update pay function

src/services/creditSystemService.js

@@ -0,0 +1,492 @@
+/**
+ * 积分系统服务
+ * 管理用户积分账户、交易、奖励等
+ */
+
+// ==================== 常量配置 ====================
+
+export const CREDIT_CONFIG = {
+  INITIAL_BALANCE: 10000,        // 初始积分
+  MIN_BALANCE: 100,              // 最低保留余额（破产保护）
+  MAX_SINGLE_BET: 1000,          // 单次下注上限
+  DAILY_BONUS: 100,              // 每日签到奖励
+  CREATE_TOPIC_COST: 100,        // 创建话题费用
+};
+
+// 积分账户存储（生产环境应使用数据库）
+const userAccounts = new Map();
+
+// 交易记录存储
+const transactions = [];
+
+// ==================== 账户管理 ====================
+
+/**
+ * 获取用户账户
+ * @param {string} userId - 用户ID
+ * @returns {Object} 用户账户信息
+ */
+export const getUserAccount = (userId) => {
+  if (!userAccounts.has(userId)) {
+    // 首次访问，创建新账户
+    const newAccount = {
+      user_id: userId,
+      balance: CREDIT_CONFIG.INITIAL_BALANCE,
+      frozen: 0,
+      total: CREDIT_CONFIG.INITIAL_BALANCE,
+      total_earned: CREDIT_CONFIG.INITIAL_BALANCE,
+      total_spent: 0,
+      total_profit: 0,
+      active_positions: [],
+      stats: {
+        total_topics: 0,
+        win_count: 0,
+        loss_count: 0,
+        win_rate: 0,
+        best_profit: 0,
+      },
+      last_daily_bonus: null,
+    };
+    userAccounts.set(userId, newAccount);
+  }
+
+  return userAccounts.get(userId);
+};
+
+/**
+ * 更新用户账户
+ * @param {string} userId - 用户ID
+ * @param {Object} updates - 更新内容
+ */
+export const updateUserAccount = (userId, updates) => {
+  const account = getUserAccount(userId);
+  const updated = { ...account, ...updates };
+  userAccounts.set(userId, updated);
+  return updated;
+};
+
+/**
+ * 获取用户积分余额
+ * @param {string} userId - 用户ID
+ * @returns {number} 可用余额
+ */
+export const getBalance = (userId) => {
+  const account = getUserAccount(userId);
+  return account.balance;
+};
+
+/**
+ * 检查用户是否能支付
+ * @param {string} userId - 用户ID
+ * @param {number} amount - 金额
+ * @returns {boolean} 是否能支付
+ */
+export const canAfford = (userId, amount) => {
+  const account = getUserAccount(userId);
+  const afterBalance = account.balance - amount;
+
+  // 必须保留最低余额
+  return afterBalance >= CREDIT_CONFIG.MIN_BALANCE;
+};
+
+// ==================== 积分操作 ====================
+
+/**
+ * 增加积分
+ * @param {string} userId - 用户ID
+ * @param {number} amount - 金额
+ * @param {string} reason - 原因
+ */
+export const addCredits = (userId, amount, reason = '系统增加') => {
+  const account = getUserAccount(userId);
+
+  const updated = {
+    balance: account.balance + amount,
+    total: account.total + amount,
+    total_earned: account.total_earned + amount,
+  };
+
+  updateUserAccount(userId, updated);
+
+  // 记录交易
+  logTransaction({
+    user_id: userId,
+    type: 'earn',
+    amount,
+    reason,
+    balance_after: updated.balance,
+  });
+
+  return updated;
+};
+
+/**
+ * 扣除积分
+ * @param {string} userId - 用户ID
+ * @param {number} amount - 金额
+ * @param {string} reason - 原因
+ * @throws {Error} 如果余额不足
+ */
+export const deductCredits = (userId, amount, reason = '系统扣除') => {
+  if (!canAfford(userId, amount)) {
+    throw new Error(`积分不足，需要${amount}积分，但只有${getBalance(userId)}积分`);
+  }
+
+  const account = getUserAccount(userId);
+
+  const updated = {
+    balance: account.balance - amount,
+    total_spent: account.total_spent + amount,
+  };
+
+  updateUserAccount(userId, updated);
+
+  // 记录交易
+  logTransaction({
+    user_id: userId,
+    type: 'spend',
+    amount: -amount,
+    reason,
+    balance_after: updated.balance,
+  });
+
+  return updated;
+};
+
+/**
+ * 冻结积分（席位占用）
+ * @param {string} userId - 用户ID
