<?php

namespace ADP\BaseVersion\Includes\Core\RuleProcessor;

use ADP\BaseVersion\Includes\Cache\CacheHelper;
use ADP\BaseVersion\Includes\Core\Cart\Cart;
use ADP\BaseVersion\Includes\Core\Cart\CartItem\Type\Basic\BasicCartItem;
use ADP\BaseVersion\Includes\Core\Cart\CartItem\Type\Base\CartItemAttributeEnum;
use ADP\BaseVersion\Includes\Core\Cart\CartItem\Type\Free\FreeCartItem;
use ADP\BaseVersion\Includes\Core\Cart\Notice;
use ADP\BaseVersion\Includes\Core\Rule\PackageRule;
use ADP\BaseVersion\Includes\Core\Rule\Rule;
use ADP\BaseVersion\Includes\Core\Rule\SingleItemRule;
use ADP\BaseVersion\Includes\Core\Rule\Structures\Discount;
use ADP\BaseVersion\Includes\Core\Rule\Structures\FreeCartItemChoices;
use ADP\BaseVersion\Includes\Core\Rule\Structures\Gift;
use ADP\BaseVersion\Includes\Core\RuleProcessor\ProductStock\ProductStockController;
use ADP\BaseVersion\Includes\Core\RuleProcessor\Structures\CartItemsCollection;
use ADP\BaseVersion\Includes\Core\RuleProcessor\Structures\CartSet;
use ADP\BaseVersion\Includes\Core\RuleProcessor\Structures\CartSetCollection;
use ADP\BaseVersion\Includes\Enums\GiftChoiceMethodEnum;
use ADP\BaseVersion\Includes\Enums\GiftChoiceTypeEnum;
use ADP\BaseVersion\Includes\Enums\GiftModeEnum;
use ADP\BaseVersion\Includes\WC\WcTaxFunctions;
use ADP\Factory;
use Exception;

defined('ABSPATH') or exit;

class GiftStrategy
{
    /**
     * @var Rule
     */
    protected $rule;

    /**
     * @var ProductStockController
     */
    protected $ruleUsedStock;

    /**
     * @var FreeCartItemChoicesSuitability
     */
    protected $freeItemChoicesSuitability;

    /**
     * @param Rule $rule
     * @param ProductStockController $ruleUsedStock
     */
    public function __construct($rule, $ruleUsedStock)
    {
        $this->rule          = $rule;
        $this->ruleUsedStock = $ruleUsedStock;

        /** @var FreeCartItemChoicesSuitability $freeCartItemChoicesSuitability */
        $this->freeItemChoicesSuitability = Factory::get("Core_RuleProcessor_FreeCartItemChoicesSuitability");
    }

    public function canGift()
    {
        return method_exists($this->rule, 'getGifts') && boolval($this->rule->getGifts());
    }

    public function canItemGifts()
    {
        return method_exists($this->rule, 'getItemGiftsCollection')
               && boolval($this->rule->getItemGiftsCollection()->asArray());
    }

    /**
     * TODO implement!
     * Not requires without frontend implementation
     *
     * @param Cart $cart
     */
    public function addGifts(&$cart)
    {
        $rule  = $this->rule;
        $gifts = $rule->getGifts();
    }

    /**
     * @param Cart $cart
     * @param CartItemsCollection $collection
     */
    public function addCartItemGifts(&$cart, $collection)
    {
        /** @var SingleItemRule $rule */
        $rule = $this->rule;

        $totalQty = floatval(0);

        /**
         * @var array $itemIndexes
         * Cheap solution to fetch product with which we add free product.
         * Needed for gifting products from collection.
         *
         * ItemIndexes is a list with items and indexes. Index in nutshell is number of attempt at which we begin to use item.
         * For example:
         *  We have 'single item' rule with collection 3 apple and 2 bananas and 1 orange.
         *  So, itemIndexes will be
         *      array(
         *          array( 'index' => 1, 'item' => apple ),
         *          array( 'index' => 4 (1 + qty of apple), 'item' => banana ),
         *          array( 'index' => 6 (1 + qty of apple + qty of bananas ), 'item' => orange ),
         *      )
         *  When we try to iterate on attempts, we get an item
         *  Attempt count | item
         *  1   | apple
         *  2   | apple
         *  3   | apple
         *  4   | banana
         *  5   | banana
         *  6   | orange
         */
        $itemIndexes = array();
        foreach ($collection->get_items() as $item) {
            $itemIndexes[] = array(
                'index' => $totalQty + 1,
                'item'  => $item,
            );
            $totalQty      += $item->getQty();
        }

