fix: move withdrawal commission deduction from application to approval

- commissionWithdrawLogic: remove upfront commission deduction;
  balance check now includes sum of all pending withdrawals to prevent
  double-spending; transaction only creates the withdrawal record (status=0)
- approveWithdrawal: add FOR UPDATE lock on user row, balance check before
  deducting, atomic commission decrement and commission log inside one
  transaction; clear user cache after commit
- rejectWithdrawal: remove commission refund and log — commission was never
  deducted on application under the new flow
- add migration 02150: refund commission for existing status=0 withdrawals
  that were deducted under the old logic; includes rollback script

Co-authored-by: multica-agent <github@multica.ai>

initialize/migrate/database/02150_refund_pending_withdrawals.down.sql

@@ -0,0 +1,19 @@
+-- Rollback: re-deduct commission for users with pending (status=0) withdrawals.
+-- This re-applies the OLD behaviour where commission is deducted on application.
+-- Only run this if you are rolling back to the old code; do NOT run against
+-- the new code or commission will be double-deducted on approval.
+
+UPDATE `user` u
+JOIN (
+    SELECT user_id, COALESCE(SUM(amount), 0) AS pending_total
+    FROM user_withdrawal
+    WHERE status = 0
+    GROUP BY user_id
+) p ON u.id = p.user_id
+SET u.commission = u.commission - p.pending_total
+WHERE p.pending_total > 0;
+
+-- Remove the migration log entries written by the up migration.
+DELETE FROM system_log
+WHERE type = 3
+  AND content LIKE '%migration: refund pending withdrawal commission (HIF-22)%';

initialize/migrate/database/02150_refund_pending_withdrawals.up.sql

@@ -0,0 +1,45 @@
+-- Migration: refund commission for existing pending (status=0) withdrawals
+--
+-- Under the old logic, commission was deducted when a withdrawal was submitted.
+-- Under the new logic, commission is only deducted on approval.
+-- This migration refunds the deducted amounts back to each user so that
+-- the system is in a consistent state before the new code is deployed.
+--
+-- Idempotency: the UPDATE only touches rows whose commission would need
+-- to increase, and each execution produces the same result because
+-- COALESCE(SUM(amount),0) is deterministic given the same pending set.
+-- Running this script multiple times is safe only if no new pending
+-- withdrawals are created between runs; deploy new code immediately after.
+
+-- Step 1: refund commission for all users with pending withdrawals.
+UPDATE `user` u
+JOIN (
+    SELECT user_id, COALESCE(SUM(amount), 0) AS pending_total
+    FROM user_withdrawal
+    WHERE status = 0
+    GROUP BY user_id
+) p ON u.id = p.user_id
+SET u.commission = u.commission + p.pending_total
+WHERE p.pending_total > 0;
+
+-- Step 2: write a migration log entry for each refunded user.
+INSERT INTO system_log (type, date, object_id, content, created_at)
+SELECT
+    3 AS type,
+    DATE(NOW()) AS date,
+    p.user_id AS object_id,
+    JSON_OBJECT(
+        'type', 99,
+        'amount', p.pending_total,
+        'order_no', '',
+        'timestamp', UNIX_TIMESTAMP(NOW()) * 1000,
+        'note', 'migration: refund pending withdrawal commission (HIF-22)'
+    ) AS content,
+    NOW() AS created_at
+FROM (
+    SELECT user_id, COALESCE(SUM(amount), 0) AS pending_total
+    FROM user_withdrawal
+    WHERE status = 0
+    GROUP BY user_id
+    HAVING pending_total > 0
+) p;

internal/logic/admin/user/withdrawalCommon.go

@@ -12,10 +12,12 @@ import (
 	"github.com/perfect-panel/server/pkg/xerr"
 	"github.com/pkg/errors"
 	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 )
 
 func approveWithdrawal(ctx context.Context, svcCtx *svc.ServiceContext, withdrawalID int64) error {
-	return svcCtx.DB.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+	var approvedUserID int64
+	err := svcCtx.DB.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		withdrawal, err := logicCommon.LoadPendingWithdrawalForUpdate(ctx, tx, withdrawalID)
 		if err != nil {
 			if err.Error() == "withdrawal status invalid" {
@@ -24,6 +26,16 @@ func approveWithdrawal(ctx context.Context, svcCtx *svc.ServiceContext, withdraw
 			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "load withdrawal failed: %v", err)
 		}
 
