MDErrorReporter/MDErrorReporter.php

<?PHP
/**
 * Debugging and error handling helper for MD.
 */
declare(strict_types = 1);

/**
 * Debugging and error handling class.
 */
class MDErrorReporter {

    const MD_ERROR_UNKNOWN  = 20;
    const MD_ERROR_CRITICAL = 10;
    const MD_ERROR_KNOWN    = 0;

    private $_context;
    private $_contact_mail_addr;

    /**
     * Categorizes an error to better decide how to act on it.
     *
     * @param Throwable $exception Exception to be categorized.
     *
     * @return integer
     */
    final public static function categorizeError(Throwable $exception):int {

        if ($exception instanceof MDpageParameterMissingException
            || $exception instanceof MDpageParameterNotNumericException
            || $exception instanceof MDpageParameterNotFromListException
            || $exception instanceof MDmainEntityNotExistentException
            || $exception instanceof MDmainEntityNotPublicException
            || $exception instanceof MDDBConnectionImpossible
            || $exception instanceof MDMysqliExpectedError
            || $exception instanceof MDMysqliTimeout
            || $exception instanceof MDMysqliInvalidInputEncoding
            || $exception instanceof MDPageNotInAggregatedException
        ) {
            return self::MD_ERROR_KNOWN;
        }

        return self::MD_ERROR_UNKNOWN;

    }

    /**
     * Function human_filesize translates byte-level filesizes to human readable ones.
     * Thanks to Jeffrey Sambells http://jeffreysambells.com/2012/10/25/human-readable-filesize-php
     *
     * @param string  $bytes    A file size, e.g. returned from filesize().
     * @param integer $decimals Number of decimal digits to allow.
     *
     * @return string
     */
    final public function human_filesize(string $bytes, int $decimals = 2):string {

        $size = ['B','kB','MB','GB','TB','PB','EB','ZB','YB'];
        $factor = floor((strlen($bytes) - 1) / 3);
        return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . $size[$factor];

    }

    /**
     * Function for formatting a section in an error mail.
     *
     * @param string       $headline Headline of the section.
     * @param array<mixed> $toFormat Associative array containing information to
     *                               be formatted.
     * @param integer      $level    Indentation level. Defaults to 0.
     *
     * @return string
     */
    final private function _formulateDebugMailSection(string $headline, array $toFormat, int $level = 0):string {

        $msg = "";
        if (!empty($headline)) {
            if ($level === 0) {
                $msg .= PHP_EOL . "## " . $headline;
                $msg .= PHP_EOL . "----------------------" . PHP_EOL . PHP_EOL;
            }
            else $msg .= "$headline" . PHP_EOL;
        }

        $longestKey = 0;
        foreach ($toFormat as $key => $value) {
            if (strlen((string)$key) + (4 * $level) > $longestKey) $longestKey = strlen((string)$key) + (4 * $level);
        }
        foreach ($toFormat as $key => $value) {
            if (is_array($value)) {
                $msg .= $this->_formulateDebugMailSection((string)$key, $value, $level + 1);
            }
            else if (is_object($value)) {
                $msg .= sprintf("%-{$longestKey}s :: %s", $key, var_export($value, true)) . PHP_EOL;
            }
            else {
                $msg .= sprintf("%-{$longestKey}s :: %s", $key, (string)$value) . PHP_EOL;
            }
        }
        $msg .= PHP_EOL;

        return $msg;

    }

    /**
     * Gets additional debugging information, e.g. RAM usage.
     *
     * @return array<string>
     */
    final public function getAdditionalDebuggingInfo():array {

        $output = [
            "Current memory usage" => $this->human_filesize((string)memory_get_usage()),
            "Peak memory usage" => $this->human_filesize((string)memory_get_peak_usage()),
            "Included / required files" => get_included_files(),
            # "Allowed memory usage" => $this->human_filesize((string)ini_get("memory_limit")),
        ];

        return $output;

    }

    /**
     * This function sends a mail to the specified address, containing relevant debug information.
     * .
     *
     * @param string       $to          Recipient mail address.
     * @param string       $subject     Optional subject of the notification. Defaults to "".
     * @param string       $description Optional text of the notification. Defaults to : "".
     * @param array<mixed> $contextInfo Context information that will be displayed in a
     *                                  key-value format at the start of the mail.
     *
     * @return void
     */
    final public function sendDebugMail(string $to, string $subject = "", string $description = "", array $contextInfo = []):void {

        $subject = "[{$this->_context}]{$subject}[Controlled error notification]";

        $msg = "
# Automated error message
=========================
    ";

        if (!empty($contextInfo)) {
            $msg .= $this->_formulateDebugMailSection("Context information", $contextInfo);
        }

        if ($description != "") {
            $msg .= "## Description" . PHP_EOL;
            $msg .= "--------------" . PHP_EOL . PHP_EOL;
            $msg .= "$description" . PHP_EOL;
        }

        $msg .= $this->_formulateDebugMailSection("Debug backtrace", debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT));

        // Append the contents of $_SERVER
        if (!empty($_SERVER)) {
            $msg .= $this->_formulateDebugMailSection("The current content of \$_SERVER", $_SERVER);
        }

        // Append the contents of $_SESSION
        if (session_status() == PHP_SESSION_ACTIVE) {
            $msg .= $this->_formulateDebugMailSection("The current content of \$_SESSION", $_SESSION);
        }
        else $msg .= "No active session";

        $msg .= $this->_formulateDebugMailSection("Additional debugging information",
            $this->getAdditionalDebuggingInfo());

        $msg .= PHP_EOL . PHP_EOL;

        $msg = shell_exec("echo " . escapeshellarg($msg) . " | gpg2 --always-trust --recipient " . escapeshellarg($to) . " --encrypt --armor --local-user 35CA0E31F6F44FB5 --sign");

        // Set header
        $header = [
            'From'          => $this->_contact_mail_addr,
            'X-Mailer'      => 'PHP/' . phpversion()
        ];

        // Send email
        mail("$to", "$subject", "$msg", $header);

    }

    /**
     * Wrapper around MDErrorReporter::sendDebugMail that can handle a throwable.
     *
     * @param Throwable $exception Exception to report on.
     * @param string    $recipient Recipient mail address.
     * @param string    $addDesc   Additional descriptive information.
     *
     * @return void
     */
    final public function sendErrorReport(Throwable $exception, string $recipient, string $addDesc = ""):void {

        $subject = get_class($exception) . ": " . $exception->getCode();

        $description = $addDesc;

        $additionalContextInfo = [
            "Message" => $exception->getMessage(),
            "File" => $exception->getFile(),
            "Line" => $exception->getLine()
        ];

        $this->sendDebugMail($recipient,
            $subject,
            $description,
            $additionalContextInfo
        );

    }

    /**
     * Constructor.
     *
     * @param string $toolName          Name of the current tool.
     * @param string $contact_mail_addr Mail address for mail's from header.
     *
     * @return void
     */
    public function __construct(string $toolName = "museum-digital (unspecified)", string $contact_mail_addr = "bugs-md") {

        $this->_context = $toolName;
        $this->_contact_mail_addr = $contact_mail_addr;

    }

}