bindbox-game/test_lottery_profit.js

// 抽奖盈亏计算测试示例
// 基于实际业务逻辑的模拟数据

// 模拟一个抽奖活动的配置
const mockActivity = {
  id: 1,
  name: "春节抽奖活动",
  price_draw: 1000, // 门票价格：10元 = 1000分
  status: 1
};

// 模拟奖项配置
const mockRewards = [
  {
    id: 1,
    name: "iPhone 15 Pro",
    weight: 1,
    quantity: 10,
    product_id: 101,
    cost: 800000 // 成本：8000元 = 800000分
  },
  {
    id: 2,
    name: "AirPods Pro",
    weight: 10,
    quantity: 50,
    product_id: 102,
    cost: 200000 // 成本：2000元 = 200000分
  },
  {
    id: 3,
    name: "小米手环",
    weight: 100,
    quantity: 200,
    product_id: 103,
    cost: 20000 // 成本：200元 = 20000分
  },
  {
    id: 4,
    name: "优惠券10元",
    weight: 1000,
    quantity: -1, // -1 表示不限量
    product_id: null,
    cost: 1000 // 成本：10元 = 1000分（平台补贴）
  },
  {
    id: 5,
    name: "谢谢参与",
    weight: 5000,
    quantity: -1,
    product_id: null,
    cost: 0 // 无成本
  }
];

// 计算理论概率和期望支出
function calculateTheoreticalData(rewards) {
  // 筛选有效奖项（weight > 0 且 quantity != 0）
  const validRewards = rewards.filter(r => r.weight > 0 && r.quantity !== 0);
  
  // 计算总权重
  const totalWeight = validRewards.reduce((sum, r) => sum + r.weight, 0);
  
  // 计算每个奖项的理论概率和期望支出
  const results = validRewards.map(reward => {
    const probability = reward.weight / totalWeight;
    const expectedCost = probability * reward.cost; // 单次抽奖的期望支出
    
    return {
      ...reward,
      probability,
      expectedCost
    };
  });
  
  // 总期望支出（单次抽奖）
  const totalExpectedCost = results.reduce((sum, r) => sum + r.expectedCost, 0);
  
  return {
    rewards: results,
    totalWeight,
    totalExpectedCost
  };
}

// 模拟抽奖结果
function simulateDraws(rewards, sampleSize) {
  const theoretical = calculateTheoreticalData(rewards);
  const results = {};
  
  // 初始化结果统计
  theoretical.rewards.forEach(reward => {
    results[reward.id] = {
      ...reward,
      count: 0,
      simulatedCost: 0
    };
  });
  
  // 模拟抽奖
  for (let i = 0; i < sampleSize; i++) {
    const random = Math.random();
    let cumulativeProbability = 0;
    
    // 根据概率选择奖项
    for (const reward of theoretical.rewards) {
      cumulativeProbability += reward.probability;
      if (random <= cumulativeProbability) {
        results[reward.id].count++;
        results[reward.id].simulatedCost += reward.cost;
        break;
      }
    }
  }
  
  return {
    theoretical,
    simulated: Object.values(results),
    sampleSize
  };
}

// 计算盈亏指标
function calculateProfitMetrics(activity, simulation) {
  const { theoretical, simulated, sampleSize } = simulation;
  const ticketPrice = activity.price_draw;
  
  // 理论计算
  const theoreticalRevenue = ticketPrice * sampleSize;
  const theoreticalPayout = theoretical.totalExpectedCost * sampleSize;
  const theoreticalProfit = theoreticalRevenue - theoreticalPayout;
  const theoreticalMargin = theoreticalProfit / theoreticalRevenue;
  
  // 模拟计算
  const simulatedRevenue = ticketPrice * sampleSize;
  const simulatedPayout = simulated.reduce((sum, r) => sum + r.simulatedCost, 0);
  const simulatedProfit = simulatedRevenue - simulatedPayout;
  const simulatedMargin = simulatedProfit / simulatedRevenue;
  
  return {
    theoretical: {
      revenue: theoreticalRevenue,
      payout: theoreticalPayout,
      profit: theoreticalProfit,
      margin: theoreticalMargin
    },
    simulated: {
      revenue: simulatedRevenue,
      payout: simulatedPayout,
      profit: simulatedProfit,
      margin: simulatedMargin
    }
  };
}

