beginnings of the backend

cmd/cgat/main.go

 package main
 
-import "pggat2/lib/frontend/frontends/v0"
+import (
+	"net"
+
+	"pggat2/lib/backend/backends/v0"
+)
 
 func main() {
-	fe, err := frontends.NewFrontend()
+	conn, err := net.Dial("tcp", "localhost:5432")
 	if err != nil {
 		panic(err)
 	}
-	err = fe.Run()
+	srv, err := backends.NewServer(conn)
 	if err != nil {
 		panic(err)
 	}
+	_ = srv
 }

lib/backend/server.go → lib/backend/backend.go

@@ -2,3 +2,6 @@ package backend
 
 type Server interface {
 }
+
+type Backend interface {
+}

lib/backend/backends/v0/backend.go

+package backends
+
+import "pggat2/lib/backend"
+
+type Backend struct {
+}
+
+var _ backend.Backend = (*Backend)(nil)

lib/backend/backends/v0/server.go

+package backends
+
+import (
+	"log"
+	"net"
+
+	"pggat2/lib/backend"
+	"pggat2/lib/pnet"
+	"pggat2/lib/pnet/packet"
+)
+
+type Server struct {
+	conn net.Conn
+
+	pnet.Reader
+	pnet.Writer
+}
+
+func NewServer(conn net.Conn) (*Server, error) {
+	server := &Server{
+		conn:   conn,
+		Reader: pnet.MakeReader(conn),
+		Writer: pnet.MakeWriter(conn),
+	}
+	err := server.accept()
+	if err != nil {
+		return nil, err
+	}
+	return server, nil
+}
+
+func (T *Server) accept() error {
+	var builder packet.Builder
+	builder.Int16(3)
+	builder.Int16(0)
+	builder.String("user")
+	builder.String("postgres")
+	builder.String("")
+
+	err := T.WriteUntyped(builder.Raw())
+	if err != nil {
+		return err
+	}
+
+	auth, err := T.Read()
+	if err != nil {
+		return err
+	}
+
+	log.Printf("%#v", auth)
+
+	return nil
+}
+
+var _ backend.Server = (*Server)(nil)