lottery/server/services/lottery.js

const axios = require('axios');
const cheerio = require('cheerio');
const NodeCache = require('node-cache');
const logger = require('./logger');
const db = require('../db/init');

// 内存缓存 - 5分钟TTL, 最多1000个键防止内存溢出
const cache = new NodeCache({ stdTTL: 300, checkperiod: 60, maxKeys: 1000 });

// 获取预计开奖时间
function getEstimatedDrawTime(game, issue) {
  const now = new Date();
  const currentDay = now.getDay();
  const currentHour = now.getHours();
  const currentMinute = now.getMinutes();

  let drawDays = []; // 开奖日期（周日=0，周一=1...）

  if (game === '双色球') {
    drawDays = [2, 4, 0]; // 周二、周四、周日
  } else if (game === '大乐透') {
    drawDays = [1, 3, 5]; // 周一、周三、周六
  }

  if (drawDays.length === 0) return null;

  // 按日期排序
  drawDays.sort((a, b) => a - b);

  // 找到最近的下一个开奖日
  let daysUntilDraw = -1;
  for (const day of drawDays) {
    if (day > currentDay) {
      daysUntilDraw = day - currentDay;
      break;
    }
  }

  // 如果今天就是开奖日，检查是否已过开奖时间
  if (daysUntilDraw === -1) {
    // 没有找到更晚的日期，循环回到第一个开奖日
    daysUntilDraw = (drawDays[0] + 7) - currentDay;
  } else if (daysUntilDraw === 0) {
    // 今天是开奖日，检查是否已过21:15
    if (currentHour > 21 || (currentHour === 21 && currentMinute >= 15)) {
      daysUntilDraw = (drawDays[0] + 7) - currentDay;
    }
  }

  const nextDraw = new Date(now);
  nextDraw.setDate(now.getDate() + daysUntilDraw);
  nextDraw.setHours(21, 15, 0, 0);

  return nextDraw.toISOString();
}

// 获取开奖结果
async function fetchLotteryResult(game, issue) {
  const cacheKey = `lottery:${game}:${issue}`;

  // 先查内存缓存
  const cached = cache.get(cacheKey);
  if (cached) {
    logger.debug(`内存缓存命中: ${cacheKey}`);
    return cached;
  }

  // 查本地数据库
  const dbCached = db.prepare('SELECT * FROM lottery_results WHERE game = ? AND issue = ?').get(game, issue);
  if (dbCached) {
    const result = { ...dbCached, numbers: JSON.parse(dbCached.numbers) };
    cache.set(cacheKey, result);
    return result;
  }

  // 从网络获取
  try {
    const result = await fetchFromWeb(game, issue);
    if (result) {
      // 缓存到数据库
      db.prepare(`
        INSERT OR REPLACE INTO lottery_results (game, issue, numbers, draw_date)
        VALUES (?, ?, ?, ?)
      `).run(game, issue, JSON.stringify(result.numbers), result.draw_date);
      cache.set(cacheKey, result);
    }
    return result;
  } catch (err) {
    logger.error('获取开奖数据失败:', err.message);
    return null;
  }
}

// 从500.com获取数据
async function fetchFromWeb(game, issue) {
  // 检查是否在冷却期 (防止频繁请求)
  const cooldownKey = `cooldown:${game}`;
  if (cache.get(cooldownKey)) {
    logger.warn(`请求冷却中: ${game}`);
    return null;
  }

  let result = null;
  try {
    if (game === '双色球') {
      result = await fetchSSQ(issue);
    } else if (game === '大乐透') {
      result = await fetchDLT(issue);
    }
  } catch (err) {
    logger.error(`获取${game}开奖数据失败:`, err.message);
  }

  // 设置请求冷却 (5分钟)
  if (!result) {
    cache.set(cooldownKey, true, 300);
  }

  return result;
}

// 获取双色球开奖数据
async function fetchSSQ(issue) {
  const url = 'https://datachart.500.com/ssq/history/newinc/history.php?limit=50';
  const response = await axios.get(url, {
    headers: { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36' },
    timeout: 10000
  });

  const $ = cheerio.load(response.data);
  let result = null;

  // 处理期号格式：2026019 -> 26019 或 26019 -> 26019
  const shortIssue = issue.length > 5 ? issue.slice(-5) : issue;

  $('#tdata tr').each((i, row) => {
    const tds = $(row).find('td');
    const rowIssue = $(tds[0]).text().trim();

    if (rowIssue === shortIssue || rowIssue === issue) {
      const red = [];
      for (let j = 1; j <= 6; j++) {
        red.push($(tds[j]).text().trim());
      }
      const blue = $(tds[7]).text().trim();
      const drawDate = $(tds[15]).text().trim();

      result = {
        game: '双色球',
        issue: issue, // 返回原始期号
        numbers: { red, blue },
        draw_date: drawDate
      };
      return false;
    }
  });

  return result;
}

// 获取大乐透开奖数据
async function fetchDLT(issue) {
  const url = 'https://datachart.500.com/dlt/history/newinc/history.php?limit=50';
  const response = await axios.get(url, {
    headers: { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36' },
    timeout: 10000
  });

  const $ = cheerio.load(response.data);
  let result = null;

