<?php

final class PhrictionDocument extends PhrictionDAO
  implements
    PhabricatorPolicyInterface,
    PhabricatorSubscribableInterface,
    PhabricatorFlaggableInterface,
    PhabricatorTokenReceiverInterface,
    PhabricatorDestructableInterface {

  protected $slug;
  protected $depth;
  protected $contentID;
  protected $status;

  private $contentObject = self::ATTACHABLE;
  private $ancestors = array();

  // TODO: This should be `self::ATTACHABLE`, but there are still a lot of call
  // sites which load PhrictionDocuments directly.
  private $project = null;

  public function getConfiguration() {
    return array(
      self::CONFIG_AUX_PHID   => true,
      self::CONFIG_TIMESTAMPS => false,
    ) + parent::getConfiguration();
  }

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

  public static function getSlugURI($slug, $type = 'document') {
    static $types = array(
      'document'  => '/w/',
      'history'   => '/phriction/history/',
    );

    if (empty($types[$type])) {
      throw new Exception("Unknown URI type '{$type}'!");
    }

    $prefix = $types[$type];

    if ($slug == '/') {
      return $prefix;
    } else {
      // NOTE: The effect here is to escape non-latin characters, since modern
      // browsers deal with escaped UTF8 characters in a reasonable way (showing
      // the user a readable URI) but older programs may not.
      $slug = phutil_escape_uri($slug);
      return $prefix.$slug;
    }
  }

  public function setSlug($slug) {
    $this->slug   = PhabricatorSlug::normalize($slug);
    $this->depth  = PhabricatorSlug::getDepth($slug);
    return $this;
  }

  public function attachContent(PhrictionContent $content) {
    $this->contentObject = $content;
    return $this;
  }

  public function getContent() {
    return $this->assertAttached($this->contentObject);
  }

  public function getProject() {
    return $this->assertAttached($this->project);
  }

  public function attachProject(PhabricatorProject $project = null) {
    $this->project = $project;
    return $this;
  }

  public function hasProject() {
    return (bool)$this->getProject();
  }

  public function getAncestors() {
    return $this->ancestors;
  }

  public function getAncestor($slug) {
    return $this->assertAttachedKey($this->ancestors, $slug);
  }

  public function attachAncestor($slug, $ancestor) {
    $this->ancestors[$slug] = $ancestor;
    return $this;
  }

  public static function isProjectSlug($slug) {
    $slug = PhabricatorSlug::normalize($slug);
    $prefix = 'projects/';
    if ($slug == $prefix) {
      // The 'projects/' document is not itself a project slug.
      return false;
    }
    return !strncmp($slug, $prefix, strlen($prefix));
  }

  public static function getProjectSlugIdentifier($slug) {
    if (!self::isProjectSlug($slug)) {
      throw new Exception("Slug '{$slug}' is not a project slug!");
    }

    $slug = PhabricatorSlug::normalize($slug);
    $parts = explode('/', $slug);
    return $parts[1].'/';
  }


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


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

  public function getPolicy($capability) {
    if ($this->hasProject()) {
      return $this->getProject()->getPolicy($capability);
    }

    return PhabricatorPolicies::POLICY_USER;
  }

  public function hasAutomaticCapability($capability, PhabricatorUser $user) {
    if ($this->hasProject()) {
      return $this->getProject()->hasAutomaticCapability($capability, $user);
    }
    return false;
  }

  public function describeAutomaticCapability($capability) {
    if ($this->hasProject()) {
      return pht(
        "This is a project wiki page, and inherits the project's policies.");
    }

    switch ($capability) {
      case PhabricatorPolicyCapability::CAN_VIEW:
        return pht(
          'To view a wiki document, you must also be able to view all '.
          'of its parents.');
    }

    return null;
  }


/* -(  PhabricatorSubscribableInterface  )----------------------------------- */


  public function isAutomaticallySubscribed($phid) {
    return false;
  }

  public function shouldShowSubscribersProperty() {
    return true;
  }

  public function shouldAllowSubscription($phid) {
    return true;
  }


/* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */


  public function getUsersToNotifyOfTokenGiven() {
    return PhabricatorSubscribersQuery::loadSubscribersForPHID($this->phid);
  }


/* -(  PhabricatorDestructableInterface  )----------------------------------- */


  public function destroyObjectPermanently(
    PhabricatorDestructionEngine $engine) {

    $this->openTransaction();

      $this->delete();

      $contents = id(new PhrictionContent())->loadAllWhere(
        'documentID = %d',
        $this->getID());
      foreach ($contents as $content) {
        $content->delete();
      }

    $this->saveTransaction();
  }

}