<?php

declare(strict_types=1);

namespace LinkCheckup\Features\LinkLists;

use InvalidArgumentException;
use LinkCheckup\Shared\Rest\PageRequest;
use ValueError;
use WP_Error;
use WP_REST_Request;

use function is_string;
use function trim;

final class LinkListQueryReader {

	private const DEFAULT_PER_PAGE   = 50;
	private const STATUS_PARAMETER   = 'status';
	private const SEARCH_PARAMETER   = 'search';
	private const ORDERBY_PARAMETER  = 'orderby';
	private const ORDER_PARAMETER    = 'order';
	private const INVALID_PARAMETER  = 'rest_invalid_param';
	private const BAD_REQUEST_STATUS = 400;

	/** @param WP_REST_Request<array<string, mixed>> $request */
	public function read( WP_REST_Request $request ): LinkListQuery|WP_Error {
		try {
			return $this->query_from( $request );
		} catch ( InvalidArgumentException | ValueError ) {
			return new WP_Error(
				self::INVALID_PARAMETER,
				__(
					'The list was asked for with a value that is not allowed.',
					'aiplaz-link-checkup'
				),
				array( 'status' => self::BAD_REQUEST_STATUS )
			);
		}
	}

	/** @param WP_REST_Request<array<string, mixed>> $request */
	private function query_from( WP_REST_Request $request ): LinkListQuery {
		$status = $this->text_param(
			$request,
			self::STATUS_PARAMETER,
			LinkStatusFilter::Problems->value
		);
		$search = $this->text_param(
			$request,
			self::SEARCH_PARAMETER,
			''
		);
		$field  = $this->text_param(
			$request,
			self::ORDERBY_PARAMETER,
			LinkSortField::Priority->value
		);
		$order  = $this->text_param(
			$request,
			self::ORDER_PARAMETER,
			SortDirection::Descending->value
		);

		return new LinkListQuery(
			status: LinkStatusFilter::from( $status ),
			search: trim( $search ),
			sort_field: LinkSortField::from( $field ),
			sort_direction: SortDirection::from( $order ),
			page_request: PageRequest::from_request(
				$request,
				self::DEFAULT_PER_PAGE
			)
		);
	}

	/** @param WP_REST_Request<array<string, mixed>> $request */
	private function text_param(
		WP_REST_Request $request,
		string $name,
		string $default_text
	): string {
		$value = $request->get_param( $name );

		if ( null === $value ) {
			return $default_text;
		}

		if ( ! is_string( $value ) ) {
			throw new InvalidArgumentException();
		}

		return $value;
	}
}