<?php

/**
 * Authentication adapter for Facebook OAuth2.
 */
final class PhutilFacebookAuthAdapter extends PhutilOAuthAuthAdapter {

  public function getAdapterType() {
    return 'facebook';
  }

  public function getAdapterDomain() {
    return 'facebook.com';
  }

  public function getAccountID() {
    return $this->getOAuthAccountData('id');
  }

  public function getAccountEmail() {
    return $this->getOAuthAccountData('email');
  }

  public function getAccountName() {
    $link = $this->getOAuthAccountData('link');
    if (!$link) {
      return null;
    }

    $matches = null;
    if (!preg_match('@/([^/]+)$@', $link, $matches)) {
      return null;
    }

    return $matches[1];
  }

  public function getAccountImageURI() {
    $picture = $this->getOAuthAccountData('picture');
    if ($picture) {
      $picture_data = idx($picture, 'data');
      if ($picture_data) {
        return idx($picture_data, 'url');
      }
    }
    return null;
  }

  public function getAccountURI() {
    return $this->getOAuthAccountData('link');
  }

  public function getAccountRealName() {
    return $this->getOAuthAccountData('name');
  }

  protected function getAuthenticateBaseURI() {
    return 'https://www.facebook.com/dialog/oauth';
  }

  protected function getTokenBaseURI() {
    return 'https://graph.facebook.com/oauth/access_token';
  }

  protected function loadOAuthAccountData() {
    $fields = array(
      'id',
      'name',
      'email',
      'link',
      'picture',
    );

    $uri = new PhutilURI('https://graph.facebook.com/me');
    $uri->replaceQueryParam('access_token', $this->getAccessToken());
    $uri->replaceQueryParam('fields', implode(',', $fields));
    list($body) = id(new HTTPSFuture($uri))->resolvex();

    $data = null;
    try {
      $data = phutil_json_decode($body);
    } catch (PhutilJSONParserException $ex) {
      throw new Exception(
        pht('Expected valid JSON response from Facebook account data request.'),
        0,
        $ex);
    }

    return $data;
  }

}