package service

import (
	"errors"
	"fmt"
	"strconv"
	"time"

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

	"laic-backend/client"
	"laic-backend/common"
	"laic-backend/logger"
	"laic-backend/model"
	"laic-backend/tool"
)

type simbossAdapter struct {
	client *client.SimbossClient
}

func InitSimboss(conf common.Simboss) error {
	if conf.AppID == "" && conf.Secret == "" {
		return nil
	}
	instance, err := client.NewSimbossClient(conf.AppID, conf.Secret, conf.APIBase)
	if err != nil {
		return err
	}
	DefaultSimRechargeService.simboss = &simbossAdapter{client: instance}
	return nil
}

type SimRechargeService struct {
	simboss *simbossAdapter
}

var DefaultSimRechargeService = &SimRechargeService{}

func (s *SimRechargeService) GetCard(userID, cardID int64, refresh bool) (*model.SimCard, *common.BusiError) {
	var card model.SimCard
	if err := common.DB.Where("id = ? AND user_id = ?", cardID, userID).First(&card).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrSimCardNotFound
		}
		return nil, common.ErrInternal
	}
	if refresh {
		if s.simboss == nil {
			return nil, common.ErrCarrierUnavailable
		}
		if err := s.refreshCard(&card); err != nil {
			logger.WARN("刷新 SIM 卡信息失败", card.ID, err)
			return nil, common.ErrCarrierUnavailable
		}
	}
	return &card, nil
}

func (s *SimRechargeService) ListPackages() ([]model.SimPackage, *common.BusiError) {
	var packages []model.SimPackage
	if err := common.DB.Where("status = ?", "active").Order("sale_fee_fen ASC, id ASC").Find(&packages).Error; err != nil {
		return nil, common.ErrInternal
	}
	return packages, nil
}

func (s *SimRechargeService) CreateOrder(userID, cardID, packageID int64) (*model.SimRechargeOrder, *common.BusiError) {
	var order model.SimRechargeOrder
	now := time.Now()
	var busiErr *common.BusiError
	err := common.DB.Transaction(func(tx *gorm.DB) error {
		var card model.SimCard
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).Where("id = ? AND user_id = ?", cardID, userID).First(&card).Error; err != nil {
			return err
		}
		var pending model.SimRechargeOrder
		if err := tx.Where("sim_card_id = ? AND payment_status IN ?", cardID, []string{"unpaid", "processing"}).First(&pending).Error; err == nil {
			busiErr = common.ErrPendingOrderExists
			return busiErr
		} else if !errors.Is(err, gorm.ErrRecordNotFound) {
			return err
		}
		if card.Status != "active" || card.CarrierStatus == "cancelled" || card.CarrierStatus == "suspended" || card.Iccid == "" {
			busiErr = common.ErrParam
			return busiErr
		}
		var pkg model.SimPackage
		if err := tx.Where("id = ? AND status = ?", packageID, "active").First(&pkg).Error; err != nil {
			return err
		}
		if pkg.ProviderRatePlanID <= 0 || pkg.AmountGb <= 0 || pkg.ValidityMonths <= 0 || pkg.SaleFeeFen <= 0 {
			busiErr = common.ErrParam
			return busiErr
		}
		if card.Carrier != "" && pkg.Carrier != "" && card.Carrier != pkg.Carrier {
			busiErr = common.ErrParam
			return busiErr
		}
		id, err := tool.NextID()
		if err != nil {
			return err
		}
		order = model.SimRechargeOrder{ID: id, UserID: userID, SimCardID: card.ID, PackageID: pkg.ID, PackageCode: pkg.Code, ProviderRatePlanID: pkg.ProviderRatePlanID, IccidSnapshot: card.Iccid, AmountGb: pkg.AmountGb, ValidityMonths: pkg.ValidityMonths, TotalFeeFen: pkg.SaleFeeFen, PaymentStatus: "unpaid", FulfillmentStatus: "pending", ExternalOrderNo: "sim-" + strconv.FormatInt(id, 10), CreatedAt: now, UpdatedAt: now}
		return tx.Create(&order).Error
	})
	if err != nil {
		if busiErr != nil {
			return nil, busiErr
		}
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrSimCardNotFound
		}
		if code, _ := common.ParseError(err); code == 1062 {
			return nil, common.ErrPendingOrderExists
		}
		logger.ERROR("创建 SIM 续费订单失败", err)
		return nil, common.ErrInternal
	}
	DefaultOperationLogService.RecordEvent(userID, "充值与履约", "创建SIM续费订单", fmt.Sprintf("orderId=%d simCardId=%d feeFen=%d", order.ID, order.SimCardID, order.TotalFeeFen), "success", "user_api")
	return &order, nil
}

