package order

import (
	"context"
	"time"

	"hfb_sys/backend/internal/model"

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

// ownerMayHideOrder 判断号主能否把订单从自己的列表里隐藏。
// 进行中的订单、未结清的款项、暂扣押金、处理中争议和未释放的分销结算都不能藏。
func ownerMayHideOrder(order model.RentalOrder, hasOpenDispute bool, distributionSettlement string) bool {
	if order.OwnerHiddenAt != nil {
		return false
	}
	switch order.Status {
	case orderStatusCompleted, orderStatusClosed:
		if order.SettlementStatus != settlementStatusSettled &&
			order.SettlementStatus != settlementStatusClosed &&
			order.SettlementStatus != settlementStatusArbitrated {
			return false
		}
		if order.OfflineSettlementStatus == offlineSettlementStatusPending {
			return false
		}
	case orderStatusCancelled:
	default:
		return false
	}
	switch order.RefundStatus {
	case "", "none", refundStatusRefunded:
	default:
		return false
	}
	if order.DepositHoldStatus == model.DepositHoldStatusHeld {
		return false
	}
	if hasOpenDispute {
		return false
	}
	if distributionSettlement != "" && distributionSettlement != "settled" {
		return false
	}
	return true
}

type ownerHideSignal struct {
	disputed map[uint64]struct{}
	dist     map[uint64]string
}

func loadOwnerHideSignals(db *gorm.DB, orderIDs []uint64) (ownerHideSignal, error) {
	signal := ownerHideSignal{
		disputed: map[uint64]struct{}{},
		dist:     map[uint64]string{},
	}
	if len(orderIDs) == 0 {
		return signal, nil
	}
	var disputeIDs []uint64
	if err := db.Model(&model.Dispute{}).
		Where("order_id IN ? AND status IN ?", orderIDs, []string{"open", "processing"}).
		Distinct().
		Pluck("order_id", &disputeIDs).Error; err != nil {
		return signal, err
	}
	for _, id := range disputeIDs {
		signal.disputed[id] = struct{}{}
	}
	var rows []struct {
		OrderID          uint64 `gorm:"column:order_id"`
		SettlementStatus string `gorm:"column:settlement_status"`
	}
	if err := db.Model(&model.DistributionOrderFinancial{}).
		Select("order_id, settlement_status").
		Where("order_id IN ?", orderIDs).
		Scan(&rows).Error; err != nil {
		return signal, err
	}
	for _, row := range rows {
		signal.dist[row.OrderID] = row.SettlementStatus
	}
	return signal, nil
}

func (r *Repository) HideForOwner(ctx context.Context, userID uint64, orderID uint64) error {
	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		var order model.RentalOrder
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).First(&order, orderID).Error; err != nil {
			return err
		}
		if order.OwnerID != userID {
			return ErrPermissionDenied
		}
		if order.OwnerHiddenAt != nil {
			return nil
		}
		signals, err := loadOwnerHideSignals(tx, []uint64{order.ID})
		if err != nil {
			return err
		}
		_, disputed := signals.disputed[order.ID]
		if !ownerMayHideOrder(order, disputed, signals.dist[order.ID]) {
			return ErrOrderCannotHide
		}
		now := time.Now()
		return tx.Model(&model.RentalOrder{}).Where("id = ?", order.ID).Update("owner_hidden_at", now).Error
	})
}