import * as fs from 'fs';
import * as path from 'path';
import * as plugins from '../../plugins.js';
import type { CertificateData, Certificates } from '../models/certificate-types.js';
import { ensureCertificateDirectory } from '../utils/certificate-helpers.js';

/**
 * FileStorage provides file system storage for certificates
 */
export class FileStorage {
  private storageDir: string;
  
  /**
   * Creates a new file storage provider
   * @param storageDir Directory to store certificates
   */
  constructor(storageDir: string) {
    this.storageDir = path.resolve(storageDir);
    ensureCertificateDirectory(this.storageDir);
  }
  
  /**
   * Save a certificate to the file system
   * @param domain Domain name 
   * @param certData Certificate data to save
   */
  public async saveCertificate(domain: string, certData: CertificateData): Promise<void> {
    const sanitizedDomain = this.sanitizeDomain(domain);
    const certDir = path.join(this.storageDir, sanitizedDomain);
    ensureCertificateDirectory(certDir);
    
    const certPath = path.join(certDir, 'fullchain.pem');
    const keyPath = path.join(certDir, 'privkey.pem');
    const metaPath = path.join(certDir, 'metadata.json');
    
    // Write certificate and private key
    await fs.promises.writeFile(certPath, certData.certificate, 'utf8');
    await fs.promises.writeFile(keyPath, certData.privateKey, 'utf8');
    
    // Write metadata
    const metadata = {
      domain: certData.domain,
      expiryDate: certData.expiryDate.toISOString(),
      source: certData.source || 'unknown',
      issuedAt: new Date().toISOString()
    };
    
    await fs.promises.writeFile(
      metaPath, 
      JSON.stringify(metadata, null, 2), 
      'utf8'
    );
  }
  
  /**
   * Load a certificate from the file system
   * @param domain Domain name
   * @returns Certificate data if found, null otherwise
   */
  public async loadCertificate(domain: string): Promise<CertificateData | null> {
    const sanitizedDomain = this.sanitizeDomain(domain);
    const certDir = path.join(this.storageDir, sanitizedDomain);
    
    if (!fs.existsSync(certDir)) {
      return null;
    }
    
    const certPath = path.join(certDir, 'fullchain.pem');
    const keyPath = path.join(certDir, 'privkey.pem');
    const metaPath = path.join(certDir, 'metadata.json');
    
    try {
      // Check if all required files exist
      if (!fs.existsSync(certPath) || !fs.existsSync(keyPath)) {
        return null;
      }
      
      // Read certificate and private key
      const certificate = await fs.promises.readFile(certPath, 'utf8');
      const privateKey = await fs.promises.readFile(keyPath, 'utf8');
      
      // Try to read metadata if available
      let expiryDate = new Date();
      let source: 'static' | 'http01' | 'dns01' | undefined;
      
      if (fs.existsSync(metaPath)) {
        const metaContent = await fs.promises.readFile(metaPath, 'utf8');
        const metadata = JSON.parse(metaContent);
        
        if (metadata.expiryDate) {
          expiryDate = new Date(metadata.expiryDate);
        }
        
        if (metadata.source) {
          source = metadata.source as 'static' | 'http01' | 'dns01';
        }
      }
      
      return {
        domain,
        certificate,
        privateKey,
        expiryDate,
        source
      };
    } catch (error) {
      console.error(`Error loading certificate for ${domain}:`, error);
      return null;
    }
  }
  
  /**
   * Delete a certificate from the file system
   * @param domain Domain name
   */
  public async deleteCertificate(domain: string): Promise<boolean> {
    const sanitizedDomain = this.sanitizeDomain(domain);
    const certDir = path.join(this.storageDir, sanitizedDomain);
    
    if (!fs.existsSync(certDir)) {
      return false;
    }
    
    try {
      // Recursively delete the certificate directory
      await this.deleteDirectory(certDir);
      return true;
    } catch (error) {
      console.error(`Error deleting certificate for ${domain}:`, error);
      return false;
    }
  }
  
  /**
   * List all domains with stored certificates
   * @returns Array of domain names
   */
  public async listCertificates(): Promise<string[]> {
    try {
      const entries = await fs.promises.readdir(this.storageDir, { withFileTypes: true });
      return entries
        .filter(entry => entry.isDirectory())
        .map(entry => entry.name);
    } catch (error) {
      console.error('Error listing certificates:', error);
      return [];
    }
  }
  
  /**
   * Check if a certificate is expiring soon
   * @param domain Domain name
   * @param thresholdDays Days threshold to consider expiring
   * @returns Information about expiring certificate or null
   */
  public async isExpiringSoon(
    domain: string, 
    thresholdDays: number = 30
  ): Promise<{ domain: string; expiryDate: Date; daysRemaining: number } | null> {
    const certData = await this.loadCertificate(domain);
    
    if (!certData) {
      return null;
    }
    
    const now = new Date();
    const expiryDate = certData.expiryDate;
    const timeRemaining = expiryDate.getTime() - now.getTime();
    const daysRemaining = Math.floor(timeRemaining / (1000 * 60 * 60 * 24));
    
    if (daysRemaining <= thresholdDays) {
      return {
        domain,
        expiryDate,
        daysRemaining
      };
    }
    
    return null;
  }
  
  /**
   * Check all certificates for expiration
   * @param thresholdDays Days threshold to consider expiring
   * @returns List of expiring certificates
   */
  public async getExpiringCertificates(
    thresholdDays: number = 30
  ): Promise<Array<{ domain: string; expiryDate: Date; daysRemaining: number }>> {
    const domains = await this.listCertificates();
    const expiringCerts = [];
    
    for (const domain of domains) {
      const expiring = await this.isExpiringSoon(domain, thresholdDays);
      if (expiring) {
        expiringCerts.push(expiring);
      }
    }
    
    return expiringCerts;
  }
  
  /**
   * Delete a directory recursively
   * @param directoryPath Directory to delete
   */
  private async deleteDirectory(directoryPath: string): Promise<void> {
    if (fs.existsSync(directoryPath)) {
      const entries = await fs.promises.readdir(directoryPath, { withFileTypes: true });
      
      for (const entry of entries) {
        const fullPath = path.join(directoryPath, entry.name);
        
        if (entry.isDirectory()) {
          await this.deleteDirectory(fullPath);
        } else {
          await fs.promises.unlink(fullPath);
        }
      }
      
      await fs.promises.rmdir(directoryPath);
    }
  }
  
  /**
   * Sanitize a domain name for use as a directory name
   * @param domain Domain name
   * @returns Sanitized domain name
   */
  private sanitizeDomain(domain: string): string {
    // Replace wildcard and any invalid filesystem characters
    return domain.replace(/\*/g, '_wildcard_').replace(/[/\\:*?"<>|]/g, '_');
  }
}