func (s *SimRechargeService) CloseExpiredOrders(cutoff time.Time) {
	var orders []model.SimRechargeOrder
	if err := common.DB.Where("payment_status IN ? AND created_at <= ?", []string{"unpaid", "processing"}, cutoff).Limit(100).Find(&orders).Error; err != nil {
		logger.ERROR("扫描超时 SIM 订单失败", err)
		return
	}
	for i := range orders {
		now := time.Now()
		closed := false
		err := common.DB.Transaction(func(tx *gorm.DB) error {
			result := tx.Model(&model.SimRechargeOrder{}).Where("id = ? AND payment_status IN ? AND created_at <= ?", orders[i].ID, []string{"unpaid", "processing"}, cutoff).Updates(map[string]any{"payment_status": "closed", "closed_at": now, "updated_at": now})
			if result.Error != nil {
				return result.Error
			}
			if result.RowsAffected != 1 {
				return nil
			}
			closed = true
			return tx.Model(&model.PaymentTransaction{}).Where("business_type = ? AND business_order_id = ? AND status IN ?", "sim_recharge_order", orders[i].ID, []string{"unpaid", "processing"}).Updates(map[string]any{"status": "closed", "updated_at": now}).Error
		})
		if err != nil {
			logger.ERROR("关闭超时 SIM 订单失败", err)
			continue
		}
		if closed {
			DefaultOperationLogService.RecordEvent(orders[i].UserID, "充值与履约", "自动关闭SIM续费订单", fmt.Sprintf("orderId=%d status=closed", orders[i].ID), "success", "system")
		}
	}
}

func (s *SimRechargeService) CancelOrder(userID, orderID int64) *common.BusiError {
	now := time.Now()
	var busiErr *common.BusiError
	err := common.DB.Transaction(func(tx *gorm.DB) error {
		var order model.SimRechargeOrder
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).Where("id = ? AND user_id = ?", orderID, userID).First(&order).Error; err != nil {
			return err
		}
		if order.PaymentStatus != "unpaid" && order.PaymentStatus != "processing" {
			busiErr = common.ErrOrderNotCancellable
			return busiErr
		}
		result := tx.Model(&order).Where("id = ? AND payment_status IN ?", orderID, []string{"unpaid", "processing"}).Updates(map[string]any{"payment_status": "cancelled", "closed_at": now, "updated_at": now})
		if result.Error != nil {
			return result.Error
		}
		if result.RowsAffected != 1 {
			busiErr = common.ErrOrderNotCancellable
			return busiErr
		}
		return tx.Model(&model.PaymentTransaction{}).Where("business_type = ? AND business_order_id = ? AND status IN ?", "sim_recharge_order", orderID, []string{"unpaid", "processing"}).Updates(map[string]any{"status": "cancelled", "updated_at": now}).Error
	})
	if err != nil {
		if busiErr != nil {
			return busiErr
		}
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return common.ErrOrderNotFound
		}
		logger.ERROR("取消 SIM 订单失败", err)
		return common.ErrInternal
	}
	DefaultOperationLogService.RecordEvent(userID, "充值与履约", "取消SIM续费订单", fmt.Sprintf("orderId=%d status=cancelled", orderID), "success", "user_api")
	return nil
}

func (s *SimRechargeService) GetOrder(userID, orderID int64) (*model.SimRechargeOrder, *common.BusiError) {
	var order model.SimRechargeOrder
	if err := common.DB.Where("id = ? AND user_id = ?", orderID, userID).First(&order).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrOrderNotFound
		}
		return nil, common.ErrInternal
	}
	return &order, nil
}

