'use strict';

// 每日进销存 · 页面截图与上传
//
// 要点：
//   1. 使用服务端签发的**短时效** JWT 作为专用身份访问页面（15 分钟过期），
//      令牌只写入浏览器 localStorage，不会出现在截图地址、日志或接口响应里。
//   2. 截图前必须等到数据真正加载完成：表格有数据行、没有 Spin 加载中、没有错误提示。
//   3. 表格带内部滚动，直接截屏只能看到一屏；截图前注入 CSS 展开滚动容器，
//      再整页截图，保证数据是完整的。
//   4. 截图落在系统临时目录，上传成功后立即删除。

const fs = require('fs');
const os = require('os');
const path = require('path');
const jwt = require('jsonwebtoken');
const { uploadFileToDefaultS3 } = require('./objectStorage');

const TIMEZONE = 'Asia/Shanghai';
const PAGE_PATH = '/planning/operation/daily-inventory';
const DEFAULT_BASE_URL = 'https://pddg.jiansuntuzhi.cn';
// 页面首次加载要扫订单明细，约 15~20 秒，等待上限给到 3 分钟
const PAGE_READY_TIMEOUT_MS = 3 * 60 * 1000;
const SCREENSHOT_SERVICE_USER = Object.freeze({
  sub: 'daily-inventory-screenshot-bot',
  username: 'daily_inventory_screenshot_bot',
  name: '每日进销存截图服务',
  role: 'admin',
  authSource: 'service',
  allowedPageKeys: [],
});

const EXPAND_CSS = `
.ant-table-body, .ant-table-content, .ant-table-container { max-height: none !important; overflow: visible !important; }
.daily-inventory-page { overflow: visible !important; }
.ant-table-cell-fix-left, .ant-table-cell-fix-right { position: static !important; }
`;

function normalizeText(value, maxLength = 500) {
  return String(value ?? '').trim().slice(0, maxLength);
}

/** 北京时间日期/时间片段：YYYY-MM-DD、YYYYMMDD、HHmmss */
function chinaTimeParts(date = new Date()) {
  const target = date instanceof Date ? date : new Date(date);
  const dateText = new Intl.DateTimeFormat('en-CA', {
    timeZone: TIMEZONE, year: 'numeric', month: '2-digit', day: '2-digit',
  }).format(target);
  const timeText = new Intl.DateTimeFormat('en-GB', {
    timeZone: TIMEZONE, hour: '2-digit', minute: '2-digit', second: '2-digit', hour12: false,
  }).format(target);
  return {
    bizDate: dateText,
    dateKey: dateText.replace(/\D/g, ''),
    timeKey: timeText.replace(/\D/g, ''),
  };
}

function resolveBaseUrl() {
  const raw = normalizeText(
    process.env.DAILY_INVENTORY_SCREENSHOT_BASE_URL
      || process.env.PUBLIC_SITE_URL
      || DEFAULT_BASE_URL,
    500
  ).replace(/\/+$/, '');
  return raw || DEFAULT_BASE_URL;
}

function resolvePageUrl() {
  return `${resolveBaseUrl()}${PAGE_PATH}`;
}

/**
 * 签发截图专用短时效令牌。
 * 只包含页面鉴权必需的最小声明，不含任何用户凭据或密钥。
 */
function signScreenshotToken() {
  const secret = process.env.CUBEJS_SECRET;
  if (!secret) throw new Error('缺少 CUBEJS_SECRET，无法签发截图文身份令牌');
  return jwt.sign({ ...SCREENSHOT_SERVICE_USER }, secret, { expiresIn: '15m' });
}

/** 截图存放的临时文件（不落业务目录，上传后立即删除） */
function buildTempFilePath(bizDate, dateKey, timeKey) {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'daily-inventory-shot-'));
  return {
    dir,
    filePath: path.join(dir, `daily-inventory-${dateKey}-${timeKey}.png`),
    objectKey: `daily-inventory/${bizDate}/daily-inventory-${dateKey}-${timeKey}.png`,
  };
}

async function launchBrowser() {
  let playwright;
  try {
    playwright = require('playwright');
  } catch (_error) {
    throw new Error('未安装 playwright，无法执行页面截图');
  }
  try {
    return await playwright.chromium.launch({
      args: ['--no-sandbox', '--disable-dev-shm-usage', '--disable-gpu'],
    });
  } catch (error) {
    const detail = normalizeText(error?.message, 300);
    throw new Error(`浏览器启动失败（服务器需先执行 npx playwright install chromium）：${detail}`);
  }
}

