package task

import (
	"context"
	"errors"
	"time"

	"github.com/bytedance/sonic"
	"github.com/hibiken/asynq"
	"github.com/redis/go-redis/v9"
	"go.uber.org/zap"
	"gorm.io/gorm"

	"github.com/break/junhong_cmp_fiber/internal/model"
	packagepkg "github.com/break/junhong_cmp_fiber/internal/service/package"
	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
)

// AutoPurchasePayload 充值后自动购包任务载荷
type AutoPurchasePayload struct {
	RechargeRecordID uint `json:"recharge_record_id"`
}

// AutoPurchaseHandler 充值后自动购包任务处理器
type AutoPurchaseHandler struct {
	db                     *gorm.DB
	orderStore             *postgres.OrderStore
	rechargeRecordStore    *postgres.AssetRechargeStore
	walletStore            *postgres.AssetWalletStore
	walletTransactionStore *postgres.AssetWalletTransactionStore
	packageUsageStore      *postgres.PackageUsageStore
	redis                  *redis.Client
	logger                 *zap.Logger
}

// NewAutoPurchaseHandler 创建充值后自动购包处理器
func NewAutoPurchaseHandler(
	db *gorm.DB,
	orderStore *postgres.OrderStore,
	rechargeRecordStore *postgres.AssetRechargeStore,
	walletStore *postgres.AssetWalletStore,
	walletTransactionStore *postgres.AssetWalletTransactionStore,
	packageUsageStore *postgres.PackageUsageStore,
	redisClient *redis.Client,
	logger *zap.Logger,
) *AutoPurchaseHandler {
	if orderStore == nil {
		orderStore = postgres.NewOrderStore(db, redisClient)
	}
	if rechargeRecordStore == nil {
		rechargeRecordStore = postgres.NewAssetRechargeStore(db, redisClient)
	}
	if walletStore == nil {
		walletStore = postgres.NewAssetWalletStore(db, redisClient)
	}
	if walletTransactionStore == nil {
		walletTransactionStore = postgres.NewAssetWalletTransactionStore(db, redisClient)
	}
	if packageUsageStore == nil {
		packageUsageStore = postgres.NewPackageUsageStore(db, redisClient)
	}

	return &AutoPurchaseHandler{
		db:                     db,
		orderStore:             orderStore,
		rechargeRecordStore:    rechargeRecordStore,
		walletStore:            walletStore,
		walletTransactionStore: walletTransactionStore,
		packageUsageStore:      packageUsageStore,
		redis:                  redisClient,
		logger:                 logger,
	}
}

// ProcessTask 处理充值后自动购包任务
func (h *AutoPurchaseHandler) ProcessTask(ctx context.Context, task *asynq.Task) error {
	var payload AutoPurchasePayload
	if err := sonic.Unmarshal(task.Payload(), &payload); err != nil {
		h.logger.Error("解析自动购包任务载荷失败", zap.Error(err))
		return asynq.SkipRetry
	}
	if payload.RechargeRecordID == 0 {
		h.logger.Error("自动购包任务载荷无效", zap.Uint("recharge_record_id", payload.RechargeRecordID))
		return asynq.SkipRetry
	}

	rechargeRecord, err := h.rechargeRecordStore.GetByID(ctx, payload.RechargeRecordID)
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			h.logger.Warn("充值记录不存在，跳过自动购包", zap.Uint("recharge_record_id", payload.RechargeRecordID))
			return asynq.SkipRetry
		}
		h.logger.Error("查询充值记录失败", zap.Uint("recharge_record_id", payload.RechargeRecordID), zap.Error(err))
		return err
	}

	if rechargeRecord.AutoPurchaseStatus == constants.AutoPurchaseStatusSuccess {
		return nil
	}
	if rechargeRecord.AutoPurchaseStatus == constants.AutoPurchaseStatusFailed {
		return nil
	}

