<?php
/**
 * Price calculator.
 *
 * @package Extrova
 */

declare( strict_types=1 );

namespace Extrova\Pricing;

use Extrova\Core\Context;
use Extrova\Core\Extra;
use Extrova\Core\Money;
use Extrova\Core\PriceResult;
use Extrova\Core\Selection;
use Extrova\Registry\PricingRegistry;
use Extrova\Registry\TypeRegistry;

defined( 'ABSPATH' ) || exit;

/**
 * Turns (extra, selection, context) into a PriceResult. Always computed on the server from
 * the stored configuration: the browser never sends amounts (except the custom tip, clamped).
 *
 * @since 1.0.0
 */
final class PriceCalculator {

	/**
	 * Constructor.
	 *
	 * @param TypeRegistry    $types   Types.
	 * @param PricingRegistry $pricing Pricing methods.
	 * @param TaxHelper       $tax     Tax helper.
	 */
	public function __construct(
		private TypeRegistry $types,
		private PricingRegistry $pricing,
		private TaxHelper $tax
	) {}

	/**
	 * Calculates the price of a selection.
	 *
	 * @param Extra     $extra     Extra.
	 * @param Selection $selection Selection.
	 * @param Context   $context   Context.
	 */
	public function calculate( Extra $extra, Selection $selection, Context $context ): PriceResult {
		$taxable = $extra->is_taxable();
		$class   = $extra->tax_class();
		$type    = $this->types->get( $extra->type );

		if ( ! $type || ! $type->is_chargeable( $extra, $selection ) ) {
			return PriceResult::zero( $taxable, $class );
		}

		$pricing = $type->pricing_for( $extra, $selection );
		$method  = $this->pricing->get( (string) ( $pricing['method'] ?? '' ) );
		if ( ! $method ) {
			return PriceResult::zero( $taxable, $class );
		}

		$amount = $method->calculate( $pricing, $extra, $selection, $context );

		/**
		 * Filters the extra amount as the store enters it (before conversion to net).
		 *
		 * @since 1.0.0
		 *
		 * @param string    $amount    Decimal string.
		 * @param Extra     $extra     Extra.
		 * @param Selection $selection Selection.
		 * @param Context   $context   Context.
		 */
		$amount = apply_filters( 'extrova_extra_price', $amount, $extra, $selection, $context );
		$amount = is_scalar( $amount ) ? (float) wc_format_decimal( (string) $amount ) : 0.0;

		if ( $amount <= 0 ) {
			return PriceResult::zero( $taxable, $class );
		}

		$is_net = $method instanceof NetAmountPricingInterface && $method->returns_net_amount( $pricing, $context );
		$net    = $is_net ? round( $amount, wc_get_price_decimals() ) : $this->tax->to_net( $amount, $taxable, $class, $context );
		$tax    = $this->tax->tax_for( $net, $taxable, $class, $context );

		$display = $this->tax->display_including_tax( $context ) ? $net + $tax : $net;

		return new PriceResult(
			(string) wc_format_decimal( $net, wc_get_rounding_precision() ),
			$taxable,
			$class,
			Money::decimal( $display ),
			Money::decimal( $tax )
		);
	}
}