<?php
/*
* 2007-2016 PrestaShop
*
* NOTICE OF LICENSE
*
* This source file is subject to the Open Software License (OSL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/osl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2016 PrestaShop SA
*  @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*/

/**
 * StockManager : implementation of StockManagerInterface
 * @since 1.5.0
 */
class StockManagerCore implements StockManagerInterface
{
    /**
     * @see StockManagerInterface::isAvailable()
     */
    public static function isAvailable()
    {
        // Default Manager : always available
        return true;
    }

    /**
     * @see StockManagerInterface::addProduct()
     *
     * @param int           $id_product
     * @param int           $id_product_attribute
     * @param Warehouse     $warehouse
     * @param int           $quantity
     * @param int           $id_stock_mvt_reason
     * @param float         $price_te
     * @param bool          $is_usable
     * @param int|null      $id_supply_order
     * @param Employee|null $employee
     *
     * @return bool
     * @throws PrestaShopException
     */
    public function addProduct(
        $id_product,
        $id_product_attribute = 0,
        Warehouse $warehouse,
        $quantity,
        $id_stock_mvt_reason,
        $price_te,
        $is_usable = true,
        $id_supply_order = null,
        $employee = null
    ) {
        if (!Validate::isLoadedObject($warehouse) || !$quantity || !$id_product) {
            return false;
        }

        $price_te = round((float)$price_te, 6);
        if ($price_te <= 0.0) {
            return false;
        }

        if (!StockMvtReason::exists($id_stock_mvt_reason)) {
            $id_stock_mvt_reason = Configuration::get('PS_STOCK_MVT_INC_REASON_DEFAULT');
        }

        $context = Context::getContext();

        $mvt_params = array(
            'id_stock' => null,
            'physical_quantity' => $quantity,
            'id_stock_mvt_reason' => $id_stock_mvt_reason,
            'id_supply_order' => $id_supply_order,
            'price_te' => $price_te,
            'last_wa' => null,
            'current_wa' => null,
            'id_employee' => (int)$context->employee->id ? (int)$context->employee->id : $employee->id,
            'employee_firstname' => $context->employee->firstname ? $context->employee->firstname : $employee->firstname,
            'employee_lastname' => $context->employee->lastname ? $context->employee->lastname : $employee->lastname,
            'sign' => 1
        );

        $stock_exists = false;

        // switch on MANAGEMENT_TYPE
        switch ($warehouse->management_type) {
            // case CUMP mode
            case 'WA':

                $stock_collection = $this->getStockCollection($id_product, $id_product_attribute, $warehouse->id);

                // if this product is already in stock
                if (count($stock_collection) > 0) {
                    $stock_exists = true;

                    /** @var Stock $stock */
                    // for a warehouse using WA, there is one and only one stock for a given product
                    $stock = $stock_collection->current();

                    // calculates WA price
                    $last_wa = $stock->price_te;
                    $current_wa = $this->calculateWA($stock, $quantity, $price_te);

                    $mvt_params['id_stock'] = $stock->id;
                    $mvt_params['last_wa'] = $last_wa;
                    $mvt_params['current_wa'] = $current_wa;

                    $stock_params = array(
                        'physical_quantity' => ($stock->physical_quantity + $quantity),
                        'price_te' => $current_wa,
                        'usable_quantity' => ($is_usable ? ($stock->usable_quantity + $quantity) : $stock->usable_quantity),
                        'id_warehouse' => $warehouse->id,
                    );

                    // saves stock in warehouse
                    $stock->hydrate($stock_params);
                    $stock->update();
                } else {
                    // else, the product is not in sock

                    $mvt_params['last_wa'] = 0;
                    $mvt_params['current_wa'] = $price_te;
                }
            break;

            // case FIFO / LIFO mode
            case 'FIFO':
            case 'LIFO':

                $stock_collection = $this->getStockCollection($id_product, $id_product_attribute, $warehouse->id, $price_te);

                // if this product is already in stock
                if (count($stock_collection) > 0) {
                    $stock_exists = true;

                    /** @var Stock $stock */
                    // there is one and only one stock for a given product in a warehouse and at the current unit price
                    $stock = $stock_collection->current();

