const express = require('express');
const session = require('express-session');
const bcrypt = require('bcryptjs');
const multer = require('multer');
const rateLimit = require('express-rate-limit');
const crypto = require('crypto');
const fs = require('fs');
const path = require('path');

const PORT = process.env.PORT || 3210;
// 127.0.0.1 by default: on a VPS, Nginx fronts this with TLS and is the only
// thing that should be reachable from outside. On the old local-Windows setup
// this was 0.0.0.0 for LAN access; set HOST=0.0.0.0 explicitly if you still
// need that. COOKIE_SECURE should be "true" once you're behind real HTTPS.
const HOST = process.env.HOST || '127.0.0.1';
const COOKIE_SECURE = process.env.COOKIE_SECURE === 'true';
const DATA_FILE = path.join(__dirname, 'data.json');
const PID_FILE = path.join(__dirname, 'server.pid');
const FRONTEND_DIST = path.join(__dirname, '..', 'frontend', 'dist');
const UPLOADS_DIR = path.join(__dirname, 'uploads');
const AUTH_FILE = path.join(__dirname, 'auth.json');
const DEFAULT_USERNAME = 'admin';
const DEFAULT_PASSWORD = 'admin123';
// AI批量导入解析时，PDF渲染成图片/OCR用的临时文件放在这里，而不是系统的 os.tmpdir()（一般是
// /tmp）——有些VPS/容器环境会把 /tmp 挂载成只读或者单独的受限分区，直接用系统临时目录在这类
// 环境下会导致 mkdtempSync 抛出 EROFS 之类的错误，而且这个调用当时没被 try/catch 包住，会
// 直接让整个Node进程崩溃。用应用自己目录下这个文件夹，保证和 uploads/ 一样一定可读写。
const OCR_TMP_ROOT = path.join(__dirname, 'tmp-ocr');

if (!fs.existsSync(UPLOADS_DIR)) fs.mkdirSync(UPLOADS_DIR, { recursive: true });
if (!fs.existsSync(OCR_TMP_ROOT)) fs.mkdirSync(OCR_TMP_ROOT, { recursive: true });

/* --------------------------------- auth ---------------------------------- */

function loadAuth() {
  if (!fs.existsSync(AUTH_FILE)) {
    const auth = { username: DEFAULT_USERNAME, passwordHash: bcrypt.hashSync(DEFAULT_PASSWORD, 10) };
    fs.writeFileSync(AUTH_FILE, JSON.stringify(auth, null, 2), 'utf8');
    return auth;
  }
  try {
    return JSON.parse(fs.readFileSync(AUTH_FILE, 'utf8'));
  } catch (e) {
    const auth = { username: DEFAULT_USERNAME, passwordHash: bcrypt.hashSync(DEFAULT_PASSWORD, 10) };
    fs.writeFileSync(AUTH_FILE, JSON.stringify(auth, null, 2), 'utf8');
    return auth;
  }
}
function saveAuth(auth) {
  fs.writeFileSync(AUTH_FILE, JSON.stringify(auth, null, 2), 'utf8');
}

/* ------------------------------ secret / crypto -------------------------- */
// Used to encrypt the DeepSeek API key (and anything else sensitive) at
// rest, so it isn't sitting around the filesystem as plain text.

const SECRET_KEY_FILE = path.join(__dirname, '.secret-key');
function getSecretKey() {
  if (!fs.existsSync(SECRET_KEY_FILE)) {
    const key = crypto.randomBytes(32);
    fs.writeFileSync(SECRET_KEY_FILE, key.toString('base64'), { encoding: 'utf8', mode: 0o600 });
    return key;
  }
  return Buffer.from(fs.readFileSync(SECRET_KEY_FILE, 'utf8').trim(), 'base64');
}
const SECRET_KEY = getSecretKey();

function encrypt(text) {
  if (!text) return '';
  const iv = crypto.randomBytes(12);
  const cipher = crypto.createCipheriv('aes-256-gcm', SECRET_KEY, iv);
  const encrypted = Buffer.concat([cipher.update(text, 'utf8'), cipher.final()]);
  const tag = cipher.getAuthTag();
  return Buffer.concat([iv, tag, encrypted]).toString('base64');
}
function decrypt(b64) {
  if (!b64) return '';
  try {
    const buf = Buffer.from(b64, 'base64');
    const iv = buf.subarray(0, 12);
    const tag = buf.subarray(12, 28);
    const encrypted = buf.subarray(28);
    const decipher = crypto.createDecipheriv('aes-256-gcm', SECRET_KEY, iv);
    decipher.setAuthTag(tag);
    return Buffer.concat([decipher.update(encrypted), decipher.final()]).toString('utf8');
  } catch (e) {
    return '';
  }
}

