<?php
/**
 * Проверка сайта по шагам и хранение результатов.
 *
 * @package Yasno
 */

defined( 'ABSPATH' ) || exit;

final class YSNO_Scan {

	const OPTION = 'ysno_results';
	const META   = '_ysno_issues';
	const STEP   = 20;

	public static function init() {
		add_action( 'save_post', array( __CLASS__, 'on_save' ), 20, 2 );
		add_action( 'wp_ajax_ysno_scan_start', array( __CLASS__, 'ajax_start' ) );
		add_action( 'wp_ajax_ysno_scan_step', array( __CLASS__, 'ajax_step' ) );
		add_action( 'wp_ajax_ysno_exception', array( __CLASS__, 'ajax_exception' ) );
	}

	/** Результаты последней проверки. */
	public static function results() {
		$r = get_option( self::OPTION, array() );
		return is_array( $r ) ? array_merge( array( 'started' => 0, 'finished' => 0, 'checked' => 0, 'items' => array(), 'queue' => array() ), $r ) : array( 'started' => 0, 'finished' => 0, 'checked' => 0, 'items' => array(), 'queue' => array() );
	}

	private static function save( array $r ) {
		update_option( self::OPTION, $r, false );
	}

	/* ---------------------------------------------------------------------
	 * Проверка по шагам
	 * ------------------------------------------------------------------- */

	/** Начать проверку: очередь источников. */
	public static function start() {
		YSNO_Checker::reset();
		$queue = array();
		$total = 0;
		foreach ( YSNO_Sources::all() as $id => $src ) {
			$n = (int) call_user_func( $src['count'] );
			if ( $n > 0 ) {
				$queue[] = array( 'source' => $id, 'offset' => 0, 'total' => $n );
				$total  += $n;
			}
		}
		self::save(
			array(
				'started'  => time(),
				'finished' => 0,
				'checked'  => 0,
				'total'    => $total,
				'items'    => array(),
				'queue'    => $queue,
			)
		);
		return $total;
	}

	/** Следующая порция. */
	public static function step() {
		$r       = self::results();
		$sources = YSNO_Sources::all();
		$budget  = self::STEP;
		while ( $budget > 0 && $r['queue'] ) {
			$head = &$r['queue'][0];
			if ( empty( $sources[ $head['source'] ] ) ) {
				array_shift( $r['queue'] );
				continue;
			}
			$items = (array) call_user_func( $sources[ $head['source'] ]['fetch'], $head['offset'], $budget );
			foreach ( $items as $item ) {
				self::store_item( $r, $item, $head['source'] );
			}
			$head['offset'] += count( $items );
			$r['checked']   += count( $items );
			$budget         -= count( $items );
			if ( ! $items || $head['offset'] >= $head['total'] ) {
				array_shift( $r['queue'] );
			}
			unset( $head );
		}
		if ( ! $r['queue'] && ! $r['finished'] ) {
			$r['finished'] = time();
			self::save( $r );
			/**
			 * Проверка сайта закончена.
			 *
			 * @param array $r Результаты.
			 */
			do_action( 'ysno/scan_finished', $r );
		} else {
			self::save( $r );
		}
		return $r;
	}

	/** Проверить элемент и записать результат. */
	private static function store_item( array &$r, array $item, $source ) {
		$found = YSNO_Checker::check( $item['text'] );
		if ( 0 === strpos( $item['key'], 'post:' ) ) {
			update_post_meta( (int) substr( $item['key'], 5 ), self::META, count( $found ) );
		}
		if ( $found ) {
			$item['latin'] = YSNO_Checker::latin_share( $item['text'] );
			unset( $item['text'] );
			$item['source']            = $source;
			$item['found']             = $found;
			$r['items'][ $item['key'] ] = $item;
		} else {
			unset( $r['items'][ $item['key'] ] );
		}
	}

