/**
 * 간단한 메일 발송 서비스 (쿼리 제외)
 * Nodemailer를 사용한 직접 발송
 */

import nodemailer from 'nodemailer';
import { mailAccountFileService } from './mailAccountFileService';
import { mailTemplateFileService } from './mailTemplateFileService';

export interface SendMailRequest {
  accountId: string;
  templateId?: string;
  to: string[]; // 수신자 이메일 배열
  subject: string;
  variables?: Record<string, string>; // 템플릿 변수 치환
  customHtml?: string; // 템플릿 없이 직접 HTML 작성 시
}

export interface SendMailResult {
  success: boolean;
  messageId?: string;
  accepted?: string[];
  rejected?: string[];
  error?: string;
}

class MailSendSimpleService {
  /**
   * 단일 메일 발송 또는 소규모 발송
   */
  async sendMail(request: SendMailRequest): Promise<SendMailResult> {
    try {
      // 1. 계정 조회
      const account = await mailAccountFileService.getAccountById(request.accountId);
      if (!account) {
        throw new Error('메일 계정을 찾을 수 없습니다.');
      }

      // 2. 계정 활성화 확인
      if (account.status !== 'active') {
        throw new Error('비활성 상태의 계정입니다.');
      }

      // 3. HTML 생성 (템플릿 또는 커스텀)
      let htmlContent = request.customHtml || '';
      
      if (!htmlContent && request.templateId) {
        const template = await mailTemplateFileService.getTemplateById(request.templateId);
        if (!template) {
          throw new Error('템플릿을 찾을 수 없습니다.');
        }
        htmlContent = this.renderTemplate(template, request.variables);
      }

      if (!htmlContent) {
        throw new Error('메일 내용이 없습니다.');
      }

      // 4. SMTP 연결 생성
      const transporter = nodemailer.createTransport({
        host: account.smtpHost,
        port: account.smtpPort,
        secure: account.smtpSecure, // SSL/TLS
        auth: {
          user: account.smtpUsername,
          pass: account.smtpPassword,
        },
      });

      // 5. 메일 발송
      const info = await transporter.sendMail({
        from: `"${account.name}" <${account.email}>`,
        to: request.to.join(', '),
        subject: this.replaceVariables(request.subject, request.variables),
        html: htmlContent,
      });

      return {
        success: true,
        messageId: info.messageId,
        accepted: info.accepted as string[],
        rejected: info.rejected as string[],
      };
    } catch (error) {
      const err = error as Error;
      return {
        success: false,
        error: err.message,
      };
    }
  }

  /**
   * 템플릿 렌더링 (간단 버전)
   */
  private renderTemplate(
    template: any,
    variables?: Record<string, string>
  ): string {
    let html = '<div style="max-width: 600px; margin: 0 auto; font-family: Arial, sans-serif;">';

    template.components.forEach((component: any) => {
      switch (component.type) {
        case 'text':
          let content = component.content || '';
          if (variables) {
            content = this.replaceVariables(content, variables);
          }
          html += `<div style="${this.styleObjectToString(component.styles)}">${content}</div>`;
          break;

        case 'button':
          let buttonText = component.text || 'Button';
          if (variables) {
            buttonText = this.replaceVariables(buttonText, variables);
          }
          html += `
            <a href="${component.url || '#'}" style="
              display: inline-block;
              padding: 12px 24px;
              background-color: ${component.styles?.backgroundColor || '#007bff'};
              color: ${component.styles?.color || 'white'};
              text-decoration: none;
              border-radius: 4px;
              ${this.styleObjectToString(component.styles)}
            ">${buttonText}</a>
          `;
          break;

        case 'image':
          html += `<img src="${component.src || ''}" style="max-width: 100%; ${this.styleObjectToString(component.styles)}" />`;
          break;

        case 'spacer':
          html += `<div style="height: ${component.height || 20}px;"></div>`;
          break;
      }
    });

    html += '</div>';
    return html;
  }

  /**
   * 변수 치환
   */
  private replaceVariables(text: string, variables?: Record<string, string>): string {
    if (!variables) return text;

    let result = text;
    Object.entries(variables).forEach(([key, value]) => {
      const regex = new RegExp(`\\{${key}\\}`, 'g');
      result = result.replace(regex, value);
    });

    return result;
  }

  /**
   * 스타일 객체를 CSS 문자열로 변환
   */
  private styleObjectToString(styles?: Record<string, string>): string {
    if (!styles) return '';
    return Object.entries(styles)
      .map(([key, value]) => `${this.camelToKebab(key)}: ${value}`)
      .join('; ');
  }

  /**
   * camelCase를 kebab-case로 변환
   */
  private camelToKebab(str: string): string {
    return str.replace(/([a-z0-9])([A-Z])/g, '$1-$2').toLowerCase();
  }

  /**
   * SMTP 연결 테스트
   */
  async testConnection(accountId: string): Promise<{ success: boolean; message: string }> {
    try {
      const account = await mailAccountFileService.getAccountById(accountId);
      if (!account) {
        throw new Error('계정을 찾을 수 없습니다.');
      }

      const transporter = nodemailer.createTransport({
        host: account.smtpHost,
        port: account.smtpPort,
        secure: account.smtpSecure,
        auth: {
          user: account.smtpUsername,
          pass: account.smtpPassword,
        },
      });

      await transporter.verify();

      return {
        success: true,
        message: 'SMTP 연결 성공!',
      };
    } catch (error) {
      const err = error as Error;
      return {
        success: false,
        message: `연결 실패: ${err.message}`,
      };
    }
  }
}

export const mailSendSimpleService = new MailSendSimpleService();