/* --------------------------------- AI config ------------------------------ */

const AI_CONFIG_FILE = path.join(__dirname, 'ai-config.json');
// Lets you point this at a different OpenAI-compatible endpoint if needed
// (e.g. testing against a mock server); defaults to the real DeepSeek API.
const DEEPSEEK_API_BASE = process.env.DEEPSEEK_API_BASE || 'https://api.deepseek.com';

function loadAiConfig() {
  try {
    const raw = JSON.parse(fs.readFileSync(AI_CONFIG_FILE, 'utf8'));
    return { apiKey: decrypt(raw.apiKeyEnc || '') };
  } catch (e) {
    return { apiKey: '' };
  }
}
function saveAiConfig(apiKey) {
  fs.writeFileSync(AI_CONFIG_FILE, JSON.stringify({ apiKeyEnc: encrypt(apiKey) }, null, 2), 'utf8');
}

const REGION_LABELS = {
  africa: 'Africa', middle_east: 'Middle East', australia: 'Australia/Oceania',
  europe: 'Europe', sea: 'Southeast Asia', other: 'Other',
};

function buildCustomerContext(c) {
  const lines = [];
  lines.push(`Company: ${c.company || '(unknown / not on file)'}`);
  if (c.contact) lines.push(`Contact person: ${c.contact}`);
  const place = [c.country, REGION_LABELS[c.region]].filter(Boolean).join(', ');
  if (place) lines.push(`Location: ${place}`);
  if (c.productLines && c.productLines.length) lines.push(`Product interest: ${c.productLines.join(', ')}`);
  if (c.intendedModel || c.intendedQty) {
    lines.push(`Specific model interest: ${c.intendedModel || '(model unspecified)'}${c.intendedQty ? `, quantity: ${c.intendedQty}` : ''}`);
  }
  if (c.lastContact) lines.push(`Last contact date: ${c.lastContact}`);
  if (c.notes) lines.push(`Background research on this customer: ${c.notes}`);
  if (c.tags) lines.push(`Additional remarks: ${c.tags}`);
  if (c.isVip) lines.push('This is a VIP / priority customer — extra attentive tone.');
  if (c.hasOrdered) lines.push('This customer has already placed an order before — this follow-up is with an existing buyer, not a cold lead.');
  return lines.join('\n');
}

async function callDeepSeek(apiKey, messages, opts) {
  const { maxTokens = 600, temperature = 0.7, model = 'deepseek-v4-flash' } = opts || {};
  const resp = await fetch(`${DEEPSEEK_API_BASE}/chat/completions`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      Authorization: `Bearer ${apiKey}`,
    },
    body: JSON.stringify({
      model,
      messages,
      temperature,
      max_tokens: maxTokens,
    }),
  });
  if (!resp.ok) {
    const errText = await resp.text().catch(() => '');
    throw new Error(`DeepSeek API error ${resp.status}: ${errText.slice(0, 200)}`);
  }
  const data = await resp.json();
  const content = data.choices && data.choices[0] && data.choices[0].message && data.choices[0].message.content;
  if (!content) throw new Error('DeepSeek API returned an empty response');
  return content;
}

// 从DeepSeek返回的内容里提取JSON——模型有时会用```json代码块包一层，或者前后带几句解释文字，
// 这里做宽松解析：优先找代码块，找不到就找第一个 { 或 [ 到最后一个 } 或 ] 之间的内容。
function extractJson(content) {
  const fenced = content.match(/```(?:json)?\s*([\s\S]*?)```/i);
  const raw = fenced ? fenced[1] : content;
  const start = raw.search(/[\[{]/);
  const endBrace = raw.lastIndexOf('}');
  const endBracket = raw.lastIndexOf(']');
  const end = Math.max(endBrace, endBracket);
  if (start === -1 || end === -1 || end < start) throw new Error('AI返回内容里没有找到JSON');
  return JSON.parse(raw.slice(start, end + 1));
}

