<?php namespace Sberbank\Payments;
// RbsDiscount
// ver. 1.0.6

class Discount
{

    private $cashBasket = array();
    private $equalPosition = -1;
    private $faultPrice;
    private $arrOrder = array(
        'order_id' => null,
        'amount' => null,
        'discount' => null,
        'basket' => array()
    );

    private $arrRecountSumm = array(
        'priceAmount' => 0,
        'priceDiscount' => 0,
        'discount' => 0,
    );

    public function discoverDiscount($amount, $positions)
    {
        $positionsSumm = $this->transformNumber(array_sum(array_column($positions, 'itemAmount')), 0);
        $discount = $this->transformNumber($positionsSumm - $amount, 0);
        return $discount;
    }

    private function transformNumber($value, $count = 2)
    {
        $count = $count ? $count : 2;
        return round($value, $count);
    }

    public function getOrder()
    {
        return $this->arrOrder;
    }

    public function getProducts()
    {
        return $this->cashBasket;
    }

    public function getBasketResult()
    {
//        $order;
        foreach ($this->arrOrder['basket'] as $key => $item) {
            $positionId = $key + 1;
            $order[$key] = array(
                'positionId' => $positionId,
                'name' => $item['name'],
                'quantity' => array(
                    'value' => $item['count'],
                    'measure' => $item['arrGate']['quantity']['measure'],
                ),
                'itemAmount' => $this->transformNumber($item['priceDiscount'] * 100, 0),
                'itemCode' => $item['id'] . "." . $positionId,
                'itemPrice' => $this->transformNumber($item['priceBaseDiscount'] * 100, 0),
                'tax' => array(
                    'taxType' => $item['arrGate']['tax']['taxType'],
                ),
            );

            if (isset($item['itemAttributes'])) {
                $order[$key]['itemAttributes'] = $item['itemAttributes'];
            }
        }
        return $order;

    }

    public function getRecountSumm()
    {
        return $this->arrRecountSumm;
    }

    public function setOrderDiscount($value)
    {
        $this->arrOrder['discount'] = $this->transformNumber($value);
    }

    public function calculateDiscount($amount, $discount)
    {
        $result = $this->transformNumber($discount * $amount / 100, 0);
        return $result;
    }

    public function normalizeItems($gatePositions)
    {

        foreach ($gatePositions as $key => $item) {
            $arrProduct = array(
                'id' => $item['positionId'],
                'name' => $item['name'],
                'priceBase' => $item['itemPrice'],
                'count' => $item['quantity']['value'],
                'arrGate' => $item
            );
            $this->addProduct($arrProduct);

        }

        $this->updateOrder();

        $arrResult = array();
        foreach ($this->arrOrder['basket'] as $key => $item) {
            $positionId = $key + 1;
            $arrResult[$key] = $item['arrGate'];
            $arrResult[$key]['positionId'] = $positionId;
            $arrResult[$key]['itemCode'] .= "." . $positionId;
            $arrResult[$key]['itemPrice'] = $this->transformNumber($item['priceBaseDiscount'], 0);
            $arrResult[$key]['itemAmount'] = $this->transformNumber($item['priceDiscount'], 0);
            $arrResult[$key]['quantity']['value'] = $item['count'];

            if (isset($item['itemAttributes'])) {
                $order[$key]['itemAttributes'] = $item['itemAttributes'];
            }
        }
        return $arrResult;
    }

    public function addProduct($product)
    {
        $product['priceAmount'] = $product['count'] * $product['priceBase'];
        $this->cashBasket[] = $product;
    }

    public function updateOrder()
    {
        $this->provideProductsToOrder();
        $this->generateReceiptAmount();
        $this->generatePositionsDiscount();
        $this->recountReceiptAmount();
        $this->finalCheck();
    }

    private function provideProductsToOrder()
    {
        $this->arrOrder['basket'] = $this->cashBasket;
    }

    private function generateReceiptAmount()
    {
        $summ = 0;
        foreach ($this->arrOrder['basket'] as $key => $item) {
            $summ += $this->transformNumber($item['priceBase'] * $item['count']);
        }
        $this->arrOrder['amount'] = $this->transformNumber($summ);
        if ($this->arrOrder['amount'] < $this->arrOrder['discount']) {
            $this->arrOrder['discount'] = $this->arrOrder['amount'];
        }


    }

    private function generatePositionsDiscount()
    {
        $difference = $this->arrOrder['amount'] - $this->arrOrder['discount'];
        if ($difference > 1) {
            foreach ($this->arrOrder['basket'] as $key => $item) {
                $item['priceAmount'] = $this->transformNumber($item['priceBase'] * $item['count']);
                $item['percentDiscount'] = $this->onPositionDiscountPercent($item);
                $item['priceBaseDiscount'] = $this->transformBasePrice($item);
                $item['discount'] = $this->onPositionDiscount($item);
                $item['priceDiscount'] = $this->onPositionDiscountPrice($item);

