import cron from 'node-cron';
import { readFileSync } from 'fs';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';
import axios from 'axios';
import * as cheerio from 'cheerio';
import iconv from 'iconv-lite';
import { sendReportEmail } from './emailService.js';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// 加载配置文件
function loadConfig() {
  try {
    const configPath = join(__dirname, '..', 'config.json');
    const configContent = readFileSync(configPath, 'utf-8');
    return JSON.parse(configContent);
  } catch (error) {
    console.error('加载配置文件失败:', error.message);
    console.error('请确保 config.json 文件存在并配置正确');
    return null;
  }
}

// 根据时间范围类型获取开始和结束日期
function getDateRangeByType(timeRange) {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, '0');
  const day = String(now.getDate()).padStart(2, '0');

  let startDate, endDate;
  endDate = `${year}-${month}-${day}`; // 结束日期都是今天

  switch (timeRange) {
    case 'today':
      // 今日
      startDate = `${year}-${month}-${day}`;
      break;

    case 'thisWeek': {
      // 本周 (从周一开始)
      const dayOfWeek = now.getDay(); // 0是周日,1是周一
      const diff = dayOfWeek === 0 ? 6 : dayOfWeek - 1; // 计算到周一的天数差
      const monday = new Date(now);
      monday.setDate(now.getDate() - diff);
      const weekYear = monday.getFullYear();
      const weekMonth = String(monday.getMonth() + 1).padStart(2, '0');
      const weekDay = String(monday.getDate()).padStart(2, '0');
      startDate = `${weekYear}-${weekMonth}-${weekDay}`;
      break;
    }

    case 'thisMonth':
    default:
      // 本月
      startDate = `${year}-${month}-01`;
      break;
  }

  return { startDate, endDate };
}

// 南京市公共资源交易平台 - 房建市政招标公告
const BASE_URL = 'https://njggzy.nanjing.gov.cn/njweb/fjsz/068001/068001002/';

const http = axios.create({
  responseType: 'arraybuffer',
  timeout: 15000,
  headers: {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
  },
});

function pickEncoding(contentType = '') {
  const match = /charset=([^;]+)/i.exec(contentType);
  if (!match) return 'utf-8';
  const charset = match[1].trim().toLowerCase();
  if (charset.includes('gb')) return 'gbk';
  return charset;
}

async function fetchHtml(url) {
  const res = await http.get(url);
  const encoding = pickEncoding(res.headers['content-type']);
  const html = iconv.decode(res.data, encoding || 'utf-8');
  return html;
}

function getPageUrl(pageIndex) {
  if (pageIndex === 1) {
    return `${BASE_URL}moreinfo.html`;
  }
  return `${BASE_URL}${pageIndex}.html`;
}

// 解析列表页HTML，提取招标信息
function parseList(html) {
  const $ = cheerio.load(html);
  const items = [];

  $('li.ewb-info-item2').each((_, row) => {
    const $row = $(row);
    const cells = $row.find('div.ewb-info-num2');

    if (cells.length >= 5) {
      const bidNo = $(cells[0]).find('p').attr('title') || $(cells[0]).find('p').text().trim();
      const projectName = $(cells[1]).find('p').attr('title') || $(cells[1]).find('p').text().trim();
      const bidName = $(cells[2]).find('p').attr('title') || $(cells[2]).find('p').text().trim();
      const estimatedPrice = $(cells[3]).find('p').text().trim();
      const publishDate = $(cells[4]).find('p').text().trim();

      const onclick = $row.attr('onclick') || '';
      const hrefMatch = onclick.match(/window\.open\(['"]([^'"]+)['"]\)/);
      let href = '';
      if (hrefMatch) {
        href = hrefMatch[1];
        if (href.startsWith('/')) {
          href = `https://njggzy.nanjing.gov.cn${href}`;
        }
      }

      if (!/^\d{4}-\d{2}-\d{2}$/.test(publishDate)) return;

      const price = parseFloat(estimatedPrice);
      if (isNaN(price)) return;

      items.push({
        bidNo,
        title: projectName,
        bidName,
        budget: {
          amount: price,
          unit: '万元'
        },
        date: publishDate,
        href
      });
    }
  });

  return items;
}

function isDateInRange(dateStr, startDate, endDate) {
  if (!dateStr) return false;
  const date = new Date(dateStr);
  if (isNaN(date.getTime())) return false;

  if (startDate && date < new Date(startDate)) return false;
  if (endDate && date > new Date(endDate)) return false;
  return true;
}

async function fetchListByDateRange(startDate, endDate, maxPages = 50) {
  const allItems = [];
  let shouldContinue = true;
  let pageIndex = 1;

  console.log(`开始按时间范围采集: ${startDate || '不限'} 至 ${endDate || '不限'}`);

  while (shouldContinue && pageIndex <= maxPages) {
    const pageUrl = getPageUrl(pageIndex);
    console.log(`正在采集第 ${pageIndex} 页: ${pageUrl}`);

    try {
      const html = await fetchHtml(pageUrl);
      const items = parseList(html);

      if (items.length === 0) {
        console.log(`第 ${pageIndex} 页没有数据，停止采集`);
        break;
      }

      let hasItemsInRange = false;
      let allItemsBeforeRange = true;

      for (const item of items) {
        if (isDateInRange(item.date, startDate, endDate)) {
          allItems.push(item);
          hasItemsInRange = true;
          allItemsBeforeRange = false;
        } else if (startDate && new Date(item.date) < new Date(startDate)) {
          allItemsBeforeRange = allItemsBeforeRange && true;
        } else {
          allItemsBeforeRange = false;
        }
      }

      if (allItemsBeforeRange && startDate) {
        console.log(`第 ${pageIndex} 页所有项目都早于起始日期，停止采集`);
        shouldContinue = false;
      }

      console.log(`第 ${pageIndex} 页找到 ${items.length} 条，符合条件 ${hasItemsInRange ? '有' : '无'}`);

      pageIndex++;

      if (shouldContinue && pageIndex <= maxPages) {
        await new Promise(resolve => setTimeout(resolve, 500));
      }
    } catch (err) {
      console.error(`采集第 ${pageIndex} 页失败: ${err.message}`);
      break;
    }
  }

  console.log(`总共采集了 ${pageIndex - 1} 页，找到 ${allItems.length} 条符合条件的公告`);
  return allItems;
}

