package voiceroomredpacket

import (
	"context"
	"errors"
	"fmt"
	"log"
	"time"

	"chatapp3-golang/internal/config"
	"chatapp3-golang/internal/integration"
	"chatapp3-golang/internal/model"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

// StartRefundWorker 启动过期红包退款扫描。
func (s *Service) StartRefundWorker(ctx context.Context) {
	interval := refundInterval(s.cfg)
	ticker := time.NewTicker(interval)
	go func() {
		defer ticker.Stop()
		for {
			select {
			case <-ctx.Done():
				return
			case <-ticker.C:
				if _, err := s.ProcessExpired(ctx, refundBatchSize(s.cfg)); err != nil {
					log.Printf("voice room red packet refund worker failed: %v", err)
				}
			}
		}
	}()
}

// ProcessExpired 扫描并处理过期红包退款。
func (s *Service) ProcessExpired(ctx context.Context, limit int) (*RefundResult, error) {
	if limit <= 0 {
		limit = defaultRefundBatchSize
	}
	var rows []model.VoiceRoomRedPacket
	if err := s.db.WithContext(ctx).
		Where("(status = ? AND expire_time <= ?) OR status = ?", packetStatusActive, time.Now(), packetStatusRefundFailed).
		Order("expire_time asc").
		Limit(limit).
		Find(&rows).Error; err != nil {
		return nil, err
	}
	result := &RefundResult{Scanned: len(rows)}
	for _, row := range rows {
		if err := s.refundOne(ctx, row.PacketNo, false); err != nil {
			result.Failed++
			log.Printf("voice room red packet refund failed packetNo=%s err=%v", row.PacketNo, err)
			continue
		}
		result.Success++
	}
	return result, nil
}

// RetryRefund 后台手动重试指定红包退款。
func (s *Service) RetryRefund(ctx context.Context, packetNo string) error {
	return s.refundOne(ctx, packetNo, true)
}

func (s *Service) refundOne(ctx context.Context, packetNo string, force bool) error {
	lockKey := fmt.Sprintf("voice_room:red_packet:refund_lock:%s", packetNo)
	lockOK, err := s.redis.SetNX(ctx, lockKey, "1", 30*time.Second).Result()
	if err != nil {
		return err
	}
	if !lockOK {
		return nil
	}
	defer s.redis.Del(context.Background(), lockKey)

	var packet model.VoiceRoomRedPacket
	refundAmount := int64(0)
	if err := s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Where("packet_no = ?", packetNo).
			First(&packet).Error
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil
		}
		if err != nil {
			return err
		}
		if packet.Status == packetStatusRefunded || packet.Status == packetStatusFinished {
			return nil
		}
		if packet.Status != packetStatusActive && packet.Status != packetStatusRefundFailed {
			return nil
		}
		if packet.Status == packetStatusActive && time.Now().Before(packet.ExpireTime) && !force {
			return nil
		}
		now := time.Now()
		if packet.RefundAmount > 0 && packet.Status == packetStatusRefundFailed {
			refundAmount = packet.RefundAmount
		} else {
			var total struct {
				Amount int64
			}
			if err := tx.Model(&model.VoiceRoomRedPacketSlice{}).
				Select("COALESCE(SUM(amount), 0) AS amount").
				Where("packet_id = ? AND status = ?", packet.ID, sliceStatusUnclaimed).
				Scan(&total).Error; err != nil {
				return err
			}
			refundAmount = total.Amount
			if err := tx.Model(&model.VoiceRoomRedPacketSlice{}).
				Where("packet_id = ? AND status = ?", packet.ID, sliceStatusUnclaimed).
				Updates(map[string]any{"status": sliceStatusReleased, "update_time": now}).Error; err != nil {
				return err
			}
		}
		if refundAmount <= 0 {
			return tx.Model(&model.VoiceRoomRedPacket{}).
				Where("id = ?", packet.ID).
				Updates(map[string]any{
					"status":        packetStatusFinished,
					"refund_status": refundStatusNone,
					"refund_amount": 0,
					"update_time":   now,
				}).Error
		}
		packet.RefundWalletEventID = walletEventID(walletOriginRefund, packet.SysOrigin, packet.PacketNo, 0)
		packet.RefundAmount = refundAmount
		return tx.Model(&model.VoiceRoomRedPacket{}).
			Where("id = ?", packet.ID).
			Updates(map[string]any{
				"status":                 packetStatusExpired,
				"refund_status":          refundStatusPending,
				"refund_wallet_event_id": packet.RefundWalletEventID,
				"refund_amount":          refundAmount,
				"update_time":            now,
			}).Error
	}); err != nil {
		return err
	}
	if packet.ID == 0 || refundAmount <= 0 {
		return nil
	}

	if err := s.wallet.ChangeGoldBalance(ctx, integration.GoldReceiptCommand{
		ReceiptType:         walletReceiptIncome,
		UserID:              packet.SenderUserID,
		SysOrigin:           packet.SysOrigin,
		EventID:             packet.RefundWalletEventID,
		Remark:              fmt.Sprintf("voice room red packet refund %s", packet.PacketNo),
		Amount:              integration.NewPennyAmountPayloadFromDollar(refundAmount),
		CloseDelayAsset:     false,
		OpUserType:          "APP",
		CustomizeOrigin:     walletOriginRefund,
		CustomizeOriginDesc: walletOriginRefundDesc,
	}); err != nil {
		_ = s.db.WithContext(context.Background()).Model(&model.VoiceRoomRedPacket{}).
			Where("id = ?", packet.ID).
			Updates(map[string]any{
				"status":        packetStatusRefundFailed,
				"refund_status": refundStatusFailed,
				"error_message": trimErrorMessage(err.Error()),
				"update_time":   time.Now(),
			}).Error
		return err
	}

	return s.db.WithContext(ctx).Model(&model.VoiceRoomRedPacket{}).
		Where("id = ?", packet.ID).
		Updates(map[string]any{
			"status":        packetStatusRefunded,
			"refund_status": refundStatusSuccess,
			"error_message": "",
			"update_time":   time.Now(),
		}).Error
}

func refundInterval(cfg config.Config) time.Duration {
	if cfg.VoiceRoomRedPacket.RefundScanIntervalSeconds <= 0 {
		return defaultRefundInterval
	}
	return time.Duration(cfg.VoiceRoomRedPacket.RefundScanIntervalSeconds) * time.Second
}

func refundBatchSize(cfg config.Config) int {
	if cfg.VoiceRoomRedPacket.RefundBatchSize <= 0 {
		return defaultRefundBatchSize
	}
	return cfg.VoiceRoomRedPacket.RefundBatchSize
}