import * as plugins from '../plugins.js';
import { EmailService } from './classes.emailservice.js';
import { logger } from '../logger.js';

// Import MTA classes
import { 
  MtaService, 
  Email as MtaEmail, 
  type IEmailOptions, 
  DeliveryStatus,
  type IAttachment
} from '../mta/index.js';

export class MtaConnector {
  public emailRef: EmailService;
  private mtaService: MtaService;

  constructor(emailRefArg: EmailService, mtaService?: MtaService) {
    this.emailRef = emailRefArg;
    this.mtaService = mtaService || this.emailRef.mtaService;
  }

  /**
   * Send an email using the MTA service
   * @param smartmail The email to send
   * @param toAddresses Recipients (comma-separated or array)
   * @param options Additional options
   */
  public async sendEmail(
    smartmail: plugins.smartmail.Smartmail<any>,
    toAddresses: string | string[],
    options: any = {}
  ): Promise<string> {
    try {
      // Process recipients
      const toArray = Array.isArray(toAddresses) 
        ? toAddresses 
        : toAddresses.split(',').map(addr => addr.trim());
      
      // Add recipients to smartmail if they're not already added
      if (!smartmail.options.to || smartmail.options.to.length === 0) {
        for (const recipient of toArray) {
          smartmail.addRecipient(recipient);
        }
      }

      // Handle options
      const emailOptions: Record<string, any> = { ...options };
      
      // Check if we should use MIME format
      const useMimeFormat = options.useMimeFormat ?? true;
      
      if (useMimeFormat) {
        // Use smartmail's MIME conversion for improved handling
        try {
          // Convert to MIME format
          const mimeEmail = await smartmail.toMimeFormat(smartmail.options.creationObjectRef);
          
          // Parse the MIME email to create an MTA Email
          return this.sendMimeEmail(mimeEmail, toArray);
        } catch (mimeError) {
          logger.log('warn', `Failed to use MIME format, falling back to direct conversion: ${mimeError.message}`);
          // Fall back to direct conversion
          return this.sendDirectEmail(smartmail, toArray);
        }
      } else {
        // Use direct conversion
        return this.sendDirectEmail(smartmail, toArray);
      }
    } catch (error) {
      logger.log('error', `Failed to send email via MTA: ${error.message}`, {
        eventType: 'emailError',
        provider: 'mta',
        error: error.message
      });
      throw error;
    }
  }
  
  /**
   * Send a MIME-formatted email
   * @param mimeEmail The MIME-formatted email content
   * @param recipients The email recipients
   */
  private async sendMimeEmail(mimeEmail: string, recipients: string[]): Promise<string> {
    try {
      // Parse the MIME email
      const parsedEmail = await plugins.mailparser.simpleParser(mimeEmail);
      
      // Extract necessary information for MTA Email
      const mtaEmail = new MtaEmail({
        from: parsedEmail.from?.text || '',
        to: recipients,
        subject: parsedEmail.subject || '',
        text: parsedEmail.text || '',
        html: parsedEmail.html || undefined,
        attachments: parsedEmail.attachments?.map(attachment => ({
          filename: attachment.filename || 'attachment',
          content: attachment.content,
          contentType: attachment.contentType || 'application/octet-stream',
          contentId: attachment.contentId
        })) || [],
        headers: Object.fromEntries([...parsedEmail.headers].map(([key, value]) => [key, String(value)]))
      });
      
      // Send using MTA
      const emailId = await this.mtaService.send(mtaEmail);
      
      logger.log('info', `MIME email sent via MTA to ${recipients.join(', ')}`, {
        eventType: 'sentEmail',
        provider: 'mta',
        emailId,
        to: recipients
      });

      return emailId;
    } catch (error) {
      logger.log('error', `Failed to send MIME email: ${error.message}`);
      throw error;
    }
  }
  
  /**
   * Send an email using direct conversion (fallback method)
   * @param smartmail The Smartmail instance
   * @param recipients The email recipients
   */
  private async sendDirectEmail(
    smartmail: plugins.smartmail.Smartmail<any>,
    recipients: string[]
  ): Promise<string> {
    // Map SmartMail attachments to MTA attachments with improved content type handling
    const attachments: IAttachment[] = smartmail.attachments.map(attachment => {
      // Try to determine content type from file extension if not explicitly set
      let contentType = (attachment as any)?.contentType;
      
      if (!contentType) {
        const extension = attachment.parsedPath.ext.toLowerCase();
        contentType = this.getContentTypeFromExtension(extension);
      }
      
      return {
        filename: attachment.parsedPath.base,
        content: Buffer.from(attachment.contentBuffer),
        contentType: contentType || 'application/octet-stream',
        // Add content ID for inline images if available
        contentId: (attachment as any)?.contentId
      };
    });

    // Create MTA Email
    const mtaEmail = new MtaEmail({
      from: smartmail.options.from,
      to: recipients,
      subject: smartmail.getSubject(),
      text: smartmail.getBody(false), // Plain text version
      html: smartmail.getBody(true),  // HTML version
      attachments
    });
    
