Add stream redirect handler

internal/echo/echo.go

@@ -2,28 +2,28 @@ package echo
 
 import (
 	"bytes"
+	"os/exec"
+
 	"github.com/AlexxIT/go2rtc/internal/app"
 	"github.com/AlexxIT/go2rtc/internal/streams"
-	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/AlexxIT/go2rtc/pkg/shell"
-	"os/exec"
 )
 
 func Init() {
 	log := app.GetLogger("echo")
 
-	streams.HandleFunc("echo", func(url string) (core.Producer, error) {
+	streams.RedirectFunc("echo", func(url string) (string, error) {
 		args := shell.QuoteSplit(url[5:])
 
 		b, err := exec.Command(args[0], args[1:]...).Output()
 		if err != nil {
-			return nil, err
+			return "", err
 		}
 
 		b = bytes.TrimSpace(b)
 
 		log.Debug().Str("url", url).Msgf("[echo] %s", b)
 
-		return streams.GetProducer(string(b))
+		return string(b), nil
 	})
 }

internal/ffmpeg/ffmpeg.go

@@ -1,7 +1,6 @@
 package ffmpeg
 
 import (
-	"errors"
 	"net/url"
 	"strings"
 
@@ -10,7 +9,6 @@ import (
 	"github.com/AlexxIT/go2rtc/internal/ffmpeg/hardware"
 	"github.com/AlexxIT/go2rtc/internal/rtsp"
 	"github.com/AlexxIT/go2rtc/internal/streams"
-	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/AlexxIT/go2rtc/pkg/ffmpeg"
 )
 
@@ -27,12 +25,9 @@ func Init() {
 		defaults["global"] += " -v error"
 	}
 
-	streams.HandleFunc("ffmpeg", func(url string) (core.Producer, error) {
-		args := parseArgs(url[7:]) // remove `ffmpeg:`
-		if args == nil {
-			return nil, errors.New("can't generate ffmpeg command")
-		}
-		return streams.GetProducer("exec:" + args.String())
+	streams.RedirectFunc("ffmpeg", func(url string) (string, error) {
+		args := parseArgs(url[7:])
+		return "exec:" + args.String(), nil
 	})
 
 	device.Init(defaults["bin"])

internal/hass/hass.go

@@ -37,12 +37,15 @@ func Init() {
 	api.HandleFunc("/streams", apiOK)
 	api.HandleFunc("/stream/", apiStream)
 
-	streams.HandleFunc("hass", func(url string) (core.Producer, error) {
-		// check entity by name
-		if url2 := entities[url[5:]]; url2 != "" {
-			return streams.GetProducer(url2)
+	streams.RedirectFunc("hass", func(url string) (string, error) {
+		if location := entities[url[5:]]; location != "" {
+			return location, nil
 		}
 
+		return "", nil
+	})
+
+	streams.HandleFunc("hass", func(url string) (core.Producer, error) {
 		// support hass://supervisor?entity_id=camera.driveway_doorbell
 		client, err := hass.NewClient(url)
 		if err != nil {

internal/streams/handlers.go

@@ -1,41 +1,75 @@
 package streams
 
 import (
-	"fmt"
-	"github.com/AlexxIT/go2rtc/pkg/core"
+	"errors"
 	"strings"
-	"sync"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
 )
 
 type Handler func(url string) (core.Producer, error)
 
 var handlers = map[string]Handler{}
-var handlersMu sync.Mutex
 
 func HandleFunc(scheme string, handler Handler) {
-	handlersMu.Lock()
 	handlers[scheme] = handler
-	handlersMu.Unlock()
-}
-
-func getHandler(url string) Handler {
-	i := strings.IndexByte(url, ':')
-	if i <= 0 { // TODO: i < 4 ?
-		return nil
-	}
-	handlersMu.Lock()
-	defer handlersMu.Unlock()
-	return handlers[url[:i]]
 }
 
 func HasProducer(url string) bool {
-	return getHandler(url) != nil
+	if i := strings.IndexByte(url, ':'); i > 0 {
+		scheme := url[:i]
+
+		if _, ok := handlers[scheme]; ok {
+			return true
+		}
+
+		if _, ok := redirects[scheme]; ok {
+			return true
+		}
+	}
+
+	return false
 }
 
 func GetProducer(url string) (core.Producer, error) {
-	handler := getHandler(url)
-	if handler == nil {
-		return nil, fmt.Errorf("unsupported scheme: %s", url)
+	if i := strings.IndexByte(url, ':'); i > 0 {
+		scheme := url[:i]
+
+		if redirect, ok := redirects[scheme]; ok {
+			location, err := redirect(url)
+			if err != nil {
+				return nil, err
+			}
+			if location != "" {
+				return GetProducer(location)
+			}
+		}
+
+		if handler, ok := handlers[scheme]; ok {
+			return handler(url)
+		}
 	}
-	return handler(url)
+
+	return nil, errors.New("streams: unsupported scheme: " + url)
+}
+
+// Redirect can return: location URL or error or empty URL and error
+type Redirect func(url string) (string, error)
+
+var redirects = map[string]Redirect{}
+
+func RedirectFunc(scheme string, redirect Redirect) {
+	redirects[scheme] = redirect
+}
+
+func Location(url string) (string, error) {
+	if i := strings.IndexByte(url, ':'); i > 0 {
+		scheme := url[:i]
+
+		if redirect, ok := redirects[scheme]; ok {
+			return redirect(url)
+		}
+	}
+
+	return "", nil
 }