                    $stock_params = array(
                        'physical_quantity' => ($stock->physical_quantity + $quantity),
                        'usable_quantity' => ($is_usable ? ($stock->usable_quantity + $quantity) : $stock->usable_quantity),
                    );

                    // updates stock in warehouse
                    $stock->hydrate($stock_params);
                    $stock->update();

                    // sets mvt_params
                    $mvt_params['id_stock'] = $stock->id;
                }

            break;

            default:
                return false;
            break;
        }

        if (!$stock_exists) {
            $stock = new Stock();

            $stock_params = array(
                'id_product_attribute' => $id_product_attribute,
                'id_product' => $id_product,
                'physical_quantity' => $quantity,
                'price_te' => $price_te,
                'usable_quantity' => ($is_usable ? $quantity : 0),
                'id_warehouse' => $warehouse->id
            );

            // saves stock in warehouse
            $stock->hydrate($stock_params);
            $stock->add();
            $mvt_params['id_stock'] = $stock->id;
        }

        // saves stock mvt
        $stock_mvt = new StockMvt();
        $stock_mvt->hydrate($mvt_params);
        $stock_mvt->add();

        return true;
    }

    /**
     * @see StockManagerInterface::removeProduct()
     *
     * @param int           $id_product
     * @param int|null      $id_product_attribute
     * @param Warehouse     $warehouse
     * @param int           $quantity
     * @param int           $id_stock_mvt_reason
     * @param bool          $is_usable
     * @param int|null      $id_order
     * @param int           $ignore_pack
     * @param Employee|null $employee
     *
     * @return array
     * @throws PrestaShopException
     */
    public function removeProduct($id_product,
                                  $id_product_attribute = null,
                                  Warehouse $warehouse,
                                  $quantity,
                                  $id_stock_mvt_reason,
                                  $is_usable = true,
                                  $id_order = null,
                                  $ignore_pack = 0,
                                  $employee = null)
    {
        $return = array();

        if (!Validate::isLoadedObject($warehouse) || !$quantity || !$id_product) {
            return $return;
        }

        if (!StockMvtReason::exists($id_stock_mvt_reason)) {
            $id_stock_mvt_reason = Configuration::get('PS_STOCK_MVT_DEC_REASON_DEFAULT');
        }

        $context = Context::getContext();

        // Special case of a pack
        if (Pack::isPack((int)$id_product) && !$ignore_pack) {
            if (Validate::isLoadedObject($product = new Product((int)$id_product))) {
                // Gets items
                if ($product->pack_stock_type == 1 || $product->pack_stock_type == 2 || ($product->pack_stock_type == 3 && Configuration::get('PS_PACK_STOCK_TYPE') > 0)) {
                    $products_pack = Pack::getItems((int)$id_product, (int)Configuration::get('PS_LANG_DEFAULT'));
                    // Foreach item
                    foreach ($products_pack as $product_pack) {
                        if ($product_pack->advanced_stock_management == 1) {
                            $product_warehouses = Warehouse::getProductWarehouseList($product_pack->id, $product_pack->id_pack_product_attribute);
                            $warehouse_stock_found = false;
                            foreach ($product_warehouses as $product_warehouse) {
                                if (!$warehouse_stock_found) {
                                    if (Warehouse::exists($product_warehouse['id_warehouse'])) {
                                        $current_warehouse = new Warehouse($product_warehouse['id_warehouse']);
                                        $return[] = $this->removeProduct($product_pack->id, $product_pack->id_pack_product_attribute, $current_warehouse, $product_pack->pack_quantity * $quantity, $id_stock_mvt_reason, $is_usable, $id_order);

                                        // The product was found on this warehouse. Stop the stock searching.
                                        $warehouse_stock_found = !empty($return[count($return) - 1]);
                                    }
                                }
                            }
                        }
                    }
                }
                if ($product->pack_stock_type == 0 || $product->pack_stock_type == 2 ||
                    ($product->pack_stock_type == 3 && (Configuration::get('PS_PACK_STOCK_TYPE') == 0 || Configuration::get('PS_PACK_STOCK_TYPE') == 2))) {
                    $return = array_merge($return, $this->removeProduct($id_product, $id_product_attribute, $warehouse, $quantity, $id_stock_mvt_reason, $is_usable, $id_order, 1));
                }
            } else {
                return false;
            }
        } else {
            // gets total quantities in stock for the current product
            $physical_quantity_in_stock = (int)$this->getProductPhysicalQuantities($id_product, $id_product_attribute, array($warehouse->id), false);
            $usable_quantity_in_stock = (int)$this->getProductPhysicalQuantities($id_product, $id_product_attribute, array($warehouse->id), true);

