<?php
/**
 * Copyright 2014 Facebook, Inc.
 *
 * You are hereby granted a non-exclusive, worldwide, royalty-free license to
 * use, copy, modify, and distribute this software in source code or binary
 * form for use in connection with the web services and APIs provided by
 * Facebook.
 *
 * As with any software that integrates with the Facebook platform, your use
 * of this software is subject to the Facebook Developer Principles and
 * Policies [http://developers.facebook.com/policy/]. This copyright notice
 * shall be included in all copies or substantial portions of the software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 */
namespace Facebook;

/**
 * Class FacebookResponse
 * @package Facebook
 * @author Fosco Marotto <fjm@fb.com>
 * @author David Poll <depoll@fb.com>
 */
class FacebookResponse
{

  /**
   * @var FacebookRequest The request which produced this response
   */
  private $request;

  /**
   * @var array The decoded response from the Graph API
   */
  private $responseData;

  /**
   * @var string The raw response from the Graph API
   */
  private $rawResponse;

  /**
   * @var bool Indicates whether sent ETag matched the one on the FB side
   */
  private $etagHit;

  /**
   * @var string ETag received with the response. `null` in case of ETag hit.
   */
  private $etag;

  /**
   * Creates a FacebookResponse object for a given request and response.
   *
   * @param FacebookRequest $request
   * @param array $responseData JSON Decoded response data
   * @param string $rawResponse Raw string response
   * @param bool $etagHit Indicates whether sent ETag matched the one on the FB side
   * @param string|null $etag ETag received with the response. `null` in case of ETag hit.
   */
  public function __construct($request, $responseData, $rawResponse, $etagHit = false, $etag = null)
  {
    $this->request = $request;
    $this->responseData = $responseData;
    $this->rawResponse = $rawResponse;
    $this->etagHit = $etagHit;
    $this->etag = $etag;
  }

  /**
   * Returns the request which produced this response.
   *
   * @return FacebookRequest
   */
  public function getRequest()
  {
    return $this->request;
  }

  /**
   * Returns the decoded response data.
   *
   * @return array
   */
  public function getResponse()
  {
    return $this->responseData;
  }

  /**
   * Returns the raw response
   *
   * @return string
   */
  public function getRawResponse()
  {
    return $this->rawResponse;
  }

  /**
   * Returns true if ETag matched the one sent with a request
   *
   * @return bool
   */
  public function isETagHit()
  {
    return $this->etagHit;
  }

  /**
   * Returns the ETag
   *
   * @return string
   */
  public function getETag()
  {
    return $this->etag;
  }

  /**
   * Gets the result as a GraphObject.  If a type is specified, returns the
   *   strongly-typed subclass of GraphObject for the data.
   *
   * @param string $type
   *
   * @return mixed
   */
  public function getGraphObject($type = 'Facebook\GraphObject') {
    return (new GraphObject($this->responseData))->cast($type);
  }

  /**
   * Returns an array of GraphObject returned by the request.  If a type is
   * specified, returns the strongly-typed subclass of GraphObject for the data.
   *
   * @param string $type
   *
   * @return mixed
   */
  public function getGraphObjectList($type = 'Facebook\GraphObject') {
    $out = array();
    $data = $this->responseData->data;
    for ($i = 0; $i < count($data); $i++) {
      $out[] = (new GraphObject($data[$i]))->cast($type);
    }
    return $out;
  }

  /**
   * If this response has paginated data, returns the FacebookRequest for the
   *   next page, or null.
   *
   * @return FacebookRequest|null
   */
  public function getRequestForNextPage()
  {
    return $this->handlePagination('next');
  }

  /**
   * If this response has paginated data, returns the FacebookRequest for the
   *   previous page, or null.
   *
   * @return FacebookRequest|null
   */
  public function getRequestForPreviousPage()
  {
    return $this->handlePagination('previous');
  }

  /**
   * Returns the FacebookRequest for the previous or next page, or null.
   *
   * @param string $direction
   *
   * @return FacebookRequest|null
   */
  private function handlePagination($direction) {
    if (isset($this->responseData->paging->$direction)) {
      $url = parse_url($this->responseData->paging->$direction);
      parse_str($url['query'], $params);

      return new FacebookRequest(
        $this->request->getSession(),
        $this->request->getMethod(),
        $this->request->getPath(),
        $params
      );
    } else {
      return null;
    }
  }

}
