<?php
/**
 * Translation between Desk-Net storage keys and Kordiam ones.
 *
 * @package Kordiam
 */

declare( strict_types=1 );

namespace Kordiam\Support;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Maps Desk-Net option names onto Kordiam option keys, in both directions.
 *
 * Legacy names repeat "desk_net" inside the key body, so a prefix swap is not enough;
 * ID-parameterised names are matched by rule.
 */
final class LegacyKeyMap {

	/**
	 * Option prefix used by the Desk-Net releases.
	 *
	 * @var string
	 */
	public const LEGACY_OPTION_PREFIX = 'wp_desk_net_';

	/**
	 * Fixed option names, keyed by the unprefixed Kordiam key they map onto.
	 *
	 * @var array<string, string>
	 */
	private const STATIC_OPTIONS = array(
		'api_key'                        => 'wp_desk_net_api_key',
		'api_secret'                     => 'wp_desk_net_api_secret',
		'platform_id'                    => 'wp_desk_net_platform_id',
		'story_id_in_permalink'          => 'wp_desk_net_id_in_permalink',
		'db_version'                     => 'wp_desk_net_db_version',
		'active_statuses'                => 'wp_desk_net_desk-net-list-active-status',
		'deactivated_statuses'           => 'wp_desk_net_desk-net-list-deactivated-status',
		'formats_list'                   => 'wp_desk_net_formats_list',
		'slug_syncing'                   => 'wp_desk_net_slug_slug_syncing',
		'initial_status_syncing'         => 'wp_desk_net_initial_status_syncing_checkbox',
		'initial_slug_syncing'           => 'wp_desk_net_initial_slug_syncing_checkbox',
		'category_target_field'          => 'wp_desk_net_category_custom_field_in_wp_custom_field',

		'custom_fields_list'             => 'wp_desk_net_desk_net_custom_fields_list',
		'publication_custom_fields_list' => 'wp_desk_net_desk_net_publication_custom_fields_list',
		'category_list'                  => 'wp_desk_net_desk_net_category_list',

		// Credentials this site uses to call Kordiam (api_key/api_secret are the reverse).
		'outbound_login'                 => 'wp_desk_net_user_login',
		'outbound_password'              => 'wp_desk_net_user_password',
	);

	/*
	 * Do not map wp_desk_net_token: deleting the Kordiam token must force re-authentication,
	 * and a legacy fallback would resurrect the stale Desk-Net one.
	 */

	/**
	 * Rules for option names parameterised by a Kordiam status or category.
	 *
	 * The new_pattern/legacy_format pair maps Kordiam to Desk-Net; legacy_pattern/new_format maps back.
	 *
	 * @var array<int, array<string, string>>
	 */
	private const DYNAMIC_OPTIONS = array(
		array(
			'new_pattern'    => '/^status_import_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_status_desk_net_to_wp_%s',
			'legacy_pattern' => '/^wp_desk_net_status_desk_net_to_wp_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'status_import_%s',
		),
		array(
			'new_pattern'    => '/^status_export_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_status_wp_to_desk_net_%s',
			'legacy_pattern' => '/^wp_desk_net_status_wp_to_desk_net_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'status_export_%s',
		),
		array(
			'new_pattern'    => '/^category_import_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_category_desk_net_to_wp_%s',
			'legacy_pattern' => '/^wp_desk_net_category_desk_net_to_wp_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'category_import_%s',
		),
		array(
			'new_pattern'    => '/^category_export_(.+)$/',
			'legacy_format'  => 'wp_desk_net_category_wp_to_desk_net_%s',
			'legacy_pattern' => '/^wp_desk_net_category_wp_to_desk_net_(.+)$/',
			'new_format'     => 'category_export_%s',
		),
		array(
			'new_pattern'    => '/^content_([A-Za-z0-9_-]+)_files$/',
			'legacy_format'  => 'wp_desk_net_content_%s-files',
			'legacy_pattern' => '/^wp_desk_net_content_([A-Za-z0-9_-]+)-files$/',
			'new_format'     => 'content_%s_files',
		),