            // check quantity if we want to decrement unusable quantity
            if (!$is_usable) {
                $quantity_in_stock = $physical_quantity_in_stock - $usable_quantity_in_stock;
            } else {
                $quantity_in_stock = $usable_quantity_in_stock;
            }

            // checks if it's possible to remove the given quantity
            if ($quantity_in_stock < $quantity) {
                return $return;
            }

            $stock_collection = $this->getStockCollection($id_product, $id_product_attribute, $warehouse->id);
            $stock_collection->getAll();

            // check if the collection is loaded
            if (count($stock_collection) <= 0) {
                return $return;
            }

            $stock_history_qty_available = array();
            $mvt_params = array();
            $stock_params = array();
            $quantity_to_decrement_by_stock = array();
            $global_quantity_to_decrement = $quantity;

            // switch on MANAGEMENT_TYPE
            switch ($warehouse->management_type) {
                // case CUMP mode
                case 'WA':
                    /** @var Stock $stock */
                    // There is one and only one stock for a given product in a warehouse in this mode
                    $stock = $stock_collection->current();

                    $mvt_params = array(
                        'id_stock' => $stock->id,
                        'physical_quantity' => $quantity,
                        'id_stock_mvt_reason' => $id_stock_mvt_reason,
                        'id_order' => $id_order,
                        'price_te' => $stock->price_te,
                        'last_wa' => $stock->price_te,
                        'current_wa' => $stock->price_te,
                        'id_employee' => (int)$context->employee->id ? (int)$context->employee->id : $employee->id,
                        'employee_firstname' => $context->employee->firstname ? $context->employee->firstname : $employee->firstname,
                        'employee_lastname' => $context->employee->lastname ? $context->employee->lastname : $employee->lastname,
                        'sign' => -1
                    );
                    $stock_params = array(
                        'physical_quantity' => ($stock->physical_quantity - $quantity),
                        'usable_quantity' => ($is_usable ? ($stock->usable_quantity - $quantity) : $stock->usable_quantity)
                    );

                    // saves stock in warehouse
                    $stock->hydrate($stock_params);
                    $stock->update();

                    // saves stock mvt
                    $stock_mvt = new StockMvt();
                    $stock_mvt->hydrate($mvt_params);
                    $stock_mvt->save();

                    $return[$stock->id]['quantity'] = $quantity;
                    $return[$stock->id]['price_te'] = $stock->price_te;

                break;

                case 'LIFO':
                case 'FIFO':

                    // for each stock, parse its mvts history to calculate the quantities left for each positive mvt,
                    // according to the instant available quantities for this stock
                    foreach ($stock_collection as $stock) {
                        /** @var Stock $stock */
                        $left_quantity_to_check = $stock->physical_quantity;
                        if ($left_quantity_to_check <= 0) {
                            continue;
                        }

                        $resource = Db::getInstance(_PS_USE_SQL_SLAVE_)->query('
							SELECT sm.`id_stock_mvt`, sm.`date_add`, sm.`physical_quantity`,
								IF ((sm2.`physical_quantity` is null), sm.`physical_quantity`, (sm.`physical_quantity` - SUM(sm2.`physical_quantity`))) as qty
							FROM `'._DB_PREFIX_.'stock_mvt` sm
							LEFT JOIN `'._DB_PREFIX_.'stock_mvt` sm2 ON sm2.`referer` = sm.`id_stock_mvt`
							WHERE sm.`sign` = 1
							AND sm.`id_stock` = '.(int)$stock->id.'
							GROUP BY sm.`id_stock_mvt`
							ORDER BY sm.`date_add` DESC'
                        );

                        while ($row = Db::getInstance()->nextRow($resource)) {
                            // break - in FIFO mode, we have to retreive the oldest positive mvts for which there are left quantities
                            if ($warehouse->management_type == 'FIFO') {
                                if ($row['qty'] == 0) {
                                    break;
                                }
                            }

