初始化

app/service/DrawService.php

@@ -0,0 +1,158 @@
+<?php
+// 抽奖核心服务
+namespace app\service;
+
+use addons\webman\model\DrawRecord;
+use addons\webman\model\Game;
+use addons\webman\model\Prize;
+use Exception;
+use support\Db;
+use support\Log;
+
+class DrawService
+{
+    /**
+     * 执行抽奖
+     * @param  $player
+     * @param int $gameId
+     * @param int $departmentId
+     * @param string $ip 用户IP
+     * @return array 抽奖结果
+     */
+    public function execute( $player, int $gameId, int $departmentId, string $ip): array
+    {
+        try {
+            DB::beginTransaction();
+
+            // 1. 查询有效奖品（加行锁防止并发问题）
+            $prizes = Prize::query()->where('game_id', $gameId)
+                ->where('department_id', $departmentId)
+                ->where('status', 1)
+                ->where('total_remaining', '>', 0)
+                ->where('daily_remaining', '>', 0)
+                ->lockForUpdate()
+                ->get()
+                ->toArray();
+
+            if (empty($prizes)) {
+                DB::rollBack();
+                return [
+                    'success' => false,
+                    'message' => '当前游戏不可用'
+                ];
+            }
+
+            $game = Game::query()->select('id', 'game_type', 'consume')->where('id', $gameId)->first()->toArray();
+            // 2. 计算中奖结果
+            $result = $this->calculateWinning($player,$prizes, $game['consume']);
+            $prizeId = $result['prize_id'];
+            $prizeName = $result['prize_name'];
+            $prizeType = $result['prize_type'];
+
+            $game['department_id'] = $departmentId;
+            // 3. 记录抽奖信息
+            $this->createRecord($player->id, $result, $game, $ip);
+
+            if ($result['prize_type'] == 3) {
+                $message = '很遗憾，未中奖';
+            } else {
+                $message = '恭喜获得' . $prizeName;
+            }
+            DB::commit();
+            return [
+                'prize_id' => $prizeId,
+                'prize_name' => $prizeName,
+                'prize_type' => $prizeType,
+                'consume' => $game['consume'],
+                'message' => $message
+            ];
+        } catch (Exception $e) {
+            DB::rollBack();
+            Log::error("抽奖失败：{$e->getMessage()}", [
+                'user_id' => $player->id,
+                'trace' => $e->getTraceAsString()
+            ]);
+            return [
+                'success' => false,
+                'message' => '抽奖过程异常，请稍后再试'
+            ];
+        }
+    }
+
+    /**
+     * 计算中奖结果
+     * @param array $prizes 有效奖品列表
+     * @return array 中奖信息
+     * @throws Exception
+     */
+    private function calculateWinning($player, array $prizes, $consume): array
+    {
+        // 计算总概率权重
+        $totalProb = array_sum(array_column($prizes, 'probability'));
+        if ($totalProb <= 0) {
+            return ['prize_id' => null, 'type' => Prize::PRIZE_TYPE_LOSE, 'prize_name' => '未中奖', 'prize_pic' => null];
+        }
+        $player->wallet->decrement('money', $consume);
+        // 生成随机数（0到总权重之间）
+        $random = mt_rand(1, $totalProb * 10000) / 10000; // 提高精度
+
+        $currentSum = 0;
+        foreach ($prizes as $prize) {
+            $currentSum += $prize['probability'];
+            if ($random <= $currentSum) {
+                // 检查并扣减库存
+                $this->deductStock($prize['id']);
+                return [
+                    'prize_id' => $prize['id'],
+                    'prize_type' => $prize['type'],
+                    'prize_name' => $prize['name'],
+                    'prize_pic' => $prize['pic']
+                ];
+            }
+        }
+
+        return ['prize_id' => null, 'type' => Prize::PRIZE_TYPE_LOSE,  'prize_name' => '未中奖', 'prize_pic' => null];
+    }
+
+    /**
+     * 扣减库存
+     * @param int $prizeId 奖品ID
+     * @throws Exception
+     */
+    private function deductStock(int $prizeId): void
+    {
+        $prize = Prize::query()->findOrFail($prizeId);
+
+        // 再次检查库存（防止并发超卖）
+        if ($prize->total_remaining <= 0 || $prize->daily_remaining <= 0) {
+            throw new \Exception("奖品库存不足");
+        }
+
+        $prize->decrement('total_remaining');
+        $prize->decrement('daily_remaining');
+        $prize->save();
+    }
+
+    /**
+     * 创建抽奖记录
+     * @param int $userId 用户ID
+     * @param array|null $prize 奖品
+     * @param string $ip IP地址
+     */
+    private function createRecord(int $userId, ?array $prize, array $game, string $ip): void
+    {
+        DrawRecord::query()->create([
+            'uid' => $userId,
+            'prize_id' => $prize['prize_id'],
+            'prize_type' => $prize['prize_type'],
+            'prize_name' => $prize['prize_name'],
+            'prize_pic' => $prize['prize_pic'],
+            'game_id' => $game['id'],
+            'consume' => $game['consume'],
+            'game_type' => $game['game_type'],
+            'department_id' => $game['department_id'],
+            'draw_time' => date('Y-m-d H:i:s'),
+            'ip' => $ip
+        ]);
+    }
+}