<?php
/**
 * TMDO_Promotion_Guard — keeps native meta authoritative on HivePress /
 * WooCommerce sites (ADR-004 "search-index mode").
 *
 * Both plugins read native meta without going through a keyed
 * get_*_meta() call: HivePress models load every key with get_*_meta( $id ),
 * WooCommerce does the same for products and writes stock / sales with direct
 * SQL. The Hook Bus cannot serve those reads from flat tables, so on these
 * sites an entity must never reach aeav_only and native rows must never be
 * cleaned up. Demotion always stays open.
 *
 * @package WP_Data_Optimizer
 */

declare(strict_types=1);

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Refuses aeav_only promotion and native-meta cleanup where an integration
 * reads native meta directly.
 */
final class TMDO_Promotion_Guard {

	/**
	 * Entity types each integration reads natively.
	 *
	 * HivePress models (Post, User, Term, Comment) all load meta with an empty
	 * key; WooCommerce does so for products and customers.
	 */
	private const GUARDED = array(
		'HivePress'   => array( 'post', 'user', 'term', 'comment' ),
		'WooCommerce' => array( 'post', 'user' ),
	);

	/**
	 * Check a mode change. Only promotion to aeav_only is guarded.
	 *
	 * @param string $entity_type Entity type.
	 * @param string $new_mode    Target mode.
	 * @return WP_Error|null Error when refused.
	 */
	public static function check_promotion( string $entity_type, string $new_mode ): ?WP_Error {
		if ( TMDO_Mode_Manager::MODE_AEAV_ONLY !== $new_mode ) {
			return null;
		}
		return self::refuse( $entity_type, TMDO_Mode_Manager::MODE_AEAV_ONLY );
	}

	/**
	 * Check a cleanup of the entity's native managed meta rows.
	 *
	 * @param string $entity_type Entity type.
	 * @return WP_Error|null Error when refused.
	 */
	public static function check_cleanup( string $entity_type ): ?WP_Error {
		return self::refuse( $entity_type, 'cleanup' );
	}

	/**
	 * Guarded entity types that are already in aeav_only (promoted before the
	 * guard existed). Native meta may be stale there.
	 *
	 * @return array<string, string[]> Entity type → integration names.
	 */
	public static function violations(): array {
		$out = array();
		foreach ( TMDO_Mode_Manager::all() as $type => $mode ) {
			if ( TMDO_Mode_Manager::MODE_AEAV_ONLY !== $mode ) {
				continue;
			}
			$integrations = self::integrations_for( $type );
			if ( ! empty( $integrations ) ) {
				$out[ $type ] = $integrations;
			}
		}
		return $out;
	}

	/**
	 * Active integrations that read this entity type natively.
	 *
	 * @param string $entity_type Entity type.
	 * @return string[]
	 */
	private static function integrations_for( string $entity_type ): array {
		$active = array(
			'HivePress'   => TMDO_Compatibility::is_hivepress_active(),
			'WooCommerce' => TMDO_Compatibility::is_woocommerce_active(),
		);

		$names = array();
		foreach ( self::GUARDED as $name => $types ) {
			if ( $active[ $name ] && in_array( $entity_type, $types, true ) ) {
				$names[] = $name;
			}
		}
		return $names;
	}

	/**
	 * Build the refusal, unless no integration applies or a filter allows it.
	 *
	 * @param string $entity_type Entity type.
	 * @param string $action      'aeav_only' or 'cleanup'.
	 * @return WP_Error|null
	 */
	private static function refuse( string $entity_type, string $action ): ?WP_Error {
		$integrations = self::integrations_for( $entity_type );
		if ( empty( $integrations ) ) {
			return null;
		}

		/**
		 * Allow a guarded aeav_only promotion or cleanup anyway.
		 *
		 * @param bool     $allow        Default false.
		 * @param string   $entity_type  Entity type.
		 * @param string   $action       'aeav_only' or 'cleanup'.
		 * @param string[] $integrations Integrations that read this entity natively.
		 */
		if ( apply_filters( 'tmdo_promotion_guard_allow', false, $entity_type, $action, $integrations ) ) {
			return null;
		}

		return new WP_Error(
			'promotion_guarded',
			sprintf(
				/* translators: 1: integration names, 2: entity type, 3: aeav_only or cleanup */
				__( '%1$s 直接讀取原生 meta，%2$s 不能執行 %3$s：這類站台以原生 meta 為唯一資料來源（搜尋索引模式）。', '2meet-data-optimizer' ),
				implode( ' / ', $integrations ),
				$entity_type,
				$action
			)
		);
	}
}