<?php

class FS_Error {

    /**
     * Stores the list of errors.
     *
     * @var array
     * @access private
     */
    var $errors = array();

    /**
     * Stores the list of data for error codes.
     *
     * @var array
     * @access private
     */
    var $error_data = array();

    /**
     * PHP4 Constructor - Sets up error message.
     *
     * If code parameter is empty then nothing will be done. It is possible to
     * add multiple messages to the same code, but with other methods in the
     * class.
     *
     * All parameters are optional, but if the code parameter is set, then the
     * data parameter is optional.
     *
     *
     * @param string|int $code Error code
     * @param string $message Error message
     * @param mixed $data Optional. Error data.
     * @return FS_Error
     */
    function __construct($code = '', $message = '', $data = '') {
        if ( empty($code) )
            return;

        $this->errors[$code][] = $message;

        if ( ! empty($data) )
            $this->error_data[$code] = $data;
    }

    function FS_Error($code = '', $message = '', $data = '') {
        $this->__construct($code, $message, $data);
    }

    /**
     * Retrieve all error codes.
     *
     * @access public
     *
     * @return array List of error codes, if avaiable.
     */
    function get_error_codes() {
        if ( empty($this->errors) )
            return array();

        return array_keys($this->errors);
    }

    /**
     * Retrieve first error code available.
     *
     * @access public
     *
     * @return string|int Empty string, if no error codes.
     */
    function get_error_code() {
        $codes = $this->get_error_codes();

        if ( empty($codes) )
            return '';

        return $codes[0];
    }

    /**
     * Retrieve all error messages or error messages matching code.
     *
     *
     * @param string|int $code Optional. Retrieve messages matching code, if exists.
     * @return array Error strings on success, or empty array on failure (if using codee parameter).
     */
    function get_error_messages($code = '') {
        // Return all messages if no code specified.
        if ( empty($code) ) {
            $all_messages = array();
            foreach ( (array) $this->errors as $code => $messages )
                $all_messages = array_merge($all_messages, $messages);

            return $all_messages;
        }

        if ( isset($this->errors[$code]) )
            return $this->errors[$code];
        else
            return array();
    }

    /**
     * Get single error message.
     *
     * This will get the first message available for the code. If no code is
     * given then the first code available will be used.
     *
     *
     * @param string|int $code Optional. Error code to retrieve message.
     * @return string
     */
    function get_error_message($code = '') {
        if ( empty($code) )
            $code = $this->get_error_code();
        $messages = $this->get_error_messages($code);
        if ( empty($messages) )
            return '';
        return $messages[0];
    }

    /**
     * Retrieve error data for error code.
     *
     * @since 2.1.0
     *
     * @param string|int $code Optional. Error code.
     * @return mixed Null, if no errors.
     */
    function get_error_data($code = '') {
        if ( empty($code) )
            $code = $this->get_error_code();

        if ( isset($this->error_data[$code]) )
            return $this->error_data[$code];
        return null;
    }

    /**
     * Append more error messages to list of error messages.
     *
     * @since 2.1.0
     * @access public
     *
     * @param string|int $code Error code.
     * @param string $message Error message.
     * @param mixed $data Optional. Error data.
     */
    function add($code, $message, $data = '') {
        $this->errors[$code][] = $message;
        if ( ! empty($data) )
            $this->error_data[$code] = $data;
    }

    /**
     * Add data for error code.
     *
     * The error code can only contain one error data.
     *
     *
     * @param mixed $data Error data.
     * @param string|int $code Error code.
     */
    function add_data($data, $code = '') {
        if ( empty($code) )
            $code = $this->get_error_code();

        $this->error_data[$code] = $data;
    }
}

/**
 * Check whether variable is a FS Error.
 *
 * Looks at the object and if a FS_Error class. Does not check to see if the
 * parent is also FS_Error, so can't inherit FS_Error and still use this
 * function.
 *
 *
 * @param mixed $thing Check if unknown variable is FS Error object.
 * @return bool True, if FS_Error. False, if not FS_Error.
 */
function is_fs_error($thing) {
    return ( $thing instanceof FS_Error );
}
    