	packageIDs, err := parseLinkedPackageIDs(rechargeRecord.LinkedPackageIDs)
	if err != nil {
		h.logger.Error("解析关联套餐ID失败", zap.Uint("recharge_record_id", rechargeRecord.ID), zap.Error(err))
		h.markAutoPurchaseFailedIfFinalRetry(ctx, rechargeRecord.ID)
		return asynq.SkipRetry
	}
	if len(packageIDs) == 0 {
		h.logger.Error("关联套餐ID为空，无法自动购包", zap.Uint("recharge_record_id", rechargeRecord.ID))
		h.markAutoPurchaseFailedIfFinalRetry(ctx, rechargeRecord.ID)
		return asynq.SkipRetry
	}

	packages, totalAmount, err := h.loadPackages(ctx, packageIDs)
	if err != nil {
		h.logger.Error("加载关联套餐失败", zap.Uint("recharge_record_id", rechargeRecord.ID), zap.Error(err))
		h.markAutoPurchaseFailedIfFinalRetry(ctx, rechargeRecord.ID)
		return err
	}

	if err := h.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		wallet, walletErr := h.walletStore.GetByID(ctx, rechargeRecord.AssetWalletID)
		if walletErr != nil {
			if walletErr == gorm.ErrRecordNotFound {
				return errors.New("资产钱包不存在")
			}
			return walletErr
		}
		if wallet.GetAvailableBalance() < totalAmount {
			return errors.New("钱包余额不足")
		}

		if err = h.walletStore.DeductBalanceWithTx(ctx, tx, wallet.ID, totalAmount, wallet.Version); err != nil {
			return err
		}

		now := time.Now()
		order, orderItems, buildErr := h.buildOrderAndItems(rechargeRecord, packages, totalAmount, now)
		if buildErr != nil {
			return buildErr
		}

		if err = tx.Create(order).Error; err != nil {
			return err
		}

		for _, item := range orderItems {
			item.OrderID = order.ID
		}
		if err = tx.CreateInBatches(orderItems, 100).Error; err != nil {
			return err
		}

		refType := constants.ReferenceTypeOrder
		walletTx := &model.AssetWalletTransaction{
			AssetWalletID:   wallet.ID,
			ResourceType:    wallet.ResourceType,
			ResourceID:      wallet.ResourceID,
			UserID:          rechargeRecord.UserID,
			TransactionType: constants.AssetTransactionTypeDeduct,
			Amount:          -totalAmount,
			BalanceBefore:   wallet.Balance,
			BalanceAfter:    wallet.Balance - totalAmount,
			Status:          constants.TransactionStatusSuccess,
			ReferenceType:   &refType,
			ReferenceNo:     &order.OrderNo,
			Creator:         rechargeRecord.UserID,
			ShopIDTag:       wallet.ShopIDTag,
			EnterpriseIDTag: wallet.EnterpriseIDTag,
		}
		if err = h.walletTransactionStore.CreateWithTx(ctx, tx, walletTx); err != nil {
			return err
		}

		if err = h.activatePackages(ctx, tx, order, packages, now); err != nil {
			return err
		}

		if err = tx.Model(&model.AssetRechargeRecord{}).
			Where("id = ?", rechargeRecord.ID).
			Update("auto_purchase_status", constants.AutoPurchaseStatusSuccess).Error; err != nil {
			return err
		}

		return nil
	}); err != nil {
		h.logger.Error("自动购包任务执行失败",
			zap.Uint("recharge_record_id", rechargeRecord.ID),
			zap.Error(err),
		)
		h.markAutoPurchaseFailedIfFinalRetry(ctx, rechargeRecord.ID)
		return err
	}

	h.logger.Info("自动购包任务执行成功", zap.Uint("recharge_record_id", rechargeRecord.ID))
	return nil
}

