<?php

namespace App\InvoiceRule;

use Doctrine\ORM\EntityManagerInterface;

use App\InvoiceRuleInterface;

use App\Ramcar\ServiceType;

use App\Entity\ServiceOffering;

class Tax implements InvoiceRuleInterface
{
    protected $em;

    public function __construct(EntityManagerInterface $em)
    {
        $this->em = $em;
    }

    public function getID()
    {
        return 'tax';
    }

    public function compute($criteria, &$total)
    {
        // check if taxable
        if (!$criteria->isTaxable())
        {
            // nothing to compute
            return [];
        }

        $tax_rate = $this->getTaxRate();

        $is_battery_sales = false;
        $total_price = 0;

        // compute tax per item if service type is battery sales
        $stype = $criteria->getServiceType();

        if ($stype == ServiceType::BATTERY_REPLACEMENT_NEW)
        {
            // get the entries
            $entries = $criteria->getEntries();

            foreach($entries as $entry)
            {
                // check if entry is trade-in
                if (isset($entry['trade_in']))
                {
                    // continue to next entry
                    continue;
                }

                $battery = $entry['battery'];
                $qty = $entry['qty'];

                $price = $battery->getSellingPrice();

                $vat = $this->getTaxAmount($price, $tax_rate);

                $qty_price = bcmul($price, $qty, 2);
                $qty_vat = bcmul($vat, $qty, 2);
                $price_minus_vat = bcsub($price, $vat, 2);
                $qty_price_minus_vat = bcmul($price_minus_vat, $qty, 2);

                $total['vat'] = bcadd($total['vat'], $qty_vat, 2);
                $total['vat_ex_price'] = bcadd($total['vat_ex_price'], $qty_price_minus_vat, 2);
            }
        }
        else
        {
            // compute VAT after adding all item costs, if service type is not battery sales
            $total_price = $total['total_price'];

            $vat_ex_price = $this->getTaxExclusivePrice($total_price, $tax_rate);
            $vat = bcsub($total_price, $vat_ex_price, 2);

            $total['vat_ex_price'] = $vat_ex_price;
            $total['vat'] = $vat;
        }

        return [];
    }

    public function validatePromo($criteria, $promo_id)
    {   
        return false;
    }

    public function validateInvoiceItems($criteria, $invoice_items)
    {
        return null;
    }

    protected function getTaxAmount($price, $tax_rate)
    {
        $vat_ex_price = $this->getTaxExclusivePrice($price, $tax_rate);
        $tax_amount = bcsub($price, $vat_ex_price, 2);

        return $tax_amount;
    }

    protected function getTaxExclusivePrice($price, $tax_rate)
    {
        $tax_ex_price = bcdiv($price, bcadd(1, $tax_rate, 2), 2);
        return $tax_ex_price;
    }

    protected function getTaxRate()
    {
        $code = 'tax';

        // find the service fee using the code
        // if we can't find the fee, return 0
        $fee = $this->em->getRepository(ServiceOffering::class)->findOneBy(['code' => $code]);

        if ($fee == null)
            return 0;
      
        return $fee->getFee();
    }
}