<?php
/**
* WordPress Error API.
*
* @package WordPress
*/

/**
* WordPress Error class.
*
* Container for checking for WordPress errors and error messages. Return
* WP_Error and use is_wp_error() to check if this class is returned. Many
* core WordPress functions pass this class in the event of an error and
* if not handled properly will result in code errors.
*
* @since 2.1.0
*/
#[AllowDynamicProperties]
class WP_Error {
/**
* Stores the list of errors.
*
* @since 2.1.0
* @var array
*/
public $errors = array();

/**
* Stores the most recently added data for each error code.
*
* @since 2.1.0
* @var array
*/
public $error_data = array();

/**
* Stores previously added data added for error codes, oldest-to-newest by code.
*
* @since 5.6.0
* @var array[]
*/
protected $additional_data = array();

/**
* Initializes the error.
*
* If `$code` is empty, the other parameters will be ignored.
* When `$code` is not empty, `$message` will be used even if
* it is empty. The `$data` parameter will be used only if it
* is not empty.
*
* Though the class is constructed with a single error code and
* message, multiple codes can be added using the `add()` method.
*
* @since 2.1.0
*
* @param string|int $code Error code.
* @param string $message Error message.
* @param mixed $data Optional. Error data. Default empty string.
*/
public function __construct( $code = '', $message = '', $data = '' ) {
if ( empty( $code ) ) {
return;
}

$this->add( $code, $message, $data );
}

/**
* Retrieves all error codes.
*
* @since 2.1.0
*
* @return array List of error codes, if available.
*/
public function get_error_codes() {
if ( ! $this->has_errors() ) {
return array();
}

return array_keys( $this->errors );
}

/**
* Retrieves the first error code available.
*
* @since 2.1.0
*
* @return string|int Empty string, if no error codes.
*/
public function get_error_code() {
$codes = $this->get_error_codes();

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

return $codes[0];
}

/**
* Retrieves all error messages, or the error messages for the given error code.
*
* @since 2.1.0
*
* @param string|int $code Optional. Error code to retrieve the messages for.
* Default empty string.
* @return string[] Error strings on success, or empty array if there are none.
*/
public 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();
}
}

/**
* Gets a 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.
*
* @since 2.1.0
*
* @param string|int $code Optional. Error code to retrieve the message for.
* Default empty string.
* @return string The error message.
*/
public 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];
}

/**
* Retrieves the most recently added error data for an error code.
*
* @since 2.1.0
*
* @param string|int $code Optional. Error code. Default empty string.
* @return mixed Error data, if it exists.
*/
public function get_error_data( $code = '' ) {
if ( empty( $code ) ) {
$code = $this->get_error_code();
}

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

/**
* Verifies if the instance contains errors.
*
* @since 5.1.0
*
* @return bool If the instance contains errors.
*/
public function has_errors() {
if ( ! empty( $this->errors ) ) {
return true;
}
return false;
}

/**
* Adds an error or appends an additional message to an existing error.
*
* @since 2.1.0
*
* @param string|int $code Error code.
* @param string $message Error message.
* @param mixed $data Optional. Error data. Default empty string.
*/
public function add( $code, $message, $data = '' ) {
$this->errors[ $code ][] = $message;

if ( ! empty( $data ) ) {
$this->add_data( $data, $code );
}

/**
* Fires when an error is added to a WP_Error object.
*
* @since 5.6.0
*
* @param string|int $code Error code.
* @param string $message Error message.
* @param mixed $data Error data. Might be empty.
* @param WP_Error $wp_error The WP_Error object.
*/
do_action( 'wp_error_added', $code, $message, $data, $this );
}

/**
* Adds data to an error with the given code.
*
* @since 2.1.0
* @since 5.6.0 Errors can now contain more than one item of error data. {@see WP_Error::$additional_data}.
*
* @param mixed $data Error data.
* @param string|int $code Error code.
*/
public function add_data( $data, $code = '' ) {
if ( empty( $code ) ) {
$code = $this->get_error_code();
}

if ( isset( $this->error_data[ $code ] ) ) {
$this->additional_data[ $code ][] = $this->error_data[ $code ];
}

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

/**
* Retrieves all error data for an error code in the order in which the data was added.
*
* @since 5.6.0
*
* @param string|int $code Error code.
* @return mixed[] Array of error data, if it exists.
*/
public function get_all_error_data( $code = '' ) {
if ( empty( $code ) ) {
$code = $this->get_error_code();
}

$data = array();

if ( isset( $this->additional_data[ $code ] ) ) {
$data = $this->additional_data[ $code ];
}

if ( isset( $this->error_data[ $code ] ) ) {
$data[] = $this->error_data[ $code ];
}

return $data;
}

/**
* Removes the specified error.
*
* This function removes all error messages associated with the specified
* error code, along with any error data for that code.
*
* @since 4.1.0
*
* @param string|int $code Error code.
*/
public function remove( $code ) {
unset( $this->errors[ $code ] );
unset( $this->error_data[ $code ] );
unset( $this->additional_data[ $code ] );
}

/**
* Merges the errors in the given error object into this one.
*
* @since 5.6.0
*
* @param WP_Error $error Error object to merge.
*/
public function merge_from( WP_Error $error ) {
static::copy_errors( $error, $this );
}

/**
* Exports the errors in this object into the given one.
*
* @since 5.6.0
*
* @param WP_Error $error Error object to export into.
*/
public function export_to( WP_Error $error ) {
static::copy_errors( $this, $error );
}

/**
* Copies errors from one WP_Error instance to another.
*
* @since 5.6.0
*
* @param WP_Error $from The WP_Error to copy from.
* @param WP_Error $to The WP_Error to copy to.
*/
protected static function copy_errors( WP_Error $from, WP_Error $to ) {
foreach ( $from->get_error_codes() as $code ) {
foreach ( $from->get_error_messages( $code ) as $error_message ) {
$to->add( $code, $error_message );
}

foreach ( $from->get_all_error_data( $code ) as $data ) {
$to->add_data( $data, $code );
}
}
}
}