// NewAutoPurchaseTask 创建充值后自动购包任务
func NewAutoPurchaseTask(rechargeRecordID uint) (*asynq.Task, error) {
	payloadBytes, err := sonic.Marshal(AutoPurchasePayload{RechargeRecordID: rechargeRecordID})
	if err != nil {
		return nil, err
	}

	return asynq.NewTask(constants.TaskTypeAutoPurchaseAfterRecharge, payloadBytes,
		asynq.MaxRetry(3),
		asynq.Timeout(2*time.Minute),
		asynq.Queue(constants.QueueDefault),
	), nil
}

func (h *AutoPurchaseHandler) markAutoPurchaseFailedIfFinalRetry(ctx context.Context, rechargeRecordID uint) {
	retryCount, ok := asynq.GetRetryCount(ctx)
	if !ok {
		return
	}
	maxRetry, ok := asynq.GetMaxRetry(ctx)
	if !ok {
		return
	}
	if retryCount < maxRetry-1 {
		return
	}

	if err := h.db.WithContext(ctx).
		Model(&model.AssetRechargeRecord{}).
		Where("id = ?", rechargeRecordID).
		Update("auto_purchase_status", constants.AutoPurchaseStatusFailed).Error; err != nil {
		h.logger.Error("更新自动购包失败状态失败",
			zap.Uint("recharge_record_id", rechargeRecordID),
			zap.Error(err),
		)
		return
	}

	h.logger.Warn("自动购包达到最大重试次数，已标记失败", zap.Uint("recharge_record_id", rechargeRecordID))
}

func (h *AutoPurchaseHandler) loadPackages(ctx context.Context, packageIDs []uint) ([]*model.Package, int64, error) {
	packages := make([]*model.Package, 0, len(packageIDs))
	if err := h.db.WithContext(ctx).Where("id IN ?", packageIDs).Find(&packages).Error; err != nil {
		return nil, 0, err
	}
	if len(packages) != len(packageIDs) {
		return nil, 0, gorm.ErrRecordNotFound
	}

	totalAmount := int64(0)
	for _, pkg := range packages {
		totalAmount += pkg.SuggestedRetailPrice
	}

	if err := validatePackageTypeMix(packages); err != nil {
		return nil, 0, err
	}

	return packages, totalAmount, nil
}

func (h *AutoPurchaseHandler) buildOrderAndItems(
	rechargeRecord *model.AssetRechargeRecord,
	packages []*model.Package,
	totalAmount int64,
	now time.Time,
) (*model.Order, []*model.OrderItem, error) {
	orderType, iotCardID, deviceID, err := parseLinkedCarrier(rechargeRecord.LinkedOrderType, rechargeRecord.LinkedCarrierType, rechargeRecord.LinkedCarrierID)
	if err != nil {
		return nil, nil, err
	}

	generation := rechargeRecord.Generation
	if generation <= 0 {
		generation = 1
	}

	paidAmount := totalAmount
	order := &model.Order{
		BaseModel: model.BaseModel{
			Creator: rechargeRecord.UserID,
			Updater: rechargeRecord.UserID,
		},
		OrderNo:                 h.orderStore.GenerateOrderNo(),
		OrderType:               orderType,
		BuyerType:               model.BuyerTypePersonal,
		BuyerID:                 rechargeRecord.UserID,
		IotCardID:               iotCardID,
		DeviceID:                deviceID,
		TotalAmount:             totalAmount,
		PaymentMethod:           model.PaymentMethodWallet,
		PaymentStatus:           model.PaymentStatusPaid,
		PaidAt:                  &now,
		CommissionStatus:        model.CommissionStatusPending,
		CommissionConfigVersion: 0,
		Source:                  constants.OrderSourceClient,
		Generation:              generation,
		ActualPaidAmount:        &paidAmount,
		SellerShopID:            &rechargeRecord.ShopIDTag,
	}

	items := make([]*model.OrderItem, 0, len(packages))
	for _, pkg := range packages {
		items = append(items, &model.OrderItem{
			BaseModel: model.BaseModel{
				Creator: rechargeRecord.UserID,
				Updater: rechargeRecord.UserID,
			},
			PackageID:   pkg.ID,
			PackageName: pkg.PackageName,
			Quantity:    1,
			UnitPrice:   pkg.SuggestedRetailPrice,
			Amount:      pkg.SuggestedRetailPrice,
		})
	}