/* ------------------------------ data file ------------------------------ */

function readData() {
  try {
    return JSON.parse(fs.readFileSync(DATA_FILE, 'utf8'));
  } catch (e) {
    return {};
  }
}

function writeData(data) {
  // write to a temp file then rename, avoids corrupting data.json if the
  // process is killed mid-write
  const tmp = DATA_FILE + '.tmp';
  fs.writeFileSync(tmp, JSON.stringify(data, null, 2), 'utf8');
  fs.renameSync(tmp, DATA_FILE);
}

// only allow simple ids (our customer ids are like "c_169..._ab12c"),
// this keeps the upload path from ever escaping the uploads/ folder
function safeId(id) {
  return /^[A-Za-z0-9_-]+$/.test(id) ? id : null;
}

/* --------------------------------- app ---------------------------------- */

const app = express();

// behind Nginx, Express needs this to read X-Forwarded-* correctly —
// otherwise req.ip is always Nginx's own address (breaks rate limiting)
// and the "secure" cookie flag can't tell the request was HTTPS.
app.set('trust proxy', 1);

app.use(express.json({ limit: '10mb' }));
app.use(session({
  secret: crypto.randomBytes(32).toString('hex'),
  resave: false,
  saveUninitialized: false,
  cookie: {
    httpOnly: true,
    sameSite: 'lax',
    secure: COOKIE_SECURE,
    maxAge: 30 * 24 * 60 * 60 * 1000, // 30 days
  },
}));

function requireAuth(req, res, next) {
  if (req.session && req.session.authed) return next();
  res.status(401).json({ error: 'not authenticated' });
}

const loginLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 5,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'too many login attempts, please try again in a few minutes' },
});

/* -------------------------------- auth api ------------------------------- */

app.post('/api/auth/login', loginLimiter, (req, res) => {
  const body = req.body || {};
  const username = body.username || '';
  const password = body.password || '';
  const auth = loadAuth();
  if (username === auth.username && bcrypt.compareSync(password, auth.passwordHash)) {
    req.session.authed = true;
    req.session.username = username;
    return res.json({ ok: true, username });
  }
  res.status(401).json({ error: 'invalid credentials' });
});

app.post('/api/auth/logout', (req, res) => {
  if (req.session) {
    req.session.destroy(() => res.json({ ok: true }));
  } else {
    res.json({ ok: true });
  }
});

app.get('/api/auth/check', (req, res) => {
  const authed = !!(req.session && req.session.authed);
  res.json({ authed, username: authed ? req.session.username : null });
});

app.post('/api/auth/change-password', requireAuth, (req, res) => {
  const body = req.body || {};
  const currentPassword = body.currentPassword || '';
  const newPassword = body.newPassword || '';
  const auth = loadAuth();
  if (!bcrypt.compareSync(currentPassword, auth.passwordHash)) {
    return res.status(400).json({ error: 'current password is incorrect' });
  }
  if (newPassword.length < 4) {
    return res.status(400).json({ error: 'new password is too short' });
  }
  auth.passwordHash = bcrypt.hashSync(newPassword, 10);
  saveAuth(auth);
  res.json({ ok: true });
});

/* ------------------------------ storage api ------------------------------ */

app.get('/api/storage/:key', requireAuth, (req, res) => {
  const data = readData();
  const key = req.params.key;
  if (!(key in data)) return res.status(404).json({ error: 'not found' });
  res.json({ value: data[key] });
});

app.put('/api/storage/:key', requireAuth, (req, res) => {
  const data = readData();
  data[req.params.key] = req.body.value;
  writeData(data);
  res.json({ ok: true });
});

/* --------------------------------- ai api --------------------------------- */

app.get('/api/ai-config', requireAuth, (req, res) => {
  const cfg = loadAiConfig();
  res.json({ hasKey: !!cfg.apiKey });
});

app.put('/api/ai-config', requireAuth, (req, res) => {
  const apiKey = ((req.body && req.body.apiKey) || '').trim();
  if (!apiKey) return res.status(400).json({ error: 'apiKey is required' });
  saveAiConfig(apiKey);
  res.json({ ok: true });
});

app.delete('/api/ai-config', requireAuth, (req, res) => {
  try { fs.unlinkSync(AI_CONFIG_FILE); } catch (e) {}
  res.json({ ok: true });
});