                            // converts date to timestamp
                            $date = new DateTime($row['date_add']);
                            $timestamp = $date->format('U');

                            // history of the mvt
                            $stock_history_qty_available[$timestamp] = array(
                                'id_stock' => $stock->id,
                                'id_stock_mvt' => (int)$row['id_stock_mvt'],
                                'qty' => (int)$row['qty']
                            );

                            // break - in LIFO mode, checks only the necessary history to handle the global quantity for the current stock
                            if ($warehouse->management_type == 'LIFO') {
                                $left_quantity_to_check -= (int)$row['qty'];
                                if ($left_quantity_to_check <= 0) {
                                    break;
                                }
                            }
                        }
                    }

                    if ($warehouse->management_type == 'LIFO') {
                        // orders stock history by timestamp to get newest history first
                        krsort($stock_history_qty_available);
                    } else {
                        // orders stock history by timestamp to get oldest history first
                        ksort($stock_history_qty_available);
                    }

                    // checks each stock to manage the real quantity to decrement for each of them
                    foreach ($stock_history_qty_available as $entry) {
                        if ($entry['qty'] >= $global_quantity_to_decrement) {
                            $quantity_to_decrement_by_stock[$entry['id_stock']][$entry['id_stock_mvt']] = $global_quantity_to_decrement;
                            $global_quantity_to_decrement = 0;
                        } else {
                            $quantity_to_decrement_by_stock[$entry['id_stock']][$entry['id_stock_mvt']] = $entry['qty'];
                            $global_quantity_to_decrement -= $entry['qty'];
                        }

                        if ($global_quantity_to_decrement <= 0) {
                            break;
                        }
                    }

                    // for each stock, decrements it and logs the mvts
                    foreach ($stock_collection as $stock) {
                        if (array_key_exists($stock->id, $quantity_to_decrement_by_stock) && is_array($quantity_to_decrement_by_stock[$stock->id])) {
                            $total_quantity_for_current_stock = 0;

                            foreach ($quantity_to_decrement_by_stock[$stock->id] as $id_mvt_referrer => $qte) {
                                $mvt_params = array(
                                    'id_stock' => $stock->id,
                                    'physical_quantity' => $qte,
                                    'id_stock_mvt_reason' => $id_stock_mvt_reason,
                                    'id_order' => $id_order,
                                    'price_te' => $stock->price_te,
                                    'sign' => -1,
                                    'referer' => $id_mvt_referrer,
                                    'id_employee' => (int)$context->employee->id ? (int)$context->employee->id : $employee->id,
                                );

                                // saves stock mvt
                                $stock_mvt = new StockMvt();
                                $stock_mvt->hydrate($mvt_params);
                                $stock_mvt->save();

                                $total_quantity_for_current_stock += $qte;
                            }

                            $stock_params = array(
                                'physical_quantity' => ($stock->physical_quantity - $total_quantity_for_current_stock),
                                'usable_quantity' => ($is_usable ? ($stock->usable_quantity - $total_quantity_for_current_stock) : $stock->usable_quantity)
                            );

                            $return[$stock->id]['quantity'] = $total_quantity_for_current_stock;
                            $return[$stock->id]['price_te'] = $stock->price_te;

                            // saves stock in warehouse
                            $stock->hydrate($stock_params);
                            $stock->update();
                        }
                    }
                break;
            }

            if (Pack::isPacked($id_product, $id_product_attribute)) {
                $packs = Pack::getPacksContainingItem($id_product, $id_product_attribute, (int)Configuration::get('PS_LANG_DEFAULT'));
                foreach($packs as $pack) {
                    // Decrease stocks of the pack only if pack is in linked stock mode (option called 'Decrement both')
                    if (!((int)$pack->pack_stock_type == 2) &&
                        !((int)$pack->pack_stock_type == 3 && (int)Configuration::get('PS_PACK_STOCK_TYPE') == 2)
                        ) {
                        continue;
                    }

                    // Decrease stocks of the pack only if there is not enough items to constituate the actual pack stocks.
                    
