<?php

declare( strict_types=1 );

namespace AcezSeo\Import;

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

/**
 * Result of an import (or dry-run): how many posts/terms were touched, how
 * many individual fields were imported vs skipped, plus free-form notes.
 * Serializable to a plain array so it can survive a transient + redirect.
 */
final class ImportReport
{
	/**
	 * Cap on the per-item detail lists — the report travels through a
	 * transient, so it must stay small even on huge sites. Items past the
	 * cap are only counted (see $more_posts / $more_terms).
	 */
	public const MAX_ITEMS = 200;

	public int $posts = 0;
	public int $terms = 0;
	public int $imported_fields = 0;
	public int $skipped_fields = 0;
	public bool $dry_run = false;

	/** @var string[] */
	public array $notes = array();

	/** @var array<int, array<string, string>> post_id => target meta key => truncated source value */
	public array $post_fields = array();

	/** @var array<int, array<string, string>> term_id => target meta key => truncated source value */
	public array $term_fields = array();

	public int $more_posts = 0;
	public int $more_terms = 0;

	public function add_note( string $note ): void
	{
		$this->notes[] = $note;
	}

	public function add_post_field( int $post_id, string $target_key, string $value = '' ): void
	{
		if ( ! isset( $this->post_fields[ $post_id ] ) && count( $this->post_fields ) >= self::MAX_ITEMS )
		{
			++$this->more_posts;

			return;
		}

		$this->post_fields[ $post_id ][ $target_key ] = self::truncate_value( $value );
	}

	public function add_term_field( int $term_id, string $target_key, string $value = '' ): void
	{
		if ( ! isset( $this->term_fields[ $term_id ] ) && count( $this->term_fields ) >= self::MAX_ITEMS )
		{
			++$this->more_terms;

			return;
		}

		$this->term_fields[ $term_id ][ $target_key ] = self::truncate_value( $value );
	}

	/**
	 * Values are shown in the dry-run preview list; the report travels
	 * through a transient, so long descriptions get clipped.
	 */
	private static function truncate_value( string $value ): string
	{
		$value = trim( $value );

		return mb_strlen( $value ) > 100 ? mb_substr( $value, 0, 99 ) . '…' : $value;
	}

	/**
	 * @return array<string, mixed>
	 */
	public function to_array(): array
	{
		return array(
			'posts'           => $this->posts,
			'terms'           => $this->terms,
			'imported_fields' => $this->imported_fields,
			'skipped_fields'  => $this->skipped_fields,
			'dry_run'         => $this->dry_run,
			'notes'           => $this->notes,
			'post_fields'     => $this->post_fields,
			'term_fields'     => $this->term_fields,
			'more_posts'      => $this->more_posts,
			'more_terms'      => $this->more_terms,
		);
	}

	/**
	 * @param array<string, mixed> $data
	 */
	public static function from_array( array $data ): self
	{
		$report                  = new self();
		$report->posts           = (int) ( $data['posts'] ?? 0 );
		$report->terms           = (int) ( $data['terms'] ?? 0 );
		$report->imported_fields = (int) ( $data['imported_fields'] ?? 0 );
		$report->skipped_fields  = (int) ( $data['skipped_fields'] ?? 0 );
		$report->dry_run         = (bool) ( $data['dry_run'] ?? false );
		$report->notes           = array_map( 'strval', (array) ( $data['notes'] ?? array() ) );
		$report->more_posts      = (int) ( $data['more_posts'] ?? 0 );
		$report->more_terms      = (int) ( $data['more_terms'] ?? 0 );

		foreach ( (array) ( $data['post_fields'] ?? array() ) as $post_id => $fields )
		{
			$report->post_fields[ (int) $post_id ] = array_map( 'strval', (array) $fields );
		}

		foreach ( (array) ( $data['term_fields'] ?? array() ) as $term_id => $fields )
		{
			$report->term_fields[ (int) $term_id ] = array_map( 'strval', (array) $fields );
		}

		return $report;
	}

	public function to_summary(): string
	{
		$summary = sprintf(
			/* translators: 1: number of posts, 2: number of terms, 3: imported field count, 4: skipped field count */
			__( 'Posts/pages: %1$d, taxonomy terms: %2$d, imported fields: %3$d, skipped fields: %4$d.', 'acez-seo' ),
			$this->posts,
			$this->terms,
			$this->imported_fields,
			$this->skipped_fields
		);

		if ( $this->dry_run )
		{
			$summary = __( '[Preview — nothing saved] ', 'acez-seo' ) . $summary;
		}

		if ( array() !== $this->notes )
		{
			$summary .= ' ' . implode( ' ', $this->notes );
		}

		return $summary;
	}
}