/** 等到数据真正渲染完成：有数据行、无加载中、无错误提示 */
async function waitForPageReady(page) {
  await page.waitForSelector('.daily-inventory-table .ant-table-tbody tr', {
    timeout: PAGE_READY_TIMEOUT_MS,
    state: 'attached',
  });

  await page.waitForFunction(
    () => {
      const spinning = document.querySelector('.daily-inventory-page .ant-spin-spinning');
      const skeleton = document.querySelector('.ant-skeleton');
      const rows = document.querySelectorAll('.daily-inventory-table .ant-table-tbody tr');
      return !spinning && !skeleton && rows.length > 0;
    },
    { timeout: PAGE_READY_TIMEOUT_MS, polling: 500 }
  );

  const errorText = await page.evaluate(() => {
    const node = document.querySelector('.daily-inventory-page .ant-alert-error');
    return node ? node.textContent || '' : '';
  });
  if (errorText) {
    throw new Error(`页面返回错误提示，放弃截图：${normalizeText(errorText, 200)}`);
  }

  const rowCount = await page.evaluate(
    () => document.querySelectorAll('.daily-inventory-table .ant-table-tbody tr').length
  );
  if (!rowCount) throw new Error('页面未渲染出任何数据行，放弃截图');
  return rowCount;
}

/**
 * 执行一次截图并上传到默认对象存储桶
 * @returns {Promise<{url:string, key:string, bizDate:string, size:number, rowCount:number, takenAt:string}>}
 */
async function captureAndUploadDailyInventory(options = {}) {
  const now = options.now ? new Date(options.now) : new Date();
  const { bizDate, dateKey, timeKey } = chinaTimeParts(now);
  const token = signScreenshotToken();
  const pageUrl = resolvePageUrl();

  const browser = await launchBrowser();
  const { dir, filePath, objectKey } = buildTempFilePath(bizDate, dateKey, timeKey);
  let rowCount = 0;

  try {
    const context = await browser.newContext({
      viewport: { width: 1680, height: 1050 },
      deviceScaleFactor: 1,
      timezoneId: TIMEZONE,
      locale: 'zh-CN',
    });
    // 令牌只注入浏览器 localStorage，URL 与日志里都不出现
    await context.addInitScript((value) => {
      try {
        window.localStorage.setItem('token', value);
      } catch (_error) {
        // 忽略：首个 document 可能还不允许访问 localStorage
      }
    }, token);

    const page = await context.newPage();
    page.on('pageerror', () => {});
    await page.goto(pageUrl, { waitUntil: 'domcontentloaded', timeout: PAGE_READY_TIMEOUT_MS });
    rowCount = await waitForPageReady(page);

    // 展开内部滚动容器，保证整页截图包含完整数据区
    await page.addStyleTag({ content: EXPAND_CSS });
    await page.waitForTimeout(500);
    await page.screenshot({ path: filePath, fullPage: true });

    const stats = await fs.promises.stat(filePath);
    if (!stats.size) throw new Error('截图文件为空');

    const uploaded = await uploadFileToDefaultS3(filePath, {
      key: objectKey,
      mimeType: 'image/png',
      folder: 'daily-inventory',
      extension: 'png',
    });

    return {
      url: uploaded.url,
      key: uploaded.key,
      bizDate,
      size: stats.size,
      rowCount,
      takenAt: now.toISOString(),
    };
  } finally {
    await browser.close().catch(() => {});
    fs.rm(dir, { recursive: true, force: true }, () => {});
  }
}

module.exports = {
  DEFAULT_BASE_URL,
  PAGE_PATH,
  PAGE_READY_TIMEOUT_MS,
  TIMEZONE,
  captureAndUploadDailyInventory,
  chinaTimeParts,
  resolveBaseUrl,
  resolvePageUrl,
  signScreenshotToken,
};