	return order, items, nil
}

func (h *AutoPurchaseHandler) activatePackages(
	ctx context.Context,
	tx *gorm.DB,
	order *model.Order,
	packages []*model.Package,
	now time.Time,
) error {
	carrierType := constants.AssetWalletResourceTypeIotCard
	carrierID := uint(0)
	if order.OrderType == model.OrderTypeSingleCard && order.IotCardID != nil {
		carrierID = *order.IotCardID
	} else if order.OrderType == model.OrderTypeDevice && order.DeviceID != nil {
		carrierType = constants.AssetWalletResourceTypeDevice
		carrierID = *order.DeviceID
	} else {
		return errors.New("无效的订单载体")
	}

	for _, pkg := range packages {
		var existingUsage model.PackageUsage
		err := tx.Where("order_id = ? AND package_id = ?", order.ID, pkg.ID).First(&existingUsage).Error
		if err == nil {
			continue
		}
		if err != gorm.ErrRecordNotFound {
			return err
		}

		if pkg.PackageType == constants.PackageTypeFormal {
			if err = h.activateMainPackage(ctx, tx, order, pkg, carrierType, carrierID, now); err != nil {
				return err
			}
			continue
		}
		if pkg.PackageType == constants.PackageTypeAddon {
			if err = h.activateAddonPackage(ctx, tx, order, pkg, carrierType, carrierID, now); err != nil {
				return err
			}
		}
	}

	return nil
}

func (h *AutoPurchaseHandler) activateMainPackage(
	ctx context.Context,
	tx *gorm.DB,
	order *model.Order,
	pkg *model.Package,
	carrierType string,
	carrierID uint,
	now time.Time,
) error {
	_ = ctx
	var activeMainPackage model.PackageUsage
	err := tx.Where("status = ?", constants.PackageUsageStatusActive).
		Where("master_usage_id IS NULL").
		Where(carrierType+"_id = ?", carrierID).
		Order("priority ASC").
		First(&activeMainPackage).Error

	hasActiveMain := err == nil

	var status int
	var priority int
	var activatedAt time.Time
	var expiresAt time.Time
	var nextResetAt *time.Time
	var pendingRealnameActivation bool

	if hasActiveMain {
		status = constants.PackageUsageStatusPending
		var maxPriority int
		tx.Model(&model.PackageUsage{}).
			Where(carrierType+"_id = ?", carrierID).
			Select("COALESCE(MAX(priority), 0)").
			Scan(&maxPriority)
		priority = maxPriority + 1
	} else {
		status = constants.PackageUsageStatusActive
		priority = 1
		activatedAt = now
		expiresAt = packagepkg.CalculateExpiryTime(pkg.CalendarType, activatedAt, pkg.DurationMonths, pkg.DurationDays)
		nextResetAt = packagepkg.CalculateNextResetTime(pkg.DataResetCycle, pkg.CalendarType, now, activatedAt)
	}

	if pkg.EnableRealnameActivation {
		status = constants.PackageUsageStatusPending
		pendingRealnameActivation = true
	}

	usage := &model.PackageUsage{
		BaseModel: model.BaseModel{
			Creator: order.Creator,
			Updater: order.Creator,
		},
		OrderID:                   order.ID,
		PackageID:                 pkg.ID,
		UsageType:                 order.OrderType,
		DataLimitMB:               pkg.RealDataMB,
		Status:                    status,
		Priority:                  priority,
		DataResetCycle:            pkg.DataResetCycle,
		PendingRealnameActivation: pendingRealnameActivation,
		Generation:                order.Generation,
	}

	if carrierType == constants.AssetWalletResourceTypeIotCard {
		usage.IotCardID = carrierID
	} else {
		usage.DeviceID = carrierID
	}

