Add mongo client interfaces

mongox/database/database.go

@@ -0,0 +1,82 @@
+package database
+
+import (
+	"context"
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/mongo"
+
+	"github.com/mainnika/mongox-go-driver/mongox"
+	"github.com/mainnika/mongox-go-driver/mongox/errors"
+)
+
+// Database handler
+type Database struct {
+	client *mongo.Client
+	dbname string
+	ctx    context.Context
+}
+
+// NewDatabase function creates new database instance with mongo client and empty context
+func NewDatabase(client *mongo.Client, dbname string) mongox.Database {
+
+	db := &Database{}
+	db.client = client
+	db.dbname = dbname
+
+	return db
+}
+
+// Client function returns a mongo client
+func (d *Database) Client() mongox.MongoClient {
+	return d.client
+}
+
+// Context function returns a context
+func (d *Database) Context() context.Context {
+	return d.ctx
+}
+
+// Name function returns a database name
+func (d *Database) Name() string {
+	return d.dbname
+}
+
+// New function creates new database context with same client
+func (d *Database) New(ctx context.Context) mongox.Database {
+
+	if ctx != nil {
+		ctx = context.Background()
+	}
+
+	return &Database{
+		client: d.client,
+		dbname: d.dbname,
+		ctx:    ctx,
+	}
+}
+
+// GetCollectionOf returns the collection object by the «collection» tag of the given document;
+// the «collection» tag should exists, e.g.:
+// type Foobar struct {
+//     base.ObjectID `bson:",inline" json:",inline" collection:"foobars"`
+// 	   ...
+// Will panic if there is no «collection» tag
+func (d *Database) GetCollectionOf(document interface{}) mongox.MongoCollection {
+
+	el := reflect.TypeOf(document).Elem()
+	numField := el.NumField()
+
+	for i := 0; i < numField; i++ {
+		field := el.Field(i)
+		tag := field.Tag
+		found, ok := tag.Lookup("collection")
+		if !ok {
+			continue
+		}
+
+		return d.client.Database(d.dbname).Collection(found)
+	}
+
+	panic(errors.InternalErrorf("document %v does not have a collection tag", document))
+}