<?php
/**
 * One box, in kilograms and centimetres, rounded the way the Rating API
 * accepts: weight up to the gram, each side up to the millimetre, sides
 * sorted longest first so the same box always has the same cache key.
 */

declare(strict_types=1);

namespace BlueBrainMedia\MapleParcel\Shipping;

defined( 'ABSPATH' ) || exit;

final class Parcel {

	/** Canada Post's limits for a parcel (audit, section 4). */
	public const MAX_WEIGHT_KG       = 30.0;
	public const MAX_SIDE_CM         = 200.0;
	public const MAX_LENGTH_GIRTH_CM = 300.0;

	public readonly float $weight;

	public readonly float $length;

	public readonly float $width;

	public readonly float $height;

	/**
	 * @param float $weight Kilograms.
	 * @param float $length Centimetres; the three sides may come in any order.
	 * @param float $width  Centimetres.
	 * @param float $height Centimetres.
	 * @param float $value  What is inside, in the store currency, for coverage.
	 */
	public function __construct( float $weight, float $length, float $width, float $height, public readonly float $value = 0.0 ) {
		$sides = array( self::side( $length ), self::side( $width ), self::side( $height ) );
		rsort( $sides );

		$this->weight = max( 0.001, ceil( round( $weight * 1000, 6 ) ) / 1000 );
		$this->length = $sides[0];
		$this->width  = $sides[1];
		$this->height = $sides[2];
	}

	public function volume(): float {
		return $this->length * $this->width * $this->height;
	}

	/** Too heavy or too big for Canada Post, so it cannot be rated at all. */
	public function exceedsLimits(): bool {
		return $this->weight > self::MAX_WEIGHT_KG
			|| $this->length > self::MAX_SIDE_CM
			|| $this->length + 2 * ( $this->width + $this->height ) > self::MAX_LENGTH_GIRTH_CM;
	}

	/** Identical parcels share a key, so they are rated once. */
	public function key( bool $withValue ): string {
		$key = sprintf( '%.3f|%.1f|%.1f|%.1f', $this->weight, $this->length, $this->width, $this->height );

		return $withValue ? $key . sprintf( '|%.2f', $this->value ) : $key;
	}

	/** @return array{weight: float, dimensions: array{length: float, width: float, height: float}} */
	public function toApi(): array {
		return array(
			'weight'     => $this->weight,
			'dimensions' => array(
				'length' => $this->length,
				'width'  => $this->width,
				'height' => $this->height,
			),
		);
	}

	private static function side( float $cm ): float {
		return max( 0.1, ceil( round( $cm * 10, 6 ) ) / 10 );
	}
}