<?php
declare(strict_types=1);

namespace Esun\Cart\Model;

use Esun\Catalog\Model\MixStepPriceProvider;
use Magento\Catalog\Api\ProductRepositoryInterface;
use Magento\Checkout\Model\Session as CheckoutSession;
use Magento\ConfigurableProduct\Model\Product\Type\Configurable;
use Magento\Framework\DataObject;
use Magento\Quote\Model\Quote;
use Magento\SalesRule\Api\Data\RuleInterface;
use Magento\SalesRule\Model\ResourceModel\Rule\CollectionFactory;
use Magento\Framework\Pricing\PriceCurrencyInterface;

class MilestoneProvider
{
    public function __construct(
        private readonly CollectionFactory $ruleCollectionFactory,
        private readonly CheckoutSession $checkoutSession,
        private readonly ProductRepositoryInterface $productRepository,
        private readonly MixStepPriceProvider $mixStepPriceProvider,
        private readonly PriceCurrencyInterface $priceCurrency
    ) {
    }

    public function getData(?Quote $quote = null): array
    {
        $quote ??= $this->checkoutSession->getQuote();
        $mixGroups = $this->getMixGroups($quote);
        if ($mixGroups) {
            return array_merge($mixGroups[0], ['groups' => $mixGroups]);
        }

        $quantity = (int)ceil((float)$quote->getItemsQty());
        $milestones = $this->getMilestones($quote);
        $maximum = $milestones ? max(array_column($milestones, 'qty')) : 0;
        $active = null;
        $next = null;

        foreach ($milestones as &$milestone) {
            $milestone['active'] = $quantity >= $milestone['qty'];
            $milestone['position'] = $maximum > 0
                ? round(min(100, ($milestone['qty'] / $maximum) * 100), 2)
                : 0;

            if ($milestone['active']) {
                $active = $milestone;
            } elseif ($next === null) {
                $next = $milestone;
            }
        }
        unset($milestone);

        return [
            'quantity' => $quantity,
            'progress_percent' => $maximum > 0 ? round(min(100, ($quantity / $maximum) * 100), 2) : 0,
            'milestones' => $milestones,
            'message' => $this->getMessage($quantity, $active, $next),
            'groups' => [],
        ];
    }

    private function getMixGroups(Quote $quote): array
    {
        $groupedItems = [];
        foreach ($quote->getAllVisibleItems() as $item) {
            if ($item->getProductType() === Configurable::TYPE_CODE) {
                $groupedItems[(int)$item->getProductId()][] = $item;
            }
        }

        $groups = [];
        foreach ($groupedItems as $parentProductId => $items) {
            try {
                $parentProduct = $this->productRepository->getById(
                    $parentProductId,
                    false,
                    (int)$quote->getStoreId()
                );
            } catch (\Magento\Framework\Exception\NoSuchEntityException) {
                continue;
            }
            $rules = $this->mixStepPriceProvider->getRules(
                $parentProduct,
                (int)$quote->getCustomerGroupId()
            );
            if (!$rules) {
                continue;
            }

            $quantity = (int)array_sum(array_map(
                static fn ($item): float => (float)$item->getQty(),
                $items
            ));
            $milestones = [];
            foreach ($rules as $rule) {
                $isFixed = ($rule['price_type'] ?? '') === 'fixed';
                $value = $isFixed
                    ? $this->priceCurrency->convertAndFormat(
                        (float)$rule['value'],
                        false,
                        2,
                        $quote->getStore()
                    )
                    : $this->formatPercent((float)$rule['value']) . '% Off';
                $milestones[] = [
                    'qty' => (int)$rule['qty'],
                    'type' => 'discount',
                    'value' => $value,
                    'label' => (string)__('%1 pcs', (int)$rule['qty']),
                ];
            }

            usort($milestones, static fn (array $left, array $right): int => $left['qty'] <=> $right['qty']);