        $attemptCount = 0;
        if ($rule->getItemGiftStrategy() === $rule::BASED_ON_LIMIT_STRATEGY) {
            $attemptCount = min($totalQty, $rule->getItemGiftLimit());
        } elseif (
            $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_EXCL_TAX_STRATEGY
            || $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_INCL_TAX_STRATEGY
        ) {
            if ($rule->getItemGiftSubtotalDivider()) {
                $inclTax = $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_INCL_TAX_STRATEGY;
                $tmpCart = clone $cart;
                foreach ($collection->get_items() as $item) {
                    $tmpCart->addToCart($item);
                }
                $itemsSubtotals = (new CartTotals($tmpCart))->getSubtotal($inclTax);
                $attemptCount   = intval($itemsSubtotals / $rule->getItemGiftSubtotalDivider());
            }
        }

        /** @var array<int, array<int,FreeCartItem>> $freeCartItemsByHash */
        $freeCartItemsByHash = array();

        $mapIsTmpItemsByHash = array();

        $maxAmountForGiftsLeft = $rule->getMaxAmountForGifts();
        if ($maxAmountForGiftsLeft !== null) {
            $maxAmountForGiftsLeft = (new WcTaxFunctions())->getBasePrice($maxAmountForGiftsLeft);
        }

        $index = 0;
        while ($index < $attemptCount) {
            $index++;
            $item = null;
            foreach ($itemIndexes as $key => $data) {
                if ($data['index'] <= $index) {
                    $item = $data['item'];
                }
            }

            if ( ! $item) {
                continue;
            }

            $giftIndex = 0;
            /** @var BasicCartItem $item */
            foreach ($rule->getItemGiftsCollection()->asArray() as $gift) {
                if ($gift->getQty() <= 0) {
                    continue;
                }

                $freeCartItemChoices = $this->convertGiftToFreeCartItemChoices($gift, array($item));
                $hash                = $freeCartItemChoices->generateHash($rule, $giftIndex, $gift);
                $mapIsTmpItemsByHash[$hash] = ($mapIsTmpItemsByHash[$hash] ?? false) || $item->hasAttr(CartItemAttributeEnum::TEMPORARY());

                if ($gift->isAllowToSelect()) {
                    continue;
                } else {
                    $this->processFreeItem(
                        $freeCartItemsByHash,
                        $hash,
                        $cart,
                        $freeCartItemChoices,
                        0.0,
                        $maxAmountForGiftsLeft
                    );
                }

                $giftIndex++;
            }
        }

        $customer = $cart->getContext()->getCustomer();

        foreach ($freeCartItemsByHash as $hash => $freeCartItems) {
            $removedFreeItems = $customer->getRemovedFreeItems($hash);

            foreach ($freeCartItems as $freeCartItem) {
                $deletedQty = $removedFreeItems->get($freeCartItem->hash());

                if ($freeCartItem->getQty() <= $deletedQty) {
                    $deletedQty = $freeCartItem->getQty();
                    $freeCartItem->setQty(0);
                } else {
                    $freeCartItem->setQty($freeCartItem->getQty() - $deletedQty);
                }

                $removedFreeItems->set($freeCartItem->hash(), $deletedQty);
                if($mapIsTmpItemsByHash[$hash] ?? false) {
                    $freeCartItem->addAttr($freeCartItem::ATTR_TEMP);
                }
                $cart->addToCart($freeCartItem);
            }
        }
    }

    /**
     * @param Gift $gift
     * @param array<int,BasicCartItem> $items
     *
     * @return FreeCartItemChoices
     */
    protected function convertGiftToFreeCartItemChoices($gift, $items)
    {
        $newGiftChoices = array();
        foreach ($gift->getChoices() as $giftChoice) {
            if ($giftChoice->getType()->getValue() === GiftChoiceTypeEnum::CLONE_ADJUSTED) {
                $newGiftChoice = clone $giftChoice;
                $newGiftChoice->setType(new GiftChoiceTypeEnum(GiftChoiceTypeEnum::PRODUCT));

                $values = array();
                foreach ($items as $item) {
                    $values[] = $item->getWcItem()->getProduct()->get_id();
                }
                $newGiftChoice->setValues($values);

                $newGiftChoice->setMethod(new GiftChoiceMethodEnum(GiftChoiceMethodEnum::IN_LIST));
                $newGiftChoices = array($newGiftChoice);
                break;
            } elseif ($giftChoice->getType()->getValue() === GiftChoiceTypeEnum::CLONE_ADJUSTED_FIRST) {
                $newGiftChoice = clone $giftChoice;
                $newGiftChoice->setType(new GiftChoiceTypeEnum(GiftChoiceTypeEnum::PRODUCT));

                $values = array();
                if ( count($items) > 0 ) {
                    $item = reset($items);
                    $values[] = $item->getWcItem()->getProduct()->get_id();
                }
                $newGiftChoice->setValues($values);