+ * @param {number} amount - 金额
+ */
+export const freezeCredits = (userId, amount) => {
+  const account = getUserAccount(userId);
+
+  if (account.balance < amount) {
+    throw new Error('可用余额不足');
+  }
+
+  const updated = {
+    balance: account.balance - amount,
+    frozen: account.frozen + amount,
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+/**
+ * 解冻积分
+ * @param {string} userId - 用户ID
+ * @param {number} amount - 金额
+ */
+export const unfreezeCredits = (userId, amount) => {
+  const account = getUserAccount(userId);
+
+  const updated = {
+    balance: account.balance + amount,
+    frozen: account.frozen - amount,
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+// ==================== 每日奖励 ====================
+
+/**
+ * 领取每日签到奖励
+ * @param {string} userId - 用户ID
+ * @returns {Object} 奖励信息
+ */
+export const claimDailyBonus = (userId) => {
+  const account = getUserAccount(userId);
+  const today = new Date().toDateString();
+
+  // 检查是否已领取
+  if (account.last_daily_bonus === today) {
+    return {
+      success: false,
+      message: '今日已领取',
+    };
+  }
+
+  // 发放奖励
+  addCredits(userId, CREDIT_CONFIG.DAILY_BONUS, '每日签到');
+
+  // 更新领取时间
+  updateUserAccount(userId, { last_daily_bonus: today });
+
+  return {
+    success: true,
+    amount: CREDIT_CONFIG.DAILY_BONUS,
+    message: `获得${CREDIT_CONFIG.DAILY_BONUS}积分`,
+  };
+};
+
+/**
+ * 检查今天是否已签到
+ * @param {string} userId - 用户ID
+ * @returns {boolean}
+ */
+export const hasClaimedToday = (userId) => {
+  const account = getUserAccount(userId);
+  const today = new Date().toDateString();
+  return account.last_daily_bonus === today;
+};
+
+// ==================== 持仓管理 ====================
+
+/**
+ * 添加持仓
+ * @param {string} userId - 用户ID
+ * @param {Object} position - 持仓信息
+ */
+export const addPosition = (userId, position) => {
+  const account = getUserAccount(userId);
+
+  const updated = {
+    active_positions: [...account.active_positions, position],
+    stats: {
+      ...account.stats,
+      total_topics: account.stats.total_topics + 1,
+    },
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+/**
+ * 移除持仓
+ * @param {string} userId - 用户ID
+ * @param {string} positionId - 持仓ID
+ */
+export const removePosition = (userId, positionId) => {
+  const account = getUserAccount(userId);
+
+  const updated = {
+    active_positions: account.active_positions.filter((p) => p.id !== positionId),
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+/**
+ * 更新持仓
+ * @param {string} userId - 用户ID
+ * @param {string} positionId - 持仓ID
+ * @param {Object} updates - 更新内容
+ */
+export const updatePosition = (userId, positionId, updates) => {
+  const account = getUserAccount(userId);
+
+  const updated = {
+    active_positions: account.active_positions.map((p) =>
+      p.id === positionId ? { ...p, ...updates } : p
+    ),
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+/**
+ * 获取用户持仓
+ * @param {string} userId - 用户ID
+ * @param {string} topicId - 话题ID（可选）
+ * @returns {Array} 持仓列表
+ */
+export const getUserPositions = (userId, topicId = null) => {
+  const account = getUserAccount(userId);
+
+  if (topicId) {
+    return account.active_positions.filter((p) => p.topic_id === topicId);
+  }
+
+  return account.active_positions;
+};
+
+// ==================== 统计更新 ====================
+
+/**
+ * 记录胜利
+ * @param {string} userId - 用户ID
+ * @param {number} profit - 盈利金额
+ */
+export const recordWin = (userId, profit) => {
+  const account = getUserAccount(userId);
+
+  const newWinCount = account.stats.win_count + 1;
