<?php
/**
 * License Manager
 *
 * @package Jeremias\WcLicensedProduct\License
 */

declare(strict_types=1);

namespace Jeremias\WcLicensedProduct\License;

use Jeremias\WcLicensedProduct\Installer;
use Jeremias\WcLicensedProduct\Product\LicensedProduct;

/**
 * Manages license operations (CRUD, validation, generation)
 */
class LicenseManager
{
    /**
     * Generate a unique license key
     */
    public function generateLicenseKey(): string
    {
        // Format: XXXX-XXXX-XXXX-XXXX (32 chars hex, 4 groups)
        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $key = '';

        for ($i = 0; $i < 4; $i++) {
            if ($i > 0) {
                $key .= '-';
            }
            for ($j = 0; $j < 4; $j++) {
                $key .= $chars[random_int(0, strlen($chars) - 1)];
            }
        }

        return $key;
    }

    /**
     * Generate a license for a completed order
     */
    public function generateLicense(
        int $orderId,
        int $productId,
        int $customerId,
        string $domain
    ): ?License {
        global $wpdb;

        // Check if license already exists for this order and product
        $existing = $this->getLicenseByOrderAndProduct($orderId, $productId);
        if ($existing) {
            return $existing;
        }

        $product = wc_get_product($productId);
        if (!$product instanceof LicensedProduct) {
            return null;
        }

        // Generate unique license key
        $licenseKey = $this->generateLicenseKey();
        while ($this->getLicenseByKey($licenseKey)) {
            $licenseKey = $this->generateLicenseKey();
        }

        // Calculate expiration date
        $expiresAt = null;
        $validityDays = $product->get_validity_days();
        if ($validityDays !== null && $validityDays > 0) {
            $expiresAt = (new \DateTimeImmutable())->modify("+{$validityDays} days")->format('Y-m-d H:i:s');
        }

        // Determine version ID if bound to version
        $versionId = null;
        if ($product->is_bound_to_version()) {
            $versionId = $this->getCurrentVersionId($productId);
        }

        $tableName = Installer::getLicensesTable();
        $result = $wpdb->insert(
            $tableName,
            [
                'license_key' => $licenseKey,
                'order_id' => $orderId,
                'product_id' => $productId,
                'customer_id' => $customerId,
                'domain' => $this->normalizeDomain($domain),
                'version_id' => $versionId,
                'status' => License::STATUS_ACTIVE,
                'activations_count' => 1,
                'max_activations' => $product->get_max_activations(),
                'expires_at' => $expiresAt,
            ],
            ['%s', '%d', '%d', '%d', '%s', '%d', '%s', '%d', '%d', '%s']
        );

        if ($result === false) {
            return null;
        }

        return $this->getLicenseById((int) $wpdb->insert_id);
    }

    /**
     * Get license by ID
     */
    public function getLicenseById(int $id): ?License
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $row = $wpdb->get_row(
            $wpdb->prepare("SELECT * FROM {$tableName} WHERE id = %d", $id),
            ARRAY_A
        );

        return $row ? License::fromArray($row) : null;
    }

    /**
     * Get license by license key
     */
    public function getLicenseByKey(string $licenseKey): ?License
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $row = $wpdb->get_row(
            $wpdb->prepare("SELECT * FROM {$tableName} WHERE license_key = %s", $licenseKey),
            ARRAY_A
        );

        return $row ? License::fromArray($row) : null;
    }

    /**
     * Get license by order and product
     */
    public function getLicenseByOrderAndProduct(int $orderId, int $productId): ?License
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $row = $wpdb->get_row(
            $wpdb->prepare(
                "SELECT * FROM {$tableName} WHERE order_id = %d AND product_id = %d",
                $orderId,
                $productId
            ),
            ARRAY_A
        );

        return $row ? License::fromArray($row) : null;
    }

    /**
     * Get all licenses for a customer
     */
    public function getLicensesByCustomer(int $customerId): array
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $rows = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT * FROM {$tableName} WHERE customer_id = %d ORDER BY created_at DESC",
                $customerId
            ),
            ARRAY_A
        );

        return array_map(fn(array $row) => License::fromArray($row), $rows ?: []);
    }

    /**
     * Get all licenses (for admin)
     */
    public function getAllLicenses(int $page = 1, int $perPage = 20): array
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $offset = ($page - 1) * $perPage;

