<?php
/**
 * Custom post statuses — registered from the workflow config's step statuses
 * (any status that isn't a WordPress core status).
 *
 * @package OST\EditorialWorkflow
 */

namespace OST\EditorialWorkflow;

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

/**
 * Registers + surfaces the workflow's custom statuses.
 */
class Statuses {

	const CORE = array( 'draft', 'pending', 'publish', 'future', 'private', 'trash', 'auto-draft', 'inherit' );

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

	/**
	 * Workflow service (for labels).
	 *
	 * @var Workflow
	 */
	private $workflow;

	/**
	 * Constructor.
	 *
	 * @param Config   $config   Config service.
	 * @param Workflow $workflow Workflow service.
	 */
	public function __construct( Config $config, Workflow $workflow ) {
		$this->config   = $config;
		$this->workflow = $workflow;
	}

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function register_hooks() {
		add_action( 'init', array( $this, 'register' ), 11 );
		add_filter( 'display_post_states', array( $this, 'display_post_states' ), 10, 2 );
		add_action( 'admin_notices', array( $this, 'orphan_notice' ) );
		add_action( 'admin_init', array( $this, 'handle_orphan_dismissal' ) );
	}

	/**
	 * The custom statuses across all workflows, as [ status => label ].
	 *
	 * @return array
	 */
	public function custom_statuses() {
		$out = array();
		foreach ( $this->config->all() as $workflow ) {
			if ( empty( $workflow['steps'] ) ) {
				continue;
			}
			foreach ( $workflow['steps'] as $step ) {
				if ( empty( $step['status'] ) || in_array( $step['status'], self::CORE, true ) ) {
					continue;
				}
				$out[ $step['status'] ] = isset( $step['label'] )
					? $step['label']
					: ucwords( str_replace( array( 'ostew_', '_' ), array( '', ' ' ), $step['status'] ) );
			}
		}
		return $out;
	}

	/**
	 * Statuses this install once configured and no longer does, as [ status => label ].
	 *
	 * Content can still be sitting in one of these. Registering them anyway is what
	 * keeps that content visible, queryable and actionable after a step is removed.
	 *
	 * @return array
	 */
	public function orphan_statuses() {
		$current = $this->custom_statuses();
		$out     = array();
		foreach ( $this->config->known_statuses() as $status ) {
			if ( isset( $current[ $status ] ) || in_array( $status, self::CORE, true ) ) {
				continue;
			}
			$out[ $status ] = sprintf(
				/* translators: %s: humanised status name. */
				__( '%s (removed from workflow)', 'ost-editorial-workflow' ),
				ucwords( str_replace( array( 'ostew_', '_' ), array( '', ' ' ), $status ) )
			);
		}
		return $out;
	}

	/**
	 * Register each custom status, plus any orphaned one still held by content.
	 *
	 * @return void
	 */
	public function register() {
		$current = $this->custom_statuses();

		// Remember the current set so a later removal can be reconciled.
		$this->config->remember_statuses( array_keys( $current ) );

		foreach ( $current + $this->orphan_statuses() as $status => $label ) {
			register_post_status(
				$status,
				array(
					'label'                     => $label,
					'public'                    => false,
					'internal'                  => false,
					'protected'                 => true,
					'exclude_from_search'       => true,
					'show_in_admin_all_list'    => true,
					'show_in_admin_status_list' => true,
					// Built directly (not _n_noop) because $label is dynamic (already
					// translated from the workflow config); the count markup is static.
					'label_count'               => array(
						'singular' => $label . ' <span class="count">(%s)</span>',
						'plural'   => $label . ' <span class="count">(%s)</span>',
						'context'  => null,
						'domain'   => 'ost-editorial-workflow',
					),
				)
			);
		}
	}

