<?php
/**
 * 在文章保存后同步到远程站点。
 *
 * @package Lesending
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Lesending_Sync {

	/**
	 * @var Lesending_Sync|null
	 */
	private static $instance = null;

	/**
	 * @return Lesending_Sync
	 */
	public static function instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	private function __construct() {
		add_action( 'rest_after_insert_post', array( $this, 'after_rest_insert' ), 20, 3 );
		add_action( 'save_post_post', array( $this, 'after_classic_save' ), 20, 3 );
	}

	/**
	 * @param \WP_Post         $post     插入后的文章。
	 * @param \WP_REST_Request $request  请求。
	 * @param bool             $creating 是否新建。
	 */
	public function after_rest_insert( $post, $request, $creating ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		$this->maybe_sync( $post->ID );
	}

	/**
	 * @param int     $post_id 文章 ID。
	 * @param \WP_Post $post    文章对象。
	 * @param bool    $update  是否更新。
	 */
	public function after_classic_save( $post_id, $post, $update ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
			return;
		}
		if ( wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) {
			return;
		}
		$this->maybe_sync( $post_id );
	}

	/**
	 * @param int $post_id 文章 ID。
	 */
	private function maybe_sync( $post_id ) {
		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
			return;
		}

		if ( ! Lesending_Plugin::is_remote_enabled() ) {
			return;
		}

		if ( ! Lesending_Plugin::current_user_can_sync( $post_id ) ) {
			return;
		}

		$mode = get_post_meta( $post_id, '_lesending_target_mode', true );
		if ( ! is_string( $mode ) || $mode === '' ) {
			$mode = 'local_only';
		}

		if ( 'local_only' === $mode ) {
			return;
		}

		$site_ids = get_post_meta( $post_id, '_lesending_remote_site_ids', true );
		if ( ! is_array( $site_ids ) || empty( $site_ids ) ) {
			if ( 'local_and_remote' === $mode || 'remote_only' === $mode ) {
				$this->store_log(
					$post_id,
					array(
						'ok'      => false,
						'message' => __( '未选择任何远程站点。', 'lesending' ),
					)
				);
			}
			return;
		}

		$post = get_post( $post_id );
		if ( ! $post instanceof WP_Post ) {
			return;
		}

		if ( 'auto-draft' === $post->post_status ) {
			return;
		}

		$site_ids = array_values( array_map( 'strval', $site_ids ) );
		sort( $site_ids );
		$sync_hash = md5(
			wp_json_encode(
				array(
					$mode,
					$site_ids,
					$post->post_title,
					$post->post_content,
					$post->post_excerpt,
					$post->post_status,
					(int) get_post_thumbnail_id( $post_id ),
					Lesending_Plugin::is_media_sync_enabled(),
				)
			)
		);
		$prev_hash = get_post_meta( $post_id, '_lesending_sync_hash', true );
		$last_log  = get_post_meta( $post_id, '_lesending_last_sync_log', true );
		$last_ok   = true;
		if ( is_string( $last_log ) && $last_log !== '' ) {
			$decoded = json_decode( $last_log, true );
			if ( is_array( $decoded ) && array_key_exists( 'ok', $decoded ) ) {
				$last_ok = (bool) $decoded['ok'];
			}
		}
		if ( $sync_hash === $prev_hash && $last_ok ) {
			return;
		}

		$map = get_post_meta( $post_id, '_lesending_remote_post_ids', true );
		if ( ! is_array( $map ) ) {
			$map = array();
		}

		$results = array();
		$all_ok  = true;

		foreach ( $site_ids as $sid ) {
			$site = Lesending_Plugin::get_site_by_id( (string) $sid );
			if ( ! $site || empty( $site['enabled'] ) ) {
				$results[ $sid ] = array(
					'ok'      => false,
					'message' => __( '站点不存在或未启用。', 'lesending' ),
				);
				$all_ok          = false;
				continue;
			}
			$existing = isset( $map[ $sid ] ) ? (int) $map[ $sid ] : null;
			$res      = Lesending_Remote_Api::upsert_post( $site, $post, $existing );
			if ( is_wp_error( $res ) ) {
				$results[ $sid ] = array(
					'ok'      => false,
					'message' => $res->get_error_message(),
				);
				$all_ok          = false;
			} else {
				$map[ $sid ]     = $res['id'];
				$results[ $sid ] = array(
					'ok'      => true,
					'message' => $res['link'],
				);
			}
		}

		update_post_meta( $post_id, '_lesending_remote_post_ids', $map );
		$this->store_log( $post_id, array( 'sites' => $results, 'ok' => $all_ok ) );
		update_post_meta( $post_id, '_lesending_sync_hash', $sync_hash );

		if ( 'remote_only' === $mode && $all_ok ) {
			wp_update_post(
				array(
					'ID'            => $post_id,
					'post_status'   => 'draft',
				)
			);
			update_post_meta( $post_id, '_lesending_target_mode', 'local_only' );
			update_post_meta( $post_id, '_lesending_remote_site_ids', array() );
			delete_post_meta( $post_id, '_lesending_sync_hash' );
			set_transient(
				'lesending_notice_' . get_current_user_id(),
				__( '已按「仅远程站点」将文章同步到远程；本地已保存为草稿，并已切回「仅本网站」以免后续保存把远程改为草稿。', 'lesending' ),
				60
			);
		} elseif ( ! $all_ok ) {
			set_transient(
				'lesending_notice_' . get_current_user_id(),
				__( '远程同步部分失败，请查看文章内的同步记录。', 'lesending' ),
				120
			);
		}
	}

	/**
	 * @param int   $post_id 文章 ID。
	 * @param array $log     日志结构。
	 */
	private function store_log( $post_id, $log ) {
		update_post_meta( $post_id, '_lesending_last_sync_log', wp_json_encode( $log ) );
		update_post_meta( $post_id, '_lesending_last_sync_at', time() );
	}
}