<?php

namespace App\Domain;

/**
 * Early Domain Parser Service
 * 
 * Provides domain parsing functionality that can be used during
 * bootstrap phase (RouteServiceProvider) and runtime (Middleware).
 * 
 * This service caches parsing results per request to avoid duplicate work.
 */
class EarlyDomainParser
{
    /**
     * Cache for parsed domain information per request
     * @var array|null
     */
    private static ?array $cachedDomainInfo = null;

    /**
     * Cache key (host) for cache invalidation
     * @var string|null
     */
    private static ?string $cachedHost = null;

    /**
     * Parse domain information from config/domains.php
     * 
     * Results are cached per request to avoid duplicate parsing.
     * 
     * @param string|null $host If null, uses HTTP_HOST or SERVER_NAME
     * @return array Domain information array
     */
    public static function parseDomain(?string $host = null): array
    {
        // Get host from request if not provided
        if ($host === null) {
            $host = $_SERVER['HTTP_HOST'] ?? $_SERVER['SERVER_NAME'] ?? 'localhost';
        }

        // Remove protocol if present
        $host = preg_replace('/^https?:\/\//', '', $host);

        // Return cached result if available for same host
        if (self::$cachedHost === $host && self::$cachedDomainInfo !== null) {
            return self::$cachedDomainInfo;
        }
        // Load domains configuration
        $domains = self::getDomainsConfig();
        $reservedSubdomains = self::getReservedSubdomains();

        // Check exact matches first (main, shop, crm, portal, checkout)
        foreach ($domains as $key => $domainConfig) {
            if ($key === 'user-shop') {
                continue; // Handle user-shop separately
            }

            if ($host === $domainConfig['host']) {
                $domainInfo = [
                    'type' => $domainConfig['type'],
                    'host' => $host,
                    'subdomain' => null,
                    'config_key' => $key,
                ];

                // Cache the result for this request
                self::$cachedHost = $host;
                self::$cachedDomainInfo = $domainInfo;

                return $domainInfo;
            }
        }

        // Check for user-shop pattern (dynamic subdomains)
        if (isset($domains['user-shop'])) {
            $userShopPattern = $domains['user-shop']['host'];
            $baseDomain = str_replace('{subdomain}.', '', $userShopPattern);

            if (str_ends_with($host, '.' . $baseDomain)) {
                $subdomain = str_replace('.' . $baseDomain, '', $host);

                // Check if subdomain is not reserved
                if (!empty($subdomain) && !in_array($subdomain, $reservedSubdomains)) {
                    $domainInfo = [
                        'type' => 'user-shop',
                        'host' => $host,
                        'subdomain' => $subdomain,
                        'config_key' => 'user-shop',
                    ];

                    // Cache the result for this request
                    self::$cachedHost = $host;
                    self::$cachedDomainInfo = $domainInfo;

                    return $domainInfo;
                }
            }
        }

        // Unknown domain
        $domainInfo = [
            'type' => 'unknown',
            'host' => $host,
            'subdomain' => null,
            'config_key' => null,
        ];

        // Cache the result for this request
        self::$cachedHost = $host;
        self::$cachedDomainInfo = $domainInfo;

        return $domainInfo;
    }

    /**
     * Get current domain type quickly (for RouteServiceProvider)
     */
    public static function getCurrentDomainType(): string
    {
        $domainInfo = self::parseDomain();
        return $domainInfo['type'];
    }

    /**
     * Check if current domain is a user shop
     */
    public static function isUserShop(): bool
    {
        return self::getCurrentDomainType() === 'user-shop';
    }

    /**
     * Get subdomain for user shops
     */
    public static function getSubdomain(): ?string
    {
        $domainInfo = self::parseDomain();
        return $domainInfo['subdomain'] ?? null;
    }

    /**
     * Get domains configuration (early bootstrap safe)
     */
    private static function getDomainsConfig(): array
    {
        // Try Laravel config first (if available)
        if (function_exists('config')) {
            $config = config('domains.domains');
            if ($config) {
                return $config;
            }
        }

        // Fallback: Read config file directly
        $configPath = __DIR__ . '/../../../../config/domains.php';
        if (file_exists($configPath)) {
            $config = include $configPath;
            return $config['domains'] ?? [];
        }

        // Last resort: Build from environment variables
        return self::buildConfigFromEnv();
    }

    /**
     * Get reserved subdomains configuration
     */
    private static function getReservedSubdomains(): array
    {
        // Try Laravel config first (if available)
        if (function_exists('config')) {
            $reserved = config('domains.reserved_subdomains');
            if ($reserved) {
                return $reserved;
            }
        }

        // Fallback: Read config file directly  
        $configPath = __DIR__ . '/../../../../config/domains.php';
        if (file_exists($configPath)) {
            $config = include $configPath;
            return $config['reserved_subdomains'] ?? [];
        }

        // Default reserved subdomains
        return ['my', 'in', 'checkout', 'www', 'api', 'mail'];
    }

    /**
     * Build basic domain configuration from environment variables
     * Used as fallback when config file is not available
     */
    private static function buildConfigFromEnv(): array
    {
        $domain = $_ENV['APP_DOMAIN'] ?? 'mivita';
        $tldCare = $_ENV['APP_TLD_CARE'] ?? '.care';
        $tldShop = $_ENV['APP_TLD_SHOP'] ?? '.shop';
        $crmPrefix = $_ENV['APP_PRE_URL_CRM'] ?? 'my.';
        $portalPrefix = $_ENV['APP_PRE_URL_PORTAL'] ?? 'in.';
        $checkoutPrefix = $_ENV['APP_URL_CHECKOUT'] ?? 'checkout.';

        return [
            'main' => [
                'host' => $domain . $tldCare,
                'type' => 'main',
            ],
            'shop' => [
                'host' => $domain . $tldShop,
                'type' => 'main-shop',
                'default_user_shop' => 'aloevera',
            ],
            'crm' => [
                'host' => $crmPrefix . $domain . $tldCare,
                'type' => 'crm',
            ],
            'portal' => [
                'host' => $portalPrefix . $domain . $tldCare,
                'type' => 'portal',
            ],
            'checkout' => [
                'host' => $checkoutPrefix . $domain . $tldCare,
                'type' => 'checkout',
            ],
            'user-shop' => [
                'host' => '{subdomain}.' . $domain . $tldCare,
                'type' => 'user-shop',
            ],
        ];
    }

    /**
     * Get protocol from configuration
     */
    public static function getProtocol(): string
    {
        if (function_exists('config')) {
            return config('domains.protocol', 'https://');
        }

        return $_ENV['APP_PROTOCOL'] ?? 'https://';
    }

    /**
     * Get main domain URL for redirects
     */
    public static function getMainUrl(): string
    {
        $domains = self::getDomainsConfig();
        $mainHost = $domains['main']['host'] ?? 'localhost';
        $protocol = self::getProtocol();

        return $protocol . $mainHost;
    }

    /**
     * Clear the internal cache (useful for testing or special cases)
     */
    public static function clearCache(): void
    {
        self::$cachedDomainInfo = null;
        self::$cachedHost = null;
    }

    /**
     * Check if result is cached for current/given host
     */
    public static function isCached(?string $host = null): bool
    {
        if ($host === null) {
            $host = $_SERVER['HTTP_HOST'] ?? $_SERVER['SERVER_NAME'] ?? 'localhost';
            $host = preg_replace('/^https?:\/\//', '', $host);
        }

        return self::$cachedHost === $host && self::$cachedDomainInfo !== null;
    }
}