From eba5bf0196eb390548696a111a96f7a9d5141efa Mon Sep 17 00:00:00 2001
From: Jim Colderwood <jim.colderwood@pnsol.com>
Date: Sat, 25 May 2024 12:05:15 +0100
Subject: [PATCH] PCM server stream working

---
 config/config.go | 12 +++++-
 main.go          |  7 ++++
 server/server.go | 98 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+), 2 deletions(-)
 create mode 100644 server/server.go

diff --git a/config/config.go b/config/config.go
index b013274..d861154 100644
--- a/config/config.go
+++ b/config/config.go
@@ -6,8 +6,9 @@ import (
 )
 
 type Config struct {
-	LocalAddr  UDP `json:"localAddr"`
-	RemoteAddr UDP `json:"remoteAddr"`
+	LocalAddr  UDP    `json:"localAddr"`
+	RemoteAddr UDP    `json:"remoteAddr"`
+	Server     Server `json:"server"`
 }
 
 type UDP struct {
@@ -15,6 +16,13 @@ type UDP struct {
 	Port int    `json:"port"`
 }
 
+type Server struct {
+	Enable bool  `json:"enable"`
+	Expire int64 `json:"expire"`
+	MAX    int   `json:"max"`
+	UDP    UDP   `json:"udp"`
+}
+
 func ParseConfig(file string) (*Config, error) {
 	raw, err := os.ReadFile(file)
 	if err != nil {
diff --git a/main.go b/main.go
index 930b641..de05e22 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	config2 "github.com/usrpserv/config"
+	"github.com/usrpserv/server"
 	"github.com/usrpserv/usrp"
 	"log"
 	"net"
@@ -16,6 +17,10 @@ func main() {
 	client := usrp.NewClient(net.UDPAddr{Port: config.RemoteAddr.Port, IP: net.ParseIP(config.RemoteAddr.IP)},
 		net.UDPAddr{Port: config.LocalAddr.Port, IP: net.ParseIP(config.LocalAddr.IP)})
 	defer client.Sock.Close()
+	serv := server.New()
+	if err = serv.Run(config); err != nil {
+		log.Println(err)
+	}
 	connectedIP := make(map[string]net.UDPAddr, 1)
 	listenAddr := net.UDPAddr{
 		Port: 4810,
@@ -52,12 +57,14 @@ func main() {
 			if err = client.WriteFrame(buffer, n); err != nil {
 				log.Println(err)
 			}
+			serv.SendData(buffer[32:n], config.Server.Expire)
 			if frame.PTT == 0 {
 				log.Println("END OF TRANSMISSION")
 			}
 		}
 	}()
 	c := func(buffer []byte, size int) {
+		serv.SendData(buffer[32:size], config.Server.Expire)
 		for _, c := range connectedIP {
 			_, err := netListener.WriteToUDP(buffer[:size], &c)
 			if err != nil {
diff --git a/server/server.go b/server/server.go
new file mode 100644
index 0000000..83268b1
--- /dev/null
+++ b/server/server.go
@@ -0,0 +1,98 @@
+package server
+
+import (
+	"fmt"
+	"github.com/usrpserv/config"
+	"log"
+	"net"
+	"sync"
+	"time"
+)
+
+type Clients struct {
+	sync.Mutex
+	Client map[string]Client
+	Sock   *net.UDPConn
+}
+
+type Client struct {
+	Connected time.Time
+	Network   net.UDPAddr
+}
+
+func New() Clients {
+	var clients Clients
+	clients.Mutex = sync.Mutex{}
+	clients.Client = make(map[string]Client, 8)
+	return clients
+}
+
+func (c *Clients) remove(name string) {
+	delete(c.Client, name)
+}
+
+func (c *Clients) Add(name string, addr *net.UDPAddr) {
+	c.Lock()
+	defer c.Unlock()
+	if client, ok := c.Client[name]; ok {
+		if time.Since(client.Connected).Minutes() < 1 {
+			return
+		}
+		client.Connected = time.Now()
+		log.Printf("client %s has updated", name)
+		return
+	}
+	log.Println("adding client:", name)
+	c.Client[name] = Client{
+		Connected: time.Now(),
+		Network:   *addr,
+	}
+}
+
+func (c *Clients) Run(config *config.Config) error {
+	if !config.Server.Enable {
+		log.Println("Server not enabled")
+		return nil
+	}
+	var err error
+	c.Sock, err = net.ListenUDP("udp4", &net.UDPAddr{IP: net.ParseIP(config.Server.UDP.IP), Port: config.Server.UDP.Port})
+	if err != nil {
+		return err
+	}
+	buffer := make([]byte, 32)
+	go func() {
+		for {
+			n, addr, err := c.Sock.ReadFromUDP(buffer)
+			if err != nil {
+				log.Printf("Error reading from %v\n", err)
+			}
+			if n < 1 {
+				continue
+			}
+			c.Add(addr.String(), addr)
+		}
+	}()
+	return nil
+}
+
+func (c *Clients) SendData(data []byte, expire int64) {
+	if len(data) == 0 {
+		return
+	}
+	c.Lock()
+	defer c.Unlock()
+	for key, client := range c.Client {
+		_, err := c.Sock.WriteToUDP(data, &client.Network)
+		if err != nil {
+			log.Println(err)
+			c.remove(key)
+			continue
+		}
+		if time.Now().Sub(client.Connected) > time.Duration(expire)*time.Minute {
+			log.Println("removing client:", key)
+			c.remove(key)
+			continue
+		}
+		fmt.Println("Sending to client:", key)
+	}
+}