<?php
/**
 * Order Weight Calculator.
 *
 * @package PaczkomatyInpost
 */

/**
 * Can calculate order weight. Also integrates with fs_calculate_order_weight
 */
class WooCommerce_Order_Weight_Calculator {

	/** @var WC_Order */
	private $order;

	/**
	 * WooCommerce_Order_Weight_Calculator constructor.
	 *
	 * @param WC_Order $order Order.
	 */
	public function __construct( WC_Order $order ) {
		$this->order = $order;
	}

	/**
	 * Returns order weight in KG.
	 *
	 * @param float $default_weight .
	 *
	 * @return float - precision 3
	 */
	public function get_order_weight_kg( $default_weight = 0.0 ) {
		if ( function_exists( 'fs_calculate_order_weight' ) ) {
			$weight = fs_calculate_order_weight( $this->order );
		} else {
			$weight = 0.0;
			if ( count( $this->order->get_items() ) > 0 ) {
				foreach ( $this->order->get_items() as $item ) {
					$weight += $this->get_raw_item_weight( $item );
				}
			}
		}

		if ( (float) $weight === 0.0 ) {
			return $this->round_weight( $default_weight );
		}

		return $this->convert_wc_weight_to_kg( $weight );
	}

	/**
	 * @param WC_Order_Item $item Order Item.
	 *
	 * @return float
	 */
	private function get_raw_item_weight( WC_Order_Item $item ) {
		if ( $item['product_id'] > 0 ) {
			$product = $item->get_product();
			if ( $product instanceof WC_Product && ! $product->is_virtual() ) {
				return $product->get_weight() * $item['qty'];
			}
		}

		return 0;
	}

	/**
	 * Convert WooCommerce weight to KG
	 *
	 * @param string $wc_weight Weight in WooCommerce default unit weight.
	 *
	 * @return float weight in kg - precision 3.
	 */
	private function convert_wc_weight_to_kg( $wc_weight ) {
		$weight = wc_get_weight( $wc_weight, 'kg' );
		$weight = str_replace( ',', '.', $weight );

		return $this->round_weight( (float) $weight );
	}

	/**
	 * @param $weight
	 *
	 * @return float
	 */
	private function round_weight( $weight ) {
		$weight = round( $weight, 3 );

		return $weight;
	}
}