                $this->arrOrder['basket'][$key] = $item;
            }
        } else {
            foreach ($this->arrOrder['basket'] as $key => $item) {
                $item['priceAmount'] = $this->transformNumber($item['priceBase'] * $item['count']);
                $item['percentDiscount'] = 0;
                $item['priceBaseDiscount'] = 0;
                $item['discount'] = $item['priceAmount'];
                $item['priceDiscount'] = $item['priceAmount'] - $item['discount'];

                $this->arrOrder['basket'][$key] = $item;
            }
        }
    }

    private function onPositionDiscountPercent($item)
    {
        $price = $item['priceAmount'];
        return $this->transformNumber((100 / $this->arrOrder['amount'] * $price), 4);
    }

    private function transformBasePrice($item)
    {
        $result = ($this->arrOrder['discount'] * $item['percentDiscount'] / 100) / $item['count'];
        $result = $this->transformNumber($item['priceBase'] - $result);
        if ($result < 0) {
            $result = 0;
        }
        return $result;
    }

    private function onPositionDiscount($item)
    {
        $result = $this->transformNumber(($item['priceBase'] - $item['priceBaseDiscount']) * $item['count']);
        return $result;
    }

    private function onPositionDiscountPrice($item)
    {
        $result = $this->transformNumber($item['priceBaseDiscount'] * $item['count']);
        if ($result < 0) {
            $result = 0;
        }
        return $result;
    }

    public function recountReceiptAmount()
    {
        $summ = array(
            'priceAmount' => 0,
            'priceDiscount' => 0,
            'discount' => 0
        );
        foreach ($this->arrOrder['basket'] as $key => $item) {
            $summ['priceAmount'] += $item['priceAmount'];
            $summ['priceDiscount'] += $item['priceBaseDiscount'] * $item['count'];
            $summ['discount'] += $item['discount'];
        }
        $this->arrRecountSumm['priceAmount'] = $this->transformNumber($summ['priceAmount']);
        $this->arrRecountSumm['priceDiscount'] = $this->transformNumber($summ['priceDiscount']);
        $this->arrRecountSumm['discount'] = $this->transformNumber($summ['discount']);

    }

    private function finalCheck()
    {
        $baseAmount = $this->transformNumber($this->arrOrder['amount'] - $this->arrOrder['discount']);
        $finalAmount = $this->arrRecountSumm['priceDiscount'];

        $this->faultPrice = $this->transformNumber($baseAmount - $finalAmount);
        if ($this->faultPrice != 0) {
            $transformMode = $this->transformBasket();
            if ($transformMode !== 'fractionPosition') {
                $this->generatePositionsDiscount();
                $this->recountReceiptAmount();
                $this->equalizePositionDiscount();
            }
            $this->recountReceiptAmount();
        }
    }

    private function transformBasket()
    {
        $onePositionFind = false;
        $positionSeparateIndex = -1;
        $basket = $this->arrOrder['basket'];
        $transformMode = 'none';
        $this->equalPosition = -1;

        if (count($basket) === 0) {
            return false;
        }

        foreach ($basket as $key => $position) {
            if ($position['count'] > 1) {
                $positionSeparateIndex = $key;
            }
            if ($position['count'] == 1) {
                $this->equalPosition = $key;
                $onePositionFind = true;
            }
        }

        if (!$onePositionFind && $positionSeparateIndex >= 0) {
            $transformMode = 'onePosition';
        } else if (!$onePositionFind) {
            $positionSeparateIndex = $this->findMaxCount();
            $transformMode = 'fractionPosition';
        }
        $this->splitPosition($transformMode, $positionSeparateIndex);
        return $transformMode;
    }

    private function findMaxCount()
    {
        $maxValue = max(array_column($this->arrOrder['basket'], 'count'));
        $result = array_search($maxValue, array_column($this->arrOrder['basket'], 'count'));
        return $result;
    }

    private function splitPosition($mode, $indexSeparate)
    {
        if ($mode === 'none') {
            return false;
        }
        $newIndex = count($this->arrOrder['basket']);
        $separatePosition = $this->arrOrder['basket'][$indexSeparate];

        if ($mode === 'onePosition') {
            $this->arrOrder['basket'][$indexSeparate]['count'] = $this->transformNumber($separatePosition['count'] - 1, 3);
            array_push($this->arrOrder['basket'], $separatePosition);
            $this->equalPosition = $newIndex;
            $this->arrOrder['basket'][$newIndex] = $separatePosition;
            $this->arrOrder['basket'][$newIndex]['count'] = 1;
        } else if ($mode === 'fractionPosition') {
            $needPositionPrice = $this->transformNumber($separatePosition['priceDiscount'] + $this->faultPrice);
            $originalCount = $separatePosition['count'];
            $success = false;
            $vishPrice = $this->transformNumber($needPositionPrice / $originalCount);

