vexplor_dev/backend-node/src/services/mailSentHistoryService.ts

/**
 * 메일 발송 이력 관리 서비스 (파일 기반)
 */

import fs from 'fs';
import path from 'path';
import { v4 as uuidv4 } from 'uuid';
import {
  SentMailHistory,
  SentMailListQuery,
  SentMailListResponse,
  AttachmentInfo,
} from '../types/mailSentHistory';

const SENT_MAIL_DIR = path.join(__dirname, '../../data/mail-sent');

class MailSentHistoryService {
  constructor() {
    // 디렉토리 생성 (없으면)
    if (!fs.existsSync(SENT_MAIL_DIR)) {
      fs.mkdirSync(SENT_MAIL_DIR, { recursive: true });
    }
  }

  /**
   * 발송 이력 저장
   */
  async saveSentMail(data: Omit<SentMailHistory, 'id' | 'sentAt'>): Promise<SentMailHistory> {
    const history: SentMailHistory = {
      id: uuidv4(),
      sentAt: new Date().toISOString(),
      ...data,
    };

    const filePath = path.join(SENT_MAIL_DIR, `${history.id}.json`);
    fs.writeFileSync(filePath, JSON.stringify(history, null, 2), 'utf-8');

    console.log('💾 발송 이력 저장:', history.id);
    return history;
  }

  /**
   * 발송 이력 목록 조회 (필터링, 페이징)
   */
  async getSentMailList(query: SentMailListQuery): Promise<SentMailListResponse> {
    const {
      page = 1,
      limit = 20,
      searchTerm = '',
      status = 'all',
      accountId,
      startDate,
      endDate,
      sortBy = 'sentAt',
      sortOrder = 'desc',
    } = query;

    // 모든 발송 이력 파일 읽기
    const files = fs.readdirSync(SENT_MAIL_DIR).filter((f) => f.endsWith('.json'));
    let allHistory: SentMailHistory[] = [];

    for (const file of files) {
      try {
        const filePath = path.join(SENT_MAIL_DIR, file);
        const content = fs.readFileSync(filePath, 'utf-8');
        const history: SentMailHistory = JSON.parse(content);
        allHistory.push(history);
      } catch (error) {
        console.error(`발송 이력 파일 읽기 실패: ${file}`, error);
      }
    }

    // 필터링
    let filtered = allHistory;

    // 상태 필터
    if (status !== 'all') {
      filtered = filtered.filter((h) => h.status === status);
    }

    // 계정 필터
    if (accountId) {
      filtered = filtered.filter((h) => h.accountId === accountId);
    }

    // 날짜 필터
    if (startDate) {
      filtered = filtered.filter((h) => h.sentAt >= startDate);
    }
    if (endDate) {
      filtered = filtered.filter((h) => h.sentAt <= endDate);
    }

    // 검색어 필터 (제목, 받는사람)
    if (searchTerm) {
      const term = searchTerm.toLowerCase();
      filtered = filtered.filter(
        (h) =>
          h.subject.toLowerCase().includes(term) ||
          h.to.some((email) => email.toLowerCase().includes(term)) ||
          (h.cc && h.cc.some((email) => email.toLowerCase().includes(term)))
      );
    }

    // 정렬
    filtered.sort((a, b) => {
      let aVal: any = a[sortBy];
      let bVal: any = b[sortBy];

      if (sortBy === 'sentAt') {
        aVal = new Date(aVal).getTime();
        bVal = new Date(bVal).getTime();
      } else {
        aVal = aVal ? aVal.toLowerCase() : '';
        bVal = bVal ? bVal.toLowerCase() : '';
      }

      if (sortOrder === 'asc') {
        return aVal > bVal ? 1 : -1;
      } else {
        return aVal < bVal ? 1 : -1;
      }
    });

    // 페이징
    const total = filtered.length;
    const totalPages = Math.ceil(total / limit);
    const start = (page - 1) * limit;
    const end = start + limit;
    const items = filtered.slice(start, end);

    return {
      items,
      total,
      page,
      limit,
      totalPages,
    };
  }

  /**
   * 특정 발송 이력 조회
   */
  async getSentMailById(id: string): Promise<SentMailHistory | null> {
    const filePath = path.join(SENT_MAIL_DIR, `${id}.json`);

    if (!fs.existsSync(filePath)) {
      return null;
    }

    try {
      const content = fs.readFileSync(filePath, 'utf-8');
      return JSON.parse(content) as SentMailHistory;
    } catch (error) {
      console.error('발송 이력 읽기 실패:', error);
      return null;
    }
  }

  /**
   * 발송 이력 삭제
   */
  async deleteSentMail(id: string): Promise<boolean> {
    const filePath = path.join(SENT_MAIL_DIR, `${id}.json`);

    if (!fs.existsSync(filePath)) {
      return false;
    }

    try {
      fs.unlinkSync(filePath);
      console.log('🗑️ 발송 이력 삭제:', id);
      return true;
    } catch (error) {
      console.error('발송 이력 삭제 실패:', error);
      return false;
    }
  }

  /**
   * 통계 조회
   */
  async getStatistics(accountId?: string): Promise<{
    totalSent: number;
    successCount: number;
    failedCount: number;
    todayCount: number;
    thisMonthCount: number;
    successRate: number;
  }> {
    const files = fs.readdirSync(SENT_MAIL_DIR).filter((f) => f.endsWith('.json'));
    let allHistory: SentMailHistory[] = [];

    for (const file of files) {
      try {
        const filePath = path.join(SENT_MAIL_DIR, file);
        const content = fs.readFileSync(filePath, 'utf-8');
        const history: SentMailHistory = JSON.parse(content);
        
        // 계정 필터
        if (!accountId || history.accountId === accountId) {
          allHistory.push(history);
        }
      } catch (error) {
        console.error(`발송 이력 파일 읽기 실패: ${file}`, error);
      }
    }

    const now = new Date();
    const todayStart = new Date(now.getFullYear(), now.getMonth(), now.getDate()).toISOString();
    const monthStart = new Date(now.getFullYear(), now.getMonth(), 1).toISOString();

    const totalSent = allHistory.length;
    const successCount = allHistory.filter((h) => h.status === 'success').length;
    const failedCount = allHistory.filter((h) => h.status === 'failed').length;
    const todayCount = allHistory.filter((h) => h.sentAt >= todayStart).length;
    const thisMonthCount = allHistory.filter((h) => h.sentAt >= monthStart).length;
    const successRate = totalSent > 0 ? Math.round((successCount / totalSent) * 100) : 0;

    return {
      totalSent,
      successCount,
      failedCount,
      todayCount,
      thisMonthCount,
      successRate,
    };
  }
}

export const mailSentHistoryService = new MailSentHistoryService();