<?php
/**
 * WooCommerce → Orders: a "Placed via a personal agent" filter (PLAN.md
 * §12.1), on both order storages.
 *
 * An order counts when the checkout handoff marked it as it was created
 * (`_agentadapt_session_id`, written by AgentAdapt_Handoff::attribute_order).
 * That meta is written server-side, so the filter finds the same orders the
 * Agents screen counts, whatever the shopper's browser did with WooCommerce's
 * own attribution script.
 *
 *   - High-performance order storage: the list table's filter row
 *     (`woocommerce_order_list_table_restrict_manage_orders`) and the
 *     arguments it passes to wc_get_orders()
 *     (`woocommerce_order_list_table_prepare_items_query_args`).
 *   - Posts storage: `restrict_manage_posts` and the list's main query
 *     (`request`). That runs after WooCommerce's own handler, which replaces
 *     `meta_query` outright, and adds to whatever is there.
 *
 * Read-only: it narrows a list the viewer can already see.
 *
 * @package AgentAdapt
 */

defined( 'ABSPATH' ) || exit;

/**
 * Orders list filter.
 */
final class AgentAdapt_Orders_Filter {

	public const PARAM = 'agentadapt_via';
	public const VALUE = 'agent';
	public const META  = '_agentadapt_session_id';

	/**
	 * Hook registration.
	 */
	public static function init(): void {
		add_action( 'woocommerce_order_list_table_restrict_manage_orders', array( __CLASS__, 'render_hpos' ), 20, 2 );
		add_filter( 'woocommerce_order_list_table_prepare_items_query_args', array( __CLASS__, 'hpos_query_args' ) );
		add_action( 'restrict_manage_posts', array( __CLASS__, 'render_posts' ), 20, 2 );
		add_filter( 'request', array( __CLASS__, 'posts_query_vars' ), 20 );
	}

	/**
	 * Whether the list was asked for agent orders only.
	 */
	public static function active(): bool {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- a read-only list filter, like WooCommerce's own.
		return isset( $_GET[ self::PARAM ] ) && self::VALUE === sanitize_key( wp_unslash( $_GET[ self::PARAM ] ) );
	}

	/**
	 * The control, in the order list table's filter row.
	 *
	 * @param string $order_type Order type listed.
	 * @param string $which      top | bottom.
	 */
	public static function render_hpos( $order_type = '', $which = '' ): void {
		if ( 'shop_order' === $order_type && 'top' === $which ) {
			self::select();
		}
	}

	/**
	 * The control, on the posts-storage orders list.
	 *
	 * @param string $post_type Post type listed.
	 * @param string $which     top | bottom.
	 */
	public static function render_posts( $post_type = '', $which = '' ): void {
		if ( 'shop_order' === $post_type && 'top' === $which ) {
			self::select();
		}
	}

	/**
	 * High-performance order storage: only agent orders, when asked.
	 *
	 * @param mixed $args wc_get_orders() arguments.
	 * @return mixed
	 */
	public static function hpos_query_args( $args ) {
		if ( ! is_array( $args ) || 'shop_order' !== ( $args['type'] ?? 'shop_order' ) || ! self::active() || ! current_user_can( 'edit_shop_orders' ) ) {
			return $args;
		}
		$args['meta_query'] = self::with_clause( $args['meta_query'] ?? array() ); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query -- an indexed meta key on one admin list.
		return $args;
	}

	/**
	 * Posts storage: only agent orders, when asked, on the orders list.
	 *
	 * @param mixed $vars Main query vars.
	 * @return mixed
	 */
	public static function posts_query_vars( $vars ) {
		global $typenow;
		if ( ! is_array( $vars ) || ! is_admin() || 'shop_order' !== $typenow || ! self::active() || ! current_user_can( 'edit_shop_orders' ) ) {
			return $vars;
		}
		$vars['meta_query'] = self::with_clause( $vars['meta_query'] ?? array() ); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query -- an indexed meta key on one admin list.
		return $vars;
	}

	/**
	 * Our condition, ANDed with any meta query already set.
	 *
	 * @param mixed $existing Existing meta query.
	 * @return array<int|string, mixed>
	 */
	private static function with_clause( $existing ): array {
		$clause = array(
			'key'     => self::META,
			'compare' => 'EXISTS',
		);
		return is_array( $existing ) && $existing ? array( 'relation' => 'AND', $existing, $clause ) : array( $clause );
	}

	/**
	 * The dropdown.
	 */
	private static function select(): void {
		if ( ! current_user_can( 'edit_shop_orders' ) ) {
			return;
		}
		$on = self::active();
		echo '<label for="agentadapt-via" class="screen-reader-text">' . esc_html__( 'Filter by personal agent', 'agent-adapt' ) . '</label>';
		echo '<select name="' . esc_attr( self::PARAM ) . '" id="agentadapt-via">';
		echo '<option value="">' . esc_html__( 'All orders', 'agent-adapt' ) . '</option>';
		echo '<option value="' . esc_attr( self::VALUE ) . '"' . ( $on ? ' selected="selected"' : '' ) . '>' . esc_html__( 'Placed via a personal agent', 'agent-adapt' ) . '</option>';
		echo '</select>';
	}
}