// 定时任务执行函数
async function executeScheduledTask(config) {
  try {
    console.log('========================================');
    console.log('定时任务开始执行');
    console.log('执行时间:', new Date().toLocaleString('zh-CN'));
    console.log('========================================');

    const timeRange = config.scheduler.timeRange || 'thisMonth';
    const { startDate, endDate } = getDateRangeByType(timeRange);
    const threshold = config.scheduler.threshold || 10000; // 默认1亿(10000万元)

    const timeRangeNames = {
      'today': '今日',
      'thisWeek': '本周',
      'thisMonth': '本月'
    };
    console.log(`采集时间段: ${timeRangeNames[timeRange] || '本月'}`);
    console.log(`采集时间范围: ${startDate} 至 ${endDate}`);
    console.log(`金额阈值: ${threshold}万元 (${(threshold / 10000).toFixed(2)}亿元)`);

    // 采集列表（直接包含合同估算价）
    const items = await fetchListByDateRange(startDate, endDate, 50);

    if (items.length === 0) {
      console.log('暂无公告数据');
      return;
    }

    // 筛选大于阈值的项目
    const filtered = items.filter((item) => {
      return item.budget && item.budget.amount > threshold;
    });

    console.log('========================================');
    console.log(`筛选结果: 找到 ${filtered.length} 个大于 ${threshold}万元 的项目`);

    if (filtered.length === 0) {
      console.log('暂无符合条件的大额项目');
      return;
    }

    // 计算总金额
    const total = filtered.reduce(
      (sum, item) => sum + (item.budget?.amount || 0),
      0
    );

    // 生成报告
    const report = {
      summary: {
        total_count: items.length,
        filtered_count: filtered.length,
        threshold: `${threshold}万元`,
        total_amount: `${total.toFixed(2)}万元`,
        generated_at: new Date().toISOString(),
        date_range: { startDate, endDate },
      },
      projects: filtered.map((item) => ({
        bidNo: item.bidNo,
        title: item.title,
        bidName: item.bidName,
        date: item.date,
        budget: item.budget,
        url: item.href,
      })),
    };

    // 发送邮件
    console.log('========================================');
    console.log('正在发送邮件报告...');
    const emailConfig = config.email;

    const result = await sendReportEmail(emailConfig, report);

    console.log('邮件发送成功!');
    console.log('收件人:', emailConfig.recipients);
    console.log('MessageId:', result.messageId);
    console.log('========================================');
    console.log('定时任务执行完成');
    console.log('========================================');

  } catch (error) {
    console.error('========================================');
    console.error('定时任务执行失败:', error.message);
    console.error(error.stack);
    console.error('========================================');
  }
}

// 存储当前的定时任务
let currentScheduledTask = null;

// 初始化定时任务
export function initScheduler() {
  const config = loadConfig();

  if (!config) {
    console.error('无法启动定时任务: 配置文件加载失败');
    return;
  }

  if (!config.scheduler || !config.scheduler.enabled) {
    console.log('定时任务已禁用');
    return;
  }

  if (!config.email || !config.email.smtpHost || !config.email.smtpUser) {
    console.error('无法启动定时任务: 邮件配置不完整');
    console.error('请在 config.json 中配置邮件信息');
    return;
  }

  const cronTime = config.scheduler.cronTime || '0 9 * * *';

  console.log('========================================');
  console.log('定时任务已启动');
  console.log('执行计划:', cronTime);
  console.log('金额阈值:', config.scheduler.threshold, '万元');
  console.log('收件人:', config.email.recipients);
  console.log('========================================');

  // 如果已有任务在运行,先停止
  if (currentScheduledTask) {
    currentScheduledTask.stop();
    console.log('已停止旧的定时任务');
  }

  // 创建定时任务
  currentScheduledTask = cron.schedule(cronTime, () => {
    executeScheduledTask(config);
  }, {
    timezone: 'Asia/Shanghai'
  });
}

// 重新加载配置并重启定时任务
export function reloadScheduler() {
  console.log('重新加载定时任务配置...');

  // 停止当前任务
  if (currentScheduledTask) {
    currentScheduledTask.stop();
    currentScheduledTask = null;
    console.log('已停止当前定时任务');
  }

  // 重新初始化
  initScheduler();
}

// 停止定时任务
export function stopScheduler() {
  if (currentScheduledTask) {
    currentScheduledTask.stop();
    currentScheduledTask = null;
    console.log('定时任务已停止');
    return true;
  }
  return false;
}

// 获取定时任务状态
export function getSchedulerStatus() {
  const config = loadConfig();
  return {
    isRunning: currentScheduledTask !== null,
    config: config ? {
      enabled: config.scheduler?.enabled || false,
      cronTime: config.scheduler?.cronTime || '0 9 * * *',
      threshold: config.scheduler?.threshold || 10000,
      timeRange: config.scheduler?.timeRange || 'thisMonth',
    } : null,
  };
}

// 手动执行任务(用于测试)
export async function runTaskNow() {
  const config = loadConfig();
  if (!config) {
    throw new Error('配置文件加载失败');
  }
  await executeScheduledTask(config);
}