app.post('/api/ai-config/test', requireAuth, async (req, res) => {
  const cfg = loadAiConfig();
  if (!cfg.apiKey) return res.status(400).json({ error: 'no API key configured' });
  try {
    const content = await callDeepSeek(cfg.apiKey, [{ role: 'user', content: 'Reply with exactly: OK' }]);
    res.json({ ok: true, reply: content.trim() });
  } catch (e) {
    res.status(400).json({ error: e.message });
  }
});

const aiLimiter = rateLimit({
  windowMs: 10 * 60 * 1000,
  max: 30,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'too many AI requests, please slow down' },
});

app.post('/api/ai/draft', requireAuth, aiLimiter, async (req, res) => {
  const body = req.body || {};
  const customerId = body.customerId;
  const channel = body.channel;
  if (!customerId || !['email', 'whatsapp'].includes(channel)) {
    return res.status(400).json({ error: 'invalid request' });
  }
  const cfg = loadAiConfig();
  if (!cfg.apiKey) return res.status(400).json({ error: 'DeepSeek API key not configured' });

  const data = readData();
  let customers = [];
  try { customers = JSON.parse(data['crm:customers'] || '[]'); } catch (e) {}
  const customer = customers.find((c) => c.id === customerId);
  if (!customer) return res.status(404).json({ error: 'customer not found' });

  const context = buildCustomerContext(customer);
  const systemPrompt = 'You are a sales assistant helping a B2B export salesperson at a Chinese power-equipment company (UPS systems, rectifiers, solar inverters, battery storage) write natural, professional follow-up outreach to overseas customers. Always write in English. Never sound like a generic template, reference specifics from the customer info given. Output only the requested content, with no meta-commentary, explanations, or markdown formatting.';

  const userPrompt = channel === 'email'
    ? `Customer info:\n${context}\n\nWrite a short, warm but professional follow-up email to this customer. Respond in EXACTLY this format with no extra text:\nSUBJECT: <subject line>\nBODY:\n<email body, 3-5 short paragraphs max, sign off with "[Your name]">`
    : `Customer info:\n${context}\n\nWrite a short, casual WhatsApp message to check in with this customer (2-4 sentences, friendly tone, no formal greeting like "Dear", a light emoji is fine if it feels natural). Respond with ONLY the message text, nothing else.`;

  try {
    const content = await callDeepSeek(cfg.apiKey, [
      { role: 'system', content: systemPrompt },
      { role: 'user', content: userPrompt },
    ]);
    if (channel === 'email') {
      const subjectMatch = content.match(/SUBJECT:\s*(.+)/i);
      const bodyMatch = content.match(/BODY:\s*([\s\S]*)/i);
      res.json({
        subject: subjectMatch ? subjectMatch[1].trim() : 'Following up',
        body: bodyMatch ? bodyMatch[1].trim() : content.trim(),
      });
    } else {
      res.json({ body: content.trim() });
    }
  } catch (e) {
    res.status(502).json({ error: e.message });
  }
});

/* --------------------------- ai catalog import --------------------------- */
// 上传一份/多份PDF或图片形式的产品目录（可能包含多个型号），做OCR文字识别后交给
// DeepSeek解析成结构化的产品字段数组，前端拿到后先给用户一个预览/确认页面，
// 用户确认后再批量建档。
//
// 实测发现很多正式排版的产品目录PDF（比如设计软件导出的宣传册）整页都是图片/矢量
// 图形，没有可提取的文字层，所以这里统一走"渲染成图片 + OCR"这条路，而不是直接
// 提取PDF文字——这样PDF和图片两种输入方式可以复用同一套OCR逻辑。
//
// 依赖：
//  1. npm包 tesseract.js（纯JS+WASM，不需要装系统级OCR程序，但第一次识别时会从
//     jsdelivr CDN下载语言包，VPS需要能访问外网）
//  2. 系统程序 poppler-utils，只有上传PDF时才需要，用来把PDF每页渲染成图片：
//     apt install -y poppler-utils

const { execFile } = require('child_process');
const Tesseract = require('tesseract.js');

const uploadMemory = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 20 * 1024 * 1024, files: 30 }, // 20MB/文件，最多30个文件
});

