<?php
/**
 * GET /wp-json/joinery/v1/price-preview — prices for a product at given quantities,
 * for the current customer. Public, like product prices are; signed-in customers
 * (cookie + nonce, or application passwords) get their role-based prices.
 *
 * @package Joinery\Core
 */

namespace Joinery\Core\Rest;

use Joinery\Core\Pricing\Preview;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

defined( 'ABSPATH' ) || exit;

/**
 * Price preview endpoint.
 */
final class PricePreviewController {

	/**
	 * Create the controller.
	 *
	 * @param Preview $preview Price preview service.
	 */
	public function __construct( private readonly Preview $preview ) {}

	/**
	 * Add hooks.
	 */
	public function register(): void {
		add_action( 'rest_api_init', array( $this, 'routes' ) );
	}

	/**
	 * Register the route.
	 */
	public function routes(): void {
		register_rest_route(
			RulesController::NAMESPACE,
			'/price-preview',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( $this, 'preview' ),
				'permission_callback' => '__return_true',
				'args'                => array(
					'product_id' => array(
						'type'              => 'integer',
						'required'          => true,
						'minimum'           => 1,
						'sanitize_callback' => 'absint',
					),
					'quantities' => array(
						'description' => __( 'Comma-separated quantities, up to 10. Defaults to the product’s quantity breaks.', 'joinery-core' ),
						'type'        => 'string',
						'default'     => '',
						'pattern'     => '^[0-9,]{0,60}$',
					),
				),
			)
		);
	}

	/**
	 * Prices for the product.
	 *
	 * @param WP_REST_Request $request Request.
	 * @phpstan-param WP_REST_Request<array<string, mixed>> $request
	 * @return WP_REST_Response|WP_Error
	 */
	public function preview( WP_REST_Request $request ) {
		$product = wc_get_product( (int) $request['product_id'] );
		if ( ! $product || 'publish' !== get_post_status( $product->get_parent_id() ? $product->get_parent_id() : $product->get_id() ) || ! $product->is_purchasable() ) {
			return new WP_Error( 'joinery_product_not_found', __( 'No product with that ID is for sale.', 'joinery-core' ), array( 'status' => 404 ) );
		}

		$requested = array_slice( array_filter( array_map( 'absint', explode( ',', (string) $request['quantities'] ) ) ), 0, 10 );
		if ( array() === $requested ) {
			$prices = $this->preview->breaks( $product );
		} else {
			$prices = array_map(
				fn( int $quantity ): array => array(
					'min_quantity' => min( $quantity, 100000 ),
					'price'        => $this->preview->unit_price( $product, min( $quantity, 100000 ) ),
				),
				$requested
			);
		}

		$regular = (float) $product->get_price( 'edit' );
		return new WP_REST_Response(
			array(
				'product_id'          => $product->get_id(),
				'currency_code'       => get_woocommerce_currency(),
				'currency_minor_unit' => wc_get_price_decimals(),
				'regular_price'       => Preview::minor_units( $regular ),
				'prices'              => array_map(
					static fn( array $row ): array => array(
						'quantity'       => $row['min_quantity'],
						'price'          => Preview::minor_units( $row['price'] ),
						'percent_saving' => $regular > 0 ? round( ( 1 - $row['price'] / $regular ) * 100, 2 ) : 0,
					),
					$prices
				),
			)
		);
	}
}