                    // How many packs can be constituated with the remaining product stocks
                    $quantity_by_pack = $pack->pack_item_quantity;
                    $stock_available_quantity = $quantity_in_stock - $quantity;
                    $max_pack_quantity = max(array(0, floor($stock_available_quantity / $quantity_by_pack)));
                    $quantity_delta = Pack::getQuantity($pack->id) - $max_pack_quantity;

                    if ($pack->advanced_stock_management == 1 && $quantity_delta > 0) {
                        $product_warehouses = Warehouse::getPackWarehouses($pack->id);
                        $warehouse_stock_found = false;
                        foreach ($product_warehouses as $product_warehouse) {

                            if (!$warehouse_stock_found) {
                                if (Warehouse::exists($product_warehouse)) {
                                    $current_warehouse = new Warehouse($product_warehouse);
                                    $return[] = $this->removeProduct($pack->id, null, $current_warehouse, $quantity_delta, $id_stock_mvt_reason, $is_usable, $id_order, 1);
                                    // The product was found on this warehouse. Stop the stock searching.
                                    $warehouse_stock_found = !empty($return[count($return) - 1]);
                                }
                            }
                        }
                    }
                }
            }
            
            
        }
        


        // if we remove a usable quantity, exec hook
        if ($is_usable) {
            Hook::exec('actionProductCoverage',
                    array(
                        'id_product' => $id_product,
                        'id_product_attribute' => $id_product_attribute,
                        'warehouse' => $warehouse
                    )
            );
        }

        return $return;
    }

    /**
     * @see StockManagerInterface::getProductPhysicalQuantities()
     */
    public function getProductPhysicalQuantities($id_product, $id_product_attribute, $ids_warehouse = null, $usable = false)
    {
        if (!is_null($ids_warehouse)) {
            // in case $ids_warehouse is not an array
            if (!is_array($ids_warehouse)) {
                $ids_warehouse = array($ids_warehouse);
            }

            // casts for security reason
            $ids_warehouse = array_map('intval', $ids_warehouse);
            if (!count($ids_warehouse)) {
                return 0;
            }
        } else {
            $ids_warehouse = array();
        }

        $query = new DbQuery();
        $query->select('SUM('.($usable ? 's.usable_quantity' : 's.physical_quantity').')');
        $query->from('stock', 's');
        $query->where('s.id_product = '.(int)$id_product);
        if (0 != $id_product_attribute) {
            $query->where('s.id_product_attribute = '.(int)$id_product_attribute);
        }

        if (count($ids_warehouse)) {
            $query->where('s.id_warehouse IN('.implode(', ', $ids_warehouse).')');
        }

        return (int)Db::getInstance(_PS_USE_SQL_SLAVE_)->getValue($query);
    }

    /**
     * @see StockManagerInterface::getProductRealQuantities()
     */
    public function getProductRealQuantities($id_product, $id_product_attribute, $ids_warehouse = null, $usable = false)
    {
        if (!is_null($ids_warehouse)) {
            // in case $ids_warehouse is not an array
            if (!is_array($ids_warehouse)) {
                $ids_warehouse = array($ids_warehouse);
            }

            // casts for security reason
            $ids_warehouse = array_map('intval', $ids_warehouse);
        }

        $client_orders_qty = 0;