func (s *SimRechargeService) SubmitPaidOrderOnce(order *model.SimRechargeOrder) {
	const supportMessage = "续费处理异常，请联系管理员。"
	DefaultOperationLogService.RecordEvent(order.UserID, "充值与履约", "提交SIMBOSS履约", fmt.Sprintf("orderId=%d attempt=1", order.ID), "success", "simboss")
	if s.simboss == nil {
		DefaultOperationLogService.RecordEvent(order.UserID, "充值与履约", "SIMBOSS履约转人工处理", fmt.Sprintf("orderId=%d errorCode=simboss_unavailable", order.ID), "failed", "simboss")
		s.markManualReview(order.ID, "simboss_unavailable", supportMessage, errors.New("SIMBOSS is not configured"))
		return
	}
	providerOrderNo, err := s.simboss.client.Recharge(order.IccidSnapshot, order.ProviderRatePlanID, order.ValidityMonths, order.ExternalOrderNo)
	if err != nil {
		logger.ERROR("SIM 续费提交 SIMBOSS 失败", err)
		DefaultOperationLogService.RecordEvent(order.UserID, "充值与履约", "SIMBOSS履约转人工处理", fmt.Sprintf("orderId=%d errorCode=simboss_request_failed", order.ID), "failed", "simboss")
		s.markManualReview(order.ID, "simboss_request_failed", supportMessage, err)
		return
	}
	if providerOrderNo == "" {
		err = errors.New("SIMBOSS returned an empty order number")
		logger.ERROR("SIMBOSS 返回空订单号", err)
		DefaultOperationLogService.RecordEvent(order.UserID, "充值与履约", "SIMBOSS履约转人工处理", fmt.Sprintf("orderId=%d errorCode=simboss_empty_order_no", order.ID), "failed", "simboss")
		s.markManualReview(order.ID, "simboss_empty_order_no", supportMessage, err)
		return
	}
	now := time.Now()
	result := common.DB.Model(&model.SimRechargeOrder{}).Where("id = ? AND payment_status = ? AND fulfillment_status = ? AND attempt_count = ?", order.ID, "paid", "submitting", 1).Updates(map[string]any{
		"fulfillment_status": "success", "provider_order_no": providerOrderNo, "fulfilled_at": now,
		"fulfillment_message": "", "last_error_code": "", "last_error_message": "", "updated_at": now,
	})
	if result.Error != nil {
		logger.ERROR("更新 SIM 续费履约结果失败", result.Error)
		return
	}
	if result.RowsAffected != 1 {
		logger.WARN("SIM 续费履约状态已变化", order.ID, errors.New("stale fulfillment state"))
	}
}

func (s *SimRechargeService) markManualReview(orderID int64, code, message string, cause error) {
	now := time.Now()
	result := common.DB.Model(&model.SimRechargeOrder{}).Where("id = ? AND payment_status = ? AND fulfillment_status = ? AND attempt_count = ?", orderID, "paid", "submitting", 1).Updates(map[string]any{
		"fulfillment_status": "manual_review", "fulfillment_message": message,
		"last_error_code": code, "last_error_message": cause.Error(), "next_attempt_at": nil,
		"fulfillment_lease_token": nil, "fulfillment_lease_until": nil, "updated_at": now,
	})
	if result.Error != nil {
		logger.ERROR("标记 SIM 续费人工处理失败", result.Error)
		return
	}
	if result.RowsAffected != 1 {
		logger.WARN("SIM 续费人工处理状态已变化", orderID, errors.New("stale fulfillment state"))
	}
}

func (s *SimRechargeService) refreshCard(card *model.SimCard) error {
	detail, err := s.simboss.client.GetDeviceDetail(card.Iccid)
	if err != nil {
		return err
	}
	now := time.Now()
	updates := map[string]any{
		"carrier": detail.Carrier, "carrier_status": normalizeCarrierStatus(detail.Status, detail.DeviceStatus),
		"used_gb": detail.DataUsage / 1024, "last_sync_at": now, "updated_at": now,
	}
	if detail.RatePlanExpirationDate != "" {
		if expiresAt, err := parseSimbossDate(detail.RatePlanExpirationDate); err == nil {
			updates["expired_at"] = expiresAt
		}
	}
	if updates["carrier_status"] == "cancelled" {
		updates["status"] = "expired"
	}
	if err := common.DB.Model(card).Updates(updates).Error; err != nil {
		return err
	}
	return common.DB.First(card, card.ID).Error
}

func parseSimbossDate(value string) (time.Time, error) {
	for _, layout := range []string{"2006-01-02", time.RFC3339, "2006-01-02 15:04:05"} {
		if parsed, err := time.ParseInLocation(layout, value, time.Local); err == nil {
			return parsed, nil
		}
	}
	return time.Time{}, errors.New("invalid SIMBOSS date")
}

func normalizeCarrierStatus(status, deviceStatus string) string {
	value := status + " " + deviceStatus
	switch {
	case containsFold(value, "cancel"):
		return "cancelled"
	case containsFold(value, "arrear"):
		return "arrears"
	case containsFold(value, "suspend"):
		return "suspended"
	default:
		return "normal"
	}
}

func containsFold(value, fragment string) bool {
	for i := 0; i+len(fragment) <= len(value); i++ {
		if equalFoldASCII(value[i:i+len(fragment)], fragment) {
			return true
		}
	}
	return false
}

func equalFoldASCII(value, fragment string) bool {
	for i := range value {
		left, right := value[i], fragment[i]
		if left >= 'A' && left <= 'Z' {
			left += 'a' - 'A'
		}
		if right >= 'A' && right <= 'Z' {
			right += 'a' - 'A'
		}
		if left != right {
			return false
		}
	}
	return true
}