<?php

namespace App\Services;

use App\Models\UserShop;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Config;

/**
 * Domain Service - Centralized domain and subdomain management
 * 
 * This service provides a centralized way to handle domain resolution,
 * subdomain validation, and domain-specific configuration management.
 */
class DomainService
{
    private const CACHE_TTL = 3600; // 1 hour
    private const FIXED_SUBDOMAINS = ['my', 'in', 'checkout'];
    
    private array $domainConfig;
    
    public function __construct()
    {
        $this->domainConfig = $this->loadDomainConfiguration();
    }
    
    /**
     * Load domain configuration from config files
     */
    private function loadDomainConfiguration(): array
    {
        return [
            'main_domain' => config('app.domain'),
            'main_tld' => config('app.tld_care'),
            'shop_tld' => config('app.tld_shop'),
            'protocol' => config('app.protocol'),
            'subdomains' => [
                'crm' => config('app.pre_url_crm', 'my.'),
                'portal' => config('app.pre_url_portal', 'in.'),
                'checkout' => config('app.pre_url_checkout', 'checkout.'),
            ]
        ];
    }
    
    /**
     * Determine the type of subdomain
     */
    public function getSubdomainType(string $subdomain): string
    {
        // Check if it's a fixed subdomain
        if (in_array($subdomain, self::FIXED_SUBDOMAINS)) {
            return match($subdomain) {
                'my' => 'crm',
                'in' => 'portal',
                'checkout' => 'checkout',
                default => 'unknown'
            };
        }
        
        // Check if it's a valid user shop
        if ($this->isValidUserShop($subdomain)) {
            return 'user-shop';
        }
        
        return 'unknown';
    }
    
    /**
     * Check if a subdomain represents a valid user shop
     */
    public function isValidUserShop(string $slug): bool
    {
        $cacheKey = "user_shop_valid_{$slug}";
        
        return Cache::remember($cacheKey, self::CACHE_TTL, function () use ($slug) {
            $userShop = UserShop::where('slug', $slug)->first();
            
            if (!$userShop) {
                return false;
            }
            
            if (!$userShop->active) {
                return false;
            }
            
            if (!$userShop->user) {
                return false;
            }
            
            if (!$userShop->user->isActiveShop()) {
                return false;
            }
            
            return true;
        });
    }
    
    /**
     * Get user shop by slug with caching
     */
    public function getUserShop(string $slug): ?UserShop
    {
        if (!$this->isValidUserShop($slug)) {
            return null;
        }
        
        $cacheKey = "user_shop_{$slug}";
        
        return Cache::remember($cacheKey, self::CACHE_TTL, function () use ($slug) {
            return UserShop::where('slug', $slug)
                ->with('user')
                ->first();
        });
    }
    
    /**
     * Parse domain from request and determine context
     */
    public function parseDomain(string $host): array
    {
        $parts = explode('.', $host);
        
        // Handle different TLD scenarios
        if (count($parts) < 2) {
            return [
                'type' => 'invalid',
                'domain' => $host,
                'subdomain' => null,
                'tld' => null
            ];
        }
        
        // Extract TLD and domain
        $tld = '.' . end($parts);
        $domain = $parts[count($parts) - 2];
        
        // Check for subdomain
        $subdomain = null;
        if (count($parts) > 2) {
            $subdomain = $parts[0];
        }
        
        // Determine domain type
        $type = $this->determineDomainType($domain, $subdomain, $tld);
        
        return [
            'type' => $type,
            'domain' => $domain,
            'subdomain' => $subdomain,
            'tld' => $tld,
            'full_domain' => $host
        ];
    }
    
    /**
     * Determine domain type based on domain, subdomain, and TLD
     */
    private function determineDomainType(string $domain, ?string $subdomain, string $tld): string
    {
        // Check if it's the main domain
        if ($domain === $this->domainConfig['main_domain']) {
            if ($subdomain === null) {
                // Main domain without subdomain
                if ($tld === $this->domainConfig['shop_tld']) {
                    return 'main-shop'; // mivita.shop
                }
                return 'main'; // mivita.care
            }
            
            // Main domain with subdomain
            return $this->getSubdomainType($subdomain);
        }
        
        return 'unknown';
    }
    
    /**
     * Build URL for specific domain type
     */
    public function buildUrl(string $type, ?string $path = null, ?string $slug = null): string
    {
        $base = $this->domainConfig['protocol'];
        
        switch ($type) {
            case 'main':
                $base .= $this->domainConfig['main_domain'] . $this->domainConfig['main_tld'];
                break;
                
            case 'main-shop':
                $base .= $this->domainConfig['main_domain'] . $this->domainConfig['shop_tld'];
                break;
                
            case 'crm':
                $base .= rtrim($this->domainConfig['subdomains']['crm'], '.') . 
                        $this->domainConfig['main_domain'] . $this->domainConfig['main_tld'];
                break;
                
            case 'portal':
                $base .= rtrim($this->domainConfig['subdomains']['portal'], '.') . 
                        $this->domainConfig['main_domain'] . $this->domainConfig['main_tld'];
                break;
                
            case 'checkout':
                $base .= rtrim($this->domainConfig['subdomains']['checkout'], '.') . 
                        $this->domainConfig['main_domain'] . $this->domainConfig['main_tld'];
                break;
                
            case 'user-shop':
                if (!$slug) {
                    throw new \InvalidArgumentException('Slug required for user-shop URLs');
                }
                $base .= $slug . '.' . $this->domainConfig['main_domain'] . $this->domainConfig['main_tld'];
                break;
                
            default:
                throw new \InvalidArgumentException("Unknown domain type: {$type}");
        }
        
        if ($path) {
            $base .= '/' . ltrim($path, '/');
        }
        
        return $base;
    }
    
    /**
     * Get domain configuration
     */
    public function getDomainConfiguration(): array
    {
        return $this->domainConfig;
    }
    
    /**
     * Clear user shop cache
     */
    public function clearUserShopCache(string $slug): void
    {
        Cache::forget("user_shop_valid_{$slug}");
        Cache::forget("user_shop_{$slug}");
    }
    
    /**
     * Get default user shop for main domain (fallback)
     */
    public function getDefaultUserShop(): ?UserShop
    {
        return $this->getUserShop('aloevera'); // Current hardcoded fallback
    }
    
    /**
     * Validate domain configuration
     */
    public function validateConfiguration(): array
    {
        $errors = [];
        
        if (empty($this->domainConfig['main_domain'])) {
            $errors[] = 'Main domain not configured';
        }
        
        if (empty($this->domainConfig['main_tld'])) {
            $errors[] = 'Main TLD not configured';
        }
        
        if (empty($this->domainConfig['protocol'])) {
            $errors[] = 'Protocol not configured';
        }
        
        return $errors;
    }
}