                $newGiftChoice->setMethod(new GiftChoiceMethodEnum(GiftChoiceMethodEnum::IN_LIST));
                $newGiftChoices = array($newGiftChoice);
                break;
            } elseif ($giftChoice->getType()->equals(GiftChoiceTypeEnum::PRODUCT())) {
                if ($gift->getMode()->equals(GiftModeEnum::GIFTABLE_PRODUCTS_IN_RANDOM())) {
                    $values = $giftChoice->getValues();
                    shuffle($values);
                    $giftChoice->setValues($values);
                }
            }

            $newGiftChoices[] = $giftChoice;
        }

        $freeCartItemChoices = new FreeCartItemChoices();
        $freeCartItemChoices->setChoices($newGiftChoices);
        $freeCartItemChoices->setRequiredQty($gift->getQty());
        $freeCartItemChoices->setRequired(
            $gift->getMode()->equals(GiftModeEnum::REQUIRE_TO_CHOOSE())
            || $gift->getMode()->equals(GiftModeEnum::REQUIRE_TO_CHOOSE_FROM_PRODUCT_CAT())
        );
        $freeCartItemChoices->setRuleId($this->rule->getId());

        return $freeCartItemChoices;
    }

    /**
     * @param Cart $cart
     * @param CartSetCollection $collection
     */
    public function addCartSetGifts(&$cart, $collection)
    {
        /** @var PackageRule $rule */
        $rule = $this->rule;

        $totalQty = floatval(0);

        $setIndexes = array();
        foreach ($collection->getSets() as $set) {
            $setIndexes[] = array(
                'index' => $totalQty + 1,
                'set'   => $set,
            );
            $totalQty     += $set->getQty();
        }

        $attemptCount = 0;
        if ($rule->getItemGiftStrategy() === $rule::BASED_ON_LIMIT_STRATEGY) {
            $attemptCount = min($totalQty, $rule->getItemGiftLimit());
        } elseif (
            $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_EXCL_TAX_STRATEGY
            || $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_INCL_TAX_STRATEGY
        ) {
            if ($rule->getItemGiftSubtotalDivider()) {
                $inclTax = $rule->getItemGiftStrategy() === $rule::BASED_ON_SUBTOTAL_INCL_TAX_STRATEGY;
                $tmpCart = clone $cart;
                foreach ($collection->getSets() as $set) {
                    foreach ($set->getItems() as $item) {
                        $tmpCart->addToCart($item);
                    }
                }
                $itemsSubtotals = (new CartTotals($tmpCart))->getSubtotal($inclTax);
                $attemptCount   = intval($itemsSubtotals / $rule->getItemGiftSubtotalDivider());
            }
        }

        /** @var FreeCartItem[][] $freeCartItemsByHash */
        $freeCartItemsByHash = array();

        $maxAmountForGiftsLeft = $rule->getMaxAmountForGifts();
        if ($maxAmountForGiftsLeft !== null) {
            $maxAmountForGiftsLeft = (new WcTaxFunctions())->getBasePrice($maxAmountForGiftsLeft);
        }

        $index = 0;
        while ($index < $attemptCount) {
            $index++;
            $set = null;
            foreach ($setIndexes as $key => $data) {
                if ($data['index'] <= $index) {
                    $set = $data['set'];
                }
            }

            if ( ! $set) {
                continue;
            }

            $giftIndex = 0;
            /** @var CartSet $set */
            foreach ($rule->getItemGiftsCollection()->asArray() as $gift) {
                if ($gift->getQty() <= 0) {
                    continue;
                }

                $freeCartItemChoices = $this->convertGiftToFreeCartItemChoices($gift, $set->getItems());
                $hash                = $freeCartItemChoices->generateHash($rule, $giftIndex, $gift);

                if ($gift->isAllowToSelect()) {
                    continue;
                } else {
                    $this->processFreeItem(
                        $freeCartItemsByHash,
                        $hash,
                        $cart,
                        $freeCartItemChoices,
                        0.0,
                        $maxAmountForGiftsLeft
                    );
                }

                $giftIndex++;
            }
        }

        $customer = $cart->getContext()->getCustomer();

        foreach ($freeCartItemsByHash as $hash => $freeCartItems) {
            $removedFreeItems = $customer->getRemovedFreeItems($hash);

            foreach ($freeCartItems as $freeCartItem) {
                $deletedQty = $removedFreeItems->get($freeCartItem->hash());

                if ($freeCartItem->getQty() <= $deletedQty) {
                    $deletedQty = $freeCartItem->getQty();
                    $freeCartItem->setQty(0);
                } else {
                    $freeCartItem->setQty($freeCartItem->getQty() - $deletedQty);
                }

                $removedFreeItems->set($freeCartItem->hash(), $deletedQty);
                $cart->addToCart($freeCartItem);
            }
        }
    }

