nodeStore.go

package nodes

import (
	"fmt"
	"log"

	"code.fbi.h-da.de/danet/gosdn/controller/nucleus/database"
	"code.fbi.h-da.de/danet/gosdn/controller/nucleus/errors"
	"code.fbi.h-da.de/danet/gosdn/controller/topology/store"
	"github.com/google/uuid"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo/options"
)

// Store defines a NodeStore interface
type Store interface {
	Add(Node) error
	Update(Node) error
	Delete(Node) error
	Get(store.Query) (Node, error)
	GetAll() ([]Node, error)
}

// DatabaseNodeStore is a database store for nodes
type DatabaseNodeStore struct {
	storeName string
}

// NewDatabaseNodeStore returns a NodeStore
func NewDatabaseNodeStore() Store {
	return &DatabaseNodeStore{
		storeName: fmt.Sprintf("node-store.json"),
	}
}

// Get takes a nodes's UUID or name and returns the nodes.
func (s *DatabaseNodeStore) Get(query store.Query) (Node, error) {
	var loadedNode Node

	if query.ID.String() != "" {
		loadedNode, err := s.getByID(query.ID)
		if err != nil {
			return loadedNode, errors.ErrCouldNotFind{ID: query.ID, Name: query.Name}
		}

		return loadedNode, nil
	}

	loadedNode, err := s.getByName(query.Name)
	if err != nil {
		return loadedNode, errors.ErrCouldNotFind{ID: query.ID, Name: query.Name}
	}

	return loadedNode, nil
}

func (s *DatabaseNodeStore) getByID(idOfNode uuid.UUID) (Node, error) {
	var loadedNode Node

	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)

	db := client.Database(database.DatabaseName)
	collection := db.Collection(s.storeName)
	result := collection.FindOne(ctx, bson.D{primitive.E{Key: "_id", Value: idOfNode.String()}})
	if result == nil {
		return loadedNode, errors.ErrCouldNotFind{ID: idOfNode}
	}

	err := result.Decode(&loadedNode)
	if err != nil {
		log.Printf("Failed marshalling %v", err)
		return loadedNode, errors.ErrCouldNotFind{ID: idOfNode}
	}

	return loadedNode, nil
}

func (s *DatabaseNodeStore) getByName(nameOfNode string) (Node, error) {
	var loadedNode Node

	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)

	db := client.Database(database.DatabaseName)
	collection := db.Collection(s.storeName)
	result := collection.FindOne(ctx, bson.D{primitive.E{Key: "name", Value: nameOfNode}})
	if result == nil {
		return loadedNode, errors.ErrCouldNotFind{Name: nameOfNode}
	}

	err := result.Decode(&loadedNode)
	if err != nil {
		log.Printf("Failed marshalling %v", err)
		return loadedNode, errors.ErrCouldNotFind{Name: nameOfNode}
	}

	return loadedNode, nil
}

// GetAll returns all stored nodes.
func (s *DatabaseNodeStore) GetAll() ([]Node, error) {
	var loadedNode []Node

	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)
	db := client.Database(database.DatabaseName)
	collection := db.Collection(s.storeName)

	cursor, err := collection.Find(ctx, bson.D{})
	if err != nil {
		return []Node{}, err
	}
	defer cursor.Close(ctx)

	err = cursor.All(ctx, &loadedNode)
	if err != nil {
		log.Printf("Failed marshalling %v", err)

		return loadedNode, errors.ErrCouldNotMarshall{Type: loadedNode, Err: err}
	}

	return loadedNode, nil
}

// Add adds a node to the node store.
func (s *DatabaseNodeStore) Add(node Node) error {
	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)

	_, err := client.Database(database.DatabaseName).
		Collection(s.storeName).
		InsertOne(ctx, node)
	if err != nil {
		log.Printf("Could not add Node: %v", err)
		return errors.ErrCouldNotCreate{Identifier: node.ID, Type: node, Err: err}
	}

	return nil
}

// Update updates a existing node.
func (s *DatabaseNodeStore) Update(node Node) error {
	var updatedLoadedNodes Node

	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)

	update := bson.D{primitive.E{Key: "$set", Value: node}}

	upsert := false
	after := options.After
	opt := options.FindOneAndUpdateOptions{
		Upsert:         &upsert,
		ReturnDocument: &after,
	}

	err := client.Database(database.DatabaseName).
		Collection(s.storeName).
		FindOneAndUpdate(
			ctx, bson.M{"_id": node.ID.String()}, update, &opt).
		Decode(&updatedLoadedNodes)
	if err != nil {
		log.Printf("Could not update Node: %v", err)

		return errors.ErrCouldNotUpdate{Identifier: node.ID, Type: node, Err: err}
	}

	return nil
}

// Delete deletes a node from the node store.
func (s *DatabaseNodeStore) Delete(node Node) error {
	client, ctx, cancel := database.GetMongoConnection()
	defer cancel()
	defer client.Disconnect(ctx)

	db := client.Database(database.DatabaseName)
	collection := db.Collection(s.storeName)
	_, err := collection.DeleteOne(ctx, bson.D{primitive.E{Key: node.ID.String()}})
	if err != nil {
		return err
	}

	return nil
}