<?php
/**
 * Finds the form control a validation message is about.
 *
 * @package FeedWeaver
 */

namespace FeedWeaver\Admin;

defined( 'ABSPATH' ) || exit;

/**
 * Validation messages name the row they refer to ("Row 2: ...", "Attribute 1: ..."). This turns a
 * message into a short list of candidate control IDs, most specific first, so the editor can
 * highlight the control, link to it and move focus to it. The page still lists every message in
 * full, so a message that matches nothing is never hidden.
 *
 * Matching reads the English wording of the messages. In another language the list of errors is
 * unchanged and each still names its row number; only the field highlighting is skipped.
 */
class Error_Targets {

	/**
	 * Candidate control IDs for one message.
	 *
	 * @param string $message Validation message.
	 * @return string[] Control IDs; empty when unknown.
	 */
	public static function locate( string $message ): array {
		$text = strtolower( $message );

		if ( 1 === preg_match( '/^row (\d+):\s*(.*)$/s', $text, $m ) ) {
			$i = (int) $m[1] - 1;
			if ( false !== strpos( $m[2], 'unknown source' ) ) {
				return array( "fw-source-$i" );
			}
			if ( false !== strpos( $m[2], 'custom field' ) || false !== strpos( $m[2], 'protected' ) || false !== strpos( $m[2], 'password' ) || false !== strpos( $m[2], 'key' ) ) {
				return array( "fw-metakey-$i", "fw-metasel-$i", "fw-path-$i" );
			}
			return array( "fw-path-$i" );
		}
		if ( 1 === preg_match( '/^namespace (\d+):\s*(.*)$/s', $text, $m ) ) {
			$i = (int) $m[1] - 1;
			return false !== strpos( $m[2], 'prefix' ) ? array( "fw-ns-$i-prefix" ) : array( "fw-ns-$i-uri" );
		}
		if ( 1 === preg_match( '/^attribute (\d+):\s*(.*)$/s', $text, $m ) ) {
			$i = (int) $m[1] - 1;
			if ( false !== strpos( $m[2], 'element it belongs' ) ) {
				return array( "fw-attr-$i-element" );
			}
			if ( false !== strpos( $m[2], 'fixed text' ) ) {
				return array( "fw-attr-$i-text", "fw-attr-$i-name" );
			}
			if ( false !== strpos( $m[2], 'WordPress field' ) || false !== strpos( $m[2], 'single value' ) ) {
				return array( "fw-attr-$i-source", "fw-attr-$i-name" );
			}
			if ( false !== strpos( $m[2], 'protected' ) || false !== strpos( $m[2], 'password' ) || false !== strpos( $m[2], 'custom field' ) ) {
				return array( "fw-attr-$i-meta", "fw-attr-$i-source", "fw-attr-$i-name" );
			}
			return array( "fw-attr-$i-name" );
		}
		if ( 1 === preg_match( '/^repeated element (\d+):\s*(.*)$/s', $text, $m ) ) {
			$i = (int) $m[1] - 1;
			if ( false !== strpos( $m[2], 'taxonomy field' ) || false !== strpos( $m[2], 'already has' ) ) {
				return array( "fw-repeat-$i-path" );
			}
			return array( "fw-repeat-$i-name" );
		}

		$map = array(
			'enclosure: choose where the media address' => array( 'fw-enc-url' ),
			'enclosure: choose where the size'          => array( 'fw-enc-length' ),
			'enclosure: choose where the type'          => array( 'fw-enc-type' ),
			'enclosure: the fixed type'                 => array( 'fw-enc-type' ),
			'enclosure:'                                => array( 'fw-enc-url' ),
			'output path "enclosure"'                   => array( 'fw-enc-url' ),
			'give the feed a name'                      => array( 'fw-name' ),
			'url slug'                                  => array( 'fw-slug' ),
			'another feed already uses'                 => array( 'fw-slug' ),
			'item limit'                                => array( 'fw-limit' ),
			'content type'                              => array( 'fw-type-post', 'feedweaver-post-types' ),
			'custom date format'                        => array( 'fw-date-custom', 'fw-date-format' ),
			'supported date format'                     => array( 'fw-date-format' ),
			'root name'                                 => array( 'fw-root' ),
			'item element name'                         => array( 'fw-item' ),
			'top-level or item name'                    => array( 'fw-root' ),
			'channel title'                             => array( 'fw-rss-title' ),
			'channel link'                              => array( 'fw-rss-link' ),
			'channel description'                       => array( 'fw-rss-description' ),
			'language must be'                          => array( 'fw-rss-language' ),
			'copyright'                                 => array( 'fw-rss-copyright' ),
			'managing editor'                           => array( 'fw-rss-editor' ),
			'title or a description'                    => array( 'fw-path-0' ),
			'at least one field mapping'                => array( 'feedweaver-add-mapping' ),
			'taxonomy'                                  => array( 'feedweaver-taxonomies' ),
			'term chosen'                               => array( 'feedweaver-taxonomies' ),
			'filter by at most'                         => array( 'feedweaver-taxonomies' ),
			'at most 50 terms'                          => array( 'feedweaver-taxonomies' ),
			'namespaces'                                => array( 'feedweaver-ns-section' ),
		);
		foreach ( $map as $needle => $targets ) {
			if ( false !== strpos( $text, $needle ) ) {
				return $targets;
			}
		}
		return array();
	}

	/**
	 * Messages with their candidate controls, ready for the page and for JSON.
	 *
	 * @param string[] $messages Validation messages.
	 * @return array<int,array{message:string,targets:string[]}>
	 */
	public static function describe( array $messages ): array {
		$out = array();
		foreach ( $messages as $message ) {
			$message = (string) $message;
			$out[]   = array(
				'message' => $message,
				'targets' => self::locate( $message ),
			);
		}
		return $out;
	}
}