// 把一份PDF的每一页渲染成PNG图片（用poppler-utils的pdftoppm），返回图片路径数组
function renderPdfToImages(pdfBuffer, tmpDir) {
  return new Promise((resolve, reject) => {
    const pdfPath = path.join(tmpDir, 'source.pdf');
    fs.writeFileSync(pdfPath, pdfBuffer);
    const outPrefix = path.join(tmpDir, 'page');
    execFile('pdftoppm', ['-png', '-r', '200', pdfPath, outPrefix], (err) => {
      if (err) {
        return reject(new Error(
          `PDF转图片失败，请确认服务器已安装 poppler-utils（SSH执行：apt install -y poppler-utils）：${err.message}`
        ));
      }
      const files = fs.readdirSync(tmpDir)
        .filter((f) => f.startsWith('page') && f.endsWith('.png'))
        .sort()
        .map((f) => path.join(tmpDir, f));
      resolve(files);
    });
  });
}

// 复用同一个OCR worker，避免每次请求都重新初始化/重新下载语言包
let ocrWorkerPromise = null;
function getOcrWorker() {
  if (!ocrWorkerPromise) {
    ocrWorkerPromise = Tesseract.createWorker('eng+chi_sim').catch((e) => {
      ocrWorkerPromise = null; // 初始化失败下次重试，不要把失败结果缓存住
      throw e;
    });
  }
  return ocrWorkerPromise;
}

async function ocrImages(imagePaths) {
  const worker = await getOcrWorker();
  const parts = [];
  for (const p of imagePaths) {
    const { data } = await worker.recognize(p);
    if (data && data.text) parts.push(data.text.trim());
  }
  return parts.join('\n\n--- 下一页 ---\n\n').trim();
}

const CATALOG_PARSE_SYSTEM_PROMPT = `你是一个电力设备（UPS/逆变器/储能电池等）产品资料的结构化提取助手。
用户会给你一份产品目录/规格书经OCR识别出的文字内容（可能包含多个不同型号的产品，每个产品通常有自己的Specifications表格；
OCR识别可能有少量错字或格式错乱，请结合上下文合理判断）。
你的任务：识别文本里有几个不同型号的产品，为每一个产品提取字段，严格按下面的JSON schema输出一个数组，每个元素是一个产品对象：

{
  "name": "型号，比如 POE-532E",
  "brand": "品牌中文名，从厂家名称/logo文字判断；看不出就填空字符串",
  "category": "产品大类中文名，从这些里选最接近的：UPS不间断电源 / 光伏逆变器 / 储能电池；不确定就填 UPS不间断电源",
  "type": "细分品类中文名。如果是这种带USB/DC/POE多路直流输出口的小型UPS，填 迷你UPS；其他常见值：机架式UPS、高频塔式UPS、工频UPS、模块化UPS、在线互动式UPS、离线式UPS；不确定就留空字符串",
  "machineVariant": "标机 或 长机：标准电池容量版本填标机，型号带L后缀或电池容量明显更大的加长版填长机，不确定就填标机",
  "powerOrCapacity": "非UPS大类的功率/容量；如果是迷你UPS，这里填输出功率（如 17W）；其他情况不确定就填空字符串",
  "voltage": "如果是迷你UPS，这里填输入电压，如 100~240Vac/50-60Hz；其他情况填常规电压参数，不确定填空字符串",
  "ratedPower": "", "ratedPowerUnit": "VA", "powerFactor": "",
  "outputPortCount": "迷你UPS专属：这个型号有几路输出口，数字字符串，如 4，不适用就填空字符串",
  "outputPortTypes": "迷你UPS专属：输出口类型数组，只能用这些token：USB、DC、DC1、DC2、DC3、POE、Type-C、DC interface、POE interface；不适用就填空数组",
  "outputPorts": "迷你UPS专属：数组，每项 {\\"type\\":\\"USB\\",\\"voltage\\":\\"5Vdc\\",\\"current\\":\\"3.0A\\"}，和outputPortTypes一一对应；不适用就填空数组",
  "batterySpec": "电池数量和容量，如 2200mAh*4，不确定填空字符串",
  "dimensions": "尺寸(mm)，如 175*105*30，不确定填空字符串",
  "netWeight": "净重(kg)，如 0.4，不确定填空字符串",
  "notes": "其他有用但上面字段装不下的信息，一两句话，没有就填空字符串"
}

