<?php


namespace Inspectio\Board\Domain\Api;



// Event Engine Aggregate Description



$eventEngine->process(Command::INSTALL_USER_BOARD)


  
  ->withNew(self::BOARD)
  ->identifiedBy(Payload::BOARD_ID)
  ->provideContext(BoardInstallerProvider::class)
  ->handle([BoardBehavior::class, 'installUserBoard'])



  ->recordThat(Event::BOARD_INSTALLED)
  ->apply([BoardBehavior::class, 'whenBoardInstalled']);

public static function installUserBoard(
    Board\Command\InstallUserBoard $command, 
    BoardInstaller $installer
): \Generator
{
    if(!$installer->hasEnoughQuotaFor($command->userInfo()->userId())) {
        throw NoBoardQuotaAvailable::forUser($command->userInfo()->userId());
    }

    yield Board\Event\BoardInstalled::fromRecordData([
        Board\Event\BoardInstalled::BOARD_ID => $command->boardId(),
        Board\Event\BoardInstalled::OWNER_ID => $command->userInfo()->userId(),
        Board\Event\BoardInstalled::NAME => $command->name(),
        Board\Event\BoardInstalled::BOARD_VERSION => BoardVersion::forNewBoardOfOwner($command->userInfo()->userId()),
        Board\Event\BoardInstalled::CURRENT_QUOTA => $installer->boardQuota(),
        Board\Event\BoardInstalled::LAST_MODIFIED => LastModified::fromDateTime(UtcDateTime::now()),
    ]);
}

public static function whenBoardInstalled(Board\Event\BoardInstalled $event): Board\Board
{
    return Board\Board::fromRecordData([
        Board\Board::BOARD_ID => $event->boardId(),
        Board\Board::OWNER_ID => $event->ownerId(),
        Board\Board::NAME => $event->name(),
        Board\Board::BOARD_VERSION => $event->boardVersion(),
        Board\Board::LAST_MODIFIED => $event->lastModified(),
    ]);
}

$eventEngine->on(self::BOARD_INSTALLED, [BoardQuotaPolicy::class, 'onBoardInstalled']);

<?php

declare(strict_types=1);

namespace Inspectio\Board\Domain\Model\User;

use Inspectio\Board\Domain\Model\Board\Event\BoardDeleted;
use Inspectio\Board\Domain\Model\Board\Event\BoardInstalled;
use Inspectio\Board\Domain\Model\User\Command\IncreaseBoardQuota;
use Inspectio\Board\Domain\Model\User\Command\ReduceBoardQuota;




final class BoardQuotaPolicy
{
    public static function onBoardInstalled(
       BoardInstalled $boardInstalled
    ): ReduceBoardQuota
    {
        return ReduceBoardQuota::fromRecordData([
            ReduceBoardQuota::USER_ID => $boardInstalled->ownerId(),
            ReduceBoardQuota::CURRENT_QUOTA => $boardInstalled->currentQuota(),
        ]);
    }

    public static function onBoardDeleted(
       BoardDeleted $boardDeleted
    ): IncreaseBoardQuota
    {
        return IncreaseBoardQuota::fromRecordData([
            IncreaseBoardQuota::USER_ID => $boardDeleted->ownerId(),
            IncreaseBoardQuota::QUOTA => $boardDeleted->newOwnerQuota(),
        ]);
    }
}

<?php


namespace Inspectio\Board\Domain\Api;



// Event Engine Aggregate Description






$eventEngine->process(Command::REDUCE_BOARD_QUOTA)







  ->withExisting(self::USER)
  ->handle([UserBehavior::class, 'reduceQuota'])
  
  
  
  
  
  
  
  ->recordThat(Event::BOARD_QUOTA_REDUCED)
  ->apply([UserBehavior::class, 'whenBoardQuotaReduced']);

<?php


namespace Inspectio\Board\Domain\Model\User;


//...


public static function reduceQuota(
  User\User $state, 
  User\Command\ReduceBoardQuota $reduceBoardQuota
  ): \Generator
{
  $newQuota = $reduceBoardQuota->currentQuota()->reduce();

  if($state->quota()->toInt() <= $newQuota->toInt()) {
	//Duplicate or outdated command received
	yield null;
	return;
  }

  yield User\Event\BoardQuotaReduced::fromRecordData([
  	User\Event\BoardQuotaReduced::USER_ID => $state->userId(),
    User\Event\BoardQuotaReduced::QUOTA => $newQuota,
  ]);
}

public static function whenBoardQuotaReduced(
  User\User $state, 
  User\Event\BoardQuotaReduced $boardQuotaReduced
): User\User
{
  return $state->with([User\User::QUOTA => $boardQuotaReduced->quota()]);
}