[色子游戏]玩家钱包流水记录-优化抽奖逻辑根据结果推断起始位置

server/app/api/logic/PlayStartLogic.php

@@ -12,6 +12,7 @@ use app\dice\model\player_ticket_record\DicePlayerTicketRecord;
 use app\dice\model\player_wallet_record\DicePlayerWalletRecord;
 use app\dice\model\reward_config\DiceRewardConfig;
 use plugin\saiadmin\exception\ApiException;
+use support\Log;
 use support\think\Cache;
 use support\think\Db;
 
@@ -69,19 +70,49 @@ class PlayStartLogic
             throw new ApiException('奖池配置不存在');
         }
 
+        // 先按奖池权重抽出档位 T1-T5
         $tier = LotteryService::drawTierByWeights($config);
-        $rewards = DiceRewardConfig::where('tier', $tier)->select();
-        if ($rewards->isEmpty()) {
+
+        // 生成 5 个 1-6 的点数，计算总和 roll_number（即本局摇到的点数）
+        $rollArray = $this->generateRollArray();
+        $rollNumber = (int) array_sum($rollArray);
+
+        // 索引范围为 0~25 共 26 个格子
+        $boardSize = 26;
+
+        // 1. 根据抽到的档位，在 tier 相等的数据中任选一条，其 id 为结束索引 target_index
+        $tierRewards = DiceRewardConfig::where('tier', $tier)->select()->toArray();
+        if (empty($tierRewards)) {
+            Log::error("档位 {$tier} 无任何奖励配置");
             throw new ApiException('该档位暂无奖励配置');
         }
-        $rewardList = $rewards->all();
-        $reward = $rewardList[array_rand($rewardList)];
+        $chosen = $tierRewards[array_rand($tierRewards)];
+        $reward = DiceRewardConfig::find($chosen['id']);
+        if (!$reward) {
+            throw new ApiException('奖励配置不存在');
+        }
+        $targetIndex = (int) $reward->id;
+        $targetIndex = (($targetIndex % $boardSize) + $boardSize) % $boardSize;
+
+        // 2. 根据结果反推起始点 start_index（由 target_index 与方向反算）
+        // 顺时针(direction=0): targetIndex = (startIndex + rollNumber) % 26  =>  startIndex = (targetIndex - rollNumber) % 26
+        // 逆时针(direction=1): targetIndex = (startIndex - rollNumber) % 26  =>  startIndex = (targetIndex + rollNumber) % 26
+        if ($direction === 0) {
+            $startIndex = ($targetIndex - $rollNumber) % $boardSize;
+        } else {
+            $startIndex = ($targetIndex + $rollNumber) % $boardSize;
+        }
+        $startIndex = ($startIndex % $boardSize + $boardSize) % $boardSize;
+
+        Log::info(sprintf(
+            '摇取点数 roll_number=%d, 方向=%d, start_index=%d, target_index=%d',
+            $rollNumber,
+            $direction,
+            $startIndex,
+            $targetIndex
+        ));
         $realEv = (float) $reward->real_ev;
         $winCoin = 100 + $realEv; // 赢取平台币 = 100 + DiceRewardConfig.real_ev
-        $gridNumber = (int) $reward->grid_number;
-        $startIndex = (int) Cache::get(LotteryService::getStartIndexKey($playerId), 0);
-        $targetIndex = (int) $reward->id;
-        $rollArray = $this->generateRollArray($gridNumber);
 
         $record = null;
         $configId = (int) $config->id;
@@ -162,8 +193,6 @@ class PlayStartLogic
                     'wallet_after'   => $coinAfter,
                     'remark'         => '抽奖|play_record_id=' . $record->id,
                 ]);
-
-                Cache::set(LotteryService::getStartIndexKey($playerId), $targetIndex, 86400 * 30);
             });
         } catch (\Throwable $e) {
             if ($record === null) {
@@ -202,23 +231,13 @@ class PlayStartLogic
         return $arr;
     }
 
-    /** 生成 5 个 1-6 的点数，和为 grid_number（5~30），严格不超范围 */
-    private function generateRollArray(int $gridNumber): array
+    /** 生成 5 个 1-6 的点数，roll_number 为其总和 */
+    private function generateRollArray(): array
     {
-        $minSum = 5;
-        $maxSum = 30;
-        $n = max($minSum, min($maxSum, $gridNumber));
-        $dice = [1, 1, 1, 1, 1];
-        $remain = $n - 5;
-        while ($remain > 0) {
-            $i = array_rand($dice);
-            if ($dice[$i] < 6) {
-                $add = min($remain, 6 - $dice[$i]);
-                $dice[$i] += $add;
-                $remain -= $add;
-            }
+        $dice = [];
+        for ($i = 0; $i < 5; $i++) {
+            $dice[] = random_int(1, 6);
         }
-        shuffle($dice);
         return $dice;
     }
 }