<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Fixes;

use LinkCheckup\Shared\Extraction\PostLinkSync;
use LinkCheckup\Shared\Posts\PageBuilders;

final class PostContentWriter {

	private const EDIT_CAPABILITY = 'edit_post';
	private const CONTENT_FIELD   = 'post_content';
	private const RAW_CONTEXT     = 'raw';

	public function __construct(
		private ContentRewriter $content_rewriter,
		private PostLinkSync $post_link_sync,
		private PageBuilders $page_builders
	) {
	}

	public function rewrite(
		int $link_id,
		int $post_id,
		LinkEdit $edit
	): JournalEntry {
		$failed = new JournalEntry( $link_id, $post_id, null );
		$post   = get_post( $post_id );

		if ( null === $post || ! $this->is_editable( $post_id ) ) {
			return $failed;
		}

		if ( null !== $this->page_builders->name_of( $post_id ) ) {
			return $failed;
		}

		$content   = $post->post_content;
		$rewritten = $this->content_rewriter->apply( $edit, $content );

		if ( $rewritten === $content ) {
			return $failed;
		}

		$this->write( $post_id, $rewritten );

		$saved_content = get_post_field(
			self::CONTENT_FIELD,
			$post_id,
			self::RAW_CONTEXT
		);

		if ( $saved_content === $content ) {
			return $failed;
		}

		$this->post_link_sync->sync( $post_id );

		return new JournalEntry( $link_id, $post_id, $content );
	}

	public function restore( JournalEntry $entry ): void {
		if ( null === $entry->content_before_fix ) {
			return;
		}

		$this->write( $entry->post_id, $entry->content_before_fix );
		$this->post_link_sync->sync( $entry->post_id );
	}

	private function is_editable( int $post_id ): bool {
		require_once ABSPATH . 'wp-admin/includes/post.php';

		return current_user_can( self::EDIT_CAPABILITY, $post_id )
			&& false === wp_check_post_lock( $post_id );
	}

	private function write( int $post_id, string $content ): void {
		wp_save_post_revision( $post_id );
		wp_update_post(
			array(
				'ID'                => $post_id,
				self::CONTENT_FIELD => wp_slash( $content ),
			)
		);
	}
}