Remove examples/internal

Users find it frustrating that example code doesn't work out of tree.
This makes copying the examples out of the repo easier.

Relates to #1981

examples/ortc/main.go

@@ -8,12 +8,21 @@
 package main
 
 import (
+	"bufio"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
 	"time"
 
+	"github.com/pion/randutil"
 	"github.com/pion/webrtc/v4"
-	"github.com/pion/webrtc/v4/examples/internal/signal"
 )
 
 func main() {
@@ -103,16 +112,16 @@ func main() {
 	iceRole := webrtc.ICERoleControlled
 
 	// Exchange the information
-	fmt.Println(signal.Encode(s))
+	fmt.Println(encode(s))
 	remoteSignal := Signal{}
 
 	if *isOffer {
-		signalingChan := signal.HTTPSDPServer(*port)
-		signal.Decode(<-signalingChan, &remoteSignal)
+		signalingChan := httpSDPServer(*port)
+		decode(<-signalingChan, &remoteSignal)
 
 		iceRole = webrtc.ICERoleControlling
 	} else {
-		signal.Decode(signal.MustReadStdin(), &remoteSignal)
+		decode(readUntilNewline(), &remoteSignal)
 	}
 
 	if err = ice.SetRemoteCandidates(remoteSignal.ICECandidates); err != nil {
@@ -175,12 +184,74 @@ func handleOnOpen(channel *webrtc.DataChannel) func() {
 		fmt.Printf("Data channel '%s'-'%d' open. Random messages will now be sent to any connected DataChannels every 5 seconds\n", channel.Label(), channel.ID())
 
 		for range time.NewTicker(5 * time.Second).C {
-			message := signal.RandSeq(15)
-			fmt.Printf("Sending '%s' \n", message)
+			message, err := randutil.GenerateCryptoRandomString(15, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+			if err != nil {
+				panic(err)
+			}
 
+			fmt.Printf("Sending %s \n", message)
 			if err := channel.SendText(message); err != nil {
 				panic(err)
 			}
 		}
 	}
 }
+
+// Read from stdin until we get a newline
+func readUntilNewline() (in string) {
+	var err error
+
+	r := bufio.NewReader(os.Stdin)
+	for {
+		in, err = r.ReadString('\n')
+		if err != nil && !errors.Is(err, io.EOF) {
+			panic(err)
+		}
+
+		if in = strings.TrimSpace(in); len(in) > 0 {
+			break
+		}
+	}
+
+	fmt.Println("")
+	return
+}
+
+// JSON encode + base64 a SessionDescription
+func encode(obj Signal) string {
+	b, err := json.Marshal(obj)
+	if err != nil {
+		panic(err)
+	}
+
+	return base64.StdEncoding.EncodeToString(b)
+}
+
+// Decode a base64 and unmarshal JSON into a SessionDescription
+func decode(in string, obj *Signal) {
+	b, err := base64.StdEncoding.DecodeString(in)
+	if err != nil {
+		panic(err)
+	}
+
+	if err = json.Unmarshal(b, obj); err != nil {
+		panic(err)
+	}
+}
+
+// httpSDPServer starts a HTTP Server that consumes SDPs
+func httpSDPServer(port int) chan string {
+	sdpChan := make(chan string)
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		body, _ := io.ReadAll(r.Body)
+		fmt.Fprintf(w, "done")
+		sdpChan <- string(body)
+	})
+
+	go func() {
+		// nolint: gosec
+		panic(http.ListenAndServe(":"+strconv.Itoa(port), nil))
+	}()
+
+	return sdpChan
+}