+  const totalGames = newWinCount + account.stats.loss_count;
+  const winRate = (newWinCount / totalGames) * 100;
+
+  const updated = {
+    total_profit: account.total_profit + profit,
+    stats: {
+      ...account.stats,
+      win_count: newWinCount,
+      win_rate: winRate,
+      best_profit: Math.max(account.stats.best_profit, profit),
+    },
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+/**
+ * 记录失败
+ * @param {string} userId - 用户ID
+ * @param {number} loss - 损失金额
+ */
+export const recordLoss = (userId, loss) => {
+  const account = getUserAccount(userId);
+
+  const newLossCount = account.stats.loss_count + 1;
+  const totalGames = account.stats.win_count + newLossCount;
+  const winRate = (account.stats.win_count / totalGames) * 100;
+
+  const updated = {
+    total_profit: account.total_profit - loss,
+    stats: {
+      ...account.stats,
+      loss_count: newLossCount,
+      win_rate: winRate,
+    },
+  };
+
+  updateUserAccount(userId, updated);
+  return updated;
+};
+
+// ==================== 排行榜 ====================
+
+/**
+ * 获取积分排行榜
+ * @param {number} limit - 返回数量
+ * @returns {Array} 排行榜数据
+ */
+export const getLeaderboard = (limit = 100) => {
+  const accounts = Array.from(userAccounts.values());
+
+  return accounts
+    .sort((a, b) => b.total - a.total)
+    .slice(0, limit)
+    .map((account, index) => ({
+      rank: index + 1,
+      user_id: account.user_id,
+      total: account.total,
+      total_profit: account.total_profit,
+      win_rate: account.stats.win_rate,
+    }));
+};
+
+/**
+ * 获取用户排名
+ * @param {string} userId - 用户ID
+ * @returns {number} 排名
+ */
+export const getUserRank = (userId) => {
+  const leaderboard = getLeaderboard(1000);
+  const index = leaderboard.findIndex((item) => item.user_id === userId);
+  return index >= 0 ? index + 1 : -1;
+};
+
+// ==================== 交易记录 ====================
+
+/**
+ * 记录交易
+ * @param {Object} transaction - 交易信息
+ */
+const logTransaction = (transaction) => {
+  const record = {
+    id: `tx_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+    timestamp: new Date().toISOString(),
+    ...transaction,
+  };
+
+  transactions.push(record);
+  return record;
+};
+
+/**
+ * 获取用户交易记录
+ * @param {string} userId - 用户ID
+ * @param {number} limit - 返回数量
+ * @returns {Array} 交易记录
+ */
+export const getUserTransactions = (userId, limit = 50) => {
+  return transactions
+    .filter((tx) => tx.user_id === userId)
+    .sort((a, b) => new Date(b.timestamp) - new Date(a.timestamp))
+    .slice(0, limit);
+};
+
+// ==================== 批量操作 ====================
+
+/**
+ * 批量发放积分（如活动奖励）
+ * @param {Array} recipients - [{user_id, amount, reason}]
+ */
+export const batchAddCredits = (recipients) => {
+  const results = recipients.map(({ user_id, amount, reason }) => {
+    try {
+      return {
+        user_id,
+        success: true,
+        account: addCredits(user_id, amount, reason),
+      };
+    } catch (error) {
+      return {
+        user_id,
+        success: false,
+        error: error.message,
+      };
+    }
+  });
+
+  return results;
+};
+
+// ==================== 导出所有功能 ====================
+
+export default {
+  CREDIT_CONFIG,
+
+  // 账户管理
+  getUserAccount,
+  updateUserAccount,
+  getBalance,
+  canAfford,
+
+  // 积分操作
+  addCredits,
+  deductCredits,
+  freezeCredits,
+  unfreezeCredits,
+
+  // 每日奖励
+  claimDailyBonus,
+  hasClaimedToday,
+
+  // 持仓管理
+  addPosition,
+  removePosition,
+  updatePosition,
+  getUserPositions,
+
+  // 统计更新
+  recordWin,
+  recordLoss,
+
+  // 排行榜
