#!/usr/bin/env node
// 邮件工具（IMAP 收发）
// 通过 stdin 接收 JSON 参数
let input = '';
process.stdin.on('data', (chunk) => input += chunk);
process.stdin.on('end', async () => {
  try {
    const params = JSON.parse(input.trim() || '{}');
    const action = params.action || 'list_unread';
    const limit = params.limit || 5;

    const host = process.env.EMAIL_IMAP_HOST;
    const port = parseInt(process.env.EMAIL_IMAP_PORT || '993');
    const user = process.env.EMAIL_IMAP_USER;
    const password = process.env.EMAIL_IMAP_PASSWORD;

    if (!host || !user || !password) {
      console.log('请设置 EMAIL_IMAP_HOST, EMAIL_IMAP_USER, EMAIL_IMAP_PASSWORD');
      process.exit(1);
    }

    // 使用 openssl s_client 连接 IMAP over SSL
    // 简单实现：列出收件箱最近 N 封邮件摘要
    const net = require('net');
    const tls = require('tls');

    const socket = tls.connect(port, host, { rejectUnauthorized: false }, () => {
      let buf = '';
      let step = 0;
      let tag = 0;

      function cmd(line) {
        tag++;
        socket.write(`A${tag} ${line}\r\n`);
        return `A${tag}`;
      }

      socket.on('data', (data) => {
        buf += data.toString('utf-8');
        // 简化处理：等服务器就绪后依次发命令
        if (step === 0 && buf.includes('OK')) {
          step = 1;
          cmd(`LOGIN "${user}" "${password}"`);
        } else if (step === 1 && buf.includes(`A1 OK`)) {
          step = 2;
          cmd('SELECT INBOX');
        } else if (step === 2 && buf.includes(`A2 OK`)) {
          step = 3;
          cmd(`FETCH 1:${limit} (FLAGS INTERNALDATE BODY.PEEK[HEADER.FIELDS (SUBJECT FROM DATE)])`);
        } else if (step === 3 && buf.includes(`A3 OK`)) {
          step = 4;
          // 解析结果
          const lines = buf.split('\n').filter(l => l.trim());
          const results = [];
          let current = {};
          for (const line of lines) {
            if (line.match(/^\* \d+ FETCH/)) {
              if (current.subject) results.push(current);
              current = {};
            }
            const subjMatch = line.match(/^SUBJECT: (.+)$/i);
            const fromMatch = line.match(/^FROM: (.+)$/i);
            const dateMatch = line.match(/^DATE: (.+)$/i);
            if (subjMatch) current.subject = subjMatch[1].trim();
            if (fromMatch) current.from = fromMatch[1].trim();
            if (dateMatch) current.date = dateMatch[1].trim();
          }
          if (current.subject) results.push(current);

          console.log(`最近 ${results.length} 封邮件:`);
          results.forEach((r, i) => {
            console.log(`\n${i+1}. 主题: ${r.subject || '(无主题)'}`);
            console.log(`   发件人: ${r.from || '未知'}`);
            console.log(`   时间: ${r.date || '未知'}`);
          });
          cmd('LOGOUT');
        }
      });
    });

    socket.setTimeout(15000, () => {
      console.log('连接 IMAP 超时');
      process.exit(1);
    });

  } catch (e) {
    console.log(`邮件查询失败: ${e.message}`);
    process.exit(1);
  }
});