        // check if product is present in a pack
        if (!Pack::isPack($id_product) && $in_pack = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS(
            'SELECT id_product_pack, quantity FROM '._DB_PREFIX_.'pack
			WHERE id_product_item = '.(int)$id_product.'
			AND id_product_attribute_item = '.($id_product_attribute ? (int)$id_product_attribute : '0'))) {
            foreach ($in_pack as $value) {
                if (Validate::isLoadedObject($product = new Product((int)$value['id_product_pack'])) &&
                    ($product->pack_stock_type == 1 || $product->pack_stock_type == 2 || ($product->pack_stock_type == 3 && Configuration::get('PS_PACK_STOCK_TYPE') > 0))) {
                    $query = new DbQuery();
                    $query->select('od.product_quantity, od.product_quantity_refunded, pk.quantity');
                    $query->from('order_detail', 'od');
                    $query->leftjoin('orders', 'o', 'o.id_order = od.id_order');
                    $query->where('od.product_id = '.(int)$value['id_product_pack']);
                    $query->leftJoin('order_history', 'oh', 'oh.id_order = o.id_order AND oh.id_order_state = o.current_state');
                    $query->leftJoin('order_state', 'os', 'os.id_order_state = oh.id_order_state');
                    $query->leftJoin('pack', 'pk', 'pk.id_product_item = '.(int)$id_product.' AND pk.id_product_attribute_item = '.($id_product_attribute ? (int)$id_product_attribute : '0').' AND id_product_pack = od.product_id');
                    $query->where('os.shipped != 1');
                    $query->where('o.valid = 1 OR (os.id_order_state != '.(int)Configuration::get('PS_OS_ERROR').'
								   AND os.id_order_state != '.(int)Configuration::get('PS_OS_CANCELED').')');
                    $query->groupBy('od.id_order_detail');
                    if (count($ids_warehouse)) {
                        $query->where('od.id_warehouse IN('.implode(', ', $ids_warehouse).')');
                    }
                    $res = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($query);
                    if (count($res)) {
                        foreach ($res as $row) {
                            $client_orders_qty += ($row['product_quantity'] - $row['product_quantity_refunded']) * $row['quantity'];
                        }
                    }
                }
            }
        }

        // skip if product is a pack without
        if (!Pack::isPack($id_product) || (Pack::isPack($id_product) && Validate::isLoadedObject($product = new Product((int)$id_product))
            && $product->pack_stock_type == 0 || $product->pack_stock_type == 2 ||
                    ($product->pack_stock_type == 3 && (Configuration::get('PS_PACK_STOCK_TYPE') == 0 || Configuration::get('PS_PACK_STOCK_TYPE') == 2)))) {
            // Gets client_orders_qty
            $query = new DbQuery();
            $query->select('od.product_quantity, od.product_quantity_refunded');
            $query->from('order_detail', 'od');
            $query->leftjoin('orders', 'o', 'o.id_order = od.id_order');
            $query->where('od.product_id = '.(int)$id_product);
            if (0 != $id_product_attribute) {
                $query->where('od.product_attribute_id = '.(int)$id_product_attribute);
            }
            $query->leftJoin('order_history', 'oh', 'oh.id_order = o.id_order AND oh.id_order_state = o.current_state');
            $query->leftJoin('order_state', 'os', 'os.id_order_state = oh.id_order_state');
            $query->where('os.shipped != 1');
            $query->where('o.valid = 1 OR (os.id_order_state != '.(int)Configuration::get('PS_OS_ERROR').'
						   AND os.id_order_state != '.(int)Configuration::get('PS_OS_CANCELED').')');
            $query->groupBy('od.id_order_detail');
            if (count($ids_warehouse)) {
                $query->where('od.id_warehouse IN('.implode(', ', $ids_warehouse).')');
            }
            $res = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($query);
            if (count($res)) {
                foreach ($res as $row) {
                    $client_orders_qty += ($row['product_quantity'] - $row['product_quantity_refunded']);
                }
            }
        }
        // Gets supply_orders_qty
        $query = new DbQuery();

        $query->select('sod.quantity_expected, sod.quantity_received');
        $query->from('supply_order', 'so');
        $query->leftjoin('supply_order_detail', 'sod', 'sod.id_supply_order = so.id_supply_order');
        $query->leftjoin('supply_order_state', 'sos', 'sos.id_supply_order_state = so.id_supply_order_state');
        $query->where('sos.pending_receipt = 1');
        $query->where('sod.id_product = '.(int)$id_product.' AND sod.id_product_attribute = '.(int)$id_product_attribute);
        if (!is_null($ids_warehouse) && count($ids_warehouse)) {
            $query->where('so.id_warehouse IN('.implode(', ', $ids_warehouse).')');
        }

        $supply_orders_qties = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($query);

        $supply_orders_qty = 0;
        foreach ($supply_orders_qties as $qty) {
            if ($qty['quantity_expected'] > $qty['quantity_received']) {
                $supply_orders_qty += ($qty['quantity_expected'] - $qty['quantity_received']);
            }
        }

        // Gets {physical OR usable}_qty
        $qty = $this->getProductPhysicalQuantities($id_product, $id_product_attribute, $ids_warehouse, $usable);