+  getLeaderboard,
+  getUserRank,
+
+  // 交易记录
+  getUserTransactions,
+
+  // 批量操作
+  batchAddCredits,
+};

src/services/predictionMarketService.js

@@ -0,0 +1,738 @@
+/**
+ * 预测市场服务
+ * 核心功能：话题管理、席位交易、动态定价、领主系统、奖池分配
+ */
+
+import {
+  addCredits,
+  deductCredits,
+  canAfford,
+  addPosition,
+  removePosition,
+  updatePosition,
+  getUserPositions,
+  recordWin,
+  recordLoss,
+  CREDIT_CONFIG,
+} from './creditSystemService';
+
+// ==================== 常量配置 ====================
+
+export const MARKET_CONFIG = {
+  MAX_SEATS_PER_SIDE: 5,         // 每个方向最多5个席位
+  TAX_RATE: 0.02,                // 交易税率 2%
+  MIN_PRICE: 50,                 // 最低价格
+  MAX_PRICE: 950,                // 最高价格
+  BASE_PRICE: 500,               // 基础价格
+};
+
+// 话题存储（生产环境应使用Elasticsearch）
+const topics = new Map();
+
+// 席位存储
+const positions = new Map();
+
+// 交易记录
+const trades = [];
+
+// ==================== 动态定价算法 ====================
+
+/**
+ * 计算当前价格（简化版AMM）
+ * @param {number} yesShares - Yes方总份额
+ * @param {number} noShares - No方总份额
+ * @returns {Object} {yes: price, no: price}
+ */
+export const calculatePrice = (yesShares, noShares) => {
+  const totalShares = yesShares + noShares;
+
+  if (totalShares === 0) {
+    // 初始状态，双方价格相同
+    return {
+      yes: MARKET_CONFIG.BASE_PRICE,
+      no: MARKET_CONFIG.BASE_PRICE,
+    };
+  }
+
+  // 概率加权定价
+  const yesProb = yesShares / totalShares;
+  const noProb = noShares / totalShares;
+
+  // 价格 = 概率 * 1000，限制在 [MIN_PRICE, MAX_PRICE]
+  const yesPrice = Math.max(
+    MARKET_CONFIG.MIN_PRICE,
+    Math.min(MARKET_CONFIG.MAX_PRICE, yesProb * 1000)
+  );
+
+  const noPrice = Math.max(
+    MARKET_CONFIG.MIN_PRICE,
+    Math.min(MARKET_CONFIG.MAX_PRICE, noProb * 1000)
+  );
+
+  return { yes: yesPrice, no: noPrice };
+};
+
+/**
+ * 计算购买成本（含滑点）
+ * @param {number} currentShares - 当前份额
+ * @param {number} otherShares - 对手方份额
+ * @param {number} buyAmount - 购买数量
+ * @returns {number} 总成本
+ */
+export const calculateBuyCost = (currentShares, otherShares, buyAmount) => {
+  let totalCost = 0;
+  let tempShares = currentShares;
+
+  // 模拟逐步购买，累计成本
+  for (let i = 0; i < buyAmount; i++) {
+    tempShares += 1;
+    const prices = calculatePrice(tempShares, otherShares);
+    // 假设购买的是yes方
+    totalCost += prices.yes;
+  }
+
+  return totalCost;
+};
+
+/**
+ * 计算卖出收益（含滑点）
+ * @param {number} currentShares - 当前份额
+ * @param {number} otherShares - 对手方份额
+ * @param {number} sellAmount - 卖出数量
+ * @returns {number} 总收益
+ */
+export const calculateSellRevenue = (currentShares, otherShares, sellAmount) => {
+  let totalRevenue = 0;
+  let tempShares = currentShares;
+
+  // 模拟逐步卖出，累计收益
+  for (let i = 0; i < sellAmount; i++) {
+    const prices = calculatePrice(tempShares, otherShares);
+    totalRevenue += prices.yes;
+    tempShares -= 1;
+  }
+
+  return totalRevenue;
+};
+
+/**
+ * 计算交易税
+ * @param {number} amount - 交易金额
+ * @returns {number} 税费
+ */
+export const calculateTax = (amount) => {
+  return Math.floor(amount * MARKET_CONFIG.TAX_RATE);
+};
+
+// ==================== 话题管理 ====================
+
+/**
+ * 创建预测话题
+ * @param {Object} topicData - 话题数据
+ * @returns {Object} 创建的话题
+ */
+export const createTopic = (topicData) => {
+  const { author_id, title, description, category, tags, deadline, settlement_date } = topicData;
+
+  // 扣除创建费用
+  deductCredits(author_id, CREDIT_CONFIG.CREATE_TOPIC_COST, '创建预测话题');
+
+  const topic = {
+    id: `topic_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+    type: 'prediction',
+
+    // 基础信息
+    title,
+    description,
+    category,
