PolyBanking.php

<?php

/**
 * Class PolyBanking
 */
class PolyBanking {
  protected $server = NULL;
  protected $configID = NULL;
  protected $keyRequest = NULL;
  protected $keyAPI = NULL;
  protected $keyIPN = NULL;

  /**
   * Standard constructor
   */
  public function __construct($server, $configID, $keyRequest, $keyAPI, $keyIPN) {
    if (substr($server, -1) != '/') {
      // Assure a trailing slash.
      $server .= '/';
    }
    $this->server = $server;
    $this->configID = $configID;
    $this->keyRequest = $keyRequest;
    $this->keyAPI = $keyAPI;
    $this->keyIPN = $keyIPN;
  }

  /**
   * Send off a new transaction to the PolyBanking server,
   *
   * @param: $amount = amount in CHF, centimes
   * @return: an array of the transaction status and the url to send the user to.
   *
   */
  public function new_transaction($amount, $reference, $extra_data = '') {
    $data['amount'] = $amount;
    $data['reference'] = $reference;
    $data['extra_data'] = $extra_data;
    $data['config_id'] = $this->configID;

    $data['sign'] = $this->compute_sig($this->keyRequest, $data);

    $url = $this->server . "paiements/start/";

    $result = $this->post_curl($url, $data);

    return $result;
  }

  /**
   * Function to compute a signature from an associative array.
   * (replaces '=' with '!!' and ';' with '??', then concatenates key=value;secret;key1=value1;secret; etc)
   * @param: $secret, the key you want to hash with; $data, the data you want hashed.
   * @return: A hash of the $secret and $data following the official PolyBanking API spec.
   */
  public function compute_sig($secret, $data) {
    $sig = "";
    ksort($data);
    foreach ($data as $key => $value) {
      $sig .= $this->escape_for_signature($key);
      $sig .= '=';
      $sig .= $this->escape_for_signature($value);
      $sig .= ';';
      $sig .= $secret;
      $sig .= ';';
    }
    return openssl_digest($sig, 'sha512');
  }

  /**
   * Escape a string according to the PolyBanking specs.
   * @param $str
   * @return mixed
   */
  private function escape_for_signature($str) {
    return strtr($str, array(';' => '!!', '=' => '??'));
  }

  /**
   *  POST an array to a certain url
   * @param: $url, the url to post to; $data, an associative array to be posted
   * @return: the server's response.
   */
  protected function post_curl($url, $data) {
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, TRUE);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

    //curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    //curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);

    $result = curl_exec($ch);

    curl_close($ch);
    return json_decode($result);
  }

  /**
   * Get the details of a specific transaction via its reference
   *
   * @param: $reference, the reference of the transaction you want details for.
   * @return: (reference, extra_data, amount, postfinance_id, postfinance_status, internal_status, ipn_needed,
   *   creation_date, last_userforwarded_date, last_user_back_from_postfinance_date, last_postfinance_ipn_date,
   *  last_ipn_date, postfinance_status_text, internal_status_text). See details @ official API spec.
   */
  public function get_transaction($reference) {
    if ($reference == NULL) {
      throw new InvalidArgumentException('Reference can not be null');
    }

    $url = $this->server . "api/transactions/" . $reference . "/";

    $data['config_id'] = $this->configID;
    $data['secret'] = $this->keyAPI;

    //$result now contains all details of the transaction.
    return $this->post_curl($url, $data);
  }

  /**
   * Get a list references of transactions
   *
   * @param: $max_transaction, the number of reference you want to be returned
   * @return: an array of (reference='ref1', reference='ref2', etc);
   * (yes it should be $max_transactions and not $max_transaction, but we're following official API standards...)
   */
  public function get_transactions($max_transaction = 100) {
    $url = $this->server . "api/transactions/";

    $data['config_id'] = $this->configID;
    $data['secret'] = $this->keyAPI;
    $data['max_transaction'] = $max_transaction;

    $result = $this->post_curl($url, $data);

    if ($result->result != "ok") {
      throw new UnexpectedValueException('Could not get a list of transactions for an unknown reason.');
    }

    return $result->data;
  }

  /**
   * Show the logs for one transaction
   * @param: $reference, the reference of the transaction you want the logs of.
   * @return (when, extra_data, log_type, log_type_text). See details @ official API spec.
   */
  public function transaction_show_logs($reference) {
    if ($reference == NULL) {
      throw new InvalidArgumentException('Reference can not be null');
    }

    $url = $this->server . "api/transactions/" . $reference . "/logs/";

    $data['config_id'] = $this->configID;
    $data['secret'] = $this->keyAPI;

    $result = $this->post_curl($url, $data);

    if ($result->result != "ok") {
      throw new UnexpectedValueException('Could not get a list of transactions for an unknown reason.');
    }

    return $result->data;
  }

  /**
   * The PolyBanking server calls our IPN URL to send an IPN notification.
   * This function checks whether the IPN is correct, to see if the transaction was ok (TODO: is this description correct?)
   * @params: POST: config, reference, postfinance_status, postfinance_status_good, last_update
   * @return: (is_ok, message, reference, postfinance_status, postfinance_status_good, last_update). See details @ official API spec.
   */
  public function check_ipn($data) {
    $response = array(
      'is_ok' => FALSE,
      'message' => NULL,
      'reference' => NULL,
      'postfinance_status' => NULL,
      'postfinance_status_good' => NULL,
      'last_update' => NULL,
    );

    if ($data['sign'] != $this->compute_sig($this->keyIPN, array_diff_key($data, array('sign' => FALSE)))) {
      $response['is_ok'] = FALSE;
      $response['message'] = 'SIGN';
      return $response;
    }
    if ($data['config'] != $this->configID) {
      $response['is_ok'] = FALSE;
      $response['message'] = 'CONFIG';
      return $response;
    }

    $response = array_replace($response, array_intersect_key($data, $response));
    $response['is_ok'] = TRUE;
    $response['message'] = '';
    //TODO: format last_update
    return $response;
  }
}