<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * ACSIL_Post_List — 投稿一覧カラム拡張
 */
class ACSIL_Post_List {

	private ACSIL_Database $db;

	/** @var array<int,array> キャッシュ（リクエスト内） */
	private array $counts_cache = array();

	public function __construct( ACSIL_Database $db ) {
		$this->db = $db;
	}

	public function register_column_hooks(): void {
		$settings = ACSIL_Core::get_settings();
		if ( ! $settings['show_list_columns'] ) {
			return;
		}

		$post_types = $settings['post_types'];
		foreach ( $post_types as $post_type ) {
			add_filter( "manage_{$post_type}_posts_columns", array( $this, 'add_columns' ) );
			add_action( "manage_{$post_type}_posts_custom_column", array( $this, 'render_column' ), 10, 2 );
			add_filter( "manage_edit-{$post_type}_sortable_columns", array( $this, 'make_sortable' ) );
		}

		add_action( 'pre_get_posts', array( $this, 'sort_query' ) );
	}

	// ── カラム追加 ────────────────────────────────────────────────────────

	public function add_columns( array $columns ): array {
		// 「タグ」の直後に挿入
		$new = array();
		foreach ( $columns as $key => $label ) {
			$new[ $key ] = $label;
			if ( 'tags' === $key || 'author' === $key ) {
				$new['acsil_outgoing'] = '<span title="' . esc_attr__( 'Number of outbound links', 'acs-internal-links' ) . '">' . esc_html__( 'Outbound', 'acs-internal-links' ) . '</span>';
				$new['acsil_incoming'] = '<span title="' . esc_attr__( 'Number of inbound links', 'acs-internal-links' ) . '">' . esc_html__( 'Inbound', 'acs-internal-links' ) . '</span>';
			}
		}

		// 挿入されなかった場合は末尾に追加
		if ( ! array_key_exists( 'acsil_outgoing', $new ) ) {
			$new['acsil_outgoing'] = esc_html__( 'Outbound', 'acs-internal-links' );
			$new['acsil_incoming'] = esc_html__( 'Inbound', 'acs-internal-links' );
		}

		return $new;
	}

	// ── カラム内容表示 ────────────────────────────────────────────────────

	public function render_column( string $column, int $post_id ): void {
		if ( ! in_array( $column, array( 'acsil_outgoing', 'acsil_incoming' ), true ) ) {
			return;
		}

		// 一覧ページの全カウントを1回だけ取得してキャッシュ
		if ( empty( $this->counts_cache ) ) {
			$this->counts_cache = $this->db->get_all_link_counts();
		}

		$outgoing = $this->counts_cache[ $post_id ]['outgoing'] ?? 0;
		$incoming = $this->counts_cache[ $post_id ]['incoming'] ?? 0;

		if ( 'acsil_outgoing' === $column ) {
			$class = 0 === $outgoing ? 'acsil-count-zero-gray' : '';
			printf( '<span class="acsil-count-cell %s">%d</span>', esc_attr( $class ), (int) $outgoing );
		} elseif ( 'acsil_incoming' === $column ) {
			$class = 0 === $incoming ? 'acsil-count-zero-red' : '';
			printf( '<span class="acsil-count-cell %s">%d</span>', esc_attr( $class ), (int) $incoming );
		}
	}

	// ── ソート対応 ────────────────────────────────────────────────────────

	public function make_sortable( array $columns ): array {
		$columns['acsil_outgoing'] = 'acsil_outgoing';
		$columns['acsil_incoming'] = 'acsil_incoming';
		return $columns;
	}

	public function sort_query( WP_Query $query ): void {
		if ( ! is_admin() || ! $query->is_main_query() ) {
			return;
		}

		$orderby = $query->get( 'orderby' );
		if ( ! in_array( $orderby, array( 'acsil_outgoing', 'acsil_incoming' ), true ) ) {
			return;
		}

		global $wpdb;
		$table = $wpdb->prefix . 'acsil_links';

		if ( 'acsil_outgoing' === $orderby ) {
			$query->set( 'orderby', 'acsil_count' );
			$query->set( 'meta_query', array() );
			add_filter(
				'posts_clauses',
				function ( $clauses ) use ( $wpdb, $table, $query ) {
					$order              = strtoupper( $query->get( 'order' ) ) === 'ASC' ? 'ASC' : 'DESC';
					$clauses['join']   .= " LEFT JOIN (SELECT source_post_id, COUNT(*) AS out_cnt FROM {$table} GROUP BY source_post_id) AS acsil_out ON acsil_out.source_post_id = {$wpdb->posts}.ID";
					$clauses['orderby'] = "COALESCE(acsil_out.out_cnt, 0) {$order}";
					return $clauses;
				}
			);
		} elseif ( 'acsil_incoming' === $orderby ) {
			add_filter(
				'posts_clauses',
				function ( $clauses ) use ( $wpdb, $table, $query ) {
					$order              = strtoupper( $query->get( 'order' ) ) === 'ASC' ? 'ASC' : 'DESC';
					$clauses['join']   .= " LEFT JOIN (SELECT target_post_id, COUNT(*) AS in_cnt FROM {$table} GROUP BY target_post_id) AS acsil_in ON acsil_in.target_post_id = {$wpdb->posts}.ID";
					$clauses['orderby'] = "COALESCE(acsil_in.in_cnt, 0) {$order}";
					return $clauses;
				}
			);
		}
	}
}