+    tags: tags || [],
+
+    // 作者信息
+    author_id,
+    author_name: topicData.author_name,
+    author_avatar: topicData.author_avatar,
+
+    // 时间管理
+    created_at: new Date().toISOString(),
+    deadline: deadline || new Date(Date.now() + 7 * 24 * 60 * 60 * 1000).toISOString(), // 默认7天
+    settlement_date: settlement_date || new Date(Date.now() + 8 * 24 * 60 * 60 * 1000).toISOString(),
+    status: 'active',
+
+    // 预测选项
+    options: [
+      { id: 'yes', label: '看涨 / Yes', color: '#48BB78' },
+      { id: 'no', label: '看跌 / No', color: '#F56565' },
+    ],
+
+    // 市场数据
+    total_pool: CREDIT_CONFIG.CREATE_TOPIC_COST, // 创建费用进入奖池
+    tax_rate: MARKET_CONFIG.TAX_RATE,
+
+    // 席位数据
+    positions: {
+      yes: {
+        seats: [],
+        total_shares: 0,
+        current_price: MARKET_CONFIG.BASE_PRICE,
+        lord_id: null,
+      },
+      no: {
+        seats: [],
+        total_shares: 0,
+        current_price: MARKET_CONFIG.BASE_PRICE,
+        lord_id: null,
+      },
+    },
+
+    // 交易统计
+    stats: {
+      total_volume: 0,
+      total_transactions: 0,
+      unique_traders: new Set(),
+    },
+
+    // 结果
+    settlement: {
+      result: null,
+      evidence: null,
+      settled_by: null,
+      settled_at: null,
+    },
+  };
+
+  topics.set(topic.id, topic);
+  return topic;
+};
+
+/**
+ * 获取话题详情
+ * @param {string} topicId - 话题ID
+ * @returns {Object} 话题详情
+ */
+export const getTopic = (topicId) => {
+  return topics.get(topicId);
+};
+
+/**
+ * 更新话题
+ * @param {string} topicId - 话题ID
+ * @param {Object} updates - 更新内容
+ */
+export const updateTopic = (topicId, updates) => {
+  const topic = getTopic(topicId);
+  const updated = { ...topic, ...updates };
+  topics.set(topicId, updated);
+  return updated;
+};
+
+/**
+ * 获取所有话题列表
+ * @param {Object} filters - 筛选条件
+ * @returns {Array} 话题列表
+ */
+export const getTopics = (filters = {}) => {
+  let topicList = Array.from(topics.values());
+
+  // 按状态筛选
+  if (filters.status) {
+    topicList = topicList.filter((t) => t.status === filters.status);
+  }
+
+  // 按分类筛选
+  if (filters.category) {
+    topicList = topicList.filter((t) => t.category === filters.category);
+  }
+
+  // 排序
+  const sortBy = filters.sortBy || 'created_at';
+  topicList.sort((a, b) => {
+    if (sortBy === 'created_at') {
+      return new Date(b.created_at) - new Date(a.created_at);
+    }
+    if (sortBy === 'total_pool') {
+      return b.total_pool - a.total_pool;
+    }
+    if (sortBy === 'total_volume') {
+      return b.stats.total_volume - a.stats.total_volume;
+    }
+    return 0;
+  });
+
+  return topicList;
+};
+
+// ==================== 席位管理 ====================
+
+/**
+ * 创建席位
+ * @param {Object} positionData - 席位数据
+ * @returns {Object} 创建的席位
+ */
+const createPosition = (positionData) => {
+  const position = {
+    id: `pos_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+    ...positionData,
+    acquired_at: new Date().toISOString(),
+    last_traded_at: new Date().toISOString(),
+    is_lord: false,
+  };
+
+  positions.set(position.id, position);
+  return position;
+};
+
+/**
+ * 获取席位
+ * @param {string} positionId - 席位ID
+ * @returns {Object} 席位信息
+ */
+export const getPosition = (positionId) => {
+  return positions.get(positionId);
+};
+
+/**
+ * 分配席位（取份额最高的前5名）
+ * @param {Array} allPositions - 所有持仓
+ * @returns {Array} 席位列表
+ */
+const allocateSeats = (allPositions) => {
+  // 按份额排序
+  const sorted = [...allPositions].sort((a, b) => b.shares - a.shares);
+
+  // 取前5名
+  return sorted.slice(0, MARKET_CONFIG.MAX_SEATS_PER_SIDE);