        $rows = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT * FROM {$tableName} ORDER BY created_at DESC LIMIT %d OFFSET %d",
                $perPage,
                $offset
            ),
            ARRAY_A
        );

        return array_map(fn(array $row) => License::fromArray($row), $rows ?: []);
    }

    /**
     * Get total license count
     */
    public function getLicenseCount(): int
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        return (int) $wpdb->get_var("SELECT COUNT(*) FROM {$tableName}");
    }

    /**
     * Validate a license key for a domain
     */
    public function validateLicense(string $licenseKey, string $domain): array
    {
        $license = $this->getLicenseByKey($licenseKey);

        if (!$license) {
            return [
                'valid' => false,
                'error' => 'license_not_found',
                'message' => __('License key not found.', 'wc-licensed-product'),
            ];
        }

        // Check license status
        if ($license->getStatus() === License::STATUS_REVOKED) {
            return [
                'valid' => false,
                'error' => 'license_revoked',
                'message' => __('This license has been revoked.', 'wc-licensed-product'),
            ];
        }

        // Check expiration
        if ($license->isExpired()) {
            $this->updateLicenseStatus($license->getId(), License::STATUS_EXPIRED);
            return [
                'valid' => false,
                'error' => 'license_expired',
                'message' => __('This license has expired.', 'wc-licensed-product'),
            ];
        }

        if ($license->getStatus() === License::STATUS_INACTIVE) {
            return [
                'valid' => false,
                'error' => 'license_inactive',
                'message' => __('This license is inactive.', 'wc-licensed-product'),
            ];
        }

        // Check domain
        $normalizedDomain = $this->normalizeDomain($domain);
        if ($license->getDomain() !== $normalizedDomain) {
            return [
                'valid' => false,
                'error' => 'domain_mismatch',
                'message' => __('This license is not valid for this domain.', 'wc-licensed-product'),
            ];
        }

        return [
            'valid' => true,
            'license' => [
                'product_id' => $license->getProductId(),
                'expires_at' => $license->getExpiresAt()?->format('Y-m-d'),
                'version_id' => $license->getVersionId(),
            ],
        ];
    }

    /**
     * Update license status
     */
    public function updateLicenseStatus(int $licenseId, string $status): bool
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $result = $wpdb->update(
            $tableName,
            ['status' => $status],
            ['id' => $licenseId],
            ['%s'],
            ['%d']
        );

        return $result !== false;
    }

    /**
     * Update license domain
     */
    public function updateLicenseDomain(int $licenseId, string $domain): bool
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $result = $wpdb->update(
            $tableName,
            ['domain' => $this->normalizeDomain($domain)],
            ['id' => $licenseId],
            ['%s'],
            ['%d']
        );

        return $result !== false;
    }

    /**
     * Delete a license
     */
    public function deleteLicense(int $licenseId): bool
    {
        global $wpdb;

        $tableName = Installer::getLicensesTable();
        $result = $wpdb->delete(
            $tableName,
            ['id' => $licenseId],
            ['%d']
        );

        return $result !== false;
    }

    /**
     * Normalize domain name
     */
    public function normalizeDomain(string $domain): string
    {
        // Remove protocol
        $domain = preg_replace('#^https?://#', '', $domain);

        // Remove trailing slash and path
        $domain = preg_replace('#/.*$#', '', $domain);

        // Remove www prefix
        $domain = preg_replace('#^www\.#', '', $domain);

        // Lowercase
        return strtolower(trim($domain));
    }

    /**
     * Get current version ID for a product
     */
    private function getCurrentVersionId(int $productId): ?int
    {
        global $wpdb;

        $tableName = Installer::getVersionsTable();
        $versionId = $wpdb->get_var(
            $wpdb->prepare(
                "SELECT id FROM {$tableName} WHERE product_id = %d AND is_active = 1 ORDER BY released_at DESC LIMIT 1",
                $productId
            )
        );

        return $versionId ? (int) $versionId : null;
    }
}