        //real qty = actual qty in stock - current client orders + current supply orders
        return ($qty - $client_orders_qty + $supply_orders_qty);
    }

    /**
     * @see StockManagerInterface::transferBetweenWarehouses()
     */
    public function transferBetweenWarehouses($id_product,
                                              $id_product_attribute,
                                              $quantity,
                                              $id_warehouse_from,
                                              $id_warehouse_to,
                                              $usable_from = true,
                                              $usable_to = true)
    {
        // Checks if this transfer is possible
        if ($this->getProductPhysicalQuantities($id_product, $id_product_attribute, array($id_warehouse_from), $usable_from) < $quantity) {
            return false;
        }

        if ($id_warehouse_from == $id_warehouse_to && $usable_from == $usable_to) {
            return false;
        }

        // Checks if the given warehouses are available
        $warehouse_from = new Warehouse($id_warehouse_from);
        $warehouse_to = new Warehouse($id_warehouse_to);
        if (!Validate::isLoadedObject($warehouse_from) ||
            !Validate::isLoadedObject($warehouse_to)) {
            return false;
        }

        // Removes from warehouse_from
        $stocks = $this->removeProduct($id_product,
                                       $id_product_attribute,
                                       $warehouse_from,
                                       $quantity,
                                       Configuration::get('PS_STOCK_MVT_TRANSFER_FROM'),
                                       $usable_from);
        if (!count($stocks)) {
            return false;
        }

        // Adds in warehouse_to
        foreach ($stocks as $stock) {
            $price = $stock['price_te'];

            // convert product price to destination warehouse currency if needed
            if ($warehouse_from->id_currency != $warehouse_to->id_currency) {
                // First convert price to the default currency
                $price_converted_to_default_currency = Tools::convertPrice($price, $warehouse_from->id_currency, false);

                // Convert the new price from default currency to needed currency
                $price = Tools::convertPrice($price_converted_to_default_currency, $warehouse_to->id_currency, true);
            }

            if (!$this->addProduct($id_product,
                                   $id_product_attribute,
                                   $warehouse_to,
                                   $stock['quantity'],
                                   Configuration::get('PS_STOCK_MVT_TRANSFER_TO'),
                                   $price,
                                   $usable_to)) {
                return false;
            }
        }
        return true;
    }

    /**
     * @see StockManagerInterface::getProductCoverage()
     * Here, $coverage is a number of days
     * @return int number of days left (-1 if infinite)
     */
    public function getProductCoverage($id_product, $id_product_attribute, $coverage, $id_warehouse = null)
    {
        if (!$id_product_attribute) {
            $id_product_attribute = 0;
        }

        if ($coverage == 0 || !$coverage) {
            $coverage = 7;
        } // Week by default

        // gets all stock_mvt for the given coverage period
        $query = '
			SELECT SUM(view.quantity) as quantity_out
			FROM
			(	SELECT sm.`physical_quantity` as quantity
				FROM `'._DB_PREFIX_.'stock_mvt` sm
				LEFT JOIN `'._DB_PREFIX_.'stock` s ON (sm.`id_stock` = s.`id_stock`)
				LEFT JOIN `'._DB_PREFIX_.'product` p ON (p.`id_product` = s.`id_product`)
				'.Shop::addSqlAssociation('product', 'p').'
				LEFT JOIN `'._DB_PREFIX_.'product_attribute` pa ON (p.`id_product` = pa.`id_product`)
				'.Shop::addSqlAssociation('product_attribute', 'pa', false).'
				WHERE sm.`sign` = -1
				AND sm.`id_stock_mvt_reason` != '.Configuration::get('PS_STOCK_MVT_TRANSFER_FROM').'
				AND TO_DAYS("'.date('Y-m-d').' 00:00:00") - TO_DAYS(sm.`date_add`) <= '.(int)$coverage.'
				AND s.`id_product` = '.(int)$id_product.'
				AND s.`id_product_attribute` = '.(int)$id_product_attribute.
                ($id_warehouse ? ' AND s.`id_warehouse` = '.(int)$id_warehouse : '').'
				GROUP BY sm.`id_stock_mvt`
			) as view';