只返回一个JSON数组，不要有任何解释文字、不要用markdown代码块包裹、不要省略任何一个识别到的型号。`;

app.post('/api/ai/parse-catalog', requireAuth, aiLimiter, (req, res) => {
  uploadMemory.array('files', 30)(req, res, async (err) => {
    if (err) return res.status(400).json({ error: err.message });
    if (!req.files || !req.files.length) return res.status(400).json({ error: 'no file received' });
    const cfg = loadAiConfig();
    if (!cfg.apiKey) return res.status(400).json({ error: 'DeepSeek API key not configured' });

    // 用户可以提前告诉我们这批文件大概是什么大类/品牌/细分品类，这样AI不用自己瞎猜这几个字段，
    // 只需要专心提取每个型号的具体规格参数；提供了的话，最后会直接用这几个值覆盖AI的猜测结果。
    const hintCategory = (req.body && req.body.hintCategory || '').trim();
    const hintBrand = (req.body && req.body.hintBrand || '').trim();
    const hintType = (req.body && req.body.hintType || '').trim();

    let tmpDir;
    try {
      tmpDir = fs.mkdtempSync(path.join(OCR_TMP_ROOT, 'catalog-ocr-'));
      const imagePaths = [];
      for (const file of req.files) {
        const isPdf = (file.mimetype || '').includes('pdf') || file.originalname.toLowerCase().endsWith('.pdf');
        const isImage = (file.mimetype || '').startsWith('image/');
        if (isPdf) {
          const pdfSubDir = fs.mkdtempSync(path.join(tmpDir, 'pdf-'));
          const pages = await renderPdfToImages(file.buffer, pdfSubDir);
          imagePaths.push(...pages);
        } else if (isImage) {
          const ext = path.extname(file.originalname) || '.png';
          const imgPath = path.join(tmpDir, `img_${imagePaths.length}${ext}`);
          fs.writeFileSync(imgPath, file.buffer);
          imagePaths.push(imgPath);
        } else {
          return res.status(400).json({ error: `不支持的文件类型：${file.originalname}（只支持PDF或图片）` });
        }
      }

      const text = await ocrImages(imagePaths);
      if (!text) return res.status(400).json({ error: 'OCR没有识别到任何文字，请确认文件清晰、内容完整' });

      // 识别出来的文本太长就截断，避免超出模型输出预算；产品目录类文档核心信息通常靠前
      const MAX_CHARS = 24000;
      const clippedText = text.length > MAX_CHARS ? text.slice(0, MAX_CHARS) : text;

      const hintLines = [];
      if (hintCategory) hintLines.push(`产品大类：${hintCategory}`);
      if (hintBrand) hintLines.push(`品牌：${hintBrand}`);
      if (hintType) hintLines.push(`细分品类：${hintType}`);
      const userContent = hintLines.length
        ? `【用户已确认以下信息，直接使用，不用自己判断】\n${hintLines.join('\n')}\n\n【以下是OCR识别出的文档内容】\n${clippedText}`
        : clippedText;

      const content = await callDeepSeek(cfg.apiKey, [
        { role: 'system', content: CATALOG_PARSE_SYSTEM_PROMPT },
        { role: 'user', content: userContent },
      ], { maxTokens: 4000, temperature: 0.2 });
      const products = extractJson(content);
      if (!Array.isArray(products)) throw new Error('AI没有返回预期的数组格式，请重试');
      // 双保险：即使AI没完全听话，这里直接强制覆盖，保证和用户预选的一致
      const finalProducts = products.map((p) => ({
        ...p,
        category: hintCategory || p.category,
        brand: hintBrand || p.brand,
        type: hintType || p.type,
      }));
      res.json({ products: finalProducts, ocrTextLength: text.length });
    } catch (e) {
      res.status(502).json({ error: e.message });
    } finally {
      try { fs.rmSync(tmpDir, { recursive: true, force: true }); } catch (e) {}
    }
  });
});

/* ------------------------------- ai translate ------------------------------ */
// 给前端的翻译词条缓存（存在 crm:translationGlossary 里，走通用storage接口）兜底：
// 前端自己先查缓存，只有命中不了的词才会调这个接口，这里只管翻译，不管缓存的存取。

const LANG_NAMES = { en: 'English', fr: 'French', ru: 'Russian', es: 'Spanish', ar: 'Arabic' };

app.post('/api/ai/translate-terms', requireAuth, aiLimiter, async (req, res) => {
  const body = req.body || {};
  const terms = Array.isArray(body.terms) ? body.terms.filter(t => typeof t === 'string' && t.trim()) : [];
  const targetLang = body.targetLang;
  if (!terms.length || !LANG_NAMES[targetLang]) return res.status(400).json({ error: 'invalid request' });

