<?php
/**
 * REST: blocklingo/v1/bulk/* - "Translate the whole site" on the settings page.
 *
 * The browser asks what still has no translation in a language, then works
 * through the list: pages and posts are translated in the block editor (the
 * same path as the Translate button, so blocks stay valid), header and footer
 * copies and navigation menus through bulk/part and bulk/menu on the server.
 */

declare( strict_types = 1 );

namespace AddBlack\Lang\Rest;

defined( 'ABSPATH' ) || exit;

use AddBlack\Lang\Parts\Menus;
use AddBlack\Lang\Parts\TemplateParts;
use AddBlack\Lang\Settings\SettingsRepository;
use AddBlack\Lang\Terms\TermTranslations;
use AddBlack\Lang\Translation\Coverage;
use AddBlack\Lang\Translation\Duplicator;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

final class BulkController extends Controller {

	/** Most items one run lists; the rest come on the next run. */
	public const LIMIT = 500;

	public function __construct(
		private readonly SettingsRepository $settings,
		private readonly TemplateParts $parts,
		private readonly Coverage $coverage,
		private readonly Menus $menus,
		private readonly TermTranslations $terms,
		private readonly Duplicator $duplicator
	) {}

	public function routes(): void {
		$lang = array(
			'lang' => array(
				'type'     => 'string',
				'required' => true,
			),
		);

		register_rest_route(
			self::NS,
			'/bulk/pending',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => $this->safely( array( $this, 'pending' ) ),
				'permission_callback' => array( $this, 'can_manage' ),
				'args'                => $lang,
			)
		);

		register_rest_route(
			self::NS,
			'/bulk/post',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => $this->safely( array( $this, 'post' ) ),
				'permission_callback' => array( $this, 'can_manage' ),
				'args'                => array_merge(
					$lang,
					array(
						'id' => array(
							'type'     => 'integer',
							'required' => true,
						),
					)
				),
			)
		);

		register_rest_route(
			self::NS,
			'/bulk/term',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => $this->safely( array( $this, 'term' ) ),
				'permission_callback' => array( $this, 'can_manage' ),
				'args'                => array_merge(
					$lang,
					array(
						'id'   => array(
							'type'     => 'integer',
							'required' => true,
						),
						'mode' => array(
							'type'    => 'string',
							'default' => 'machine',
						),
					)
				),
			)
		);

		register_rest_route(
			self::NS,
			'/bulk/menu',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => $this->safely( array( $this, 'menu' ) ),
				'permission_callback' => array( $this, 'can_manage' ),
				'args'                => array_merge(
					$lang,
					array(
						'id' => array(
							'type'     => 'integer',
							'required' => true,
						),
					)
				),
			)
		);

		register_rest_route(
			self::NS,
			'/bulk/part',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => $this->safely( array( $this, 'part' ) ),
				'permission_callback' => array( $this, 'can_manage' ),
				'args'                => array_merge(
					$lang,
					array(
						'slug' => array(
							'type'     => 'string',
							'required' => true,
						),
					)
				),
			)
		);
	}

	/**
	 * Published content of the default language with no version in $lang,
	 * and header/footer parts with no copy in $lang.
	 *
	 * @param WP_REST_Request<array<string, mixed>> $request
	 */
	public function pending( WP_REST_Request $request ): WP_REST_Response|WP_Error {
		$lang  = (string) $request['lang'];
		$error = $this->check_language( $lang );
		if ( $error ) {
			return $error;
		}
		require_once ABSPATH . 'wp-admin/includes/post.php'; // Defines use_block_editor_for_post outside wp-admin.

		$posts = array();
		foreach ( $this->coverage->missing_posts( $lang, self::LIMIT ) as $post ) {
			$type    = get_post_type_object( $post->post_type );
			$posts[] = array(
				'id'        => $post->ID,
				'title'     => '' !== $post->post_title ? html_entity_decode( $post->post_title, ENT_QUOTES, 'UTF-8' ) : '#' . $post->ID,
				'type'      => $type ? (string) $type->labels->singular_name : $post->post_type,
				'edit_link' => (string) get_edit_post_link( $post->ID, 'raw' ),
				// Block editor: translated in a hidden editor (blocks stay valid). Classic: on the server.
				'editor'    => use_block_editor_for_post( $post ) ? 'block' : 'classic',
			);
		}

		$parts = array();
		foreach ( $this->coverage->parts_status( $lang ) as $part ) {
			if ( ! $part['exists'] ) {
				$parts[] = array(
					'slug'  => $part['slug'],
					'title' => $part['title'],
				);
			}
		}

		$menus = array();
		foreach ( $this->menus->status( $lang ) as $menu ) {
			if ( ! $menu['copy'] ) {
				$menus[] = array(
					'id'    => $menu['id'],
					'title' => $menu['title'],
				);
			}
		}

		return new WP_REST_Response(
			array(
				'posts' => $posts,
				'parts' => $parts,
				'menus' => $menus,
				'terms' => $this->missing_terms( $lang ),
			)
		);
	}