	/**
	 * How many posts currently hold each of the given statuses.
	 *
	 * Statuses with no content are omitted from the result.
	 *
	 * @param string[] $statuses Status keys.
	 * @return array [ status => count ]
	 */
	public function count_posts_in_statuses( array $statuses ) {
		$out = array();
		foreach ( $this->breakdown_posts_in_statuses( $statuses ) as $row ) {
			if ( ! isset( $out[ $row['status'] ] ) ) {
				$out[ $row['status'] ] = 0;
			}
			$out[ $row['status'] ] += $row['total'];
		}
		return $out;
	}

	/**
	 * Posts holding the given statuses, broken down by status and post type.
	 *
	 * Rows with a zero count are omitted.
	 *
	 * @param string[] $statuses Status keys.
	 * @return array[] Each row: [ 'status' => string, 'post_type' => string, 'total' => int ].
	 */
	public function breakdown_posts_in_statuses( array $statuses ) {
		global $wpdb;

		$statuses = array_values( array_unique( array_filter( $statuses ) ) );
		if ( empty( $statuses ) ) {
			return array();
		}

		$placeholders = implode( ', ', array_fill( 0, count( $statuses ), '%s' ) );

		/*
		 * A direct query is deliberate here. The point of this method is to find
		 * content whose status may no longer be registered, which is exactly what
		 * the WordPress query APIs will not return. The table name comes from
		 * $wpdb, the placeholder list is generated from a count, and every value
		 * goes through prepare(), so nothing external reaches the SQL.
		 */
		// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare, WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
		$sql = $wpdb->prepare(
			"SELECT post_status, post_type, COUNT(*) AS total FROM {$wpdb->posts}
			 WHERE post_status IN ( {$placeholders} )
			 AND post_type NOT IN ( 'revision', 'nav_menu_item' )
			 GROUP BY post_status, post_type",
			$statuses
		);

		$rows = $wpdb->get_results( $sql, ARRAY_A );
		// phpcs:enable

		$out = array();
		foreach ( (array) $rows as $row ) {
			$total = (int) $row['total'];
			if ( $total > 0 ) {
				$out[] = array(
					'status'    => (string) $row['post_status'],
					'post_type' => (string) $row['post_type'],
					'total'     => $total,
				);
			}
		}
		return $out;
	}

	const DISMISS_META = '_ostew_orphans_dismissed';

	/**
	 * Is the current screen one where the stranded-content warning belongs?
	 *
	 * The warning is deliberately not shown across the whole admin. It appears on
	 * the Dashboard, on this plugin's own screens, and on the post lists where the
	 * affected content actually is — the places where someone can act on it.
	 *
	 * @return bool
	 */
	private function notice_screen_is_relevant() {
		if ( ! function_exists( 'get_current_screen' ) ) {
			return false;
		}
		$screen = get_current_screen();
		if ( ! $screen ) {
			return false;
		}

		if ( 'dashboard' === $screen->id ) {
			return true;
		}
		if ( false !== strpos( (string) $screen->id, 'ost-editorial-workflow' ) ) {
			return true;
		}
		if ( 'edit' === $screen->base && in_array( (string) $screen->post_type, $this->config->managed_post_types(), true ) ) {
			return true;
		}
		return false;
	}

	/**
	 * A fingerprint of the current stranded set, so a dismissal applies to this
	 * situation only and the warning returns if something new gets stranded.
	 *
	 * @param array $rows Breakdown rows.
	 * @return string
	 */
	private function orphan_fingerprint( array $rows ) {
		$parts = array();
		foreach ( $rows as $row ) {
			$parts[] = $row['status'] . ':' . $row['post_type'] . ':' . $row['total'];
		}
		sort( $parts );
		return md5( implode( '|', $parts ) );
	}

