Resolve "Need common configuration storage"

Closes #15 (closed)

database/database.go

+package database
+
+import (
+	"log"
+
+	"github.com/neo4j/neo4j-go-driver/neo4j"
+)
+
+//Database
+type Database struct {
+	driver  neo4j.Driver
+	session neo4j.Session
+}
+
+//NewDatabaseClient creates a database client
+func NewDatabaseClient(uri, username, password string, encrypted bool) Database {
+	//TODO: defer close()?
+	//		probably pretty nasty since it creates copies
+	driver := createDriver(uri, username, password, encrypted)
+	session := createSession(driver)
+
+	return Database{
+		driver:  driver,
+		session: session,
+	}
+
+}
+
+//createDriver creates a neo4j.Driver instance
+func createDriver(uri, username, password string, encrypted bool) neo4j.Driver {
+	driver, err := neo4j.NewDriver(
+		uri,
+		neo4j.BasicAuth(username, password, ""),
+		func(c *neo4j.Config) {
+			c.Encrypted = encrypted
+		},
+	)
+
+	logError("failed creating database Driver", err)
+
+	return driver
+}
+
+//createSession creates a neo4j.Session
+func createSession(driver neo4j.Driver) neo4j.Session {
+	sessionConfig := neo4j.SessionConfig{AccessMode: neo4j.AccessModeWrite}
+	session, err := driver.NewSession(sessionConfig)
+
+	logError("failed creating database session", err)
+
+	return session
+}
+
+//StoreNodes stores the given nodes to the database
+func (d Database) StoreNodes(json string) {
+	session := d.session
+
+	query :=
+		`
+		WITH apoc.convert.fromJsonMap($stringToAdd)
+		AS value
+		UNWIND value.data as d
+		MERGE (device:Device {id: d.object_id})
+		ON CREATE SET device.nativeName = d.object_data.name[0].value,
+			device.deviceType = d.object_data.name[1].value,
+			device.serialNumber = d.object_data.name[2].value,
+			device.softwareVersion = d.object_data.name[3].value,
+			device.` + "`operational-state` = d.object_data.`operational-state`"
+
+	_, err := session.Run(
+		query, map[string]interface{}{
+			"stringToAdd": json,
+		})
+
+	logError("failed storing Nodes into database", err)
+
+	log.Printf("successfully added Nodes into database")
+}
+
+//StoreNodeEdgePoints stores the given node edge points (interfaces)
+func (d Database) StoreNodeEdgePoints(json string) {
+	session := d.session
+
+	queryEdgePoints :=
+		`
+		WITH apoc.convert.fromJsonMap($stringToAdd)
+		AS value
+		UNWIND value.data as i
+		MERGE (interface:Interface {id: i.object_id})
+		ON CREATE SET interface.object_type =i.object_type,
+		interface.localId = i.object_data.name[0].value,
+		interface.location = i.object_data.name[1].value,
+		interface.` + "`containing-node` = i.object_data.`containing-node`"
+
+	_, err := session.Run(
+		queryEdgePoints, map[string]interface{}{
+			"stringToAdd": json,
+		})
+
+	logError("failed storing NodeEdgePoints into database", err)
+
+	setNodeNodeEdgePointsRelation(session)
+
+	log.Printf("successfully added NodeEdgePoints into database")
+
+}
+
+func (d Database) StoreConnections(json string){}
+
+//setNodeNodeEdgePointsRelation creates the database relations between "nodes" and "node edge points"
+func setNodeNodeEdgePointsRelation(session neo4j.Session) {
+	query :=
+		`
+		MATCH (d:Device), (i:Interface)
+		WHERE d.id = i.` + "`containing-node`" + `
+		CREATE (i)-[:BELONGS_TO]->(d)
+		`
+
+	_, err := session.Run(
+		query, map[string]interface{}{})
+
+	logError("failed storing NodeNodeEdgePointsRelation into database", err)
+
+	log.Printf("successfully stored NodeNodeEdgePointsRelation into database")
+}
+
+//logError logs error with custom and error message
+func logError(message string, err error) {
+	if err != nil {
+		log.Fatalf("%v: %v", message, err)
+	}
+}