<?php

final class DrydockResource extends DrydockDAO
  implements PhabricatorPolicyInterface {

  protected $id;
  protected $phid;
  protected $blueprintPHID;
  protected $status;

  protected $type;
  protected $name;
  protected $attributes   = array();
  protected $capabilities = array();
  protected $ownerPHID;

  private $blueprint = self::ATTACHABLE;
  private $isAllocated = false;
  private $isActivated = false;
  private $activateWhenAllocated = false;
  private $slotLocks = array();

  protected function getConfiguration() {
    return array(
      self::CONFIG_AUX_PHID => true,
      self::CONFIG_SERIALIZATION => array(
        'attributes'    => self::SERIALIZATION_JSON,
        'capabilities'  => self::SERIALIZATION_JSON,
      ),
      self::CONFIG_COLUMN_SCHEMA => array(
        'name' => 'text255',
        'ownerPHID' => 'phid?',
        'status' => 'uint32',
        'type' => 'text64',
      ),
      self::CONFIG_KEY_SCHEMA => array(
        'key_phid' => null,
        'phid' => array(
          'columns' => array('phid'),
          'unique' => true,
        ),
      ),
    ) + parent::getConfiguration();
  }

  public function generatePHID() {
    return PhabricatorPHID::generateNewPHID(DrydockResourcePHIDType::TYPECONST);
  }

  public function getAttribute($key, $default = null) {
    return idx($this->attributes, $key, $default);
  }

  public function getAttributesForTypeSpec(array $attribute_names) {
    return array_select_keys($this->attributes, $attribute_names);
  }

  public function setAttribute($key, $value) {
    $this->attributes[$key] = $value;
    return $this;
  }

  public function getCapability($key, $default = null) {
    return idx($this->capbilities, $key, $default);
  }

  public function getInterface(DrydockLease $lease, $type) {
    return $this->getBlueprint()->getInterface($this, $lease, $type);
  }

  public function getBlueprint() {
    return $this->assertAttached($this->blueprint);
  }

  public function attachBlueprint(DrydockBlueprint $blueprint) {
    $this->blueprint = $blueprint;
    return $this;
  }

  public function setActivateWhenAllocated($activate) {
    $this->activateWhenAllocated = $activate;
    return $this;
  }

  public function needSlotLock($key) {
    $this->slotLocks[] = $key;
    return $this;
  }

  public function allocateResource() {
    if ($this->getID()) {
      throw new Exception(
        pht(
          'Trying to allocate a resource which has already been persisted. '.
          'Only new resources may be allocated.'));
    }

    $expect_status = DrydockResourceStatus::STATUS_PENDING;
    $actual_status = $this->getStatus();
    if ($actual_status != $expect_status) {
      throw new Exception(
        pht(
          'Trying to allocate a resource from the wrong status. Status must '.
          'be "%s", actually "%s".',
          $expect_status,
          $actual_status));
    }

    if ($this->activateWhenAllocated) {
      $new_status = DrydockResourceStatus::STATUS_OPEN;
    } else {
      $new_status = DrydockResourceStatus::STATUS_PENDING;
    }

    $this->openTransaction();

      $this
        ->setStatus($new_status)
        ->save();

      DrydockSlotLock::acquireLocks($this->getPHID(), $this->slotLocks);
      $this->slotLocks = array();

    $this->saveTransaction();

    $this->isAllocated = true;

    return $this;
  }

  public function isAllocatedResource() {
    return $this->isAllocated;
  }

  public function activateResource() {
    if (!$this->getID()) {
      throw new Exception(
        pht(
          'Trying to activate a resource which has not yet been persisted.'));
    }

    $expect_status = DrydockResourceStatus::STATUS_PENDING;
    $actual_status = $this->getStatus();
    if ($actual_status != $expect_status) {
      throw new Exception(
        pht(
          'Trying to activate a resource from the wrong status. Status must '.
          'be "%s", actually "%s".',
          $expect_status,
          $actual_status));
    }

    $this->openTransaction();

      $this
        ->setStatus(DrydockResourceStatus::STATUS_OPEN)
        ->save();

      DrydockSlotLock::acquireLocks($this->getPHID(), $this->slotLocks);
      $this->slotLocks = array();

    $this->saveTransaction();

    $this->isActivated = true;

    return $this;
  }

  public function isActivatedResource() {
    return $this->isActivated;
  }

  public function canRelease() {
    switch ($this->getStatus()) {
      case DrydockResourceStatus::STATUS_CLOSED:
      case DrydockResourceStatus::STATUS_DESTROYED:
        return false;
      default:
        return true;
    }
  }

  public function scheduleUpdate() {
    PhabricatorWorker::scheduleTask(
      'DrydockResourceUpdateWorker',
      array(
        'resourcePHID' => $this->getPHID(),
      ),
      array(
        'objectPHID' => $this->getPHID(),
      ));
  }

  private function didActivate() {
    $viewer = PhabricatorUser::getOmnipotentUser();

    $need_update = false;

    $commands = id(new DrydockCommandQuery())
      ->setViewer($viewer)
      ->withTargetPHIDs(array($this->getPHID()))
      ->withConsumed(false)
      ->execute();
    if ($commands) {
      $need_update = true;
    }

    if ($need_update) {
      $this->scheduleUpdate();
    }
  }


/* -(  PhabricatorPolicyInterface  )----------------------------------------- */


  public function getCapabilities() {
    return array(
      PhabricatorPolicyCapability::CAN_VIEW,
      PhabricatorPolicyCapability::CAN_EDIT,
    );
  }

  public function getPolicy($capability) {
    switch ($capability) {
      case PhabricatorPolicyCapability::CAN_VIEW:
      case PhabricatorPolicyCapability::CAN_EDIT:
        // TODO: Implement reasonable policies.
        return PhabricatorPolicies::getMostOpenPolicy();
    }
  }

  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
    return false;
  }

  public function describeAutomaticCapability($capability) {
    return null;
  }
}