	/**
	 * Record that this user has dismissed the warning for the current situation.
	 *
	 * @return void
	 */
	public function handle_orphan_dismissal() {
		if ( ! isset( $_GET['ostew_dismiss_orphans'] ) ) {
			return;
		}
		$fingerprint = sanitize_key( wp_unslash( $_GET['ostew_dismiss_orphans'] ) );
		if ( ! wp_verify_nonce( isset( $_GET['_wpnonce'] ) ? sanitize_key( wp_unslash( $_GET['_wpnonce'] ) ) : '', 'ostew_dismiss_orphans' ) ) {
			return;
		}
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}
		update_user_meta( get_current_user_id(), self::DISMISS_META, $fingerprint );

		wp_safe_redirect( remove_query_arg( array( 'ostew_dismiss_orphans', '_wpnonce' ) ) );
		exit;
	}

	/**
	 * Warn an administrator when content is stranded in a removed status, and
	 * forget statuses that nothing holds any more.
	 *
	 * @return void
	 */
	public function orphan_notice() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}
		if ( ! $this->notice_screen_is_relevant() ) {
			return;
		}
		$orphans = $this->orphan_statuses();
		if ( empty( $orphans ) ) {
			return;
		}

		$rows = $this->breakdown_posts_in_statuses( array_keys( $orphans ) );

		// Nothing holds these any more — stop registering them.
		$held  = wp_list_pluck( $rows, 'status' );
		$empty = array_diff( array_keys( $orphans ), $held );
		if ( ! empty( $empty ) ) {
			$this->config->forget_statuses( $empty );
		}
		if ( empty( $rows ) ) {
			return;
		}

		// Respect a dismissal, until the stranded set itself changes.
		$fingerprint = $this->orphan_fingerprint( $rows );
		if ( get_user_meta( get_current_user_id(), self::DISMISS_META, true ) === $fingerprint ) {
			return;
		}

		echo '<div class="notice notice-warning is-dismissible"><p><strong>';
		esc_html_e( 'Editorial Workflow: content is sitting in a status that is no longer part of any workflow.', 'ost-editorial-workflow' );
		echo '</strong></p><ul style="list-style:disc;margin-left:20px;">';
		foreach ( $rows as $row ) {
			$type_object = get_post_type_object( $row['post_type'] );
			if ( $type_object && isset( $type_object->labels ) ) {
				$type_label = ( 1 === $row['total'] )
					? $type_object->labels->singular_name
					: $type_object->labels->name;
			} else {
				$type_label = $row['post_type'];
			}

			printf(
				'<li><a href="%1$s">%2$s</a></li>',
				esc_url(
					add_query_arg(
						array(
							'post_status' => $row['status'],
							'post_type'   => $row['post_type'],
						),
						admin_url( 'edit.php' )
					)
				),
				esc_html(
					sprintf(
						/* translators: 1: number of items, 2: post type name, 3: status key. */
						__( '%1$d %2$s in "%3$s"', 'ost-editorial-workflow' ),
						$row['total'],
						$type_label,
						$row['status']
					)
				)
			);
		}
		echo '</ul><p>';
		esc_html_e( 'The status is still registered so the content stays reachable. Move these items to a status in the current workflow, and the warning will clear itself.', 'ost-editorial-workflow' );

		printf(
			' <a href="%1$s">%2$s</a>',
			esc_url(
				wp_nonce_url(
					add_query_arg( 'ostew_dismiss_orphans', $fingerprint ),
					'ostew_dismiss_orphans'
				)
			),
			esc_html__( 'Dismiss this warning', 'ost-editorial-workflow' )
		);

		echo '</p></div>';
	}

	/**
	 * Show the workflow status as a post-state label in admin lists.
	 *
	 * @param array    $states Post states.
	 * @param \WP_Post $post   Post.
	 * @return array
	 */
	public function display_post_states( $states, $post ) {
		if ( ! $post instanceof \WP_Post ) {
			return $states;
		}
		$custom = $this->custom_statuses() + $this->orphan_statuses();
		if ( isset( $custom[ $post->post_status ] ) ) {
			$states[ 'ostew_' . $post->post_status ] = $custom[ $post->post_status ];
		}
		return $states;
	}
}