	/** Перепроверка записи при сохранении. */
	public static function on_save( $post_id, $post ) {
		if ( wp_is_post_revision( $post_id ) || wp_is_post_autosave( $post_id ) || ! in_array( $post->post_type, YSNO_Sources::post_types(), true ) ) {
			return;
		}
		if ( 'publish' !== $post->post_status ) {
			delete_post_meta( $post_id, self::META );
			$r = self::results();
			unset( $r['items'][ 'post:' . $post_id ] );
			self::save( $r );
			return;
		}
		$r = self::results();
		self::store_item( $r, YSNO_Sources::post_item( $post ), 'posts' );
		self::save( $r );
	}

	/* ---------------------------------------------------------------------
	 * Сводка
	 * ------------------------------------------------------------------- */

	/**
	 * Слова по всему сайту: ключ => [word, type, suggest, note, count, items[]].
	 *
	 * @return array
	 */
	public static function words() {
		$words = array();
		foreach ( self::results()['items'] as $key => $item ) {
			foreach ( $item['found'] as $wkey => $f ) {
				if ( ! isset( $words[ $wkey ] ) ) {
					$words[ $wkey ] = array_merge( $f, array( 'count' => 0, 'items' => array() ) );
				}
				$words[ $wkey ]['count']  += (int) $f['count'];
				$words[ $wkey ]['items'][] = $key;
			}
		}
		uasort(
			$words,
			static function ( $a, $b ) {
				$order = array( 'word' => 0, 'latin' => 1, 'abbr' => 2 );
				return array( $order[ $a['type'] ] ?? 3, -count( $a['items'] ), -$a['count'] ) <=> array( $order[ $b['type'] ] ?? 3, -count( $b['items'] ), -$b['count'] );
			}
		);
		return $words;
	}

	/** Убрать слово из результатов (после добавления в исключения). */
	public static function forget_word( $word ) {
		$r   = self::results();
		$low = YSNO_Checker::lower( $word );
		foreach ( $r['items'] as $key => &$item ) {
			foreach ( array_keys( $item['found'] ) as $wkey ) {
				if ( $wkey === $low || 'w:' . $low === $wkey ) {
					unset( $item['found'][ $wkey ] );
				}
			}
			if ( 0 === strpos( $key, 'post:' ) ) {
				update_post_meta( (int) substr( $key, 5 ), self::META, count( $item['found'] ) );
			}
			if ( ! $item['found'] ) {
				unset( $r['items'][ $key ] );
			}
		}
		unset( $item );
		self::save( $r );
	}

	/* ---------------------------------------------------------------------
	 * AJAX
	 * ------------------------------------------------------------------- */

	private static function guard() {
		check_ajax_referer( 'ysno_ajax', 'nonce' );
		if ( ! current_user_can( YSNO_Admin::CAP ) ) {
			wp_send_json_error( array( 'message' => __( 'Недостаточно прав', 'yasno' ) ), 403 );
		}
	}

	public static function ajax_start() {
		self::guard();
		wp_send_json_success( array( 'total' => self::start() ) );
	}

	public static function ajax_step() {
		self::guard();
		$r = self::step();
		wp_send_json_success(
			array(
				'checked'  => (int) $r['checked'],
				'total'    => (int) ( $r['total'] ?? 0 ),
				'finished' => (bool) $r['finished'],
				'issues'   => count( $r['items'] ),
			)
		);
	}

	public static function ajax_exception() {
		self::guard();
		$word = isset( $_POST['word'] ) ? sanitize_text_field( wp_unslash( $_POST['word'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Missing -- nonce проверен в guard().
		if ( '' === $word ) {
			wp_send_json_error( array( 'message' => __( 'Пустое слово', 'yasno' ) ) );
		}
		YSNO_Settings::add_exception( $word );
		self::forget_word( $word );
		wp_send_json_success( array( 'message' => __( 'Добавлено в исключения', 'yasno' ) ) );
	}
}