+};
+
+/**
+ * 确定领主（份额最多的人）
+ * @param {Array} seats - 席位列表
+ * @returns {string|null} 领主用户ID
+ */
+const determineLord = (seats) => {
+  if (seats.length === 0) return null;
+
+  const lord = seats.reduce((max, seat) => (seat.shares > max.shares ? seat : max));
+
+  return lord.holder_id;
+};
+
+/**
+ * 更新领主标识
+ * @param {string} topicId - 话题ID
+ * @param {string} optionId - 选项ID
+ */
+const updateLordStatus = (topicId, optionId) => {
+  const topic = getTopic(topicId);
+  const sideData = topic.positions[optionId];
+
+  // 重新分配席位
+  const allPositions = Array.from(positions.values()).filter(
+    (p) => p.topic_id === topicId && p.option_id === optionId
+  );
+
+  const seats = allocateSeats(allPositions);
+  const lordId = determineLord(seats);
+
+  // 更新所有席位的领主标识
+  allPositions.forEach((position) => {
+    const isLord = position.holder_id === lordId;
+    positions.set(position.id, { ...position, is_lord: isLord });
+  });
+
+  // 更新话题数据
+  updateTopic(topicId, {
+    positions: {
+      ...topic.positions,
+      [optionId]: {
+        ...sideData,
+        seats,
+        lord_id: lordId,
+      },
+    },
+  });
+
+  return lordId;
+};
+
+// ==================== 交易执行 ====================
+
+/**
+ * 购买席位
+ * @param {Object} tradeData - 交易数据
+ * @returns {Object} 交易结果
+ */
+export const buyPosition = (tradeData) => {
+  const { user_id, user_name, user_avatar, topic_id, option_id, shares } = tradeData;
+
+  // 验证
+  const topic = getTopic(topic_id);
+  if (!topic) throw new Error('话题不存在');
+  if (topic.status !== 'active') throw new Error('话题已关闭交易');
+  if (topic.author_id === user_id) throw new Error('不能参与自己发起的话题');
+
+  // 检查购买上限
+  if (shares * MARKET_CONFIG.BASE_PRICE > CREDIT_CONFIG.MAX_SINGLE_BET) {
+    throw new Error(`单次购买上限为${CREDIT_CONFIG.MAX_SINGLE_BET}积分`);
+  }
+
+  // 获取当前市场数据
+  const sideData = topic.positions[option_id];
+  const otherOptionId = option_id === 'yes' ? 'no' : 'yes';
+  const otherSideData = topic.positions[otherOptionId];
+
+  // 计算成本
+  const cost = calculateBuyCost(sideData.total_shares, otherSideData.total_shares, shares);
+  const tax = calculateTax(cost);
+  const totalCost = cost + tax;
+
+  // 检查余额
+  if (!canAfford(user_id, totalCost)) {
+    throw new Error(`积分不足，需要${totalCost}积分`);
+  }
+
+  // 扣除积分
+  deductCredits(user_id, totalCost, `购买预测席位 - ${topic.title}`);
+
+  // 税费进入奖池
+  updateTopic(topic_id, {
+    total_pool: topic.total_pool + tax,
+    stats: {
+      ...topic.stats,
+      total_volume: topic.stats.total_volume + totalCost,
+      total_transactions: topic.stats.total_transactions + 1,
+      unique_traders: topic.stats.unique_traders.add(user_id),
+    },
+  });
+
+  // 查找用户是否已有该选项的席位
+  let userPosition = Array.from(positions.values()).find(
+    (p) => p.topic_id === topic_id && p.option_id === option_id && p.holder_id === user_id
+  );
+
+  if (userPosition) {
+    // 更新现有席位
+    const newShares = userPosition.shares + shares;
+    const newAvgCost = (userPosition.avg_cost * userPosition.shares + cost) / newShares;
+
+    positions.set(userPosition.id, {
+      ...userPosition,
+      shares: newShares,
+      avg_cost: newAvgCost,
+      last_traded_at: new Date().toISOString(),
+    });
+
+    // 更新用户账户持仓
+    updatePosition(user_id, userPosition.id, {
+      shares: newShares,
+      avg_cost: newAvgCost,
+    });
+  } else {
+    // 创建新席位
+    const newPosition = createPosition({
+      topic_id,
+      option_id,
+      holder_id: user_id,
+      holder_name: user_name,
+      holder_avatar: user_avatar,
+      shares,
