<?php
/**
 * Bulk actions for Exclusive Products.
 *
 * Uses Select2 with AJAX (remote) data source instead of
 * loading all users statically in the notice form.
 *
 * @package AISP_User_Exclusive_Products
 */

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

if ( ! class_exists( 'AISP_Exclusive_Products_Bulk_Actions' ) ) :

class AISP_Exclusive_Products_Bulk_Actions {

	public static function init() {

		// Add bulk actions.
		add_filter( 'bulk_actions-edit-product', array( __CLASS__, 'register_actions' ) );

		// Handle initial bulk click (store IDs + show user-select box).
		add_filter( 'handle_bulk_actions-edit-product', array( __CLASS__, 'handle_action' ), 10, 3 );

		// Notice with user selection UI.
		add_action( 'admin_notices', array( __CLASS__, 'render_notice' ) );

		// Handle POST (when user clicks Apply).
		add_action( 'admin_init', array( __CLASS__, 'process_bulk_user_action' ) );

		// Select2.
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'enqueue_admin_assets' ) );
	}

	/**
	 * Per-user transient key prefix to avoid collisions between concurrent admins.
	 *
	 * @param string $suffix  'products' or 'action'
	 * @return string
	 */
	private static function transient_key( $suffix ) {
		return 'aisp_bulk_' . $suffix . '_u' . get_current_user_id();
	}

	/**
	 * Register custom bulk actions.
	 *
	 * @param array $actions
	 * @return array
	 */
	public static function register_actions( $actions ) {
		$actions['aisp_exclusive_add']    = __( 'Add Exclusive User', 'aisp-user-exclusive-products' );
		$actions['aisp_exclusive_remove'] = __( 'Remove Exclusive User', 'aisp-user-exclusive-products' );
		return $actions;
	}

	/**
	 * Handle selection of bulk action — store product IDs and redirect.
	 *
	 * @param string $redirect_url
	 * @param string $action
	 * @param int[]  $post_ids
	 * @return string
	 */
	public static function handle_action( $redirect_url, $action, $post_ids ) {

		if ( ! in_array( $action, array( 'aisp_exclusive_add', 'aisp_exclusive_remove' ), true ) ) {
			return $redirect_url;
		}

		set_transient( self::transient_key( 'products' ), $post_ids, 120 );
		set_transient( self::transient_key( 'action' ), $action, 120 );

		$redirect_url = add_query_arg(
			array(
				'aisp-bulk-exclusive'   => '1',
				'_aisp_bulk_step_nonce' => wp_create_nonce( 'aisp_bulk_step' ),
			),
			$redirect_url
		);

		return $redirect_url;
	}

	/**
	 * Load Select2 + AJAX config on product list screen.
	 *
	 * @param string $hook
	 */
	public static function enqueue_admin_assets( $hook ) {

		if ( $hook !== 'edit.php' ) {
			return;
		}

		$screen = get_current_screen();
		if ( ! $screen || $screen->post_type !== 'product' ) {
			return;
		}

		wp_enqueue_style( 'select2' );
		wp_enqueue_script( 'select2' );

		wp_add_inline_script(
			'select2',
			'jQuery(function($){
				$("#aisp_bulk_user_select").select2({
					width             : "100%",
					minimumInputLength: 0,
					ajax: {
						url      : ' . wp_json_encode( admin_url( 'admin-ajax.php' ) ) . ',
						dataType : "json",
						delay    : 250,
						data: function(params){
							return {
								action     : "aisp_search_users",
								term       : params.term || "",
								page       : params.page || 1,
								_ajax_nonce: ' . wp_json_encode( wp_create_nonce( 'aisp_search_users_nonce' ) ) . '
							};
						},
						processResults: function(data){
							return {
								results   : data.results,
								pagination: data.pagination
							};
						},
						cache: true
					},
					placeholder    : ' . wp_json_encode( __( 'Search user…', 'aisp-user-exclusive-products' ) ) . ',
					allowClear     : false,
					language: {
						inputTooShort: function(){ return ' . wp_json_encode( __( 'Start typing to search…', 'aisp-user-exclusive-products' ) ) . '; },
						searching    : function(){ return ' . wp_json_encode( __( 'Searching…', 'aisp-user-exclusive-products' ) ) . '; },
						noResults    : function(){ return ' . wp_json_encode( __( 'No users found.', 'aisp-user-exclusive-products' ) ) . '; }
					}
				});
			});'
		);
	}