        $quantity_out = Db::getInstance(_PS_USE_SQL_SLAVE_)->getValue($query);
        if (!$quantity_out) {
            return -1;
        }

        $quantity_per_day = Tools::ps_round($quantity_out / $coverage);
        $physical_quantity = $this->getProductPhysicalQuantities($id_product,
                                                                 $id_product_attribute,
                                                                 ($id_warehouse ? array($id_warehouse) : null),
                                                                 true);
        $time_left = ($quantity_per_day == 0) ? (-1) : Tools::ps_round($physical_quantity / $quantity_per_day);

        return $time_left;
    }

    /**
     * For a given stock, calculates its new WA(Weighted Average) price based on the new quantities and price
     * Formula : (physicalStock * lastCump + quantityToAdd * unitPrice) / (physicalStock + quantityToAdd)
     *
     * @param Stock|PrestaShopCollection $stock
     * @param int $quantity
     * @param float $price_te
     * @return int WA
     */
    protected function calculateWA(Stock $stock, $quantity, $price_te)
    {
        return (float)Tools::ps_round(((($stock->physical_quantity * $stock->price_te) + ($quantity * $price_te)) / ($stock->physical_quantity + $quantity)), 6);
    }

    /**
     * For a given product, retrieves the stock collection
     *
     * @param int $id_product
     * @param int $id_product_attribute
     * @param int $id_warehouse Optional
     * @param int $price_te Optional
     * @return PrestaShopCollection Collection of Stock
     */
    protected function getStockCollection($id_product, $id_product_attribute, $id_warehouse = null, $price_te = null)
    {
        $stocks = new PrestaShopCollection('Stock');
        $stocks->where('id_product', '=', $id_product);
        $stocks->where('id_product_attribute', '=', $id_product_attribute);
        if ($id_warehouse) {
            $stocks->where('id_warehouse', '=', $id_warehouse);
        }
        if ($price_te) {
            $stocks->where('price_te', '=', $price_te);
        }

        return $stocks;
    }

    /**
     * For a given product, retrieves the stock in function of the delivery option
     *
     * @param int $id_product
     * @param int $id_product_attribute optional
     * @param array $delivery_option
     * @return int quantity
     */
    public static function getStockByCarrier($id_product = 0, $id_product_attribute = 0, $delivery_option = null)
    {
        if (!(int)$id_product || !is_array($delivery_option) || !is_int($id_product_attribute)) {
            return false;
        }

        $results = Warehouse::getWarehousesByProductId($id_product, $id_product_attribute);
        $stock_quantity = 0;

        foreach ($results as $result) {
            if (isset($result['id_warehouse']) && (int)$result['id_warehouse']) {
                $ws = new Warehouse((int)$result['id_warehouse']);
                $carriers = $ws->getWsCarriers();

                if (is_array($carriers) && !empty($carriers)) {
                    $stock_quantity += Db::getInstance(_PS_USE_SQL_SLAVE_)->getValue('SELECT SUM(s.`usable_quantity`) as quantity
						FROM '._DB_PREFIX_.'stock s
						LEFT JOIN '._DB_PREFIX_.'warehouse_carrier wc ON wc.`id_warehouse` = s.`id_warehouse`
						LEFT JOIN '._DB_PREFIX_.'carrier c ON wc.`id_carrier` = c.`id_reference`
						WHERE s.`id_product` = '.(int)$id_product.' AND s.`id_product_attribute` = '.(int)$id_product_attribute.' AND s.`id_warehouse` = '.$result['id_warehouse'].' AND c.`id_carrier` IN ('.rtrim($delivery_option[(int)Context::getContext()->cart->id_address_delivery], ',').') GROUP BY s.`id_product`');
                } else {
                    $stock_quantity += Db::getInstance(_PS_USE_SQL_SLAVE_)->getValue('SELECT SUM(s.`usable_quantity`) as quantity
						FROM '._DB_PREFIX_.'stock s
						WHERE s.`id_product` = '.(int)$id_product.' AND s.`id_product_attribute` = '.(int)$id_product_attribute.' AND s.`id_warehouse` = '.$result['id_warehouse'].' GROUP BY s.`id_product`');
                }
            }
        }

        return $stock_quantity;
    }
}