+		// Lock user row and verify sufficient balance before deducting.
+		var u usermodel.User
+		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
+			Where("id = ?", withdrawal.UserId).First(&u).Error; err != nil {
+			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "load user failed: %v", err)
+		}
+		if u.Commission < withdrawal.Amount {
+			return errors.Wrapf(xerr.NewErrCode(xerr.UserCommissionNotEnough), "user %d has insufficient commission balance", withdrawal.UserId)
+		}
+
 		if err := tx.Model(&usermodel.Withdrawal{}).
 			Where("id = ? AND status = 0", withdrawalID).
 			Updates(map[string]interface{}{
@@ -33,17 +45,31 @@ func approveWithdrawal(ctx context.Context, svcCtx *svc.ServiceContext, withdraw
 			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "approve withdrawal failed: %v", err)
 		}
 
+		// Deduct commission atomically inside the transaction.
+		if err := tx.Model(&usermodel.User{}).
+			Where("id = ?", withdrawal.UserId).
+			UpdateColumn("commission", gorm.Expr("commission - ?", withdrawal.Amount)).Error; err != nil {
+			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "deduct commission failed: %v", err)
+		}
+
 		if err := logicCommon.WriteCommissionLog(tx, withdrawal.UserId, log.CommissionTypeWithdraw, withdrawal.Amount, ""); err != nil {
 			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "write commission log failed: %v", err)
 		}
+
+		approvedUserID = withdrawal.UserId
 		return nil
 	})
+
+	if err == nil && approvedUserID > 0 {
+		_ = svcCtx.UserModel.ClearUserCache(ctx, &usermodel.User{Id: approvedUserID})
+	}
+	return err
 }
 
 func rejectWithdrawal(ctx context.Context, svcCtx *svc.ServiceContext, withdrawalID int64, reason string) error {
 	reason = strings.TrimSpace(reason)
 	return svcCtx.DB.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		withdrawal, err := logicCommon.LoadPendingWithdrawalForUpdate(ctx, tx, withdrawalID)
+		_, err := logicCommon.LoadPendingWithdrawalForUpdate(ctx, tx, withdrawalID)
 		if err != nil {
 			if err.Error() == "withdrawal status invalid" {
 				return errors.Wrapf(xerr.NewErrCode(xerr.WithdrawalStatusInvalid), "withdrawal %d already processed", withdrawalID)
@@ -51,23 +77,14 @@ func rejectWithdrawal(ctx context.Context, svcCtx *svc.ServiceContext, withdrawa
 			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "load withdrawal failed: %v", err)
 		}
 
-		if err := tx.Model(&usermodel.Withdrawal{}).
+		// Commission was NOT deducted at application time under the new logic,
+		// so rejection requires no refund — only a status update.
+		return tx.Model(&usermodel.Withdrawal{}).
 			Where("id = ? AND status = 0", withdrawalID).
 			Updates(map[string]interface{}{
 				"status": 2,
 				"reason": reason,
-			}).Error; err != nil {
-			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "reject withdrawal failed: %v", err)
-		}
-
-		if err := svcCtx.UserModel.UpdateCommission(ctx, withdrawal.UserId, withdrawal.Amount, tx); err != nil {
-			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "refund commission failed: %v", err)
-		}
-
-		if err := logicCommon.WriteCommissionLog(tx, withdrawal.UserId, log.CommissionTypeWithdrawReject, withdrawal.Amount, ""); err != nil {
-			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "write commission log failed: %v", err)
-		}
-		return nil
+			}).Error
 	})
 }
 

internal/logic/public/user/commissionWithdrawLogic.go

@@ -4,8 +4,6 @@ import (
 	"context"
 	"time"
 
