe_recovery;

   updateauth update;
   fc::from_variant(recovery["update"], update);

   action act(vector<permission_level>{{account,config::owner_name}}, update);
   context.execute_inline(move(act));

   remove_pending_recovery(context, account);
   context.console_append_formatted("Account ${account} successfully recoverd!\n", mutable_variant_object()("account", account));
}

void apply_eosio_vetorecovery(apply_context& context) {
   context.require_write_lock( config::eosio_auth_scope );
   auto pass_act = context.act.data_as<vetorecovery>();
   const auto& account = pass_act.account;
   context.require_authorization(account);

   auto maybe_recovery = get_pending_recovery(context, account);
   FC_ASSERT(maybe_recovery, "No pending recovery found for account ${account}", ("account", account));
   auto recovery = *maybe_recovery;

   context.cancel_deferred(recovery["request_id"].as<uint32_t>());

   remove_pending_recovery(context, account);
   context.console_append_formatted("Recovery for account ${account} vetoed!\n", mutable_variant_object()("account", account));
}

void apply_eosio_canceldelay(apply_context& context) {
   auto cancel = context.act.data_as<canceldelay>();
   const auto sender_id = cancel.sender_id.convert_to<uint32_t>();
   const auto& generated_transaction_idx = context.controller.get_database().get_index<generated_transaction_multi_index>();
   const auto& generated_index = generated_transaction_idx.indices().get<by_sender_id>();
   const auto& itr = generated_index.lower_bound(boost::make_tuple(config::system_account_name, sender_id));
   FC_ASSERT (itr == generated_index.end() || itr->sender != config::system_account_name || itr->sender_id != sender_id,
              "cannot cancel sender_id=${sid}, there is no deferred transaction with that sender_id",("sid",sender_id));

   auto dtrx = fc::raw::unpack<deferred_transaction>(itr->packed_trx.data(), itr->packed_trx.size());
   set<account_name> accounts;
   for (const auto& act : dtrx.actions) {
      for (const auto& auth : act.authorization) {
         accounts.insert(auth.actor);
      }
   }

   bool found = false;
   for (const auto& auth : context.act.authorization) {
      if (auth.permission == config::active_name && accounts.count(auth.actor)) {
         found = true;
         break;
      }
   }

   FC_ASSERT (found, "canceldelay action must be signed with the \"active\" permission for one of the actors"
                     " provided in the authorizations on the original transaction");
   context.cancel_deferred(sender_id);
}

void apply_eosio_mindelay(apply_context& context) {
   // all processing is performed in chain_controller::check_authorization
}

} } } // namespace eosio::chain::contracts