            $separateObject = array();
            $separateObject['needSumm'] = $needPositionPrice;
            $separateObject['oldPositionCount'] = $this->transformNumber($originalCount / 2, 3);
            $separateObject['newPositionCount'] = $this->transformNumber($originalCount - $separateObject['oldPositionCount'], 3);


            for ($toIndex = 0; $toIndex < 5; $toIndex++) {
                $separateObject['oldPositionCount'] = $this->transformNumber($separateObject['oldPositionCount'] - 0.001, 3);
                $separateObject['newPositionCount'] = $this->transformNumber($separateObject['newPositionCount'] + 0.001, 3);
                $separateObject['oldPositionPrice'] = $this->transformNumber($separateObject['oldPositionCount'] * $vishPrice);
                $separateObject['newPositionPrice'] = $this->transformNumber($separateObject['newPositionCount'] * $vishPrice);
                $separateObject['oldPositionVishPrice'] = $this->transformNumber($separateObject['oldPositionPrice'] / $separateObject['oldPositionCount']);
                $separateObject['newPositionVishPrice'] = $this->transformNumber($separateObject['newPositionPrice'] / $separateObject['newPositionCount']);
                $separateObject['recountSumm'] = $this->transformNumber($separateObject['oldPositionPrice'] + $separateObject['newPositionPrice']);
                if ($separateObject['recountSumm'] == $separateObject['needSumm']) {
                    $success = true;
                    break;
                }
            }
            if (!$success) {
                $res = $this->transformNumber(($separateObject['newPositionPrice'] - ($separateObject['recountSumm'] - $separateObject['needSumm'])) / $separateObject['newPositionCount']);
                $separateObject['newPositionPrice'] = $this->transformNumber($res * $separateObject['newPositionCount']);
                $separateObject['recountSumm'] = $this->transformNumber($separateObject['oldPositionPrice'] + $separateObject['newPositionPrice']);
                if ($separateObject['recountSumm'] === $separateObject['needSumm']) {
                    $success = true;
                }
            }
            if ($success) {
                $separatePosition['count'] = $separateObject['oldPositionCount'];
                $separatePosition['priceBaseDiscount'] = $separateObject['oldPositionVishPrice'];
                $separatePosition['priceAmount'] = $this->transformNumber($separatePosition['count'] * $separatePosition['priceBase']);
                $separatePosition['priceDiscount'] = $separateObject['oldPositionPrice'];
                $separatePosition['discount'] = $this->transformNumber($separatePosition['priceAmount'] - $separatePosition['priceDiscount']);
                $this->arrOrder['basket'][$indexSeparate] = $separatePosition;
                array_push($this->arrOrder['basket'], $separatePosition);

                $newPosition = $this->arrOrder['basket'][$newIndex];
                $newPosition['count'] = $separateObject['newPositionCount'];
                $newPosition['priceAmount'] = $this->transformNumber($newPosition['count'] * $newPosition['priceBase']);
                $newPosition['priceBaseDiscount'] = $separateObject['newPositionVishPrice'];
                $newPosition['priceDiscount'] = $separateObject['newPositionPrice'];
                $newPosition['discount'] = $this->transformNumber($newPosition['priceAmount'] - $newPosition['priceDiscount']);
                $this->arrOrder['basket'][$newIndex] = $newPosition;

            } else {

            }
        }
    }

    private function equalizePositionDiscount()
    {

        if ($this->equalPosition < 0) {
            return false;
        }
        $equalPosition = $this->arrOrder['basket'][$this->equalPosition];
        $baseSumm = $this->arrOrder['amount'] - $this->arrOrder['discount'];
        $recountSumm = $this->arrRecountSumm['priceDiscount'];
//        $remain = 0;

        if ($baseSumm != $recountSumm) {
            $remain = $this->transformNumber($baseSumm - $recountSumm);
            $this->arrOrder['basket'][$this->equalPosition]['priceBaseDiscount'] = $this->transformNumber($equalPosition['priceBaseDiscount'] + $remain);
            $this->arrOrder['basket'][$this->equalPosition]['priceDiscount'] = $equalPosition['priceBaseDiscount'];
            $this->arrOrder['basket'][$this->equalPosition]['discount'] = $this->transformNumber($equalPosition['discount'] - $remain);
            $this->arrOrder['basket'][$this->equalPosition]['priceDiscount'] = $this->arrOrder['basket'][$this->equalPosition]['priceBaseDiscount'];
        }
    }

    public function getResultAmount()
    {
        return $this->transformNumber($this->arrRecountSumm['priceDiscount'], 0);
    }

    public function test($message = '')
    {
        echo "<pre>";
        print_r($this->arrOrder);
        print_r($this->arrRecountSumm);
        echo "</pre>";
    }

    private function priceTransform()
    {
        $this->arrOrder['discount'] = $this->arrOrder['discount'] * 100;
        foreach ($this->arrOrder['basket'] as $key => $item) {
            $item['discount'] = $item['discount'] * 100;
            $item['priceAmount'] = $item['priceAmount'] * 100;
            $item['priceBase'] = $item['priceBase'] * 100;
            $item['priceDiscount'] = $item['priceDiscount'] * 100;
            $this->arrOrder['basket'][$key] = $item;
        }
    }

}