<?php
/**
 * Product sync: one product's entry.
 *
 * @package CortexCommerce
 */

namespace CortexCommerce\Sync;

use CortexCommerce\Seo\SeoAdapter;

defined( 'ABSPATH' ) || exit;

/**
 * `{ product, variations, seo }` for one product (contract §5c). `product` and `variations` come from WordPress's
 * in-process REST dispatch of wc/v3, so they are exactly the JSON the backend's mapper parses, with no HTTP call
 * to the store itself. The caller runs this with read_private_products on the products it reads (SyncPermissions), as
 * nobody.
 */
final class ProductPayload {

	const VARIATIONS_PER_PAGE = 100;

	/**
	 * An unpublished product (draft, private, pending, trash, ...) is sent as this stub, never as its content.
	 *
	 * @return array{id: int, status: string}
	 */
	public static function stub( int $id, string $status ): array {
		return array(
			'id'     => $id,
			'status' => $status,
		);
	}

	/**
	 * @return array{product: array<string, mixed>, variations: array<int, mixed>, seo: array{title: string, description: string, source: string}}
	 * @throws \RuntimeException When WooCommerce does not answer 200 for the product or its variations.
	 */
	public static function build( int $id, SeoAdapter $seo ): array {
		$product    = array( 'data' => self::product( $id ) );
		$variations = array();
		if ( ! empty( $product['data']['variations'] ) ) {
			$page = 1;
			do {
				$response   = self::get(
					'/wc/v3/products/' . $id . '/variations',
					array(
						'per_page' => self::VARIATIONS_PER_PAGE,
						'page'     => $page,
					)
				);
				$variations = array_merge( $variations, array_values( (array) $response['data'] ) );
				$pages      = (int) ( $response['headers']['X-WP-TotalPages'] ?? 1 );
				++$page;
			} while ( $page <= $pages );
		}
		$fields = $seo->get( $id );
		return array(
			'product'    => (array) $product['data'],
			'variations' => $variations,
			'seo'        => array(
				'title'       => $fields['title'],
				'description' => $fields['description'],
				'source'      => $seo->id(),
			),
		);
	}

	/**
	 * The product as the catalog push sends it: wc/v3, view context, as the current user.
	 *
	 * @return array<string, mixed>
	 * @throws \RuntimeException When WooCommerce does not answer 200.
	 */
	public static function product( int $id ): array {
		return (array) self::get( '/wc/v3/products/' . $id, array() )['data'];
	}

	/**
	 * @param array<string, int> $query Query params.
	 * @return array{data: mixed, headers: array<string, mixed>}
	 * @throws \RuntimeException When the answer is not 200.
	 */
	private static function get( string $route, array $query ): array {
		$request = new \WP_REST_Request( 'GET', $route );
		$request->set_query_params( $query );
		$response = rest_do_request( $request );
		if ( 200 !== $response->get_status() ) {
			// phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped -- Exception message for logs, not rendered output.
			throw new \RuntimeException( sprintf( 'GET %s answered HTTP %d', $route, $response->get_status() ) );
		}
		return array(
			'data'    => rest_get_server()->response_to_data( $response, false ),
			'headers' => $response->get_headers(),
		);
	}
}