<?php
namespace Domain\Promotion;

class PromotionRepository
{
    private const MAX_PER_PAGE = 100;

    private $db;
    private ?string $defaultLangId = null;

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

    /**
     * @return array{items: array<int, array<string, mixed>>, total: int}
     */
    public function listForAdmin(
        array $filters,
        string $sortColumn = 'id',
        string $sortDir = 'DESC',
        int $page = 1,
        int $perPage = 15
    ): array {
        $allowedSortColumns = [
            'id' => 'sp.id',
            'name' => 'sp.name',
            'status' => 'sp.status',
            'condition_type' => 'sp.condition_type',
            'date_from' => 'sp.date_from',
            'date_to' => 'sp.date_to',
        ];

        $sortSql = $allowedSortColumns[$sortColumn] ?? 'sp.id';
        $sortDir = strtoupper(trim($sortDir)) === 'ASC' ? 'ASC' : 'DESC';
        $page = max(1, $page);
        $perPage = min(self::MAX_PER_PAGE, max(1, $perPage));
        $offset = ($page - 1) * $perPage;

        $where = ['1 = 1'];
        $params = [];

        $name = trim((string)($filters['name'] ?? ''));
        if ($name !== '') {
            if (strlen($name) > 255) {
                $name = substr($name, 0, 255);
            }
            $where[] = 'sp.name LIKE :name';
            $params[':name'] = '%' . $name . '%';
        }

        $status = trim((string)($filters['status'] ?? ''));
        if ($status === '0' || $status === '1') {
            $where[] = 'sp.status = :status';
            $params[':status'] = (int)$status;
        }

        $whereSql = implode(' AND ', $where);

        $sqlCount = "
            SELECT COUNT(0)
            FROM pp_shop_promotion AS sp
            WHERE {$whereSql}
        ";

        $stmtCount = $this->db->query($sqlCount, $params);
        $countRows = $stmtCount ? $stmtCount->fetchAll() : [];
        $total = isset($countRows[0][0]) ? (int)$countRows[0][0] : 0;

        $sql = "
            SELECT
                sp.id,
                sp.name,
                sp.status,
                sp.condition_type,
                sp.discount_type,
                sp.amount,
                sp.date_from,
                sp.date_to,
                sp.include_coupon,
                sp.include_product_promo,
                sp.min_product_count,
                sp.price_cheapest_product
            FROM pp_shop_promotion AS sp
            WHERE {$whereSql}
            ORDER BY {$sortSql} {$sortDir}, sp.id DESC
            LIMIT {$perPage} OFFSET {$offset}
        ";

        $stmt = $this->db->query($sql, $params);
        $items = $stmt ? $stmt->fetchAll() : [];

        return [
            'items' => is_array($items) ? $items : [],
            'total' => $total,
        ];
    }

    public function find(int $promotionId): array
    {
        if ($promotionId <= 0) {
            return $this->defaultPromotion();
        }

        $promotion = $this->db->get('pp_shop_promotion', '*', ['id' => $promotionId]);
        if (!is_array($promotion)) {
            return $this->defaultPromotion();
        }

        $promotion['id'] = (int)($promotion['id'] ?? 0);
        $promotion['status'] = $this->toSwitchValue($promotion['status'] ?? 0);
        $promotion['include_coupon'] = $this->toSwitchValue($promotion['include_coupon'] ?? 0);
        $promotion['include_product_promo'] = $this->toSwitchValue($promotion['include_product_promo'] ?? 0);
        $promotion['condition_type'] = (int)($promotion['condition_type'] ?? 1);
        $promotion['discount_type'] = (int)($promotion['discount_type'] ?? 1);
        $promotion['categories'] = $this->decodeIdList($promotion['categories'] ?? null);
        $promotion['condition_categories'] = $this->decodeIdList($promotion['condition_categories'] ?? null);

        return $promotion;
    }

    public function save(array $data): ?int
    {
        $promotionId = (int)($data['id'] ?? 0);

        $row = [
            'name' => trim((string)($data['name'] ?? '')),
            'status' => $this->toSwitchValue($data['status'] ?? 0),
            'condition_type' => (int)($data['condition_type'] ?? 1),
            'discount_type' => (int)($data['discount_type'] ?? 1),
            'amount' => $this->toNullableNumeric($data['amount'] ?? null),
            'date_from' => $this->toNullableDate($data['date_from'] ?? null),
            'date_to' => $this->toNullableDate($data['date_to'] ?? null),
            'categories' => $this->encodeIdList($data['categories'] ?? null),
            'condition_categories' => $this->encodeIdList($data['condition_categories'] ?? null),
            'include_coupon' => $this->toSwitchValue($data['include_coupon'] ?? 0),
            'include_product_promo' => $this->toSwitchValue($data['include_product_promo'] ?? 0),
            'min_product_count' => $this->toNullableInt($data['min_product_count'] ?? null),
            'price_cheapest_product' => $this->toNullableNumeric($data['price_cheapest_product'] ?? null),
        ];

        if ($promotionId <= 0) {
            $this->db->insert('pp_shop_promotion', $row);
            $id = (int)$this->db->id();
            if ($id <= 0) {
                return null;
            }

            $this->invalidateActivePromotionsCache();
            \Shared\Helpers\Helpers::delete_dir('../temp/');
            return $id;
        }

        $this->db->update('pp_shop_promotion', $row, ['id' => $promotionId]);
        $this->invalidateActivePromotionsCache();
        \Shared\Helpers\Helpers::delete_dir('../temp/');

        return $promotionId;
    }

    public function delete(int $promotionId): bool
    {
        if ($promotionId <= 0) {
            return false;
        }

