<?php
/**
 * Notifications orchestrator — listens on ostew/after_transition, matches the
 * workflow's notification rules, resolves recipients, and dispatches per channel.
 *
 * @package OST\EditorialWorkflow
 */

namespace OST\EditorialWorkflow\Notifications;

use OST\EditorialWorkflow\Config;
use OST\EditorialWorkflow\Workflow;

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

/**
 * Fires notifications on workflow transitions.
 */
class Notifications {

	/**
	 * Config service.
	 *
	 * @var Config
	 */
	private $config;

	/**
	 * Workflow service.
	 *
	 * @var Workflow
	 */
	private $workflow;

	/**
	 * Recipient resolver.
	 *
	 * @var Recipients
	 */
	private $recipients;

	/**
	 * Mailer.
	 *
	 * @var Mailer
	 */
	private $mailer;

	/**
	 * Review queue / badge.
	 *
	 * @var ReviewQueue
	 */
	private $queue;

	/**
	 * Constructor.
	 *
	 * @param Config      $config     Config service.
	 * @param Workflow    $workflow   Workflow service.
	 * @param Recipients  $recipients Recipient resolver.
	 * @param Mailer      $mailer     Mailer.
	 * @param ReviewQueue $queue      Review queue.
	 */
	public function __construct( Config $config, Workflow $workflow, Recipients $recipients, Mailer $mailer, ReviewQueue $queue ) {
		$this->config     = $config;
		$this->workflow   = $workflow;
		$this->recipients = $recipients;
		$this->mailer     = $mailer;
		$this->queue      = $queue;
	}

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function register_hooks() {
		add_action( 'ostew/after_transition', array( $this, 'on_transition' ), 10, 5 );
	}

	/**
	 * Handle a transition: match rules, dispatch.
	 *
	 * @param int    $post_id    Post ID.
	 * @param string $old_status Old status.
	 * @param string $new_status New status.
	 * @param int    $actor_id   Acting user ID.
	 * @param string $note       Editorial note.
	 * @return void
	 */
	public function on_transition( $post_id, $old_status, $new_status, $actor_id, $note ) {
		$post = get_post( $post_id );
		if ( ! $post ) {
			return;
		}
		$workflow = $this->workflow->for_post( $post );
		if ( ! $workflow || empty( $workflow['notifications'] ) ) {
			return;
		}

		// Bust cached review counts (statuses changed).
		$this->flush_queue_cache();

		foreach ( $workflow['notifications'] as $rule ) {
			if ( ! isset( $rule['on_status'] ) || $rule['on_status'] !== $new_status ) {
				continue;
			}
			if ( isset( $rule['when_from'] ) && ! in_array( $old_status, (array) $rule['when_from'], true ) ) {
				continue;
			}

			$channels   = isset( $rule['channels'] ) ? (array) $rule['channels'] : array( 'email' );
			$recipients = $this->recipients->resolve( $rule['notify'], $post, $workflow, $new_status, $actor_id );

			/**
			 * Filter the resolved recipients for a notification rule.
			 *
			 * @param \WP_User[] $recipients Recipients.
			 * @param array      $rule       Notification rule.
			 * @param \WP_Post   $post       Post.
			 */
			$recipients = apply_filters( 'ostew/notify_recipients', $recipients, $rule, $post );
			if ( empty( $recipients ) ) {
				continue;
			}

			$vars     = $this->merge_vars( $post, $old_status, $new_status, $actor_id, $note, $workflow );
			$template = isset( $rule['template'] ) ? $rule['template'] : 'review_request';

			foreach ( $recipients as $user ) {
				if ( in_array( 'email', $channels, true ) ) {
					$this->mailer->send( $template, $user, $vars );
				}
			}

			/**
			 * Fires after a notification rule is dispatched (a Slack/Teams add-on hooks here).
			 *
			 * @param array      $rule       Notification rule.
			 * @param \WP_User[] $recipients Recipients.
			 * @param \WP_Post   $post       Post.
			 * @param array      $vars       Merge vars.
			 */
			do_action( 'ostew/send_notification', $rule, $recipients, $post, $vars );
		}
	}

	/**
	 * Build the merge variables for templates.
	 *
	 * @param \WP_Post $post       Post.
	 * @param string   $old_status Old status.
	 * @param string   $new_status New status.
	 * @param int      $actor_id   Acting user ID.
	 * @param string   $note       Editorial note.
	 * @param array    $workflow   Workflow.
	 * @return array
	 */
	private function merge_vars( $post, $old_status, $new_status, $actor_id, $note, array $workflow ) {
		$actor  = get_user_by( 'id', $actor_id );
		$pt_obj = get_post_type_object( $post->post_type );

		return array(
			'post_title'      => get_the_title( $post ),
			'post_type_label' => $pt_obj ? $pt_obj->labels->singular_name : $post->post_type,
			'editor_url'      => (string) get_edit_post_link( $post->ID, 'raw' ),
			'view_url'        => (string) get_permalink( $post->ID ),
			'actor_name'      => $actor ? $actor->display_name : __( 'Someone', 'ost-editorial-workflow' ),
			'from_status'     => $this->workflow->status_label( $workflow, $old_status ),
			'to_status'       => $this->workflow->status_label( $workflow, $new_status ),
			'note'            => $note,
			'site_name'       => get_bloginfo( 'name' ),
			'recipient_name'  => '',
		);
	}

	/**
	 * Delete cached per-user review counts.
	 *
	 * @return void
	 */
	private function flush_queue_cache() {
		global $wpdb;
		// Small, best-effort: clear all ostew_qcount_* transients.
		$wpdb->query( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			"DELETE FROM {$wpdb->options} WHERE option_name LIKE '_transient_ostew_qcount_%' OR option_name LIKE '_transient_timeout_ostew_qcount_%'"
		);
	}
}