    /**
     * @param float $initialPrice
     * @return float
     */
    protected function calculateGiftPrice($initialPrice)
    {
        return self::calculateGiftPriceForRule($this->rule, $initialPrice);
    }

    /**
     * @param Rule $rule
     * @param float $initialPrice
     * @return float
     */
    public static function calculateGiftPriceForRule($rule, $initialPrice)
    {
        if (!$rule || !method_exists($rule, 'getItemGiftsDiscount')) {
            return floatval(0);
        }

        $discount = $rule->getItemGiftsDiscount();

        if (!($discount instanceof Discount)) {
            return floatval(0);
        }

        /** @var PriceCalculator $priceCalculator */
        $priceCalculator = Factory::get("Core_RuleProcessor_PriceCalculator", $rule, $discount);

        return floatval($priceCalculator->calculateSinglePrice(floatval($initialPrice)));
    }

    /**
     * @param Cart $cart
     * @param int $productId
     * @param float $qty
     * @param string $associatedGiftHash
     * @param array $variation
     * @param array $cartItemData
     *
     * @return FreeCartItem|false
     */
    protected function prepareFreeCartItem(
        $cart,
        $productId,
        $qty,
        $associatedGiftHash,
        $variation = array(),
        $cartItemData = array()
    ) {
        if ( ! ($cart instanceof Cart && is_numeric($productId) && is_numeric($qty))) {
            return false;
        }

        if ( ! $this->canItemGifts()) {
            return false;
        }

        /** @var SingleItemRule|PackageRule $rule */
        $rule = $this->rule;

        $productId = intval($productId);
        $product   = CacheHelper::getWcProduct($productId);
        $qty       = floatval($qty);

        if ($qty < floatval(0)) {
            return false;
        }

        if ($qty === floatval(0)) {
            return false;
        }

        $isReplace   = $rule->isReplaceItemGifts();
        $replaceCode = $rule->getReplaceItemGiftsCode();

        try {
            $freeItem = new FreeCartItem($product, $qty, $this->rule->getId(), $associatedGiftHash);
        } catch (Exception $e) {
            return false;
        }

        if (count($variation) > 0) {
            $freeItem->setVariation($variation);
        }

        $freeItem->setCartItemData($cartItemData);
        $freeItem->setPrice($this->calculateGiftPrice($freeItem->getInitialPrice()));

        if ($isReplace && $replaceCode) {
            $freeItem->setReplaceWithCoupon($isReplace);
            $freeItem->setReplaceCouponCode($replaceCode);
        }

        return $freeItem;
    }

    /**
     * @param array<int, array<int,FreeCartItem>> $freeCartItemsByHash
     * @param string $hash
     * @param Cart $cart
     * @param FreeCartItemChoices $freeCartItemChoices
     * @param float $giftedCount
     */
    protected function processFreeItem(
        &$freeCartItemsByHash,
        $hash,
        $cart,
        $freeCartItemChoices,
        $giftedCount = 0.0,
        &$maxAmountForGiftsLeft = null,
        $maxAmountForGift = null
    ) {
        $readyList = $this->freeItemChoicesSuitability->getProductsSuitableToGift(
            $freeCartItemChoices,
            $this->ruleUsedStock,
            $giftedCount,
            $cart,
            $maxAmountForGiftsLeft,
            $maxAmountForGift
        );

        if ( ! isset($freeCartItemsByHash[$hash])) {
            $freeCartItemsByHash[$hash] = array();
        }

        /** @var FreeCartItem[] $freeCartItems */
        $freeCartItems = $freeCartItemsByHash[$hash];

        foreach ($readyList as $value) {
            list($productId, $qty, $notEnoughStock) = $value;

            if ( $notEnoughStock ) {
                $cart->addNotice(new Notice('not_enough_stock_for_gift', ['product_id' => $productId]));
            }

            if ( ! ($freeCartItem = $this->prepareFreeCartItem($cart, $productId, $qty, $hash))) {
                continue;
            }
            $calculatedGiftHash = $freeCartItem->hash();

            if (isset($freeCartItems[$calculatedGiftHash])) {
                $freeCartItems[$calculatedGiftHash]->setQty(
                    $freeCartItems[$calculatedGiftHash]->getQty() + $freeCartItem->getQty()
                );
            } else {
                $freeCartItems[$calculatedGiftHash] = clone $freeCartItem;
            }

            $this->ruleUsedStock->add(
                $freeCartItem->getProduct()->get_id(),
                $freeCartItem->getQty(),
                $freeCartItem->getProduct()->get_parent_id(),
                $freeCartItem->getVariation(),
                $freeCartItem->getCartItemData()
            );
        }

        $freeCartItemsByHash[$hash] = $freeCartItems;
    }
}