+      avg_cost: cost / shares,
+      current_value: cost,
+      unrealized_pnl: 0,
+    });
+
+    // 添加到用户账户
+    addPosition(user_id, {
+      id: newPosition.id,
+      topic_id,
+      option_id,
+      shares,
+      avg_cost: cost / shares,
+    });
+
+    userPosition = newPosition;
+  }
+
+  // 更新话题席位数据
+  updateTopic(topic_id, {
+    positions: {
+      ...topic.positions,
+      [option_id]: {
+        ...sideData,
+        total_shares: sideData.total_shares + shares,
+      },
+    },
+  });
+
+  // 更新价格
+  const newPrices = calculatePrice(
+    topic.positions[option_id].total_shares + shares,
+    topic.positions[otherOptionId].total_shares
+  );
+
+  updateTopic(topic_id, {
+    positions: {
+      ...topic.positions,
+      yes: { ...topic.positions.yes, current_price: newPrices.yes },
+      no: { ...topic.positions.no, current_price: newPrices.no },
+    },
+  });
+
+  // 更新领主状态
+  const newLordId = updateLordStatus(topic_id, option_id);
+
+  // 记录交易
+  const trade = {
+    id: `trade_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+    topic_id,
+    option_id,
+    buyer_id: user_id,
+    seller_id: null,
+    type: 'buy',
+    shares,
+    price: cost / shares,
+    total_cost: totalCost,
+    tax,
+    created_at: new Date().toISOString(),
+  };
+  trades.push(trade);
+
+  return {
+    success: true,
+    position: userPosition,
+    trade,
+    new_lord_id: newLordId,
+    current_price: newPrices[option_id],
+  };
+};
+
+/**
+ * 卖出席位
+ * @param {Object} tradeData - 交易数据
+ * @returns {Object} 交易结果
+ */
+export const sellPosition = (tradeData) => {
+  const { user_id, topic_id, option_id, shares } = tradeData;
+
+  // 验证
+  const topic = getTopic(topic_id);
+  if (!topic) throw new Error('话题不存在');
+  if (topic.status !== 'active') throw new Error('话题已关闭交易');
+
+  // 查找用户席位
+  const userPosition = Array.from(positions.values()).find(
+    (p) => p.topic_id === topic_id && p.option_id === option_id && p.holder_id === user_id
+  );
+
+  if (!userPosition) throw new Error('未持有该席位');
+  if (userPosition.shares < shares) throw new Error('持有份额不足');
+
+  // 获取当前市场数据
+  const sideData = topic.positions[option_id];
+  const otherOptionId = option_id === 'yes' ? 'no' : 'yes';
+  const otherSideData = topic.positions[otherOptionId];
+
+  // 计算收益
+  const revenue = calculateSellRevenue(sideData.total_shares, otherSideData.total_shares, shares);
+  const tax = calculateTax(revenue);
+  const netRevenue = revenue - tax;
+
+  // 返还积分
+  addCredits(user_id, netRevenue, `卖出预测席位 - ${topic.title}`);
+
+  // 税费进入奖池
+  updateTopic(topic_id, {
+    total_pool: topic.total_pool + tax,
+    stats: {
+      ...topic.stats,
+      total_volume: topic.stats.total_volume + revenue,
+      total_transactions: topic.stats.total_transactions + 1,
+    },
+  });
+
+  // 更新席位
+  const newShares = userPosition.shares - shares;
+
+  if (newShares === 0) {
+    // 完全卖出，删除席位
+    positions.delete(userPosition.id);
+    removePosition(user_id, userPosition.id);
+  } else {
+    // 部分卖出，更新份额
+    positions.set(userPosition.id, {
+      ...userPosition,
+      shares: newShares,
+      last_traded_at: new Date().toISOString(),
+    });
+
+    updatePosition(user_id, userPosition.id, { shares: newShares });
+  }
+
+  // 更新话题席位数据
+  updateTopic(topic_id, {
+    positions: {
+      ...topic.positions,
+      [option_id]: {
+        ...sideData,
+        total_shares: sideData.total_shares - shares,
+      },
+    },
+  });
+
+  // 更新价格
+  const newPrices = calculatePrice(
+    topic.positions[option_id].total_shares - shares,