        $deleted = $this->db->delete('pp_shop_promotion', ['id' => $promotionId]);
        $ok = (bool)$deleted;

        if ($ok) {
            $this->invalidateActivePromotionsCache();
        }

        return $ok;
    }

    /**
     * @return array<int, array<string, mixed>>
     */
    public function categoriesTree($parentId = null): array
    {
        $rows = $this->db->select('pp_shop_categories', ['id'], [
            'parent_id' => $parentId,
            'ORDER' => ['o' => 'ASC'],
        ]);

        if (!is_array($rows)) {
            return [];
        }

        $categories = [];
        foreach ($rows as $row) {
            $categoryId = (int)($row['id'] ?? 0);
            if ($categoryId <= 0) {
                continue;
            }

            $category = $this->db->get('pp_shop_categories', '*', ['id' => $categoryId]);
            if (!is_array($category)) {
                continue;
            }

            $translations = $this->db->select('pp_shop_categories_langs', '*', ['category_id' => $categoryId]);
            $category['languages'] = [];
            if (is_array($translations)) {
                foreach ($translations as $translation) {
                    $langId = (string)($translation['lang_id'] ?? '');
                    if ($langId !== '') {
                        $category['languages'][$langId] = $translation;
                    }
                }
            }

            $category['title'] = $this->categoryTitle($category['languages']);
            $category['subcategories'] = $this->categoriesTree($categoryId);
            $categories[] = $category;
        }

        return $categories;
    }

    private function defaultPromotion(): array
    {
        return [
            'id' => 0,
            'name' => '',
            'status' => 1,
            'condition_type' => 1,
            'discount_type' => 1,
            'amount' => null,
            'date_from' => null,
            'date_to' => null,
            'categories' => [],
            'condition_categories' => [],
            'include_coupon' => 0,
            'include_product_promo' => 0,
            'min_product_count' => null,
            'price_cheapest_product' => null,
        ];
    }

    private function toSwitchValue($value): int
    {
        if (is_bool($value)) {
            return $value ? 1 : 0;
        }

        if (is_numeric($value)) {
            return ((int)$value) === 1 ? 1 : 0;
        }

        if (is_string($value)) {
            $normalized = strtolower(trim($value));
            return in_array($normalized, ['1', 'on', 'true', 'yes'], true) ? 1 : 0;
        }

        return 0;
    }

    private function toNullableInt($value): ?int
    {
        if ($value === null) {
            return null;
        }

        if (is_string($value)) {
            $value = trim($value);
            if ($value === '') {
                return null;
            }
        }

        $intValue = (int)$value;
        return $intValue > 0 ? $intValue : null;
    }

    private function toNullableNumeric($value): ?string
    {
        if ($value === null) {
            return null;
        }

        $stringValue = trim((string)$value);
        if ($stringValue === '') {
            return null;
        }

        return str_replace(',', '.', $stringValue);
    }

    private function toNullableDate($value): ?string
    {
        $date = trim((string)$value);
        if ($date === '') {
            return null;
        }

        return $date;
    }

    private function encodeIdList($values): ?string
    {
        $ids = $this->normalizeIdList($values);
        if (empty($ids)) {
            return null;
        }

        return json_encode($ids);
    }

    /**
     * @return int[]
     */
    private function decodeIdList($raw): array
    {
        if (is_array($raw)) {
            return $this->normalizeIdList($raw);
        }

        $text = trim((string)$raw);
        if ($text === '') {
            return [];
        }

        $decoded = json_decode($text, true);
        if (!is_array($decoded)) {
            return [];
        }

        return $this->normalizeIdList($decoded);
    }

    /**
     * @return int[]
     */
    private function normalizeIdList($values): array
    {
        if ($values === null) {
            return [];
        }

        if (!is_array($values)) {
            $text = trim((string)$values);
            if ($text === '') {
                return [];
            }

            if (strpos($text, ',') !== false) {
                $values = explode(',', $text);
            } else {
                $values = [$text];
            }
        }

        $ids = [];
        foreach ($values as $value) {
            $id = (int)$value;
            if ($id > 0) {
                $ids[$id] = $id;
            }
        }

        return array_values($ids);
    }

    private function categoryTitle(array $languages): string
    {
        $defaultLang = $this->defaultLanguageId();
        if ($defaultLang !== '' && isset($languages[$defaultLang]['title'])) {
            $title = trim((string)$languages[$defaultLang]['title']);
            if ($title !== '') {
                return $title;
            }
        }

        foreach ($languages as $language) {
            $title = trim((string)($language['title'] ?? ''));
            if ($title !== '') {
                return $title;
            }
        }

        return '';
    }

    private function defaultLanguageId(): string
    {
        if ($this->defaultLangId !== null) {
            return $this->defaultLangId;
        }

        $rows = $this->db->select('pp_langs', ['id', 'start', 'o'], [
            'status' => 1,
            'ORDER' => ['start' => 'DESC', 'o' => 'ASC'],
        ]);

        if (is_array($rows) && !empty($rows)) {
            $this->defaultLangId = (string)($rows[0]['id'] ?? '');
        } else {
            $this->defaultLangId = '';
        }

        return $this->defaultLangId;
    }

    private function invalidateActivePromotionsCache(): void
    {
        if (!class_exists('\Shared\Cache\CacheHandler')) {
            return;
        }

        try {
            $cache = new \Shared\Cache\CacheHandler();
            if (method_exists($cache, 'delete')) {
                $cache->delete('\shop\Promotion::get_active_promotions');
            }
        } catch (\Throwable $e) {
            // Cache invalidation should not block save/delete.
        }
    }
}