	/**
	 * Machine-translated copy of one header/footer part.
	 *
	 * @param WP_REST_Request<array<string, mixed>> $request
	 */
	public function part( WP_REST_Request $request ): WP_REST_Response|WP_Error {
		$lang  = (string) $request['lang'];
		$error = $this->check_language( $lang );
		if ( $error ) {
			return $error;
		}
		if ( function_exists( 'set_time_limit' ) ) {
			@set_time_limit( 300 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- may be disabled by the host.
		}
		$slug   = sanitize_title( (string) $request['slug'] );
		$result = $this->parts->create_translation( $slug, $lang, 'machine' );
		if ( $result instanceof WP_Error ) {
			return self::fail( $result, 'blocklingo_exists' === $result->get_error_code() ? 409 : 502 );
		}
		return new WP_REST_Response(
			array(
				'id'        => $result,
				'slug'      => TemplateParts::slug_for( $slug, $lang ),
				'edit_link' => TemplateParts::edit_link( TemplateParts::slug_for( $slug, $lang ) ),
			)
		);
	}

	/**
	 * Terms of the default language with no version in $lang, parents first.
	 *
	 * @return array<int, array{id: int, title: string, type: string}>
	 */
	private function missing_terms( string $lang ): array {
		$taxonomies = $this->terms->taxonomies();
		if ( ! $taxonomies ) {
			return array();
		}
		$default = $this->settings->get()->default_code();
		$all     = get_terms(
			array(
				'taxonomy'   => $taxonomies,
				'hide_empty' => false,
				'number'     => self::LIMIT,
				'orderby'    => 'parent',
			)
		);
		$out     = array();
		foreach ( is_array( $all ) ? $all : array() as $term ) {
			if ( $this->terms->language_of( $term->term_id ) !== $default || $this->terms->in_language( $term->term_id, $lang ) ) {
				continue;
			}
			if ( 'uncategorized' === $term->slug ) {
				continue; // The fallback category stays shared.
			}
			$tax   = get_taxonomy( $term->taxonomy );
			$out[] = array(
				'id'    => $term->term_id,
				'title' => html_entity_decode( $term->name, ENT_QUOTES, 'UTF-8' ),
				'type'  => $tax ? (string) $tax->labels->singular_name : $term->taxonomy,
			);
		}
		return $out;
	}

	/**
	 * Machine-translated draft of one post that does not use the block editor
	 * (classic editor, title and fields only): translated on the server.
	 *
	 * @param WP_REST_Request<array<string, mixed>> $request
	 */
	public function post( WP_REST_Request $request ): WP_REST_Response|WP_Error {
		$lang  = (string) $request['lang'];
		$error = $this->check_language( $lang );
		if ( $error ) {
			return $error;
		}
		$id   = (int) $request['id'];
		$post = get_post( $id );
		if ( ! $post || ! $this->settings->get()->is_translatable_type( $post->post_type ) ) {
			return new WP_Error( 'blocklingo_no_post', __( 'Post not found.', 'blocklingo' ), array( 'status' => 404 ) );
		}
		if ( function_exists( 'set_time_limit' ) ) {
			@set_time_limit( 300 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- may be disabled by the host.
		}
		$result = $this->duplicator->create( $id, $lang, Duplicator::MODE_MACHINE );
		if ( $result instanceof WP_Error ) {
			return self::fail( $result, 'blocklingo_exists' === $result->get_error_code() ? 409 : 502 );
		}
		return new WP_REST_Response(
			array(
				'id'        => $result,
				'edit_link' => (string) get_edit_post_link( $result, 'raw' ),
			)
		);
	}

	/**
	 * Machine-translated version of one term (mode "copy" for tests and manual use).
	 *
	 * @param WP_REST_Request<array<string, mixed>> $request
	 */
	public function term( WP_REST_Request $request ): WP_REST_Response|WP_Error {
		$lang  = (string) $request['lang'];
		$error = $this->check_language( $lang );
		if ( $error ) {
			return $error;
		}
		$mode   = 'copy' === $request['mode'] ? 'copy' : 'machine';
		$result = $this->terms->create_translation( (int) $request['id'], $lang, $mode );
		if ( $result instanceof WP_Error ) {
			return self::fail( $result, 'blocklingo_exists' === $result->get_error_code() ? 409 : 502 );
		}
		return new WP_REST_Response(
			array(
				'id'        => $result,
				'edit_link' => (string) get_edit_term_link( $result ),
			)
		);
	}

	/**
	 * Machine-translated, published copy of one navigation menu.
	 *
	 * @param WP_REST_Request<array<string, mixed>> $request
	 */
	public function menu( WP_REST_Request $request ): WP_REST_Response|WP_Error {
		$lang  = (string) $request['lang'];
		$error = $this->check_language( $lang );
		if ( $error ) {
			return $error;
		}
		$result = $this->menus->create_translation( (int) $request['id'], $lang, 'machine' );
		if ( $result instanceof WP_Error ) {
			return self::fail( $result, 'blocklingo_exists' === $result->get_error_code() ? 409 : 502 );
		}
		return new WP_REST_Response(
			array(
				'id'        => $result,
				'edit_link' => Menus::edit_link( $result ),
			)
		);
	}

	private function check_language( string $lang ): ?WP_Error {
		$settings = $this->settings->get();
		if ( ! $settings->is_language( $lang ) || $settings->default_code() === $lang ) {
			return new WP_Error( 'blocklingo_bad_lang', __( 'Pick a language other than the default one.', 'blocklingo' ), array( 'status' => 400 ) );
		}
		return null;
	}
}