    // Prepare arrays for CC and BCC recipients
    let ccRecipients: string[] = [];
    let bccRecipients: string[] = [];
    
    // Add CC recipients if present
    if (smartmail.options.cc?.length > 0) {
      // Handle CC recipients - smartmail options may contain email objects
      ccRecipients = smartmail.options.cc.map(r => {
        if (typeof r === 'string') return r;
        return typeof (r as any).address === 'string' ? (r as any).address : 
               typeof (r as any).email === 'string' ? (r as any).email : '';
      });
      mtaEmail.cc = ccRecipients;
    }
    
    // Add BCC recipients if present
    if (smartmail.options.bcc?.length > 0) {
      // Handle BCC recipients - smartmail options may contain email objects
      bccRecipients = smartmail.options.bcc.map(r => {
        if (typeof r === 'string') return r;
        return typeof (r as any).address === 'string' ? (r as any).address : 
               typeof (r as any).email === 'string' ? (r as any).email : '';
      });
      mtaEmail.bcc = bccRecipients;
    }

    // Send using MTA
    const emailId = await this.mtaService.send(mtaEmail);
    
    logger.log('info', `Email sent via MTA to ${recipients.join(', ')}`, {
      eventType: 'sentEmail',
      provider: 'mta',
      emailId,
      to: recipients
    });

    return emailId;
  }
  
  /**
   * Get content type from file extension
   * @param extension The file extension (with or without dot)
   * @returns The content type or undefined if unknown
   */
  private getContentTypeFromExtension(extension: string): string | undefined {
    // Remove dot if present
    const ext = extension.startsWith('.') ? extension.substring(1) : extension;
    
    // Common content types
    const contentTypes: Record<string, string> = {
      'pdf': 'application/pdf',
      'jpg': 'image/jpeg',
      'jpeg': 'image/jpeg',
      'png': 'image/png',
      'gif': 'image/gif',
      'svg': 'image/svg+xml',
      'webp': 'image/webp',
      'txt': 'text/plain',
      'html': 'text/html',
      'csv': 'text/csv',
      'json': 'application/json',
      'xml': 'application/xml',
      'zip': 'application/zip',
      'doc': 'application/msword',
      'docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
      'xls': 'application/vnd.ms-excel',
      'xlsx': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      'ppt': 'application/vnd.ms-powerpoint',
      'pptx': 'application/vnd.openxmlformats-officedocument.presentationml.presentation'
    };
    
    return contentTypes[ext.toLowerCase()];
  }

  /**
   * Retrieve and process an incoming email
   * For MTA, this would handle an email already received by the SMTP server
   * @param emailData The raw email data or identifier
   * @param options Additional processing options
   */
  public async receiveEmail(
    emailData: string,
    options: {
      preserveHeaders?: boolean;
      includeRawData?: boolean;
      validateSender?: boolean;
    } = {}
  ): Promise<plugins.smartmail.Smartmail<any>> {
    try {
      // In a real implementation, this would retrieve an email from the MTA storage
      // For now, we can use a simplified approach:
      
      // Parse the email (assuming emailData is a raw email or a file path)
      const parsedEmail = await plugins.mailparser.simpleParser(emailData);
      
      // Extract sender information
      const sender = parsedEmail.from?.text || '';
      let senderName = '';
      let senderEmail = sender;
      
      // Try to extract name and email from "Name <email>" format
      const senderMatch = sender.match(/(.*?)\s*<([^>]+)>/);
      if (senderMatch) {
        senderName = senderMatch[1].trim();
        senderEmail = senderMatch[2].trim();
      }
      
      // Extract recipients
      const recipients = [];
      if (parsedEmail.to) {
        // Extract recipients safely
        try {
          // Handle AddressObject or AddressObject[]
          if (parsedEmail.to && typeof parsedEmail.to === 'object' && 'value' in parsedEmail.to) {
            const addressList = Array.isArray(parsedEmail.to.value) 
              ? parsedEmail.to.value 
              : [parsedEmail.to.value];
              
            for (const addr of addressList) {
              if (addr && typeof addr === 'object' && 'address' in addr) {
                recipients.push({
                  name: addr.name || '',
                  email: addr.address || ''
                });
              }
            }
          }
        } catch (error) {
          // If parsing fails, try to extract as string
          let toStr = '';
          if (parsedEmail.to && typeof parsedEmail.to === 'object' && 'text' in parsedEmail.to) {
            toStr = String(parsedEmail.to.text || '');
          }
          if (toStr) {
            recipients.push({
              name: '',
              email: toStr
            });
          }
        }
      }
      
      // Create a more comprehensive creation object reference
      const creationObjectRef: Record<string, any> = {
        sender: {
          name: senderName,
          email: senderEmail
        },
        recipients: recipients,
        subject: parsedEmail.subject || '',
        date: parsedEmail.date || new Date(),
        messageId: parsedEmail.messageId || '',
        inReplyTo: parsedEmail.inReplyTo || null,
        references: parsedEmail.references || []
      };
      