// 运行测试
function runLotteryProfitTest() {
  console.log("=== 抽奖盈亏分析测试 ===");
  console.log(`活动: ${mockActivity.name}`);
  console.log(`门票价格: ¥${(mockActivity.price_draw / 100).toFixed(2)}`);
  console.log("");
  
  // 理论计算
  const theoreticalData = calculateTheoreticalData(mockRewards);
  console.log("--- 理论概率分析 ---");
  console.log(`总权重: ${theoreticalData.totalWeight}`);
  console.log(`单次期望支出: ¥${(theoreticalData.totalExpectedCost / 100).toFixed(4)}`);
  console.log(`单次期望利润: ¥${((mockActivity.price_draw - theoreticalData.totalExpectedCost) / 100).toFixed(4)}`);
  console.log("");
  
  theoreticalData.rewards.forEach(reward => {
    console.log(`${reward.name}:`);
    console.log(`  权重: ${reward.weight}, 概率: ${(reward.probability * 100).toFixed(4)}%`);
    console.log(`  成本: ¥${(reward.cost / 100).toFixed(2)}, 期望支出: ¥${(reward.expectedCost / 100).toFixed(4)}`);
  });
  
  console.log("\n--- 模拟结果 (样本数: 10000) ---");
  const simulation = simulateDraws(mockRewards, 10000);
  const metrics = calculateProfitMetrics(mockActivity, simulation);
  
  console.log("理论值:");
  console.log(`  总收入: ¥${(metrics.theoretical.revenue / 100).toFixed(2)}`);
  console.log(`  总支出: ¥${(metrics.theoretical.payout / 100).toFixed(2)}`);
  console.log(`  总利润: ¥${(metrics.theoretical.profit / 100).toFixed(2)}`);
  console.log(`  利润率: ${(metrics.theoretical.margin * 100).toFixed(2)}%`);
  
  console.log("\n模拟值:");
  console.log(`  总收入: ¥${(metrics.simulated.revenue / 100).toFixed(2)}`);
  console.log(`  总支出: ¥${(metrics.simulated.payout / 100).toFixed(2)}`);
  console.log(`  总利润: ¥${(metrics.simulated.profit / 100).toFixed(2)}`);
  console.log(`  利润率: ${(metrics.simulated.margin * 100).toFixed(2)}%`);
  
  console.log("\n--- 各奖项模拟结果 ---");
  simulation.simulated.forEach(result => {
    const simulatedRate = result.count / simulation.sampleSize;
    const theoreticalRate = result.probability;
    const diff = Math.abs(simulatedRate - theoreticalRate) * 100;
    
    console.log(`${result.name}:`);
    console.log(`  模拟次数: ${result.count}, 模拟概率: ${(simulatedRate * 100).toFixed(3)}%`);
    console.log(`  理论概率: ${(theoreticalRate * 100).toFixed(3)}%, 差异: ${diff.toFixed(3)}%`);
    console.log(`  模拟支出: ¥${(result.simulatedCost / 100).toFixed(2)}`);
  });
  
  // 验证大数定律
  console.log("\n--- 大数定律验证 ---");
  const largeSample = simulateDraws(mockRewards, 100000);
  largeSample.simulated.forEach(result => {
    const simulatedRate = result.count / largeSample.sampleSize;
    const theoreticalRate = result.probability;
    const diff = Math.abs(simulatedRate - theoreticalRate) * 100;
    
    console.log(`${result.name}: 模拟概率 ${(simulatedRate * 100).toFixed(4)}% vs 理论概率 ${(theoreticalRate * 100).toFixed(4)}%, 差异 ${diff.toFixed(4)}%`);
  });
}

// 运行测试
runLotteryProfitTest();