+    topic.positions[otherOptionId].total_shares
+  );
+
+  updateTopic(topic_id, {
+    positions: {
+      ...topic.positions,
+      yes: { ...topic.positions.yes, current_price: newPrices.yes },
+      no: { ...topic.positions.no, current_price: newPrices.no },
+    },
+  });
+
+  // 更新领主状态
+  const newLordId = updateLordStatus(topic_id, option_id);
+
+  // 记录交易
+  const trade = {
+    id: `trade_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
+    topic_id,
+    option_id,
+    buyer_id: null,
+    seller_id: user_id,
+    type: 'sell',
+    shares,
+    price: revenue / shares,
+    total_cost: netRevenue,
+    tax,
+    created_at: new Date().toISOString(),
+  };
+  trades.push(trade);
+
+  return {
+    success: true,
+    trade,
+    new_lord_id: newLordId,
+    current_price: newPrices[option_id],
+  };
+};
+
+// ==================== 结算 ====================
+
+/**
+ * 结算话题
+ * @param {string} topicId - 话题ID
+ * @param {string} result - 结果 'yes' | 'no'
+ * @param {string} evidence - 证据说明
+ * @param {string} settledBy - 裁决者ID
+ * @returns {Object} 结算结果
+ */
+export const settleTopic = (topicId, result, evidence, settledBy) => {
+  const topic = getTopic(topicId);
+
+  if (!topic) throw new Error('话题不存在');
+  if (topic.status === 'settled') throw new Error('话题已结算');
+
+  // 只有作者可以结算
+  if (topic.author_id !== settledBy) throw new Error('无权结算');
+
+  // 获取获胜方和失败方
+  const winningOption = result;
+  const losingOption = result === 'yes' ? 'no' : 'yes';
+
+  const winners = Array.from(positions.values()).filter(
+    (p) => p.topic_id === topicId && p.option_id === winningOption
+  );
+
+  const losers = Array.from(positions.values()).filter(
+    (p) => p.topic_id === topicId && p.option_id === losingOption
+  );
+
+  // 分配奖池
+  if (winners.length === 0) {
+    // 无人获胜，奖池返还给作者
+    addCredits(topic.author_id, topic.total_pool, '话题奖池返还');
+  } else {
+    // 计算获胜方总份额
+    const totalWinningShares = winners.reduce((sum, p) => sum + p.shares, 0);
+
+    // 按份额分配
+    winners.forEach((position) => {
+      const share = position.shares / totalWinningShares;
+      const reward = Math.floor(topic.total_pool * share);
+
+      // 返还本金 + 奖池分成
+      const refund = Math.floor(position.avg_cost * position.shares);
+      const total = refund + reward;
+
+      addCredits(position.holder_id, total, `预测获胜 - ${topic.title}`);
+
+      // 记录胜利
+      recordWin(position.holder_id, reward);
+
+      // 删除席位
+      positions.delete(position.id);
+      removePosition(position.holder_id, position.id);
+    });
+  }
+
+  // 失败方损失本金
+  losers.forEach((position) => {
+    const loss = Math.floor(position.avg_cost * position.shares);
+
+    // 记录失败
+    recordLoss(position.holder_id, loss);
+
+    // 删除席位
+    positions.delete(position.id);
+    removePosition(position.holder_id, position.id);
+  });
+
+  // 更新话题状态
+  updateTopic(topicId, {
+    status: 'settled',
+    settlement: {
+      result,
+      evidence,
+      settled_by: settledBy,
+      settled_at: new Date().toISOString(),
+    },
+  });
+
+  return {
+    success: true,
+    winners_count: winners.length,
+    losers_count: losers.length,
+    total_distributed: topic.total_pool,
+  };
+};
+
+// ==================== 数据导出 ====================
+
+export default {
+  MARKET_CONFIG,
+
+  // 定价算法
+  calculatePrice,
+  calculateBuyCost,
+  calculateSellRevenue,
+  calculateTax,
+
+  // 话题管理
+  createTopic,
+  getTopic,
+  updateTopic,
+  getTopics,
+
+  // 席位管理
+  getPosition,
+
+  // 交易
+  buyPosition,
+  sellPosition,
+
+  // 结算
+  settleTopic,
+};