      // Include headers if requested
      if (options.preserveHeaders) {
        creationObjectRef.headers = parsedEmail.headers;
      }
      
      // Include raw data if requested
      if (options.includeRawData) {
        creationObjectRef.rawData = emailData;
      }
      
      // Create a Smartmail from the parsed email
      const smartmail = new plugins.smartmail.Smartmail({
        from: senderEmail,
        subject: parsedEmail.subject || '',
        body: parsedEmail.html || parsedEmail.text || '',
        creationObjectRef
      });
      
      // Add recipients
      if (recipients.length > 0) {
        for (const recipient of recipients) {
          smartmail.addRecipient(recipient.email);
        }
      }
      
      // Add CC recipients if present
      if (parsedEmail.cc) {
        try {
          // Extract CC recipients safely
          if (parsedEmail.cc && typeof parsedEmail.cc === 'object' && 'value' in parsedEmail.cc) {
            const ccList = Array.isArray(parsedEmail.cc.value) 
              ? parsedEmail.cc.value 
              : [parsedEmail.cc.value];
              
            for (const addr of ccList) {
              if (addr && typeof addr === 'object' && 'address' in addr) {
                smartmail.addRecipient(addr.address, 'cc');
              }
            }
          }
        } catch (error) {
          // If parsing fails, try to extract as string
          let ccStr = '';
          if (parsedEmail.cc && typeof parsedEmail.cc === 'object' && 'text' in parsedEmail.cc) {
            ccStr = String(parsedEmail.cc.text || '');
          }
          if (ccStr) {
            smartmail.addRecipient(ccStr, 'cc');
          }
        }
      }
      
      // Add BCC recipients if present (usually not in received emails, but just in case)
      if (parsedEmail.bcc) {
        try {
          // Extract BCC recipients safely
          if (parsedEmail.bcc && typeof parsedEmail.bcc === 'object' && 'value' in parsedEmail.bcc) {
            const bccList = Array.isArray(parsedEmail.bcc.value) 
              ? parsedEmail.bcc.value 
              : [parsedEmail.bcc.value];
              
            for (const addr of bccList) {
              if (addr && typeof addr === 'object' && 'address' in addr) {
                smartmail.addRecipient(addr.address, 'bcc');
              }
            }
          }
        } catch (error) {
          // If parsing fails, try to extract as string
          let bccStr = '';
          if (parsedEmail.bcc && typeof parsedEmail.bcc === 'object' && 'text' in parsedEmail.bcc) {
            bccStr = String(parsedEmail.bcc.text || '');
          }
          if (bccStr) {
            smartmail.addRecipient(bccStr, 'bcc');
          }
        }
      }

      // Add attachments if present
      if (parsedEmail.attachments && parsedEmail.attachments.length > 0) {
        for (const attachment of parsedEmail.attachments) {
          // Create smartfile with proper constructor options
          const file = new plugins.smartfile.SmartFile({
            path: attachment.filename || 'attachment',
            contentBuffer: attachment.content,
            base: ''
          });
          
          // Set content type and content ID for proper MIME handling
          if (attachment.contentType) {
            (file as any).contentType = attachment.contentType;
          }
          
          if (attachment.contentId) {
            (file as any).contentId = attachment.contentId;
          }
          
          smartmail.addAttachment(file);
        }
      }
      
      // Validate sender if requested
      if (options.validateSender && this.emailRef.emailValidator) {
        try {
          const validationResult = await this.emailRef.emailValidator.validate(senderEmail, {
            checkSyntaxOnly: true // Use syntax-only for performance
          });
          
          // Add validation info to the creation object
          creationObjectRef.senderValidation = validationResult;
        } catch (validationError) {
          logger.log('warn', `Sender validation error: ${validationError.message}`);
        }
      }

      return smartmail;
    } catch (error) {
      logger.log('error', `Failed to receive email via MTA: ${error.message}`, {
        eventType: 'emailError',
        provider: 'mta',
        error: error.message
      });
      throw error;
    }
  }

  /**
   * Check the status of a sent email
   * @param emailId The email ID to check
   */
  public async checkEmailStatus(emailId: string): Promise<{
    status: string;
    details?: any;
  }> {
    try {
      const status = this.mtaService.getEmailStatus(emailId);
      
      if (!status) {
        return {
          status: 'unknown',
          details: { message: 'Email not found' }
        };
      }

      return {
        status: status.status,
        details: {
          attempts: status.attempts,
          lastAttempt: status.lastAttempt,
          nextAttempt: status.nextAttempt,
          error: status.error?.message
        }
      };
    } catch (error) {
      logger.log('error', `Failed to check email status: ${error.message}`, {
        eventType: 'emailError',
        provider: 'mta',
        emailId,
        error: error.message
      });
      
      return {
        status: 'error',
        details: { message: error.message }
      };
    }
  }
}