Implement a basic smpp client

client/client.go

@@ -1 +1,62 @@
-package client
+package client
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"smpptester/pdu"
+)
+
+type SMPPClient struct {
+	Id   int
+	conn net.Conn
+	port string
+	log  log.Logger
+}
+
+func NewSMPPClient(port string, id int) *SMPPClient {
+	client := &SMPPClient{
+		Id:   id,
+		port: port,
+		log:  log.Logger{},
+	}
+	client.log = *log.New(log.Writer(), "", log.LstdFlags)
+	client.log.SetPrefix(fmt.Sprintf("SMPP client %d: ", client.Id))
+	return client
+}
+
+func (c *SMPPClient) Connect() error {
+	conn, err := net.Dial("tcp", c.port)
+	if err != nil {
+		return fmt.Errorf("failed to connect to SMPP server: %w", err)
+	}
+	c.log.Printf("SMPP client %d connected to %s", c.Id, c.port)
+	c.conn = conn
+	return nil
+}
+
+func (c *SMPPClient) Close() {
+	c.conn.Close()
+	c.log.Printf("SMPP client %d closed connection", c.Id)
+}
+
+func (c *SMPPClient) Send(pdata pdu.PDU) error {
+	if c.conn == nil {
+		return fmt.Errorf("connection is not established")
+	}
+
+	pdata.UpdateSize()
+	buf := pdu.ByteBufferPool.Get(pdata.Size())
+	err := pdata.Encode(buf)
+	if err != nil {
+		return fmt.Errorf("failed to encode PDU: %w", err)
+	}
+
+	_, err = c.conn.Write(buf.Bytes())
+	if err != nil {
+		return fmt.Errorf("failed to send PDU: %w", err)
+	}
+
+	c.log.Printf("SMPP client %d sent PDU: %+v", c.Id, pdata)
+	return nil
+}