<?php
declare( strict_types=1 );

namespace Dashbread\Notifications;

use Dashbread\Core\HostedPages;
use Dashbread\Core\Registry;

/**
 * One notification store, many surfaces (header badge, bell dropdown, flyout, full list).
 * Add-ons declare a type with Registry::register_notification_type() and call dashbread_notify().
 * Core ships a few built-in sources so the bell is never empty on a fresh site.
 */
final class Notifications {

	public function register(): void {
		add_action( 'init', array( Store::class, 'maybe_upgrade' ) );
		add_action( 'dashbread_daily', static fn() => Store::prune() ); // Cron passes '' as the first arg; keep the int default.
		add_action( 'init', array( $this, 'schedule' ) );
		add_action( 'dashbread_register', array( $this, 'core_types' ) );
		// Built-in sources.
		add_action( 'comment_post', array( $this, 'on_comment' ), 10, 3 );
		add_action( 'transition_post_status', array( $this, 'on_publish' ), 10, 3 );
		add_action( 'woocommerce_order_status_changed', array( $this, 'on_order_status' ), 10, 3 );
		add_action( 'dashbread_notify_batch', array( $this, 'notify_batch' ), 10, 3 );
	}

	public function schedule(): void {
		if ( ! wp_next_scheduled( 'dashbread_daily' ) ) {
			wp_schedule_event( time() + HOUR_IN_SECONDS, 'daily', 'dashbread_daily' );
		}
	}

	public function core_types( Registry $r ): void {
		$r->register_page( 'notifications', array(
			'title'    => __( 'Notifications', 'dashbread' ),
			'icon'     => 'bell',
			'position' => 940,
			'render'   => static function (): void {
				echo wp_kses( \Dashbread\Shell\Islands::render( 'notifications-list', array( 'perPage' => 20 ) ), \Dashbread\Core\Kses::ui() );
			},
		) );
		$r->register_notification_type( 'comment_reply', array( 'label' => __( 'Replies to your comments', 'dashbread' ), 'icon' => 'message-square' ) );
		$r->register_notification_type( 'new_content', array( 'label' => __( 'New content in the app', 'dashbread' ), 'icon' => 'file-text' ) );
		$r->register_notification_type( 'order_status', array( 'label' => __( 'Order updates', 'dashbread' ), 'icon' => 'shopping-bag' ) );
		$r->register_notification_type( 'broadcast', array( 'label' => __( 'Announcements', 'dashbread' ), 'icon' => 'megaphone' ) );
	}

	/**
	 * Send a notification. Honors the member's per-type preference (usermeta dashbread_notify_off[]).
	 *
	 * @param array{title?:string,body?:string,url?:string,icon?:string,data?:array} $payload
	 */
	public static function notify( int $user_id, string $type, array $payload ): int {
		$type = sanitize_key( $type );
		$off  = (array) get_user_meta( $user_id, 'dashbread_notify_off', true );
		if ( in_array( $type, $off, true ) ) {
			return 0;
		}
		$types = Registry::instance()->notification_types();
		if ( empty( $payload['icon'] ) && isset( $types[ $type ]['icon'] ) ) {
			$payload['icon'] = (string) $types[ $type ]['icon'];
		}
		/** @param array $payload @param int $user_id @param string $type */
		$payload = (array) apply_filters( 'dashbread_notify_payload', $payload, $user_id, $type );
		$id = Store::insert( $user_id, $type, $payload );
		/** Fires after a notification is stored; Pro hooks email delivery here. */
		do_action( 'dashbread_notified', $id, $user_id, $type, $payload );
		return $id;
	}

	/** Notify many users without blocking the request: 200 per cron batch. @param int[] $user_ids */
	public static function notify_many( array $user_ids, string $type, array $payload ): void {
		$user_ids = array_values( array_unique( array_map( 'intval', $user_ids ) ) );
		if ( count( $user_ids ) <= 50 ) {
			foreach ( $user_ids as $uid ) {
				self::notify( $uid, $type, $payload );
			}
			return;
		}
		foreach ( array_chunk( $user_ids, 200 ) as $i => $chunk ) {
			wp_schedule_single_event( time() + $i * 5, 'dashbread_notify_batch', array( $chunk, $type, $payload ) );
		}
	}

	public function notify_batch( array $user_ids, string $type, array $payload ): void {
		foreach ( $user_ids as $uid ) {
			self::notify( (int) $uid, $type, $payload );
		}
	}

	/* ---------- built-in sources ---------- */

	public function on_comment( int $comment_id, $approved, array $data ): void {
		if ( 1 !== (int) $approved ) {
			return;
		}
		$comment = get_comment( $comment_id );
		if ( ! $comment ) {
			return;
		}
		$post    = get_post( (int) $comment->comment_post_ID );
		$targets = array();
		if ( $comment->comment_parent ) {
			$parent = get_comment( (int) $comment->comment_parent );
			if ( $parent && (int) $parent->user_id && (int) $parent->user_id !== (int) $comment->user_id ) {
				$targets[] = (int) $parent->user_id;
			}
		}
		if ( $post && (int) $post->post_author && (int) $post->post_author !== (int) $comment->user_id ) {
			$targets[] = (int) $post->post_author;
		}
		foreach ( array_unique( $targets ) as $uid ) {
			self::notify( $uid, 'comment_reply', array(
				'title' => sprintf( /* translators: 1: commenter, 2: post title */ __( '%1$s replied on "%2$s"', 'dashbread' ), $comment->comment_author, $post ? get_the_title( $post ) : '' ),
				'body'  => wp_trim_words( wp_strip_all_tags( (string) $comment->comment_content ), 20 ),
				'url'   => get_comment_link( $comment ),
			) );
		}
	}

	/** A post flagged "Show in Dashbread app" going live notifies every member who can see it. */
	public function on_publish( string $new, string $old, \WP_Post $post ): void {
		if ( 'publish' !== $new || 'publish' === $old || ! (bool) get_post_meta( $post->ID, HostedPages::META_IN_APP, true ) ) {
			return;
		}
		$roles = array_filter( (array) get_post_meta( $post->ID, HostedPages::META_ROLES, true ) );
		$args  = array( 'fields' => 'ID', 'number' => 5000 );
		if ( $roles ) {
			$args['role__in'] = $roles;
		}
		$ids = array_map( 'intval', (array) get_users( $args ) );
		self::notify_many( array_diff( $ids, array( (int) $post->post_author ) ), 'new_content', array(
			'title' => sprintf( /* translators: %s: post title */ __( 'New: %s', 'dashbread' ), get_the_title( $post ) ),
			'body'  => wp_trim_words( wp_strip_all_tags( get_the_excerpt( $post ) ), 20 ),
			'url'   => \Dashbread\Core\Settings::app_url( $post->post_name ),
		) );
	}

	public function on_order_status( int $order_id, string $from, string $to ): void {
		if ( ! function_exists( 'wc_get_order' ) ) {
			return;
		}
		$order = wc_get_order( $order_id );
		if ( ! $order || ! $order->get_customer_id() ) {
			return;
		}
		self::notify( (int) $order->get_customer_id(), 'order_status', array(
			'title' => sprintf( /* translators: 1: order number, 2: status */ __( 'Order #%1$s is now %2$s', 'dashbread' ), $order->get_order_number(), wc_get_order_status_name( $to ) ),
			'url'   => $order->get_view_order_url(),
			'data'  => array( 'order_id' => $order_id, 'status' => $to ),
		) );
	}
}