  const cfg = loadAiConfig();
  if (!cfg.apiKey) return res.status(400).json({ error: 'DeepSeek API key not configured' });

  const systemPrompt = `你是专业的电力设备（UPS/逆变器/储能电池）技术资料翻译。把用户给出的中文技术/业务词汇逐条翻译成${LANG_NAMES[targetLang]}，
要符合这个行业规范书面用词（不要逐字直译），单位符号（如Vdc、A、kg、mm）保持原样不翻译。
严格按JSON对象格式返回：key是原始中文词，value是翻译结果，不要有多余文字、不要用markdown代码块包裹，每个词都必须有对应的翻译。`;
  const userPrompt = JSON.stringify(terms);

  try {
    const content = await callDeepSeek(cfg.apiKey, [
      { role: 'system', content: systemPrompt },
      { role: 'user', content: userPrompt },
    ], { maxTokens: 2000, temperature: 0.3 });
    const translations = extractJson(content);
    res.json({ translations });
  } catch (e) {
    res.status(502).json({ error: e.message });
  }
});

/* ------------------------- communication attachments ------------------------- */

const upload = multer({
  storage: multer.diskStorage({
    destination: (req, file, cb) => {
      const cid = safeId(req.params.customerId);
      if (!cid) return cb(new Error('invalid customer id'));
      const dir = path.join(UPLOADS_DIR, cid);
      fs.mkdirSync(dir, { recursive: true });
      cb(null, dir);
    },
    filename: (req, file, cb) => {
      const ts = Date.now();
      const rand = Math.random().toString(36).slice(2, 8);
      const ext = path.extname(file.originalname).slice(0, 10);
      cb(null, `${ts}_${rand}${ext}`);
    },
  }),
  limits: { fileSize: 25 * 1024 * 1024 }, // 25MB per file
});

app.post('/api/uploads/:customerId', requireAuth, (req, res) => {
  if (!safeId(req.params.customerId)) return res.status(400).json({ error: 'invalid customer id' });
  upload.single('file')(req, res, (err) => {
    if (err) return res.status(400).json({ error: err.message });
    if (!req.file) return res.status(400).json({ error: 'no file received' });
    // multer/busboy 默认按 latin1 解析 multipart 里的文件名字段（这是老版HTTP规范的行为），
    // 但浏览器实际发送的中文文件名是 UTF-8 字节，所以这里要把它从 latin1 转回 UTF-8，
    // 不然中文文件名会变成乱码存进 data.json。
    const originalName = Buffer.from(req.file.originalname, 'latin1').toString('utf8');
    res.json({ fileName: req.file.filename, originalName, size: req.file.size });
  });
});

app.delete('/api/uploads/:customerId/:fileName', requireAuth, (req, res) => {
  const cid = safeId(req.params.customerId);
  const fname = req.params.fileName;
  const isSafeFile = fname && !fname.includes('..') && !fname.includes('/') && !fname.includes('\\');
  if (!cid || !isSafeFile) return res.status(400).json({ error: 'invalid request' });
  fs.unlink(path.join(UPLOADS_DIR, cid, fname), () => {
    // a missing file is also treated as success, so clicking delete twice never errors
    res.json({ ok: true });
  });
});

app.use('/uploads', requireAuth, express.static(UPLOADS_DIR));

app.use(express.static(FRONTEND_DIST));
app.get('*', (req, res) => {
  res.sendFile(path.join(FRONTEND_DIST, 'index.html'));
});

/* ------------------------------- bootstrap ------------------------------ */

loadAuth(); // make sure auth.json exists with default credentials on first run

fs.writeFileSync(PID_FILE, String(process.pid), 'utf8');
process.on('exit', () => {
  try { fs.unlinkSync(PID_FILE); } catch (e) {}
});
process.on('SIGINT', () => process.exit(0));
process.on('SIGTERM', () => process.exit(0));

const server = app.listen(PORT, HOST, () => {
  console.log(`[customer-crm] running at http://${HOST}:${PORT}`);
});

server.on('error', (e) => {
  if (e.code === 'EADDRINUSE') {
    console.log('[customer-crm] another instance is already running on this port, exiting.');
    try { fs.unlinkSync(PID_FILE); } catch (err) {}
    process.exit(0);
  }
  throw e;
});