<?php
/**
 * Machine translation of collected strings, and cleanup of strings the
 * current rules would no longer collect.
 */

declare( strict_types = 1 );

namespace AddBlack\Lang\Strings;

defined( 'ABSPATH' ) || exit;

use AddBlack\Lang\MachineTranslation\Translator;
use AddBlack\Lang\Settings\SettingsRepository;
use WP_Error;

final class StringTranslator {

	public function __construct(
		private readonly StringCatalog $catalog,
		private readonly StringRules $rules,
		private readonly Translator $translator,
		private readonly SettingsRepository $settings
	) {}

	/**
	 * Translate up to $limit strings that have no translation in $lang yet.
	 *
	 * @return array{done: int, remaining: int}|WP_Error
	 */
	public function machine_translate( string $lang, int $limit = 40, string $domain = '' ): array|WP_Error {
		$settings = $this->settings->get();
		if ( ! $settings->is_language( $lang ) || $settings->default_code() === $lang ) {
			return new WP_Error( 'blocklingo_bad_lang', __( 'Unknown language.', 'blocklingo' ) );
		}
		$filter = array(
			'lang'   => $lang,
			'status' => 'untranslated',
			'domain' => $domain,
		);
		$page   = $this->catalog->query( $filter + array( 'per_page' => max( 1, min( 100, $limit ) ) ) );
		if ( ! $page['items'] ) {
			return array(
				'done'      => 0,
				'remaining' => 0,
			);
		}
		$texts = array();
		$kinds = array();
		$hints = array();
		foreach ( $page['items'] as $i => $row ) {
			$texts[ $i ] = (string) $row->original;
			$kinds[ $i ] = preg_match( '/<[a-z\/!]/i', $texts[ $i ] ) ? 'html' : 'text';
			$hints[ $i ] = trim( 'UI string' . ( $row->context ? ', context: ' . $row->context : '' ) . ( $row->domain ? ', from ' . $row->domain : '' ) );
		}
		$out = $this->translator->translate_strings(
			$texts,
			$kinds,
			$settings->default_code(),
			$lang,
			null,
			array(
				'hints'   => $hints,
				'context' => array(
					'title' => 'Website interface strings',
					'type'  => 'buttons, labels, notices and messages of the theme and plugins; keep them short and keep placeholders like %s or %1$s',
				),
			)
		);
		if ( is_wp_error( $out ) ) {
			return $out;
		}
		$done = 0;
		foreach ( $page['items'] as $i => $row ) {
			if ( isset( $out[ $i ] ) && '' !== trim( $out[ $i ] ) ) {
				$this->catalog->set_translation( (int) $row->id, $lang, wp_kses_post( trim( $out[ $i ] ) ) ); // Same rule as saving by hand.
				++$done;
			}
		}
		$left = $this->catalog->query( $filter + array( 'per_page' => 1 ) );
		return array(
			'done'      => $done,
			'remaining' => $left['total'],
		);
	}

	/**
	 * Delete untranslated strings the current rules would not collect (core,
	 * editor metadata). Runs before each "Scan site".
	 *
	 * @return int Strings deleted.
	 */
	public function prune(): int {
		$ids = array();
		foreach ( $this->catalog->untranslated() as $r ) {
			if ( ! $this->rules->collectable( (string) $r->original, (string) $r->domain, (string) $r->context ) ) {
				$ids[] = (int) $r->id;
			}
		}
		return $ids ? $this->catalog->delete( $ids ) : 0;
	}
}