		// (.+) captures a WordPress meta key, which may contain characters an ID never would.
		array(
			'new_pattern'    => '/^task_import_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_task_desk_net_to_wp_%s',
			'legacy_pattern' => '/^wp_desk_net_task_desk_net_to_wp_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'task_import_%s',
		),
		array(
			'new_pattern'    => '/^task_export_(.+)$/',
			'legacy_format'  => 'wp_desk_net_task_wp_to_desk_net_%s',
			'legacy_pattern' => '/^wp_desk_net_task_wp_to_desk_net_(.+)$/',
			'new_format'     => 'task_export_%s',
		),
		array(
			'new_pattern'    => '/^publication_custom_field_import_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_publication_custom_fields_desk_net_to_wp_%s',
			'legacy_pattern' => '/^wp_desk_net_publication_custom_fields_desk_net_to_wp_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'publication_custom_field_import_%s',
		),
		array(
			'new_pattern'    => '/^publication_custom_field_export_(.+)$/',
			'legacy_format'  => 'wp_desk_net_publication_custom_fields_wp_to_desk_net_%s',
			'legacy_pattern' => '/^wp_desk_net_publication_custom_fields_wp_to_desk_net_(.+)$/',
			'new_format'     => 'publication_custom_field_export_%s',
		),
		array(
			'new_pattern'    => '/^custom_field_import_([A-Za-z0-9_-]+)$/',
			'legacy_format'  => 'wp_desk_net_custom_fields_desk_net_to_wp_%s',
			'legacy_pattern' => '/^wp_desk_net_custom_fields_desk_net_to_wp_([A-Za-z0-9_-]+)$/',
			'new_format'     => 'custom_field_import_%s',
		),
		array(
			'new_pattern'    => '/^custom_field_export_(.+)$/',
			'legacy_format'  => 'wp_desk_net_custom_fields_wp_to_desk_net_%s',
			'legacy_pattern' => '/^wp_desk_net_custom_fields_wp_to_desk_net_(.+)$/',
			'new_format'     => 'custom_field_export_%s',
		),
	);

	/**
	 * Blocking instantiation: this class is a lookup table.
	 */
	private function __construct() {
	}

	/**
	 * Getting the Desk-Net option name a Kordiam key came from.
	 *
	 * @param string $key Unprefixed Kordiam option key.
	 *
	 * @return string|null Legacy option name, or null when the key has no ancestor.
	 */
	public static function to_legacy_option( string $key ): ?string {
		if ( isset( self::STATIC_OPTIONS[ $key ] ) ) {
			return self::STATIC_OPTIONS[ $key ];
		}

		foreach ( self::DYNAMIC_OPTIONS as $rule ) {
			if ( 1 === preg_match( $rule['new_pattern'], $key, $matches ) ) {
				return sprintf( $rule['legacy_format'], $matches[1] );
			}
		}

		return null;
	}

	/**
	 * Getting the Kordiam key a Desk-Net option name maps onto.
	 *
	 * @param string $legacy_name Full Desk-Net option name, prefix included.
	 *
	 * @return string|null Unprefixed Kordiam key, or null when the name is unknown.
	 */
	public static function to_new_option( string $legacy_name ): ?string {
		$static = array_search( $legacy_name, self::STATIC_OPTIONS, true );

		if ( false !== $static ) {
			return (string) $static;
		}

		foreach ( self::DYNAMIC_OPTIONS as $rule ) {
			if ( 1 === preg_match( $rule['legacy_pattern'], $legacy_name, $matches ) ) {
				return sprintf( $rule['new_format'], $matches[1] );
			}
		}

		return null;
	}

	/**
	 * Listing the fixed option pairs.
	 *
	 * @return array<string, string> Kordiam key => Desk-Net option name.
	 */
	public static function static_options(): array {
		return self::STATIC_OPTIONS;
	}
}