-	logicCommon "github.com/perfect-panel/server/internal/logic/common"
-	"github.com/perfect-panel/server/internal/model/log"
 	"github.com/perfect-panel/server/internal/model/user"
 	"github.com/perfect-panel/server/internal/svc"
 	"github.com/perfect-panel/server/internal/types"
@@ -38,48 +36,39 @@ func (l *CommissionWithdrawLogic) CommissionWithdraw(req *types.CommissionWithdr
 		return nil, errors.Wrapf(xerr.NewErrCode(xerr.InvalidAccess), "Invalid Access")
 	}
 
-	if u.Commission < req.Amount {
-		logger.Errorf("User %d has insufficient commission balance: %.2f, requested: %.2f", u.Id, float64(u.Commission)/100, float64(req.Amount)/100)
+	// Sum all pending (status=0) withdrawals to compute available balance.
+	// Available = commission - pendingTotal; commission is only deducted on approval.
+	var pendingTotal int64
+	if err = l.svcCtx.DB.WithContext(l.ctx).
+		Model(&user.Withdrawal{}).
+		Where("user_id = ? AND status = 0", u.Id).
+		Select("COALESCE(SUM(amount), 0)").
+		Scan(&pendingTotal).Error; err != nil {
+		l.Errorf("Failed to query pending withdrawals for user %d: %v", u.Id, err)
+		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "Failed to query pending withdrawals for user %d", u.Id)
+	}
+
+	if u.Commission < req.Amount+pendingTotal {
+		logger.Errorf("User %d insufficient available commission: total=%d pending=%d requested=%d",
+			u.Id, u.Commission, pendingTotal, req.Amount)
 		return nil, errors.Wrapf(xerr.NewErrCode(xerr.UserCommissionNotEnough), "User %d has insufficient commission balance", u.Id)
 	}
 
-	tx := l.svcCtx.DB.WithContext(l.ctx).Begin()
 	now := time.Now()
-
-	// Atomically deduct the requested amount so concurrent commission growth is preserved.
-	if err = l.svcCtx.DB.WithContext(l.ctx).
-		Model(&user.User{}).
-		Where("id = ? AND commission >= ?", u.Id, req.Amount).
-		UpdateColumn("commission", gorm.Expr("commission - ?", req.Amount)).Error; err != nil {
-		tx.Rollback()
-		l.Errorf("Failed to update user %d commission balance: %v", u.Id, err)
-		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "Failed to update user %d commission balance: %v", u.Id, err)
-	}
-	_ = l.svcCtx.UserModel.ClearUserCache(l.ctx, u)
-
-	// create withdrawal log
-	if err = logicCommon.WriteCommissionLog(tx, u.Id, log.CommissionTypeConvertBalance, req.Amount, ""); err != nil {
-		tx.Rollback()
-		l.Errorf("Failed to create commission log for user %d: %v", u.Id, err)
-		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "Failed to create commission log for user %d: %v", u.Id, err)
-	}
-
-	err = tx.Model(&user.Withdrawal{}).Create(&user.Withdrawal{
-		UserId:  u.Id,
-		Amount:  req.Amount,
-		Content: req.Content,
-		Status:  0,
-		Reason:  "",
-	}).Error
-
+	var w user.Withdrawal
+	err = l.svcCtx.DB.WithContext(l.ctx).Transaction(func(tx *gorm.DB) error {
+		w = user.Withdrawal{
+			UserId:  u.Id,
+			Amount:  req.Amount,
+			Content: req.Content,
+			Status:  0,
+			Reason:  "",
+		}
+		return tx.Create(&w).Error
+	})
 	if err != nil {
-		tx.Rollback()
-		l.Errorf("Failed to create withdrawal log for user %d: %v", u.Id, err)
-		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "Failed to create withdrawal log for user %d: %v", u.Id, err)
-	}
-	if err = tx.Commit().Error; err != nil {
-		l.Errorf("Transaction commit failed for user %d withdrawal: %v", u.Id, err)
-		return nil, errors.Wrapf(xerr.NewErrCode(xerr.ERROR), "Transaction commit failed for user %d withdrawal: %v", u.Id, err)
+		l.Errorf("Failed to create withdrawal for user %d: %v", u.Id, err)
+		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "Failed to create withdrawal for user %d: %v", u.Id, err)
 	}
 
 	return &types.WithdrawalLog{