	if status == constants.PackageUsageStatusActive {
		usage.ActivatedAt = activatedAt
		usage.ExpiresAt = expiresAt
		usage.NextResetAt = nextResetAt
	}

	if err = tx.Omit("status", "pending_realname_activation").Create(usage).Error; err != nil {
		return err
	}

	return tx.Model(usage).Updates(map[string]any{
		"status":                      usage.Status,
		"pending_realname_activation": usage.PendingRealnameActivation,
	}).Error
}

func (h *AutoPurchaseHandler) activateAddonPackage(
	ctx context.Context,
	tx *gorm.DB,
	order *model.Order,
	pkg *model.Package,
	carrierType string,
	carrierID uint,
	now time.Time,
) error {
	_ = ctx
	var mainPackage model.PackageUsage
	err := tx.Where("status IN ?", []int{constants.PackageUsageStatusPending, constants.PackageUsageStatusActive}).
		Where("master_usage_id IS NULL").
		Where(carrierType+"_id = ?", carrierID).
		Order("priority ASC").
		First(&mainPackage).Error
	if err == gorm.ErrRecordNotFound {
		return errors.New("必须有主套餐才能购买加油包")
	}
	if err != nil {
		return err
	}

	var maxPriority int
	tx.Model(&model.PackageUsage{}).
		Where(carrierType+"_id = ?", carrierID).
		Select("COALESCE(MAX(priority), 0)").
		Scan(&maxPriority)

	priority := maxPriority + 1
	expiresAt := mainPackage.ExpiresAt

	usage := &model.PackageUsage{
		BaseModel: model.BaseModel{
			Creator: order.Creator,
			Updater: order.Creator,
		},
		OrderID:        order.ID,
		PackageID:      pkg.ID,
		UsageType:      order.OrderType,
		DataLimitMB:    pkg.RealDataMB,
		Status:         constants.PackageUsageStatusActive,
		Priority:       priority,
		MasterUsageID:  &mainPackage.ID,
		ActivatedAt:    now,
		ExpiresAt:      expiresAt,
		DataResetCycle: pkg.DataResetCycle,
		Generation:     order.Generation,
	}

	if carrierType == constants.AssetWalletResourceTypeIotCard {
		usage.IotCardID = carrierID
	} else {
		usage.DeviceID = carrierID
	}

	return tx.Create(usage).Error
}

func parseLinkedPackageIDs(raw []byte) ([]uint, error) {
	var packageIDs []uint
	if len(raw) == 0 {
		return nil, nil
	}
	if err := sonic.Unmarshal(raw, &packageIDs); err != nil {
		return nil, err
	}
	return packageIDs, nil
}

func parseLinkedCarrier(linkedOrderType string, linkedCarrierType string, linkedCarrierID *uint) (string, *uint, *uint, error) {
	if linkedCarrierID == nil || *linkedCarrierID == 0 {
		return "", nil, nil, errors.New("关联载体ID为空")
	}

	if linkedOrderType == model.OrderTypeSingleCard || linkedCarrierType == "card" || linkedCarrierType == constants.AssetWalletResourceTypeIotCard {
		id := *linkedCarrierID
		return model.OrderTypeSingleCard, &id, nil, nil
	}
	if linkedOrderType == model.OrderTypeDevice || linkedCarrierType == "device" || linkedCarrierType == constants.AssetWalletResourceTypeDevice {
		id := *linkedCarrierID
		return model.OrderTypeDevice, nil, &id, nil
	}

	return "", nil, nil, errors.New("关联载体类型无效")
}

func validatePackageTypeMix(packages []*model.Package) error {
	hasFormal := false
	hasAddon := false

	for _, pkg := range packages {
		switch pkg.PackageType {
		case constants.PackageTypeFormal:
			hasFormal = true
		case constants.PackageTypeAddon:
			hasAddon = true
		}

		if hasFormal && hasAddon {
			return errors.New("不允许在同一订单中同时购买正式套餐和加油包")
		}
	}

	return nil
}