	/**
	 * Output the form UI after selecting bulk action.
	 * The <select> is empty on load; Select2 AJAX populates it on interaction.
	 */
	public static function render_notice() {

		if ( ! isset( $_GET['aisp-bulk-exclusive'] ) ) {
			return;
		}

		if ( ! current_user_can( 'manage_woocommerce' ) ) {
			return;
		}

		if (
			! isset( $_GET['_aisp_bulk_step_nonce'] )
			|| ! wp_verify_nonce(
				sanitize_text_field( wp_unslash( $_GET['_aisp_bulk_step_nonce'] ) ),
				'aisp_bulk_step'
			)
		) {
			return;
		}

		$products = get_transient( self::transient_key( 'products' ) );
		$action   = get_transient( self::transient_key( 'action' ) );

		if ( ! $products || ! $action ) {
			return;
		}

		$title = ( 'aisp_exclusive_add' === $action )
			? __( 'Add Exclusive User to Selected Products', 'aisp-user-exclusive-products' )
			: __( 'Remove Exclusive User from Selected Products', 'aisp-user-exclusive-products' );
		?>

		<div class="notice notice-info">
			<h2><?php echo esc_html( $title ); ?></h2>

			<form method="post">
				<?php wp_nonce_field( 'aisp_bulk_user_action', 'aisp_bulk_nonce' ); ?>

				<input type="hidden" name="aisp_bulk_do" value="1">
				<input type="hidden" name="aisp_bulk_action" value="<?php echo esc_attr( $action ); ?>">

				<p>
					<label><strong><?php esc_html_e( 'Select user:', 'aisp-user-exclusive-products' ); ?></strong></label><br>

					<?php /* Empty select — Select2 AJAX will populate options on search */ ?>
					<select id="aisp_bulk_user_select" name="aisp_bulk_user" style="width:100%;min-width:300px;">
					</select>
				</p>

				<p>
					<input
						type="submit"
						class="button button-primary"
						value="<?php esc_attr_e( 'Apply', 'aisp-user-exclusive-products' ); ?>"
					>
				</p>
			</form>
		</div>

		<?php
	}

	/**
	 * Process final POST (user has selected a user + clicked Apply).
	 */
	public static function process_bulk_user_action() {

		if ( ! isset( $_POST['aisp_bulk_do'] ) ) {
			return;
		}

		if ( ! current_user_can( 'manage_woocommerce' ) ) {
			return;
		}

		if ( ! check_admin_referer( 'aisp_bulk_user_action', 'aisp_bulk_nonce' ) ) {
			return;
		}

		$products = get_transient( self::transient_key( 'products' ) );
		$action   = get_transient( self::transient_key( 'action' ) );

		if ( ! $products || ! $action ) {
			return;
		}

		$user_id = isset( $_POST['aisp_bulk_user'] )
			? intval( sanitize_text_field( wp_unslash( $_POST['aisp_bulk_user'] ) ) )
			: 0;

		if ( $user_id <= 0 ) {
			return;
		}

		foreach ( $products as $pid ) {

			$current = get_post_meta( $pid, '_aisp_exclusive_users', true );
			$current = is_array( $current ) ? $current : array();

			if ( 'aisp_exclusive_add' === $action ) {
				if ( ! in_array( $user_id, $current, true ) ) {
					$current[] = $user_id;
				}
				update_post_meta( $pid, '_aisp_exclusive_users', array_values( $current ) );

			} elseif ( 'aisp_exclusive_remove' === $action ) {
				$current = array_diff( $current, array( $user_id ) );

				if ( empty( $current ) ) {
					delete_post_meta( $pid, '_aisp_exclusive_users' );
				} else {
					update_post_meta( $pid, '_aisp_exclusive_users', array_values( $current ) );
				}
			}
		}

		delete_transient( self::transient_key( 'products' ) );
		delete_transient( self::transient_key( 'action' ) );

		add_action( 'admin_notices', function() {
			echo '<div class="updated"><p>' .
				esc_html__( 'Bulk operation completed.', 'aisp-user-exclusive-products' ) .
			'</p></div>';
		} );
	}
}

endif;