  // 处理期号格式：2026019 -> 26019 或 26019 -> 26019
  const shortIssue = issue.length > 5 ? issue.slice(-5) : issue;

  $('#tdata tr').each((i, row) => {
    const tds = $(row).find('td');
    const rowIssue = $(tds[0]).text().trim();

    if (rowIssue === shortIssue || rowIssue === issue) {
      const front = [];
      for (let j = 1; j <= 5; j++) {
        front.push($(tds[j]).text().trim());
      }
      const back = [];
      for (let j = 6; j <= 7; j++) {
        back.push($(tds[j]).text().trim());
      }
      const drawDate = $(tds[14]).text().trim();

      result = {
        game: '大乐透',
        issue: issue, // 返回原始期号
        numbers: { front, back },
        draw_date: drawDate
      };
      return false;
    }
  });

  return result;
}

// 检查中奖
function checkWinning(game, ticketNumbers, resultNumbers) {
  if (!ticketNumbers || !resultNumbers) return { won: false, prize: 0 };

  if (game === '双色球') {
    return checkSSQWinning(ticketNumbers, resultNumbers);
  } else if (game === '大乐透') {
    return checkDLTWinning(ticketNumbers, resultNumbers);
  }

  return { won: false, prize: 0 };
}

// 双色球中奖检查
function checkSSQWinning(ticket, result) {
  const redMatch = ticket.red.filter(n => result.red.includes(n)).length;
  const blueMatch = ticket.blue === result.blue;

  if (redMatch === 6 && blueMatch) return { won: true, level: 1, prize: 5000000 };
  if (redMatch === 6) return { won: true, level: 2, prize: 100000 };
  if (redMatch === 5 && blueMatch) return { won: true, level: 3, prize: 3000 };
  if (redMatch === 5 || (redMatch === 4 && blueMatch)) return { won: true, level: 4, prize: 200 };
  if (redMatch === 4 || (redMatch === 3 && blueMatch)) return { won: true, level: 5, prize: 10 };
  if (blueMatch) return { won: true, level: 6, prize: 5 };

  return { won: false, prize: 0 };
}

// 大乐透中奖检查
function checkDLTWinning(ticket, result) {
  const frontMatch = ticket.front.filter(n => result.front.includes(n)).length;
  const backMatch = ticket.back.filter(n => result.back.includes(n)).length;

  if (frontMatch === 5 && backMatch === 2) return { won: true, level: 1, prize: 10000000 };
  if (frontMatch === 5 && backMatch === 1) return { won: true, level: 2, prize: 100000 };
  if (frontMatch === 5) return { won: true, level: 3, prize: 10000 };
  if (frontMatch === 4 && backMatch === 2) return { won: true, level: 4, prize: 3000 };
  if (frontMatch === 4 && backMatch === 1) return { won: true, level: 5, prize: 300 };
  if (frontMatch === 3 && backMatch === 2) return { won: true, level: 6, prize: 200 };
  if (frontMatch === 4) return { won: true, level: 7, prize: 100 };
  // 8等奖：3+1 或 2+2，15元
  if ((frontMatch === 3 && backMatch === 1) || (frontMatch === 2 && backMatch === 2)) return { won: true, level: 8, prize: 15 };
  // 9等奖：3+0 或 2+1 或 1+2 或 后区2个，5元
  if (frontMatch === 3 || (frontMatch === 2 && backMatch === 1) || (frontMatch === 1 && backMatch === 2) || backMatch === 2) return { won: true, level: 9, prize: 5 };

  return { won: false, prize: 0 };
}

// 批量更新彩票状态
async function updateTicketsStatus(userId) {
  const pendingTickets = db.prepare(`
    SELECT * FROM tickets WHERE user_id = ? AND status = 'pending' AND issue IS NOT NULL
  `).all(userId);

  for (const ticket of pendingTickets) {
    try {
      const result = await fetchLotteryResult(ticket.game, ticket.issue);
      if (result) {
        const ticketNumbers = ticket.numbers ? JSON.parse(ticket.numbers) : null;
        if (ticketNumbers && ticketNumbers.length > 0) {
          let totalPrize = 0;
          for (const num of ticketNumbers) {
            const winning = checkWinning(ticket.game, num, result.numbers);
            if (winning.won) {
              totalPrize += winning.prize * ticket.multiple;
              if (ticket.is_additional && winning.level >= 1 && winning.level <= 2) {
                totalPrize += Math.floor(winning.prize * 0.8) * ticket.multiple;
              }
            }
          }

          db.prepare('UPDATE tickets SET prize = ?, status = ? WHERE id = ?')
            .run(totalPrize, totalPrize > 0 ? 'won' : 'lost', ticket.id);
        }
      }
    } catch (err) {
      logger.error(`更新彩票 ${ticket.id} 状态失败`, { error: err.message });
      // 继续处理其他彩票，不因单个失败中止
    }
  }
}

module.exports = { fetchLotteryResult, checkWinning, updateTicketsStatus, getEstimatedDrawTime };