            $maximum = $milestones ? max(array_column($milestones, 'qty')) : 0;
            $active = null;
            $next = null;
            foreach ($milestones as &$milestone) {
                $milestone['active'] = $quantity >= $milestone['qty'];
                $milestone['position'] = $maximum > 0
                    ? round(min(100, ($milestone['qty'] / $maximum) * 100), 2)
                    : 0;
                if ($milestone['active']) {
                    $active = $milestone;
                } elseif ($next === null) {
                    $next = $milestone;
                }
            }
            unset($milestone);

            $groups[] = [
                'product_id' => $parentProductId,
                'name' => (string)$parentProduct->getName(),
                'quantity' => $quantity,
                'progress_percent' => $maximum > 0
                    ? round(min(100, ($quantity / $maximum) * 100), 2)
                    : 0,
                'milestones' => $milestones,
                'message' => $this->getMessage($quantity, $active, $next),
            ];
        }

        return $groups;
    }

    private function getMilestones(Quote $quote): array
    {
        if (!$quote->getStoreId()) {
            return [];
        }

        $collection = $this->ruleCollectionFactory->create();
        $collection->setValidationFilter(
            (int)$quote->getStore()->getWebsiteId(),
            (int)$quote->getCustomerGroupId(),
            (string)$quote->getCouponCode(),
            null,
            $quote->getShippingAddress()
        );

        $items = [];
        foreach ($collection as $rule) {
            $quantity = $this->findQuantityThreshold($rule->getConditions());
            if ($quantity === null || $quantity < 1) {
                continue;
            }

            $discountAmount = (float)$rule->getDiscountAmount();
            if ($rule->getSimpleAction() === RuleInterface::DISCOUNT_ACTION_BY_PERCENT && $discountAmount > 0) {
                $key = $quantity . ':discount';
                $items[$key] = [
                    'qty' => $quantity,
                    'type' => 'discount',
                    'value' => $this->formatPercent($discountAmount) . '% Off',
                    'label' => (string)__('%1 pcs %2% off', $quantity, $this->formatPercent($discountAmount)),
                    'discount' => $discountAmount,
                ];
            }

            if ((int)$rule->getSimpleFreeShipping() > 0) {
                $items[$quantity . ':free_shipping'] = [
                    'qty' => $quantity,
                    'type' => 'free_shipping',
                    'value' => (string)__('Free Shipping'),
                    'label' => (string)__('%1 pcs', $quantity),
                ];
            }
        }

        $milestones = array_values($items);
        usort($milestones, static function (array $left, array $right): int {
            $quantityComparison = $left['qty'] <=> $right['qty'];
            if ($quantityComparison !== 0) {
                return $quantityComparison;
            }

            return $left['type'] === 'discount' ? -1 : 1;
        });

        return $milestones;
    }

    private function findQuantityThreshold(DataObject $condition): ?int
    {
        $thresholds = [];
        $this->collectQuantityThresholds($condition, $thresholds);

        return $thresholds ? max($thresholds) : null;
    }

    private function collectQuantityThresholds(DataObject $condition, array &$thresholds): void
    {
        if ((string)$condition->getData('attribute') === 'total_qty') {
            $value = (float)$condition->getData('value');
            $operator = (string)$condition->getData('operator');

            if ($operator === '>=') {
                $thresholds[] = (int)ceil($value);
            } elseif ($operator === '>') {
                $thresholds[] = (int)floor($value) + 1;
            } elseif ($operator === '==') {
                $thresholds[] = (int)round($value);
            }
        }

        $children = method_exists($condition, 'getConditions')
            ? (array)$condition->getConditions()
            : (array)$condition->getData('conditions');

        foreach ($children as $child) {
            if ($child instanceof DataObject) {
                $this->collectQuantityThresholds($child, $thresholds);
            }
        }
    }

    private function getMessage(int $quantity, ?array $active, ?array $next): string
    {
        if ($next) {
            $remaining = max(0, (int)$next['qty'] - $quantity);
            $prefix = $active ? $active['value'] . ' | ' : '';

            return $prefix . (string)__('Add %1 More For %2', $remaining, $next['value']);
        }

        if ($active) {
            return (string)__('Unlocked: %1', $active['value']);
        }

        return '';
    }

    private function formatPercent(float $value): string
    {
        return rtrim(rtrim(number_format($value, 2, '.', ''), '0'), '.');
    }
}