package order

import (
	"context"
	"strings"
	"time"

	"hfb_sys/backend/internal/model"
	"hfb_sys/backend/internal/modules/notification"
	"hfb_sys/backend/internal/processlog"

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

func canAdminForceHandoff(order model.RentalOrder) bool {
	if isPlatformHandoffOrder(order) {
		if order.Status == orderStatusPendingHandoff {
			return order.HandoffStatus == handoffStatusPendingRenterConfirm
		}
		return order.Status == orderStatusAbnormal && order.HandoffStatus == handoffStatusRenterConfirmTimeout
	}
	if isPlatformSettlementOrder(order) {
		return false
	}
	if order.Status == orderStatusPendingHandoff {
		return order.HandoffStatus == handoffStatusPendingOwner ||
			order.HandoffStatus == handoffStatusOwnerTimeout ||
			order.HandoffStatus == handoffStatusPendingRenterConfirm
	}
	return order.Status == orderStatusAbnormal && order.HandoffStatus == handoffStatusRenterConfirmTimeout
}

func forceHandoffRecordType(order model.RentalOrder) string {
	if isPlatformHandoffOrder(order) {
		return "platform_handoff"
	}
	return "owner_handoff"
}

func forceHandoffNeedsContent(order model.RentalOrder) bool {
	return order.HandoffStatus == handoffStatusPendingOwner || order.HandoffStatus == handoffStatusOwnerTimeout
}

// AdminForceHandoff 由客服确认订单已完成交接，并立即开始租期。
func (r *Repository) AdminForceHandoff(ctx context.Context, adminID uint64, orderID uint64, req ForceHandoffRequest, meta AuditMeta) 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 !canAdminForceHandoff(order) || strings.TrimSpace(req.Reason) == "" {
			return ErrOrderCannotForceHandoff
		}
		before := orderState(order)
		if order.RefundStatus == refundStatusPending || order.RefundStatus == refundStatusPendingReview {
			return ErrOrderCannotForceHandoff
		}

		var activeDisputeCount int64
		if err := tx.Model(&model.Dispute{}).
			Where("order_id = ? AND status IN ?", order.ID, []string{"open", "processing"}).
			Count(&activeDisputeCount).Error; err != nil {
			return err
		}
		if activeDisputeCount > 0 {
			return ErrOrderCannotForceHandoff
		}

		needsContent := forceHandoffNeedsContent(order)
		content := strings.TrimSpace(req.Content)
		if needsContent && content == "" {
			return ErrOrderCannotForceHandoff
		}
		if !needsContent {
			var handoffCount int64
			if err := tx.Model(&model.HandoffRecord{}).
				Where("order_id = ? AND type = ?", order.ID, forceHandoffRecordType(order)).
				Count(&handoffCount).Error; err != nil {
				return err
			}
			if handoffCount == 0 {
				return ErrOrderCannotForceHandoff
			}
			content = "客服已确认双方完成交接，订单已进入使用中。"
		}

		beforeOrderStatus := order.Status
		beforeHandoffStatus := order.HandoffStatus
		now := time.Now()
		record := model.HandoffRecord{
			OrderID:    order.ID,
			FromUserID: adminID,
			ToUserID:   order.RenterID,
			Type:       "admin_force_handoff",
			Content:    content,
		}
		if err := tx.Create(&record).Error; err != nil {
			return err
		}
		order.Status = orderStatusRenting
		order.HandoffStatus = handoffStatusReceived
		order.EstimatedDurationHours = estimateOrderDurationHours(order.AccountSnapshot)
		order.RentedAt = &now
		if err := appendOrderEvent(tx, order, "handoff", "admin_force_handoff", processlog.ActorAdmin, adminID, processlog.ActorUser, &order.RenterID, content, req.Reason, nil, before, nil); err != nil {
			return err
		}
		orderID := order.ID
		if err := notification.Append(tx,
			notification.Entry{
				UserID:  order.RenterID,
				Type:    "order_admin",
				Title:   "客服已确认交接",
				Content: "客服已确认双方完成交接，订单已进入使用中，租期已开始计算。",
				BizType: "order",
				BizID:   &orderID,
			},
			notification.Entry{
				UserID:  order.OwnerID,
				Type:    "order_admin",
				Title:   "客服已确认交接",
				Content: "客服已确认双方完成交接，订单已进入使用中，租期已开始计算。",
				BizType: "order",
				BizID:   &orderID,
			},
		); err != nil {
			return err
		}
		if err := appendAuditLog(tx, adminID, "order.force_handoff", "order", order.ID, meta, map[string]any{
			"order_id":              order.ID,
			"order_no":              order.OrderNo,
			"reason":                strings.TrimSpace(req.Reason),
			"content_length":        len(content),
			"before_order_status":   beforeOrderStatus,
			"after_order_status":    order.Status,
			"before_handoff_status": beforeHandoffStatus,
			"after_handoff_status":  order.HandoffStatus,
		}); err != nil {
			return err
		}
		return tx.Save(&order).Error
	})
}